subject:(Xenopus)

University of Debrecen

1. Nagyváradi, László Pál. A kétéltűek és az ember immunrendszerének antimikrobiális hatásának vizsgálata Pseudomonas aeruginosa fertőzéssel szemben .

Degree: DE – TEK – Természettudományi és Technológiai Kar – Biológiai és Ökológiai Intézet, 2011, University of Debrecen

URL: http://hdl.handle.net/2437/108304

► A békák és ember immunválaszainak vizsgálata Pseudomonas aerugionosa fertőzéssel szemben. Klinikai kémiai, mikrobiológiai, és molekuláris biológiai vizsgálómódszerek alkalmazásával. Mely eredmények azt mutatják, hogy a kétéltűek… (more)

Subjects/Keywords: Xenopus; immunbiológia; humánbiológia

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APA (6^th Edition):

Nagyváradi, L. P. (2011). A kétéltűek és az ember immunrendszerének antimikrobiális hatásának vizsgálata Pseudomonas aeruginosa fertőzéssel szemben . (Thesis). University of Debrecen. Retrieved from http://hdl.handle.net/2437/108304

Note: this citation may be lacking information needed for this citation format:
Not specified: Masters Thesis or Doctoral Dissertation

Chicago Manual of Style (16^th Edition):

Nagyváradi, László Pál. “A kétéltűek és az ember immunrendszerének antimikrobiális hatásának vizsgálata Pseudomonas aeruginosa fertőzéssel szemben .” 2011. Thesis, University of Debrecen. Accessed January 22, 2021. http://hdl.handle.net/2437/108304.

Note: this citation may be lacking information needed for this citation format:
Not specified: Masters Thesis or Doctoral Dissertation

MLA Handbook (7^th Edition):

Nagyváradi, László Pál. “A kétéltűek és az ember immunrendszerének antimikrobiális hatásának vizsgálata Pseudomonas aeruginosa fertőzéssel szemben .” 2011. Web. 22 Jan 2021.

Vancouver:

Nagyváradi LP. A kétéltűek és az ember immunrendszerének antimikrobiális hatásának vizsgálata Pseudomonas aeruginosa fertőzéssel szemben . [Internet] [Thesis]. University of Debrecen; 2011. [cited 2021 Jan 22]. Available from: http://hdl.handle.net/2437/108304.

Note: this citation may be lacking information needed for this citation format:
Not specified: Masters Thesis or Doctoral Dissertation

Council of Science Editors:

Nagyváradi LP. A kétéltűek és az ember immunrendszerének antimikrobiális hatásának vizsgálata Pseudomonas aeruginosa fertőzéssel szemben . [Thesis]. University of Debrecen; 2011. Available from: http://hdl.handle.net/2437/108304

Note: this citation may be lacking information needed for this citation format:
Not specified: Masters Thesis or Doctoral Dissertation

2. Shah, Rucha, 1982-. Novel methods and application of optogenetics for determining the functions of keratin filaments in early embryogenesis.

Degree: PhD, Biology, 2019, Rutgers University

URL: https://rucore.libraries.rutgers.edu/rutgers-lib/61665/

►

To study the functional role of keratin filaments during early embryological development I developed a novel biomolecular tool for specifically disrupting keratin filaments in living… (more)

▼

To study the functional role of keratin filaments during early embryological development I developed a novel biomolecular tool for specifically disrupting keratin filaments in living cells. Conventional genetic approaches such as, knockdown, knockout and transgenic overexpression have attempted to study the role of keratin IFs but fall short of identifying the functional significance of keratin filamentous network during early development. The utility of small molecular inhibitors withaferin A and acrylamide to experimentally interfere with keratin network organization were also evaluated in this study. The comparative analysis done here emphasizes that the effect of these inhibitors is dependent on many factors, such as cell type, cell density, dose of the drug and time of exposure. Furthermore, correlative evidence suggests that the keratin network in the vicinity of the cell-cell contacts was resistant to both the small molecular inhibitors. It was also observed that both keratin filaments and keratin precursor particles have spatially defined subcellular localization in tissues, such as presumptive ectoderm and mesendoderm. In order to specifically study the functional role of keratin filamentous network, a genetically encoded PhotoActivatable disruptor of keratin filaments was developed, taking advantage of Xenopus keratin 8 mimetic peptide and a light sensitive LOV domain of the Avena sativa phototropin. The inhibitory effects of this peptide were validated in multiple cell lines and tissues. Upon photoactivation, PA-2B2 induces localized rapid subcellular disruption of the keratin filaments and thus destabilization of the network leading to cell shape changes. Specific disruption of keratin filaments by light-based activation of PA-2B2 leads to a dramatic disruption of early embryological development in Xenopus. Additionally, disruption of keratin filaments leads to failure of fibronectin assembly along the blastocoel roof. Collectively, the data shows the critical importance of keratin filaments in morphogenetically active tissues and early embryogenesis. The optogenetic novel tools developed here to disrupt keratin filaments with spatiotemporal precision are a powerful means to probe keratin filament function within living cells and direct future investigations.

Advisors/Committee Members: Kim, Heasun (chair), Weber, Gregory (internal member), Bonder, Edward (internal member), Conway, Daniel (outside member).

Subjects/Keywords: Keratin; Xenopus – Embryology

10 more images…

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APA (6^th Edition):

Shah, Rucha, 1. (2019). Novel methods and application of optogenetics for determining the functions of keratin filaments in early embryogenesis. (Doctoral Dissertation). Rutgers University. Retrieved from https://rucore.libraries.rutgers.edu/rutgers-lib/61665/

Chicago Manual of Style (16^th Edition):

Shah, Rucha, 1982-. “Novel methods and application of optogenetics for determining the functions of keratin filaments in early embryogenesis.” 2019. Doctoral Dissertation, Rutgers University. Accessed January 22, 2021. https://rucore.libraries.rutgers.edu/rutgers-lib/61665/.

MLA Handbook (7^th Edition):

Shah, Rucha, 1982-. “Novel methods and application of optogenetics for determining the functions of keratin filaments in early embryogenesis.” 2019. Web. 22 Jan 2021.

Vancouver:

Shah, Rucha 1. Novel methods and application of optogenetics for determining the functions of keratin filaments in early embryogenesis. [Internet] [Doctoral dissertation]. Rutgers University; 2019. [cited 2021 Jan 22]. Available from: https://rucore.libraries.rutgers.edu/rutgers-lib/61665/.

Council of Science Editors:

Shah, Rucha 1. Novel methods and application of optogenetics for determining the functions of keratin filaments in early embryogenesis. [Doctoral Dissertation]. Rutgers University; 2019. Available from: https://rucore.libraries.rutgers.edu/rutgers-lib/61665/

3. 小野, 達也. アフリカツメガエル初期発生における転写因子E2Fの機能解析 : Analysis of E2F function during early embryogenesis of Xenopus; アフリカツメガエルショキハッセイニオケルテンシャインシ E2F ノキノウカイセキ.

Degree: Nara Institute of Science and Technology / 奈良先端科学技術大学院大学

URL: http://hdl.handle.net/10061/2822

Subjects/Keywords: Xenopus laevis

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APA (6^th Edition):

小野, �. (n.d.). アフリカツメガエル初期発生における転写因子E2Fの機能解析 : Analysis of E2F function during early embryogenesis of Xenopus; アフリカツメガエルショキハッセイニオケルテンシャインシ E2F ノキノウカイセキ. (Thesis). Nara Institute of Science and Technology / 奈良先端科学技術大学院大学. Retrieved from http://hdl.handle.net/10061/2822

Note: this citation may be lacking information needed for this citation format:
No year of publication.
Not specified: Masters Thesis or Doctoral Dissertation

Chicago Manual of Style (16^th Edition):

小野, 達也. “アフリカツメガエル初期発生における転写因子E2Fの機能解析 : Analysis of E2F function during early embryogenesis of Xenopus; アフリカツメガエルショキハッセイニオケルテンシャインシ E2F ノキノウカイセキ.” Thesis, Nara Institute of Science and Technology / 奈良先端科学技術大学院大学. Accessed January 22, 2021. http://hdl.handle.net/10061/2822.

Note: this citation may be lacking information needed for this citation format:
No year of publication.
Not specified: Masters Thesis or Doctoral Dissertation

MLA Handbook (7^th Edition):

小野, 達也. “アフリカツメガエル初期発生における転写因子E2Fの機能解析 : Analysis of E2F function during early embryogenesis of Xenopus; アフリカツメガエルショキハッセイニオケルテンシャインシ E2F ノキノウカイセキ.” Web. 22 Jan 2021.

Note: this citation may be lacking information needed for this citation format:
No year of publication.

Vancouver:

小野 �. アフリカツメガエル初期発生における転写因子E2Fの機能解析 : Analysis of E2F function during early embryogenesis of Xenopus; アフリカツメガエルショキハッセイニオケルテンシャインシ E2F ノキノウカイセキ. [Internet] [Thesis]. Nara Institute of Science and Technology / 奈良先端科学技術大学院大学; [cited 2021 Jan 22]. Available from: http://hdl.handle.net/10061/2822.

Note: this citation may be lacking information needed for this citation format:
Not specified: Masters Thesis or Doctoral Dissertation
No year of publication.

Council of Science Editors:

小野 �. アフリカツメガエル初期発生における転写因子E2Fの機能解析 : Analysis of E2F function during early embryogenesis of Xenopus; アフリカツメガエルショキハッセイニオケルテンシャインシ E2F ノキノウカイセキ. [Thesis]. Nara Institute of Science and Technology / 奈良先端科学技術大学院大学; Available from: http://hdl.handle.net/10061/2822

Note: this citation may be lacking information needed for this citation format:
Not specified: Masters Thesis or Doctoral Dissertation
No year of publication.

University of Utah

4. Finerty, Patrick Joseph. Studies on a double-stranded RNA-binding zinc finger protein;.

Degree: PhD, Biochemistry;, 1999, University of Utah

URL: http://content.lib.utah.edu/cdm/singleitem/collection/etd1/id/135/rec/1264

► Proteins containing C 2 H 2 type zinc finger motifs are perhaps the largest class of nucleic acid-binding proteins found in nature. This dissertation describes… (more)

Subjects/Keywords: dsRNA; Xenopus

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APA (6^th Edition):

Finerty, P. J. (1999). Studies on a double-stranded RNA-binding zinc finger protein;. (Doctoral Dissertation). University of Utah. Retrieved from http://content.lib.utah.edu/cdm/singleitem/collection/etd1/id/135/rec/1264

Chicago Manual of Style (16^th Edition):

Finerty, Patrick Joseph. “Studies on a double-stranded RNA-binding zinc finger protein;.” 1999. Doctoral Dissertation, University of Utah. Accessed January 22, 2021. http://content.lib.utah.edu/cdm/singleitem/collection/etd1/id/135/rec/1264.

MLA Handbook (7^th Edition):

Finerty, Patrick Joseph. “Studies on a double-stranded RNA-binding zinc finger protein;.” 1999. Web. 22 Jan 2021.

Vancouver:

Finerty PJ. Studies on a double-stranded RNA-binding zinc finger protein;. [Internet] [Doctoral dissertation]. University of Utah; 1999. [cited 2021 Jan 22]. Available from: http://content.lib.utah.edu/cdm/singleitem/collection/etd1/id/135/rec/1264.

Council of Science Editors:

Finerty PJ. Studies on a double-stranded RNA-binding zinc finger protein;. [Doctoral Dissertation]. University of Utah; 1999. Available from: http://content.lib.utah.edu/cdm/singleitem/collection/etd1/id/135/rec/1264

University of Manchester

5. Zhao, Yanan. The Role of Thymosin β4 during Embryonic Wound Healing and Tail Regeneration in Xenopus.

Degree: 2013, University of Manchester

URL: http://www.manchester.ac.uk/escholar/uk-ac-man-scw:212707

► At the outset of my PhD, my aim was to investigate the mechanisms responsible for the directed migration of primitive myeloid cells (PMCs) to wounds… (more)

▼ At the outset of my PhD, my aim was to investigate the mechanisms responsible for the directed migration of primitive myeloid cells (PMCs) to wounds in Xenopus embryos. PMCs are the first blood cells to differentiate and become functional in Xenopus embryos, and have a notable migratory ability to be recruited by embryonic wounds before a functional vasculature is established. To find the mechanism underlying PMCs migration toward embryonic wounds, I first performed a screen to identify candidate cytoskeleton related genes, which might be responsible for facilitating the inflammatory response to injury in embryos. In situ hybridization and RT-PCR showed that coronin1a and l-plastin were specifically expressed in PMCs. I carried out loss-of-function experiments for coronin 1a and l-plastin in Xenopus embryos. Unfortunately neither knockdown affected the ability for PMCs to migrate during embryonic development or during the wound healing process. Loss-of-function experiments on coronin 1a and l-plastin also did not affect epidermal wound closure speed. Thus, although coronin 1a and l- plastin are expressed specifically in PMCs, they do not appear to be necessary for the migration of PMCs during development and during wound healing in Xenopuos embryos.Since my initial aim failed to provide insight into the mechanisms that mediate 9the inflammatory response to embryonic wounds, I decided to investigate the function of a previously identified monomeric actin protein during embryonic wound healing and appendage regeneration: namely Thymosin beta4 (Tβ4). In situ hybridization experiments showed that Tβ4 is expressed exclusively in the epidermis of developing frog embryos. Tβ4 knockdown embryos resulted in a significantly delay in the speed of wound closure during the early phase of wound healing. This delay correlated with a decrease in the actin contractile ring at the wound margin. Furthermore I found that the cell shapes of epidermal cells in the Tβ4 knockdown embryos were different from epidermal cells in control embryos. I hypothesize that this reduction caused the actin filaments changes in the epidermal cells, and were responsible for the failure of the cells to form an actin contractile ring, thus delaying the initial speed of wound closure. I tried to confirm that most of these defects specific to Tβ4, by performing rescue experiments with Tβ4 mRNA injections. Furthermore, I discovered that Tβ4 knockdown embryos displayed defects in tail development, including the absence of blood vessel branching within the fin of the tail. Finally, I found that the tails in Tβ4 knocked-down tadpoles failed to regenerate, while tails in control embryos regenerated completely following amputation. Both in situ hybridization and real-time PCR showed that Tβ4 was up regulated in the regenerated part of the tail in Xenopus tadpoles. Together with the tail amputation results, Tβ4 might be important for tail development and regeneration. These findings suggest that Tβ4 might play an important roles in the modulation of the actin… Advisors/Committee Members: Amaya, Enrique.

Subjects/Keywords: Thymosin beta4; wound healing; Xenopus

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APA · Chicago · MLA · Vancouver · CSE | Export to Zotero / EndNote / Reference Manager

APA (6^th Edition):

Zhao, Y. (2013). The Role of Thymosin β4 during Embryonic Wound Healing and Tail Regeneration in Xenopus. (Doctoral Dissertation). University of Manchester. Retrieved from http://www.manchester.ac.uk/escholar/uk-ac-man-scw:212707

Chicago Manual of Style (16^th Edition):

Zhao, Yanan. “The Role of Thymosin β4 during Embryonic Wound Healing and Tail Regeneration in Xenopus.” 2013. Doctoral Dissertation, University of Manchester. Accessed January 22, 2021. http://www.manchester.ac.uk/escholar/uk-ac-man-scw:212707.

MLA Handbook (7^th Edition):

Zhao, Yanan. “The Role of Thymosin β4 during Embryonic Wound Healing and Tail Regeneration in Xenopus.” 2013. Web. 22 Jan 2021.

Vancouver:

Zhao Y. The Role of Thymosin β4 during Embryonic Wound Healing and Tail Regeneration in Xenopus. [Internet] [Doctoral dissertation]. University of Manchester; 2013. [cited 2021 Jan 22]. Available from: http://www.manchester.ac.uk/escholar/uk-ac-man-scw:212707.

Council of Science Editors:

Zhao Y. The Role of Thymosin β4 during Embryonic Wound Healing and Tail Regeneration in Xenopus. [Doctoral Dissertation]. University of Manchester; 2013. Available from: http://www.manchester.ac.uk/escholar/uk-ac-man-scw:212707

University of Waterloo

6. Studholme, Catherine. Beta-parvin Mediates Adhesion Receptor Cross-Talk During Xenopus laevis Gastrulation.

Degree: 2013, University of Waterloo

URL: http://hdl.handle.net/10012/7969

► Modulation of cell adhesion is essential to the cell rearrangements that characterize Xenopus gastrulation. The spatial and temporal regulation of cell movement requires a highly… (more)

▼ Modulation of cell adhesion is essential to the cell rearrangements that characterize Xenopus gastrulation. The spatial and temporal regulation of cell movement requires a highly coordinated cross-talk between cadherin and integrin adhesion receptors. Beta-parvin is an integrin associated scaffolding protein consisting of two calponin homology (CH) domains. Xenopus beta-parvin is highly conserved being ~95% similar to mammalian orthologs. Beta-parvin is expressed in the blastocoel roof and dorsal marginal zone of the embryo during gastrulation, suggesting a potential role in morphogenesis. Over-expression of full-length beta-parvin has no effect on embryogenesis, however, over-expression of either CH domain causes a failure in gastrulation. When over-expressed the CH1 domain causes a failure in fibronectin (FN) matrix assembly, epiboly and convergent extension in vivo. CH1 domain over-expression also inhibits tissue separation (TS) and Brachet’s cleft formation. The CH1 domain of beta-parvin localizes to sites of cell-cell adhesion, and down-regulates C-cadherin adhesion through activation of Rac1, independent of receptor expression. Significantly, the CH1 domain can rescue convergent extension downstream of integrin ex vivo suggesting a role for beta-parvin in the integrin mediated control of cell intercalation. Over-expression of the CH2 domain also inhibits morphogenesis in a similar fashion as CH1. However, the CH2 domain localizes to sites of integrin adhesion and inhibits integrin function resulting in a loss of FN assembly. The CH2 domain binds ILK and inhibits integrin function. When over-expressed the CH2 domain promotes TS in the pre-involution mesoderm through the activation of Rho. While the CH1 domain inhibits TS through Rac and the CH2 domain promotes TS through Rho, full-length beta-parvin over-expression has no embryonic phenotype and its signaling properties appear to be intermediate between expression of either isolated CH domain. At the dorsal lip full-length beta-parvin shuttles between integrin in the pre-involution mesoderm and cell-cell adhesion sites in the post-involution mesoderm indicating it plays significant roles in the previously characterized integrin-cadherin cross talk. My research has defined novel roles for beta-parvin as a key player in the regulation of integrin-cadherin cross-talk during tissue morphogenesis.

Subjects/Keywords: parvin; xenopus; gastrulation; tissue separation

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APA (6^th Edition):

Studholme, C. (2013). Beta-parvin Mediates Adhesion Receptor Cross-Talk During Xenopus laevis Gastrulation. (Thesis). University of Waterloo. Retrieved from http://hdl.handle.net/10012/7969

Note: this citation may be lacking information needed for this citation format:
Not specified: Masters Thesis or Doctoral Dissertation

Chicago Manual of Style (16^th Edition):

Studholme, Catherine. “Beta-parvin Mediates Adhesion Receptor Cross-Talk During Xenopus laevis Gastrulation.” 2013. Thesis, University of Waterloo. Accessed January 22, 2021. http://hdl.handle.net/10012/7969.

Note: this citation may be lacking information needed for this citation format:
Not specified: Masters Thesis or Doctoral Dissertation

MLA Handbook (7^th Edition):

Studholme, Catherine. “Beta-parvin Mediates Adhesion Receptor Cross-Talk During Xenopus laevis Gastrulation.” 2013. Web. 22 Jan 2021.

Vancouver:

Studholme C. Beta-parvin Mediates Adhesion Receptor Cross-Talk During Xenopus laevis Gastrulation. [Internet] [Thesis]. University of Waterloo; 2013. [cited 2021 Jan 22]. Available from: http://hdl.handle.net/10012/7969.

Note: this citation may be lacking information needed for this citation format:
Not specified: Masters Thesis or Doctoral Dissertation

Council of Science Editors:

Studholme C. Beta-parvin Mediates Adhesion Receptor Cross-Talk During Xenopus laevis Gastrulation. [Thesis]. University of Waterloo; 2013. Available from: http://hdl.handle.net/10012/7969

Note: this citation may be lacking information needed for this citation format:
Not specified: Masters Thesis or Doctoral Dissertation

Stellenbosch University

7. De Villiers, Francois Andre. The dispersal ability, performance and population dynamics of Cape Xenopus frogs.

Degree: MSc, Botany and Zoology, 2016, Stellenbosch University

URL: http://hdl.handle.net/10019.1/98350

► ENGLISH ABSTRACT: Dispersal is an important life history trait which is present in most organisms, and can affect the population structure, such as survival and… (more)

▼ ENGLISH ABSTRACT: Dispersal is an important life history trait which is present in most organisms, and can affect the population structure, such as survival and age structure, of a species. An organism’s dispersal ability is related to the individual’s performance ability, which is ultimately determined by the individual’s morphology. Amphibians have been classically viewed as poor dispersers, but studies have shown that there are some exceptions. However, these studies represent terrestrial frog species and lack aquatic frog species. Frogs in the genus Xenopus are principally aquatic, and have been known to make use of water corridors for dispersal, however overland dispersal has been observed. There are two Xenopus present in the south Western Cape; X. gilli and X. laevis. In this study I compare and determine the dispersal ability, performance and morphology of X. gilli and X. laevis. I hypothesize that X. laevis will outperform X. gilli in both dispersal and relative performance. Two sites were used in this study; an area east of Kleinmond and the Cape of Good Hope section of TMNP (CoGH). In Kleinmond both X. laevis and X. gilli were marked with PIT tags, whereas only X. gilli was tagged in CoGH. Jumping and swimming performance was obtained by filming the frogs at 240fps, and wet and dry endurance was measured in a 4m track. Dispersal distances between two ponds were represented by Euclidean distances based on recapture of individually marked animals. The results show that X. laevis was the better jumper and swimmer of the two species. All performance trails that included jumping were found to be related to the leg morphology of the two Xenopus species. There was no difference in the dispersal distance of the two species, which was mirrored by the lack of difference in dry endurance; however Xenopus laevis had the highest proportion of individuals dispersing. Population structure is an important tool to determine the state of a given population. In a species that experiences high juvenile predation it is expected that the age structure would be skewed towards the older individuals and that the juveniles will have a low survival rate. Xenopus laevis poses a threat to X. gilli through predation, competition and hybridization. I compared the survival and age structure of X. laevis and the two X. gilli populations. I hypothesized that X. laevis will have a negative effect on the survival and age structure of X. gilli. Recaptures at Kleinmond and CoGH recurred between three to six weeks. The second phalange of the outer toe of 20 males and 20 females of X. laevis and X. gilli at both sites were sectioned. The number of lines of arrested growth (LAG) were recorded as a proxy for age. All frogs that were recaptured in 2015 were photographed again and growth was determined. The results indicate that Kleinmond X. gilli had the lowest survival (0.319), which was accredited to competition and predation by X. laevis, whereas CoGH X. gilli had the highest survival (0.562). Age structure was not determined possibly due to… Advisors/Committee Members: Measey, G. John, Stellenbosch University. Faculty of Science. Dept. of Botany and Zoology..

Subjects/Keywords: Xenopus frogs – South Africa – Western Cape; Xenopus frogs – Movement ability; Xenopus frogs – Population structure; Xenopus frogs – Morphology; UCTD

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APA (6^th Edition):

De Villiers, F. A. (2016). The dispersal ability, performance and population dynamics of Cape Xenopus frogs. (Masters Thesis). Stellenbosch University. Retrieved from http://hdl.handle.net/10019.1/98350

Chicago Manual of Style (16^th Edition):

De Villiers, Francois Andre. “The dispersal ability, performance and population dynamics of Cape Xenopus frogs.” 2016. Masters Thesis, Stellenbosch University. Accessed January 22, 2021. http://hdl.handle.net/10019.1/98350.

MLA Handbook (7^th Edition):

De Villiers, Francois Andre. “The dispersal ability, performance and population dynamics of Cape Xenopus frogs.” 2016. Web. 22 Jan 2021.

Vancouver:

De Villiers FA. The dispersal ability, performance and population dynamics of Cape Xenopus frogs. [Internet] [Masters thesis]. Stellenbosch University; 2016. [cited 2021 Jan 22]. Available from: http://hdl.handle.net/10019.1/98350.

Council of Science Editors:

De Villiers FA. The dispersal ability, performance and population dynamics of Cape Xenopus frogs. [Masters Thesis]. Stellenbosch University; 2016. Available from: http://hdl.handle.net/10019.1/98350

Texas Tech University

8. Cromie, Meghan. An examination of the effects of Methyltriclosan on early embryonic development in the South African clawed frog (Xenopus laevis).

Degree: MS, Biology, 2012, Texas Tech University

URL: http://hdl.handle.net/2346/73880

► Triclosan (5-chloro-2-(2,4-dichlorophenoxy)phenol) is a commonly used bactericide present in many personal care products such as liquid detergents, liquid hand soaps, deodorants, cosmetics, creams, lotions, mouthwash,… (more)

▼ Triclosan (5-chloro-2-(2,4-dichlorophenoxy)phenol) is a commonly used bactericide present in many personal care products such as liquid detergents, liquid hand soaps, deodorants, cosmetics, creams, lotions, mouthwash, and toothpaste. Triclosan also can be added to fabrics, plastics, carpets, plastic kitchenware, and toys. Methyltriclosan is a derivative that is formed from triclosan via biological methylation at an unknown interval during waste water treatment. Methyltriclosan is more abundant in the environment, more lipophilic than triclosan, and has a greater potential to accumulate in fatty tissues. The global decline of amphibian populations has raised awareness surrounding the possible effects of poor water quality on the health of habitats. Since metamorphosis and reproductive development in amphibians is highly regulated by thyroid hormone (TH), and the structure of triclosan is similar to that of TH, there is the possibility that methyltriclosan may act on TH receptors to alter development. The response of Xenopus laevis embryos to various concentrations of methyltriclosan were tested in standard 96-hour Frog Embryo Teratogenic Assay-Xenopus (FETAX) protocols. After the 96-hour FETAX exposure, the larvae were photographed and total body lengths, snout-to-vent lengths and crown widths were measured using image analysis. The data revealed that early embryonic exposure to environmentally relevant concentrations of methyltriclosan resulted in significant (p<0.05) alterations in all of the measurements made that differed from the concentration-related response to triiodothyronine. Furthermore, molecular studies were performed in whole body tissues of the 96-hour-exposed larvae to identify the effects of methyltriclosan exposure on the TH-responsive gene, thyroid hormone bZIP. The results of the quantitative real-time polymerase chain reaction did not support the induction of TH/bZIP gene expression after exposure to environmentally relevant concentrations of methyltriclosan. We conclude that low environmental concentrations of methyltriclosan alter somatic growth in embryonic X. laevis through a mechanism that does not involve the activation of thyroid hormone receptors. Collectively, these data are the first to report on the responsiveness of vertebrate embryos to methyltriclosan exposure. Advisors/Committee Members: Carr, Jim (advisor), Smith, Ernest (committee member), Patino, Reynaldo (committee member), Carr, James A. (Committee Chair).

Subjects/Keywords: Methyltriclosan; Xenopus Laevis; FETAX; Embryonic

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APA (6^th Edition):

Cromie, M. (2012). An examination of the effects of Methyltriclosan on early embryonic development in the South African clawed frog (Xenopus laevis). (Masters Thesis). Texas Tech University. Retrieved from http://hdl.handle.net/2346/73880

Chicago Manual of Style (16^th Edition):

Cromie, Meghan. “An examination of the effects of Methyltriclosan on early embryonic development in the South African clawed frog (Xenopus laevis).” 2012. Masters Thesis, Texas Tech University. Accessed January 22, 2021. http://hdl.handle.net/2346/73880.

MLA Handbook (7^th Edition):

Cromie, Meghan. “An examination of the effects of Methyltriclosan on early embryonic development in the South African clawed frog (Xenopus laevis).” 2012. Web. 22 Jan 2021.

Vancouver:

Cromie M. An examination of the effects of Methyltriclosan on early embryonic development in the South African clawed frog (Xenopus laevis). [Internet] [Masters thesis]. Texas Tech University; 2012. [cited 2021 Jan 22]. Available from: http://hdl.handle.net/2346/73880.

Council of Science Editors:

Cromie M. An examination of the effects of Methyltriclosan on early embryonic development in the South African clawed frog (Xenopus laevis). [Masters Thesis]. Texas Tech University; 2012. Available from: http://hdl.handle.net/2346/73880

North Carolina State University

9. Zhang, Bo. The Role of Claudin-5 on Xenopus Heart Development.

Degree: MS, Zoology, 2009, North Carolina State University

URL: http://www.lib.ncsu.edu/resolver/1840.16/413

► Claudin-5 is an important member of the claudin gene family. The expression of claudin-5 in the heart of Xenopus laevis was determined by whole mount… (more)

Subjects/Keywords: Xenopus; claudin; heart development

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APA · Chicago · MLA · Vancouver · CSE | Export to Zotero / EndNote / Reference Manager

APA (6^th Edition):

Zhang, B. (2009). The Role of Claudin-5 on Xenopus Heart Development. (Thesis). North Carolina State University. Retrieved from http://www.lib.ncsu.edu/resolver/1840.16/413

Note: this citation may be lacking information needed for this citation format:
Not specified: Masters Thesis or Doctoral Dissertation

Chicago Manual of Style (16^th Edition):

Zhang, Bo. “The Role of Claudin-5 on Xenopus Heart Development.” 2009. Thesis, North Carolina State University. Accessed January 22, 2021. http://www.lib.ncsu.edu/resolver/1840.16/413.

Note: this citation may be lacking information needed for this citation format:
Not specified: Masters Thesis or Doctoral Dissertation

MLA Handbook (7^th Edition):

Zhang, Bo. “The Role of Claudin-5 on Xenopus Heart Development.” 2009. Web. 22 Jan 2021.

Vancouver:

Zhang B. The Role of Claudin-5 on Xenopus Heart Development. [Internet] [Thesis]. North Carolina State University; 2009. [cited 2021 Jan 22]. Available from: http://www.lib.ncsu.edu/resolver/1840.16/413.

Note: this citation may be lacking information needed for this citation format:
Not specified: Masters Thesis or Doctoral Dissertation

Council of Science Editors:

Zhang B. The Role of Claudin-5 on Xenopus Heart Development. [Thesis]. North Carolina State University; 2009. Available from: http://www.lib.ncsu.edu/resolver/1840.16/413

Note: this citation may be lacking information needed for this citation format:
Not specified: Masters Thesis or Doctoral Dissertation

University of Otago

10. Wang, Yi-Hsuan (Elisha). Revised function of the BMP inhibtor, Gremlin, in Xenopus limb development, and its potential in hindlimb regeneration .

Degree: 2011, University of Otago

URL: http://hdl.handle.net/10523/1738

► Gremlin (Grm) is a potent antagonist of bone morphogenetic proteins (BMPs), which is highly conserved among vertebrates. A combination of functional studies and gene expression… (more)

▼ Gremlin (Grm) is a potent antagonist of bone morphogenetic proteins (BMPs), which is highly conserved among vertebrates. A combination of functional studies and gene expression analyses in mice and chicks showed that the antagonistic relationship between Grm and the BMPs form part of epithelial-mesenchyme interactive network that plays an important part in early limb development (Zeller, et al., 2009). Together with the Sonic hedgehog-Fibroblast growth factor signalling loop, they form a self-regulatory system that controls the outgrowth, termination and patterning of the avian and murine limbs (Zeller, et al., 2009). Interestingly, a recent report by Pearl et al (2008) demonstrated Grm as one of the developmental genes that was significantly overexpressed in the regenerating blastema tissues of wildtype tadpoles compared to samples obtained from the non-regeneration competent tadpoles. The same study also revealed differential patterns of Grm expression in the developing hindlimb bud in Xenopus compared to those in the avian and murine limbs (Khokha, et al., 2003; Merino, et al., 1999; Pearl, et al., 2008). Moreover, the team also showed differential patterns of expression of the gene during normal hindlimb development and regeneration. These results raised new questions concerning the functions of Grm in amphibian limb development as well as suggesting potential involvement of the gene in regenerative success of Xenopus hindlimb. This project aims to investigate the involvement of the BMP antagonist in X. laevis hindlimb regeneration as well as the function of the gene during early amphibian limb development via a combination of expression and functional analyses. Grm was expressed in the distal region of the regenerating hindlimbs and the early limb bud stages during development. The expression data discussed here not only correlates with the results described in Pearl et al (2008), they also reveal spatial expression of the gene during development in more detail. Additionally, this study also covered the expression of Grm in stage 50 hindlimb buds, which was not tested in the previous study by (Pearl, et al., 2008). The resulting data showed that the expression pattern was vaguely similar to the patterns previously described in early limb buds of chick and mice (Khokha, et al., 2003; Merino, et al., 1999). Overexpression of Grm during early phases of hindlimb regeneration in stage 54 tadpoles using the heat shock-inducible transgenic technique developed by Beck et al (2003) reduced the ability of the animals to regenerate lost structures significantly. The induction of Grm expression also had a significant impact on autopod patterning in both hind- and forelimbs, which was manifested through a range of phenotypes. Finally, this thesis also includes a brief discussion on the project of generating a line of heat shock-inducible RNAi-mediated “knockout” frogs, which may facilitate the studies of developmental genes, such as Grm, that are essential during early development. We have successfully produced… Advisors/Committee Members: Beck, Caroline (advisor).

Subjects/Keywords: Gremlin; Xenopus; limb development; regeneration

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APA · Chicago · MLA · Vancouver · CSE | Export to Zotero / EndNote / Reference Manager

APA (6^th Edition):

Wang, Y. (. (2011). Revised function of the BMP inhibtor, Gremlin, in Xenopus limb development, and its potential in hindlimb regeneration . (Masters Thesis). University of Otago. Retrieved from http://hdl.handle.net/10523/1738

Chicago Manual of Style (16^th Edition):

Wang, Yi-Hsuan (Elisha). “Revised function of the BMP inhibtor, Gremlin, in Xenopus limb development, and its potential in hindlimb regeneration .” 2011. Masters Thesis, University of Otago. Accessed January 22, 2021. http://hdl.handle.net/10523/1738.

MLA Handbook (7^th Edition):

Wang, Yi-Hsuan (Elisha). “Revised function of the BMP inhibtor, Gremlin, in Xenopus limb development, and its potential in hindlimb regeneration .” 2011. Web. 22 Jan 2021.

Vancouver:

Wang Y(. Revised function of the BMP inhibtor, Gremlin, in Xenopus limb development, and its potential in hindlimb regeneration . [Internet] [Masters thesis]. University of Otago; 2011. [cited 2021 Jan 22]. Available from: http://hdl.handle.net/10523/1738.

Council of Science Editors:

Wang Y(. Revised function of the BMP inhibtor, Gremlin, in Xenopus limb development, and its potential in hindlimb regeneration . [Masters Thesis]. University of Otago; 2011. Available from: http://hdl.handle.net/10523/1738

University of Miami

11. Luo, Xueting. Translational Control of Maternal nanos1 and VegT in Xenopus Germline.

Degree: PhD, Biochemistry and Molecular Biology (Medicine), 2011, University of Miami

URL: https://scholarlyrepository.miami.edu/oa_dissertations/566

► Early embryonic development proceeds without zygotic transcription. Genetic control is executed by maternally inherited mRNAs that are expressed in a temporally regulated manner. To set… (more)

▼ Early embryonic development proceeds without zygotic transcription. Genetic control is executed by maternally inherited mRNAs that are expressed in a temporally regulated manner. To set up the body plan, it is pivotal to both exert translational regulation of maternal mRNAs and to integrate maternal signals that drive cell fate determination. Xenopus nanos1, dead end (dnd) and VegT are maternal messages critical for the germline and somatic development. nanos1 and dnd localize to the germ plasm at the vegetal cortex of oocytes, while VegT occupies a cortical region overlapping with, but broader than, that of the germ plasm. In this dissertation, we observed that unlike other mRNAs, synthetic nanos1 RNA translates very poorly if at all after injection into Xenopus oocytes. We find that a RNA secondary structural element immediately downstream of the AUG start site is both necessary and sufficient to prevent ribosome scanning in the absence of a repressor. nanos1 is translated shortly after fertilization, pointing to the existence of a developmentally regulated activator. These observations unravel a new mode of nanos1 regulation at the post-transcriptional level for eukaryotes that is essential for normal development. Further studies showed that co-injection of dnd and nanos1 into oocytes resulted in nanos1 activation. Consistent with Dnd being the activator, Nanos1 expression was attenuated in the absence of dnd activity. Recombinant Dnd interacted directly with nanos1 RNA in vitro and possessed ATPase activity. Our findings suggested that Dnd is the potential activator for nanos1 translation by directly disrupting the repressive structural element. We previously showed that VegT, the maternal transcription factor, is normally inherited by the primordial germ cells (PGCs). VegT is the endoderm determinant and must be silenced in PGCs to preserve the germline. We showed that a classic Pumilio Binding Element (PBE) within the VegT 3’UTR mediated translational repression of a fluorescent reporter in the germline. Accordingly, a direct interaction between Xenopus Pumilio1 RNA binding domain and the VegT PBE was demonstrated in a band shift assay. The Pumilio protein belongs to the Pum-FBF family that functions in translational repression. We show that Pumilio represses VegT in vivo. Our results suggest that the germline stays unresponsive to the somatic determinant VegT in part by Pumilio- and Nanos-mediated translational repression. Advisors/Committee Members: Mary Lou King, Feng Gong, Murray P. Deutscher, Richard L. Rotundo, Isaac Skromne.

Subjects/Keywords: nanos; Xenopus; germline; translation

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APA · Chicago · MLA · Vancouver · CSE | Export to Zotero / EndNote / Reference Manager

APA (6^th Edition):

Luo, X. (2011). Translational Control of Maternal nanos1 and VegT in Xenopus Germline. (Doctoral Dissertation). University of Miami. Retrieved from https://scholarlyrepository.miami.edu/oa_dissertations/566

Chicago Manual of Style (16^th Edition):

Luo, Xueting. “Translational Control of Maternal nanos1 and VegT in Xenopus Germline.” 2011. Doctoral Dissertation, University of Miami. Accessed January 22, 2021. https://scholarlyrepository.miami.edu/oa_dissertations/566.

MLA Handbook (7^th Edition):

Luo, Xueting. “Translational Control of Maternal nanos1 and VegT in Xenopus Germline.” 2011. Web. 22 Jan 2021.

Vancouver:

Luo X. Translational Control of Maternal nanos1 and VegT in Xenopus Germline. [Internet] [Doctoral dissertation]. University of Miami; 2011. [cited 2021 Jan 22]. Available from: https://scholarlyrepository.miami.edu/oa_dissertations/566.

Council of Science Editors:

Luo X. Translational Control of Maternal nanos1 and VegT in Xenopus Germline. [Doctoral Dissertation]. University of Miami; 2011. Available from: https://scholarlyrepository.miami.edu/oa_dissertations/566

University of Miami

12. Nichols, Andrew S. Subunit Contributions to the Structure and Function of Insect Olfactory Receptors.

Degree: PhD, Molecular and Cellular Pharmacology (Medicine), 2010, University of Miami

URL: https://scholarlyrepository.miami.edu/oa_dissertations/361

► Insects detect specific chemicals in the environment with olfactory receptors (ORs), which represent a novel class of ligand-gated ion channel. Insect ORs are comprised… (more)

▼ Insects detect specific chemicals in the environment with olfactory receptors (ORs), which represent a novel class of ligand-gated ion channel. Insect ORs are comprised of at least one common subunit (OR83b in Drosophila) and at least one odorant-binding subunit. However, the molecular details of insect OR architecture, such as how they bind odorants, are unknown. This lack of knowledge hinders the development of compounds that may modulate OR function and potentially control insects involved in disease propagation and agricultural damage. The intent of this project is to investigate the structure and function of insect ORs. To this end, the utility of the Xenopus oocyte heterologous expression system was explored. Assay optimization, accuracy, and investigations on functional requirements were first performed using the Drosophila OR (DmOR) 35a/83b. The utility of the assay system was also demonstrated by identification of the honey bee (Apis mellifera) OR 11/2 as a receptor for the queen pheromone, 9-oxo-2-decenoic acid. A series of DmORs was cloned and expressed in Xenopus oocytes and individual receptors were selected for further study. DmOR85a/83b was shown to possess an incredibly high degree of enantioselectivity for the odorant ethyl 3-hydroxybutyrate. The receptive range of DmOR67a/83b was explored and observations were made on potential features of the odorant-binding site and a ligand odorophore. DmORs were also used to investigate the contributions of individual subunits toward the odorant-binding site and pore structure. Also, evidence for receptor antagonism by odorants was revealed. DmORs were screened with methanethiosulfonate reagents and the substituted cysteine accessibility method to identify residues 146-150 of DmOR85b as functionally important in receptor activation. This region, located at the predicted interface between transmembrane segment 3 (TMS3) and extracellular loop 2, was shown to be physically adjacent to the odorant-binding site itself. Finally, residues within the extracellular half of TMS3 in DmOR85b were implicated in odorant-induced activation by screening DmOR85b mutants for altered ligand preferences. Therefore, this project provides the first identification of insect OR subunit components involved in odorant recognition, and represents an important starting point for detailed analysis of the molecular basis for insect OR activation by odorants. Advisors/Committee Members: Vladen Z. Slepak, R. Grace Zhai, Nirupa Chaudhari, Charles W. Luetje, Laurence Zwiebel.

Subjects/Keywords: Electrophysiology; Xenopus; Receptor; Mutagenesis; Orco

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APA · Chicago · MLA · Vancouver · CSE | Export to Zotero / EndNote / Reference Manager

APA (6^th Edition):

Nichols, A. S. (2010). Subunit Contributions to the Structure and Function of Insect Olfactory Receptors. (Doctoral Dissertation). University of Miami. Retrieved from https://scholarlyrepository.miami.edu/oa_dissertations/361

Chicago Manual of Style (16^th Edition):

Nichols, Andrew S. “Subunit Contributions to the Structure and Function of Insect Olfactory Receptors.” 2010. Doctoral Dissertation, University of Miami. Accessed January 22, 2021. https://scholarlyrepository.miami.edu/oa_dissertations/361.

MLA Handbook (7^th Edition):

Nichols, Andrew S. “Subunit Contributions to the Structure and Function of Insect Olfactory Receptors.” 2010. Web. 22 Jan 2021.

Vancouver:

Nichols AS. Subunit Contributions to the Structure and Function of Insect Olfactory Receptors. [Internet] [Doctoral dissertation]. University of Miami; 2010. [cited 2021 Jan 22]. Available from: https://scholarlyrepository.miami.edu/oa_dissertations/361.

Council of Science Editors:

Nichols AS. Subunit Contributions to the Structure and Function of Insect Olfactory Receptors. [Doctoral Dissertation]. University of Miami; 2010. Available from: https://scholarlyrepository.miami.edu/oa_dissertations/361

University of Aberdeen

13. Gibb, Natalie L. sfrp 1 promotes myocardial differentiation in Xenopus laevis by inhibiting canonical wnt6 signalling.

Degree: PhD, 2013, University of Aberdeen

URL: https://eu03.alma.exlibrisgroup.com/view/delivery/44ABE_INST/12153160530005941 ; https://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.577593

► Wnt signalling is a key regulator of vertebrate heart development yet the exact requirements of the Wnt signalling components remains unclear. The endogenous Wnt ligand… (more)

Subjects/Keywords: 616.1; Xenopus laevis; Wnt proteins

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APA (6^th Edition):

Gibb, N. L. (2013). sfrp 1 promotes myocardial differentiation in Xenopus laevis by inhibiting canonical wnt6 signalling. (Doctoral Dissertation). University of Aberdeen. Retrieved from https://eu03.alma.exlibrisgroup.com/view/delivery/44ABE_INST/12153160530005941 ; https://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.577593

Chicago Manual of Style (16^th Edition):

Gibb, Natalie L. “sfrp 1 promotes myocardial differentiation in Xenopus laevis by inhibiting canonical wnt6 signalling.” 2013. Doctoral Dissertation, University of Aberdeen. Accessed January 22, 2021. https://eu03.alma.exlibrisgroup.com/view/delivery/44ABE_INST/12153160530005941 ; https://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.577593.

MLA Handbook (7^th Edition):

Gibb, Natalie L. “sfrp 1 promotes myocardial differentiation in Xenopus laevis by inhibiting canonical wnt6 signalling.” 2013. Web. 22 Jan 2021.

Vancouver:

Gibb NL. sfrp 1 promotes myocardial differentiation in Xenopus laevis by inhibiting canonical wnt6 signalling. [Internet] [Doctoral dissertation]. University of Aberdeen; 2013. [cited 2021 Jan 22]. Available from: https://eu03.alma.exlibrisgroup.com/view/delivery/44ABE_INST/12153160530005941 ; https://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.577593.

Council of Science Editors:

Gibb NL. sfrp 1 promotes myocardial differentiation in Xenopus laevis by inhibiting canonical wnt6 signalling. [Doctoral Dissertation]. University of Aberdeen; 2013. Available from: https://eu03.alma.exlibrisgroup.com/view/delivery/44ABE_INST/12153160530005941 ; https://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.577593

University of Aberdeen

14. Schulze, Sabrine. Wnt6 function in eye development in Xenopus laevis.

Degree: PhD, 2012, University of Aberdeen

URL: https://eu03.alma.exlibrisgroup.com/view/delivery/44ABE_INST/12152166290005941 ; https://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.569610

► The eyes are the most important sensory organs for most vertebrates. Their structure and development is conserved between several vertebrate species. The development is regulated… (more)

Subjects/Keywords: 570; Xenopus laevis; Frogs; Vision

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APA (6^th Edition):

Schulze, S. (2012). Wnt6 function in eye development in Xenopus laevis. (Doctoral Dissertation). University of Aberdeen. Retrieved from https://eu03.alma.exlibrisgroup.com/view/delivery/44ABE_INST/12152166290005941 ; https://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.569610

Chicago Manual of Style (16^th Edition):

Schulze, Sabrine. “Wnt6 function in eye development in Xenopus laevis.” 2012. Doctoral Dissertation, University of Aberdeen. Accessed January 22, 2021. https://eu03.alma.exlibrisgroup.com/view/delivery/44ABE_INST/12152166290005941 ; https://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.569610.

MLA Handbook (7^th Edition):

Schulze, Sabrine. “Wnt6 function in eye development in Xenopus laevis.” 2012. Web. 22 Jan 2021.

Vancouver:

Schulze S. Wnt6 function in eye development in Xenopus laevis. [Internet] [Doctoral dissertation]. University of Aberdeen; 2012. [cited 2021 Jan 22]. Available from: https://eu03.alma.exlibrisgroup.com/view/delivery/44ABE_INST/12152166290005941 ; https://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.569610.

Council of Science Editors:

Schulze S. Wnt6 function in eye development in Xenopus laevis. [Doctoral Dissertation]. University of Aberdeen; 2012. Available from: https://eu03.alma.exlibrisgroup.com/view/delivery/44ABE_INST/12152166290005941 ; https://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.569610

University of Illinois – Urbana-Champaign

15. Thomas, Alvin G. Investigating the role of CYP26 and retinoic acid signaling regulation in vertebrate cornea and lens regeneration.

Degree: PhD, Cell and Developmental Biology, 2016, University of Illinois – Urbana-Champaign

URL: http://hdl.handle.net/2142/90910

► The larvae of Xenopus laevis can naturally regenerate a lost lens from the outer cornea epithelium after it is triggered to do so by signals… (more)

▼ The larvae of Xenopus laevis can naturally regenerate a lost lens from the outer cornea epithelium after it is triggered to do so by signals from the neural retina. The signals have been widely studied, and FGFs are reported to play a key role in causing the cornea to transform into a lens. However, the factors that make the cornea itself competent to respond to these signals are unknown. Understanding the factors that underlie regeneration competency is the key to granting otherwise ordinary tissues the ability to regenerate, including in our own bodies. Thus, the focus of this work has been on the cornea, in order to unravel the signaling schemes that operate within it. The Retinoic Acid (RA) signaling pathway is a major cellular signaling pathway involved in development, organogenesis, and regeneration. It was strongly implicated in the regeneration of the lens in another model system, the newt, where retinal signals trigger the dorsal region of the iris to differentiate and give rise to a lens. Antagonism of RA signaling was shown to inhibit lens regeneration, demonstrating its necessity. We investigated whether the same was true in Xenopus. We inhibited RA signaling using inhibitors of RA synthesizing enzymes, and of the RAR nuclear receptors. In all cases we found there to be no effect on regeneration. We validated that the drug treatments were meaningful by observing, via qPCR, a decrease in the expression cyp26a1, a well-established marker of RA signaling. We also examined the expression of multiple RA signaling pathway members both in control corneas and in corneas harvested in the first 4 days following lentectomy. In both these normal and regenerating tissues we found the expression of cyp26 genes, which encode the RA metabolizing enzyme CYP26. In light of this finding, we assessed whether CYP26 was necessary for supporting lens regeneration. In contrast to the experiment described above, exogenous addition of an antagonist of CYP26 greatly inhibited lens regeneration. Likewise, a synthetic retinoid that activates RA signaling without being metabolized by CYP26 also inhibited regeneration, as did excess exogenous RA. In all treatments, we observed profound upregulation of the RA signaling marker cyp26a1. Taken together, we demonstrated that the action of CYP26 is necessary for lens regeneration, which implies a necessity to attenuate RA signaling by metabolism in order for lens regeneration to occur in Xenopus. This represents a species-specific difference in the signaling schemes that underlie lens regeneration, and a previously undescribed role for CYP26 in regeneration. Using immunohistochemistry and a whole-cornea mounting technique, we observed the widespread expression of RALDH and CYP26 enzymes within the corneal layers under a confocal microscope. We next investigated the possible mechanistic roles of CYP26 that could explain its necessity in lens regeneration. We assessed whether RA signaling regulated cell proliferation in the cornea by quantifying changes in cell division following… Advisors/Committee Members: Henry, Jonathan J. (advisor), Ceman, Stephanie S. (Committee Chair), Brieher, William M. (committee member), Chen, Jie (committee member), Raetzman, Lori T. (committee member).

Subjects/Keywords: Xenopus; regeneration; cornea; CYP26

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APA (6^th Edition):

Thomas, A. G. (2016). Investigating the role of CYP26 and retinoic acid signaling regulation in vertebrate cornea and lens regeneration. (Doctoral Dissertation). University of Illinois – Urbana-Champaign. Retrieved from http://hdl.handle.net/2142/90910

Chicago Manual of Style (16^th Edition):

Thomas, Alvin G. “Investigating the role of CYP26 and retinoic acid signaling regulation in vertebrate cornea and lens regeneration.” 2016. Doctoral Dissertation, University of Illinois – Urbana-Champaign. Accessed January 22, 2021. http://hdl.handle.net/2142/90910.

MLA Handbook (7^th Edition):

Thomas, Alvin G. “Investigating the role of CYP26 and retinoic acid signaling regulation in vertebrate cornea and lens regeneration.” 2016. Web. 22 Jan 2021.

Vancouver:

Thomas AG. Investigating the role of CYP26 and retinoic acid signaling regulation in vertebrate cornea and lens regeneration. [Internet] [Doctoral dissertation]. University of Illinois – Urbana-Champaign; 2016. [cited 2021 Jan 22]. Available from: http://hdl.handle.net/2142/90910.

Council of Science Editors:

Thomas AG. Investigating the role of CYP26 and retinoic acid signaling regulation in vertebrate cornea and lens regeneration. [Doctoral Dissertation]. University of Illinois – Urbana-Champaign; 2016. Available from: http://hdl.handle.net/2142/90910

University of Illinois – Urbana-Champaign

16. Hamilton, Paul William. New insights into cornea-lens regeneration in Xenopus laevis: the role of Wnt/beta-catenin signaling and the regenerative capacity of the limbal region.

Degree: PhD, Cell and Developmental Biology, 2016, University of Illinois – Urbana-Champaign

URL: http://hdl.handle.net/2142/92926

► One of the large outstanding questions in the field of developmental biology is how some tissues and organs of certain species are able to regenerate… (more)

▼ One of the large outstanding questions in the field of developmental biology is how some tissues and organs of certain species are able to regenerate while others cannot. It is only by understanding the molecular mechanisms that drive residual cells in a damaged or diseased tissue to proliferate and differentiate to replace lost structures that we will have the knowledge to attempt to recapitulate these regenerative processes in other species, including our own. Towards this end, the focus of this work is centered on understanding the cell and molecular mechanisms of lens regeneration in the frog, Xenopus laevis, which possesses a high capacity to regenerate larval tissues, such as the complete regeneration of the lens from the cornea epithelium. To fill in a large void in our current knowledge of the cell signaling pathways necessary for regeneration, we investigated the Wnt/β-catenin signaling pathway in the context of lens regeneration (Chapter 2) as it has been shown to be important in both embryonic lens development as well as in Wolffian lens regeneration that takes place in newts and salamanders; however, it had not been functionally studied in the context of cornea-lens regeneration in Xenopus despite being implicated to be involved in the early events of lens regeneration from two independent studies. We examined the expression of frizzled receptors and wnt ligands in the frog cornea epithelium. Numerous frizzled receptors (fzd1, fzd2, fzd3, fzd4, fzd6, fzd7, fzd8, and fzd10) and wnt ligands (wnt2b.a, wnt3a, wnt4, wnt5a, wnt5b, wnt6, wnt7b, wnt10a, wnt11, and wnt11b) are expressed in the cornea epithelium, demonstrating that this tissue is transcribing many of the components of the Wnt signaling pathway. When compared to flank epithelium, which is lens regeneration incompetent, only wnt11 and wnt11b are different (expressed only in the cornea epithelium), identifying them as potential regulators of cornea-lens regeneration. To detect changes in canonical Wnt/β-catenin signaling occurring within the cornea epithelium, axin2 expression was measured over the course of regeneration. axin2 is a well-established reporter of active Wnt/β-catenin signaling, and its expression shows a significant decrease at 24 hours post-lentectomy. This decrease recovers to normal endogenous levels by 48 hours. To test whether this signaling decrease was necessary for lens regeneration to occur, regenerating eyes were treated with either 6-bromoindirubin-3'-oxime (BIO) or 1-azakenpaullone - both activators of Wnt signaling - resulting in a significant reduction in the percentage of cases with successful regeneration. In contrast, inhibition of Wnt signaling using either the small molecule IWR-1, treatment with recombinant human Dickkopf-1 (rhDKK1) protein, or transgenic expression of Xenopus DKK1, did not significantly affect the percentage of successful regeneration. Together, these results suggest a model where Wnt/β-catenin signaling is active in the larval cornea epithelium and needs to be suppressed during early lens… Advisors/Committee Members: Henry, Jonathan J (advisor), Henry, Jonathan J (Committee Chair), Chen, Jie (committee member), Newmark, Phillip A (committee member), Sears, Karen E (committee member), Smith-Bolton, Rachel (committee member).

Subjects/Keywords: Xenopus laevis; Cornea; Lens; Regeneration

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APA (6^th Edition):

Hamilton, P. W. (2016). New insights into cornea-lens regeneration in Xenopus laevis: the role of Wnt/beta-catenin signaling and the regenerative capacity of the limbal region. (Doctoral Dissertation). University of Illinois – Urbana-Champaign. Retrieved from http://hdl.handle.net/2142/92926

Chicago Manual of Style (16^th Edition):

Hamilton, Paul William. “New insights into cornea-lens regeneration in Xenopus laevis: the role of Wnt/beta-catenin signaling and the regenerative capacity of the limbal region.” 2016. Doctoral Dissertation, University of Illinois – Urbana-Champaign. Accessed January 22, 2021. http://hdl.handle.net/2142/92926.

MLA Handbook (7^th Edition):

Hamilton, Paul William. “New insights into cornea-lens regeneration in Xenopus laevis: the role of Wnt/beta-catenin signaling and the regenerative capacity of the limbal region.” 2016. Web. 22 Jan 2021.

Vancouver:

Hamilton PW. New insights into cornea-lens regeneration in Xenopus laevis: the role of Wnt/beta-catenin signaling and the regenerative capacity of the limbal region. [Internet] [Doctoral dissertation]. University of Illinois – Urbana-Champaign; 2016. [cited 2021 Jan 22]. Available from: http://hdl.handle.net/2142/92926.

Council of Science Editors:

Hamilton PW. New insights into cornea-lens regeneration in Xenopus laevis: the role of Wnt/beta-catenin signaling and the regenerative capacity of the limbal region. [Doctoral Dissertation]. University of Illinois – Urbana-Champaign; 2016. Available from: http://hdl.handle.net/2142/92926

Texas Tech University

17. Liu, Zhiming. Characteristics of a maturation-including steroid receptor in the plasma membrane of xenopus oocytes.

Degree: 1994, Texas Tech University

URL: http://hdl.handle.net/2346/18416

► Xenopus laevis is a widely used animal in general and molecular biology research (Dawid and Sargent, 1988). This animal can be conveniently maintained under laboratory… (more)

Subjects/Keywords: Frogs; Xenopus

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APA (6^th Edition):

Liu, Z. (1994). Characteristics of a maturation-including steroid receptor in the plasma membrane of xenopus oocytes. (Thesis). Texas Tech University. Retrieved from http://hdl.handle.net/2346/18416

Note: this citation may be lacking information needed for this citation format:
Not specified: Masters Thesis or Doctoral Dissertation

Chicago Manual of Style (16^th Edition):

Liu, Zhiming. “Characteristics of a maturation-including steroid receptor in the plasma membrane of xenopus oocytes.” 1994. Thesis, Texas Tech University. Accessed January 22, 2021. http://hdl.handle.net/2346/18416.

Note: this citation may be lacking information needed for this citation format:
Not specified: Masters Thesis or Doctoral Dissertation

MLA Handbook (7^th Edition):

Liu, Zhiming. “Characteristics of a maturation-including steroid receptor in the plasma membrane of xenopus oocytes.” 1994. Web. 22 Jan 2021.

Vancouver:

Liu Z. Characteristics of a maturation-including steroid receptor in the plasma membrane of xenopus oocytes. [Internet] [Thesis]. Texas Tech University; 1994. [cited 2021 Jan 22]. Available from: http://hdl.handle.net/2346/18416.

Note: this citation may be lacking information needed for this citation format:
Not specified: Masters Thesis or Doctoral Dissertation

Council of Science Editors:

Liu Z. Characteristics of a maturation-including steroid receptor in the plasma membrane of xenopus oocytes. [Thesis]. Texas Tech University; 1994. Available from: http://hdl.handle.net/2346/18416

Note: this citation may be lacking information needed for this citation format:
Not specified: Masters Thesis or Doctoral Dissertation

University of Waterloo

18. Shires, Kallie. Characterization on PAR-3 in early Xenopus laevis development.

Degree: 2013, University of Waterloo

URL: http://hdl.handle.net/10012/7261

► Polarized cell movements are essential to the cell rearrangements that occur during morphogenesis. In Xenopus, cell polarity is reflected in the directional cell intercalations that… (more)

Subjects/Keywords: PAR-3; Polarity; Xenopus

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APA (6^th Edition):

Shires, K. (2013). Characterization on PAR-3 in early Xenopus laevis development. (Thesis). University of Waterloo. Retrieved from http://hdl.handle.net/10012/7261

Note: this citation may be lacking information needed for this citation format:
Not specified: Masters Thesis or Doctoral Dissertation

Chicago Manual of Style (16^th Edition):

Shires, Kallie. “Characterization on PAR-3 in early Xenopus laevis development.” 2013. Thesis, University of Waterloo. Accessed January 22, 2021. http://hdl.handle.net/10012/7261.

Note: this citation may be lacking information needed for this citation format:
Not specified: Masters Thesis or Doctoral Dissertation

MLA Handbook (7^th Edition):

Shires, Kallie. “Characterization on PAR-3 in early Xenopus laevis development.” 2013. Web. 22 Jan 2021.

Vancouver:

Shires K. Characterization on PAR-3 in early Xenopus laevis development. [Internet] [Thesis]. University of Waterloo; 2013. [cited 2021 Jan 22]. Available from: http://hdl.handle.net/10012/7261.

Note: this citation may be lacking information needed for this citation format:
Not specified: Masters Thesis or Doctoral Dissertation

Council of Science Editors:

Shires K. Characterization on PAR-3 in early Xenopus laevis development. [Thesis]. University of Waterloo; 2013. Available from: http://hdl.handle.net/10012/7261

Note: this citation may be lacking information needed for this citation format:
Not specified: Masters Thesis or Doctoral Dissertation

Rutgers University

19. Mariani, Richard, 1986-. The role of 14-3-3 proteins in regulating the dynamic activity and compartmentalization of cytokeratin intermediate filaments.

Degree: PhD, Biology, 2019, Rutgers University

URL: https://rucore.libraries.rutgers.edu/rutgers-lib/61659/

►

Intermediate filament cytoskeletal networks simultaneously support mechanical integrity and influence signal transduction pathways. Marked remodeling of the keratin intermediate filament network accompanies collective cellular morphogenetic… (more)

Subjects/Keywords: Keratin; Xenopus laevis – Embryology

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APA (6^th Edition):

Mariani, Richard, 1. (2019). The role of 14-3-3 proteins in regulating the dynamic activity and compartmentalization of cytokeratin intermediate filaments. (Doctoral Dissertation). Rutgers University. Retrieved from https://rucore.libraries.rutgers.edu/rutgers-lib/61659/

Chicago Manual of Style (16^th Edition):

Mariani, Richard, 1986-. “The role of 14-3-3 proteins in regulating the dynamic activity and compartmentalization of cytokeratin intermediate filaments.” 2019. Doctoral Dissertation, Rutgers University. Accessed January 22, 2021. https://rucore.libraries.rutgers.edu/rutgers-lib/61659/.

MLA Handbook (7^th Edition):

Mariani, Richard, 1986-. “The role of 14-3-3 proteins in regulating the dynamic activity and compartmentalization of cytokeratin intermediate filaments.” 2019. Web. 22 Jan 2021.

Vancouver:

Mariani, Richard 1. The role of 14-3-3 proteins in regulating the dynamic activity and compartmentalization of cytokeratin intermediate filaments. [Internet] [Doctoral dissertation]. Rutgers University; 2019. [cited 2021 Jan 22]. Available from: https://rucore.libraries.rutgers.edu/rutgers-lib/61659/.

Council of Science Editors:

Mariani, Richard 1. The role of 14-3-3 proteins in regulating the dynamic activity and compartmentalization of cytokeratin intermediate filaments. [Doctoral Dissertation]. Rutgers University; 2019. Available from: https://rucore.libraries.rutgers.edu/rutgers-lib/61659/

Wayne State University

20. Vasquez, Adrian Amelio. The Xenopus Lefty (xlefty) Prodomain Negatively Regulates Xlefty Activity And Is Necessary For Proper Xlefty Secretion.

Degree: MS, Biological Sciences, 2013, Wayne State University

URL: https://digitalcommons.wayne.edu/oa_theses/318

► In vertebrates, the TGF914; superfamily of secreted peptides are stringently regulated since they are responsible for multiple cell processes and behaviors that give rise… (more)

▼ In vertebrates, the TGF914; superfamily of secreted peptides are stringently regulated since they are responsible for multiple cell processes and behaviors that give rise to the proper patterning of embryonic tissues. Examples of members of the TGF #914; superfamily are Nodal and Lefty. Dysregulation of these proteins can lead to many diseases and developmental syndromes in humans. Lefty functions by antagonizing Nodal an essential organizer signal that patterns dorsal mesoderm and the embryonic axes. Loss of Lefty expression results in excess Nodal signaling which has been shown to cause several perturbations including metastatic cancer. Although studies have clearly shown that Lefty antagonizes Nodal signaling, there is a lack of understanding of the regulatory mechanism of Lefty itself. Previous studies have shown that proteolytic cleavage of the prodomain (PD) from mature Lefty (Mat-Lefty) is necessary for Lefty activity. Here we present studies carried out using the Xenopus laevis embryo that demonstrate that PD over-expression causes exogastrulation, a phenotype also resulting from a loss of Xenopus Lefty (Xlefty) function. Furthermore, when the PD and Xlefty are co-expressed, the effects of Xlefty over-expression are rescued. Our biochemical studies also showed that the PD interacts with Mat-Xlefty but a PD mutated (PDmut) molecule does not. The sites mutated in the PDmut are evolutionarily-conserved residues that mediate the interaction between the prodomain and the mature ligand in other TGF #914; proteins making our results consistent with previously observed behavior of TGF #914; prodomains but new to Lefty. Our study also shows that the PDmut is unable to rescue the effects of a Xlefty over-expression phenotype unlike the un-mutated PD. In addition we show here that mutations of the PD affect the secretion of these Xlefty-mutated derivatives. Taken together, these results suggest that the PD negatively regulates Xlefty activity by interacting with Mat-Xlefty and cleavage of the PD releases regulation allowing proper secretion and function. This new insight into the regulatory role of the Xlefty PD provides potential therapeutic value to address dysfunctional Nodal signaling. Furthermore, our secretion studies of the PD and Xlefty revealed that Xlefty is secreted but the PD is not. The Xlefty-mutated derivatives, including a PD Less, Xlefty, Xlefty cleavage mutants and the PDmut, resulted in no secreted products. These secretion results open a Pandora's box and further studies are warranted to elucidate the mechanism of PD regulation of Xlefty and whether it occurs in an intracellular or extracellular context. Advisors/Committee Members: William W. Branford.

Subjects/Keywords: Gastrulation; Nodal; Prodomain; TGF beta; Xenopus laevis; Xenopus Lefty; Developmental Biology

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APA (6^th Edition):

Vasquez, A. A. (2013). The Xenopus Lefty (xlefty) Prodomain Negatively Regulates Xlefty Activity And Is Necessary For Proper Xlefty Secretion. (Masters Thesis). Wayne State University. Retrieved from https://digitalcommons.wayne.edu/oa_theses/318

Chicago Manual of Style (16^th Edition):

Vasquez, Adrian Amelio. “The Xenopus Lefty (xlefty) Prodomain Negatively Regulates Xlefty Activity And Is Necessary For Proper Xlefty Secretion.” 2013. Masters Thesis, Wayne State University. Accessed January 22, 2021. https://digitalcommons.wayne.edu/oa_theses/318.

MLA Handbook (7^th Edition):

Vasquez, Adrian Amelio. “The Xenopus Lefty (xlefty) Prodomain Negatively Regulates Xlefty Activity And Is Necessary For Proper Xlefty Secretion.” 2013. Web. 22 Jan 2021.

Vancouver:

Vasquez AA. The Xenopus Lefty (xlefty) Prodomain Negatively Regulates Xlefty Activity And Is Necessary For Proper Xlefty Secretion. [Internet] [Masters thesis]. Wayne State University; 2013. [cited 2021 Jan 22]. Available from: https://digitalcommons.wayne.edu/oa_theses/318.

Council of Science Editors:

Vasquez AA. The Xenopus Lefty (xlefty) Prodomain Negatively Regulates Xlefty Activity And Is Necessary For Proper Xlefty Secretion. [Masters Thesis]. Wayne State University; 2013. Available from: https://digitalcommons.wayne.edu/oa_theses/318

Columbia University

21. Barkan, Charlotte Barkan. Evolution of Xenopus Vocal Patterns: Retuning a Hindbrain Circuit During Species Divergence.

Degree: 2017, Columbia University

URL: https://doi.org/10.7916/D8862TQP

► Circuits underlying motor patterns of closely related species provide an ideal framework in which to study how evolution shapes behavioral variation. Male African clawed frogs… (more)

Subjects/Keywords: Neurosciences; Xenopus; Xenopus laevis – Genetics; Evolutionary genetics; Frog sounds

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APA (6^th Edition):

Barkan, C. B. (2017). Evolution of Xenopus Vocal Patterns: Retuning a Hindbrain Circuit During Species Divergence. (Doctoral Dissertation). Columbia University. Retrieved from https://doi.org/10.7916/D8862TQP

Chicago Manual of Style (16^th Edition):

Barkan, Charlotte Barkan. “Evolution of Xenopus Vocal Patterns: Retuning a Hindbrain Circuit During Species Divergence.” 2017. Doctoral Dissertation, Columbia University. Accessed January 22, 2021. https://doi.org/10.7916/D8862TQP.

MLA Handbook (7^th Edition):

Barkan, Charlotte Barkan. “Evolution of Xenopus Vocal Patterns: Retuning a Hindbrain Circuit During Species Divergence.” 2017. Web. 22 Jan 2021.

Vancouver:

Barkan CB. Evolution of Xenopus Vocal Patterns: Retuning a Hindbrain Circuit During Species Divergence. [Internet] [Doctoral dissertation]. Columbia University; 2017. [cited 2021 Jan 22]. Available from: https://doi.org/10.7916/D8862TQP.

Council of Science Editors:

Barkan CB. Evolution of Xenopus Vocal Patterns: Retuning a Hindbrain Circuit During Species Divergence. [Doctoral Dissertation]. Columbia University; 2017. Available from: https://doi.org/10.7916/D8862TQP

22. Duperray, Maëlle. Rôle des gènes de la voie de biosynthèse des purines au cours du développement embryonnaire de Xenopus laevis : Role of purine biosynthesis genes during Xenopus laevis embryogenesis.

Degree: Docteur es, Génétique, 2017, Bordeaux

URL: http://www.theses.fr/2017BORD0750

►

La voie de biosynthèse des purines est une voie métabolique conservée et essentielle. Chez l’Homme, des mutations dans plusieurs gènes impliqués dans cette voie provoquent… (more)

▼

La voie de biosynthèse des purines est une voie métabolique conservée et essentielle. Chez l’Homme, des mutations dans plusieurs gènes impliqués dans cette voie provoquent de sévères maladies neuro-musculaires à composante développementale. Cependant, le lien entre génotypes et phénotypes n’est pas connu. Afin de mieux comprendre le rôle des gènes de la voie des purines au cours du développement, nous avons utilisé Xenopus laevis comme modèle vertébré. Les principaux gènes de la voie des purines du xénope n’étaient pas connus, ils ont donc tout d’abord été identifiés in sillico, puis les fonctions enzymatiques pour lesquels ils codent ont été validées in vivo en système hétérologue chez S. cerevisiae. Des analyses d’expression spatiotemporelle chez l’embryon de xénope ont montré que ces gènes sont exprimés tout au long du développement et en particulier dans les tissus neuro-musculaires, suggérant un rôle dans le développement de ces tissus. Le knock-down des gènes, ppat, hprt ou adsl, trois gènes clés de la voie des purines, conduit dans chaque cas à de sévères altérations des muscles squelettiques et en particulier des somites et des muscles hypaxiaux des embryons. Ces phénotypes musculaires sont la conséquence d’une altération précoce de l’expression des gènes MRF (Myogenic Regulatory Factors) myoD et myf5. Un défaut de migration des myoblastes précurseurs des muscles hypaxiaux a également été mis en évidence. Pour conclure, X. laevis est un modèle pertinent qui apporte de nouvelles connaissances permettant de mieux comprendre la cause des altérations musculaires développementales associées aux déficiences en purines.

The purine biosynthesis pathway is a conserved metabolic pathway essential for many cell functions. In Human, several mutations in genes involved in this pathway lead to severe neuromuscular diseases, which are at least in part caused by unknown developmental impairments. We established a Xenopus laevis model to decipher the role of the purine biosynthesis genes during vertebrate development. As no data was available regarding this pathway, the main Xenopus purine genes were first identified in silico and functionally validated in vivo using the yeast Saccharomyces cerevisiae as a heterologous system. Spatio-temporal analyses revealed that these genes are expressed all along the development, especially in neuromuscular tissues, suggesting an important role during their formation. The knock-down of ppat, adsl or hprt, three key purine genes, leads in each case to severe defects in skeletal muscles embryonic defects, in particular in somites and hypaxial muscles. These muscular phenotypes are the consequence of an early alteration in expression of some crucial Myogenic Regulatory Factors (MRF), such as myoD and myf5. Moreover, an alteration of the hypaxial muscles precursors was observed. In conclusion our results establish X. laevis as an ideal model to get new insights into the neuromuscular developmental alterations associated to purine deficiencies.

Advisors/Committee Members: Pinson, Benoît (thesis director).

Subjects/Keywords: Purines; Développement; Xenopus laevis; Muscles; Purines; Development; Xenopus laevis; Muscles

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APA (6^th Edition):

Duperray, M. (2017). Rôle des gènes de la voie de biosynthèse des purines au cours du développement embryonnaire de Xenopus laevis : Role of purine biosynthesis genes during Xenopus laevis embryogenesis. (Doctoral Dissertation). Bordeaux. Retrieved from http://www.theses.fr/2017BORD0750

Chicago Manual of Style (16^th Edition):

Duperray, Maëlle. “Rôle des gènes de la voie de biosynthèse des purines au cours du développement embryonnaire de Xenopus laevis : Role of purine biosynthesis genes during Xenopus laevis embryogenesis.” 2017. Doctoral Dissertation, Bordeaux. Accessed January 22, 2021. http://www.theses.fr/2017BORD0750.

MLA Handbook (7^th Edition):

Duperray, Maëlle. “Rôle des gènes de la voie de biosynthèse des purines au cours du développement embryonnaire de Xenopus laevis : Role of purine biosynthesis genes during Xenopus laevis embryogenesis.” 2017. Web. 22 Jan 2021.

Vancouver:

Duperray M. Rôle des gènes de la voie de biosynthèse des purines au cours du développement embryonnaire de Xenopus laevis : Role of purine biosynthesis genes during Xenopus laevis embryogenesis. [Internet] [Doctoral dissertation]. Bordeaux; 2017. [cited 2021 Jan 22]. Available from: http://www.theses.fr/2017BORD0750.

Council of Science Editors:

Duperray M. Rôle des gènes de la voie de biosynthèse des purines au cours du développement embryonnaire de Xenopus laevis : Role of purine biosynthesis genes during Xenopus laevis embryogenesis. [Doctoral Dissertation]. Bordeaux; 2017. Available from: http://www.theses.fr/2017BORD0750

Stellenbosch University

23. Thorp, Corey James. The impact of Xenopus laevis predation on aquatic ecosystems.

Degree: MSc, Botany and Zoology, 2017, Stellenbosch University

URL: http://hdl.handle.net/10019.1/101481

► ENGLISH ABSTRACT: Predator-prey interactions are dynamic and the ability to predict their impact on prey species has become an important aspect in ecology. One method… (more)

▼ ENGLISH ABSTRACT: Predator-prey interactions are dynamic and the ability to predict their impact on prey species has become an important aspect in ecology. One method to predict the impact of a predator species on a prey population is by analysing the predator’s functional response. However, predators are not all functionally similar and may differ intraspecifically. Predators are also not limited to prey from other species as they can cannibalise vulnerable individuals within their own population. The African clawed frog (Xenopus laevis) is a predator with a broad diet, known to consume multiple prey species, including its congeners. They are notorious cannibals with populations consisting of different sized conspecifics. They occur in sympatry with several congeners including the endangered X. gilli which are thought to be under threat through competition, hybridisation and predation from X. laevis. In this study, I investigated the role of predator size on the functional response of X. laevis predators using mosquito larvae (Culex pipiens) as a common prey. I also investigated the threat of X. laevis predation on X. gilli using choice and no-choice experiments to evaluate the relative vulnerability of X. laevis and X. gilli larvae to X. laevis predation. For the functional response experiments, predators were classified by size into small (15-30mm snout-vent length), medium (50-60mm) and large (105-120mm) size classes. Predator-prey interactions were filmed in order to compare handling time and attack rate to the functional response model. In the choice and no-choice experiments, both X. laevis and X. gilli larvae species were collectively and separately exposed to treatments with the presence or absence of a predator. Results showed that the functional response of X. laevis predators change with size: small predators were found to have a Type II response, while medium and large predators had a Type III response. Both functional response and behavioural data showed an inversely proportional relationship between predator attack rate and predator size. Small and medium predators had the highest and lowest handling time, respectively. That the functional response was found to change with the size of predator suggests that predators with overlapping cohorts may have a dynamic impact on prey populations. Therefore, predicting a predator’s impact from the functional response of a single size-matched predator experiment may be a misrepresentation of the predator’s potential impact on a prey population. Results from the choice and no-choice experiments showed that large X. gilli showed a significantly higher vulnerability to X. laevis predation compared to small X. laevis. Large and small X. laevis larvae, and same size X. gilli and X. laevis larvae showed no significant differences in relative vulnerability. Behaviour may be a factor in contributing to large X. gilli larvae’s vulnerability to X. leavis predation, and this will likely have negative implications for the population structure of the endangered X. gilli. … Advisors/Committee Members: Measey, John G., Vonesh, James, Mhairi, Alexander, Stellenbosch University. Faculty of Science. Dept. of Botany and Zoology..

Subjects/Keywords: Predator-prey interactions; Aquatic ecology; Xenopus gilli – Effect of xenopus laevis predation on; Xenopus laevis predation; UCTD

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APA (6^th Edition):

Thorp, C. J. (2017). The impact of Xenopus laevis predation on aquatic ecosystems. (Masters Thesis). Stellenbosch University. Retrieved from http://hdl.handle.net/10019.1/101481

Chicago Manual of Style (16^th Edition):

Thorp, Corey James. “The impact of Xenopus laevis predation on aquatic ecosystems.” 2017. Masters Thesis, Stellenbosch University. Accessed January 22, 2021. http://hdl.handle.net/10019.1/101481.

MLA Handbook (7^th Edition):

Thorp, Corey James. “The impact of Xenopus laevis predation on aquatic ecosystems.” 2017. Web. 22 Jan 2021.

Vancouver:

Thorp CJ. The impact of Xenopus laevis predation on aquatic ecosystems. [Internet] [Masters thesis]. Stellenbosch University; 2017. [cited 2021 Jan 22]. Available from: http://hdl.handle.net/10019.1/101481.

Council of Science Editors:

Thorp CJ. The impact of Xenopus laevis predation on aquatic ecosystems. [Masters Thesis]. Stellenbosch University; 2017. Available from: http://hdl.handle.net/10019.1/101481

University of Alberta

24. Harris, Harriet L. The endogenous galactose-spedific lectin in early development of Xenopus laevis.

Degree: PhD, Department of Zoology, 1986, University of Alberta

URL: https://era.library.ualberta.ca/files/kk91fn948

Subjects/Keywords: Lectins.; Xenopus laevis.

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APA (6^th Edition):

Harris, H. L. (1986). The endogenous galactose-spedific lectin in early development of Xenopus laevis. (Doctoral Dissertation). University of Alberta. Retrieved from https://era.library.ualberta.ca/files/kk91fn948

Chicago Manual of Style (16^th Edition):

Harris, Harriet L. “The endogenous galactose-spedific lectin in early development of Xenopus laevis.” 1986. Doctoral Dissertation, University of Alberta. Accessed January 22, 2021. https://era.library.ualberta.ca/files/kk91fn948.

MLA Handbook (7^th Edition):

Harris, Harriet L. “The endogenous galactose-spedific lectin in early development of Xenopus laevis.” 1986. Web. 22 Jan 2021.

Vancouver:

Harris HL. The endogenous galactose-spedific lectin in early development of Xenopus laevis. [Internet] [Doctoral dissertation]. University of Alberta; 1986. [cited 2021 Jan 22]. Available from: https://era.library.ualberta.ca/files/kk91fn948.

Council of Science Editors:

Harris HL. The endogenous galactose-spedific lectin in early development of Xenopus laevis. [Doctoral Dissertation]. University of Alberta; 1986. Available from: https://era.library.ualberta.ca/files/kk91fn948

University of Manchester

25. Zhang, Siwei. An Investigation on the Modulation of Signalling Transduction Pathways during Early Xenopus Development.

Degree: 2013, University of Manchester

URL: http://www.manchester.ac.uk/escholar/uk-ac-man-scw:185078

►

The thesis titled Investigation of signalling transduction during early Xenopus embryogenesis (thesis) has been composed and redacted by Siwei Zhang. The final version was submitted… (more)

▼

The thesis titled Investigation of signalling transduction during early Xenopus embryogenesis (thesis) has been composed and redacted by Siwei Zhang. The final version was submitted to the University of Manchester for the degree of Doctor of Philosophy (PhD) in the Faculty of Life Sciences on January 2013.The primary aim of my PhD thesis was to identify and characterise novel modulators of intracellular signalling during early vertebrate development. The first phase of my thesis was to design and execute a large-scale gain of function screen in order to identify novel modulators of various important signal transduction pathways during early Xenopus development. From this screen I identified twenty novel of growth factor signalling. In the second phase of my PhD study, I concentrated on the characterization and mode of action of one of the genes I identified in the screen; namely fezf2. I showed that Fezf2 regulates neurogenesis in the diencephalon by locally promoting Wnt signalling through repression of lhx2 and lhx9. Notably, this investigation on the function of fezf2 not only revealed the previously undiscovered role of fezf2-mediated Wnt regulatory mechanism during diencephalon development, but also confirmed our in vivo screening approach in identifying potential regulators of signalling pathways. To the end, my PhD project has provided me with a fruitful journey of discovery, which started with the design and execution of a large-scale screen, ending with the detailed characterization of a factor involved in the modulation of signalling and forebrain development. This study is has broadened our understanding of how intracellular and extracellular signals are integrated during embryonic development process, which forms an interactive network ultimately resulting in appropriate cell differentiation, organ formation, and regional patterning.

Head development, including craniofacial and brain development, is crucial for proper brain function upon growth. Any mis-regulation during head development usually resulted in severe head defects in the head and associated structure, such as cleft-lip/palate, microcephaly, septo-potic dysplasia, which all are very difficult for treatment with current medical knowledge and technique. Considering the vital role of head for proper body functioning, multiple regulatory machineries have been imposed to ensure the face and brain will grow in a properly controlled manner. In this proposal, we will investigate the molecular mechanisms that determine brain development during early embryo development. Frog embryos are large, easily manipulated, and develop in an aquatic environment that allows easy observance. More importantly, the brain structure of Xenopus is highly comparable to that of humans. In addition, key genetic machineries that determine forebrain development are highly conserved between Xenopus and human. Thus, we consider our investigation results would provide invaluable knowledge in treatment of early brain defects in human.

Advisors/Committee Members: Amaya, Enrique.

Subjects/Keywords: Xenopus; Wnt signalling; forebrain; developmental biology

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APA (6^th Edition):

Zhang, S. (2013). An Investigation on the Modulation of Signalling Transduction Pathways during Early Xenopus Development. (Doctoral Dissertation). University of Manchester. Retrieved from http://www.manchester.ac.uk/escholar/uk-ac-man-scw:185078

Chicago Manual of Style (16^th Edition):

Zhang, Siwei. “An Investigation on the Modulation of Signalling Transduction Pathways during Early Xenopus Development.” 2013. Doctoral Dissertation, University of Manchester. Accessed January 22, 2021. http://www.manchester.ac.uk/escholar/uk-ac-man-scw:185078.

MLA Handbook (7^th Edition):

Zhang, Siwei. “An Investigation on the Modulation of Signalling Transduction Pathways during Early Xenopus Development.” 2013. Web. 22 Jan 2021.

Vancouver:

Zhang S. An Investigation on the Modulation of Signalling Transduction Pathways during Early Xenopus Development. [Internet] [Doctoral dissertation]. University of Manchester; 2013. [cited 2021 Jan 22]. Available from: http://www.manchester.ac.uk/escholar/uk-ac-man-scw:185078.

Council of Science Editors:

Zhang S. An Investigation on the Modulation of Signalling Transduction Pathways during Early Xenopus Development. [Doctoral Dissertation]. University of Manchester; 2013. Available from: http://www.manchester.ac.uk/escholar/uk-ac-man-scw:185078

University of Saskatchewan

26. Gallant, Melanie J 1991-. Developmental sensitivity and immunotoxicity of benzo[a]pyrene in the amphibian Xenopus laevis.

Degree: 2019, University of Saskatchewan

URL: http://hdl.handle.net/10388/12517

► The immune system is increasingly recognized as a vulnerable and sensitive target of contaminant exposure. Disruption of this critical system can lead to significant morbidity… (more)

▼ The immune system is increasingly recognized as a vulnerable and sensitive target of contaminant exposure. Disruption of this critical system can lead to significant morbidity and/or mortality of organisms in contaminated environments. Amphibians can be simultaneously exposed to both pathogens and contaminants within aquatic habitats, making contaminant-induced immunotoxicity particularly relevant for this taxonomic group. Polycyclic aromatic hydrocarbons (PAHs) are a major group of environmental contaminants that widely occur as mixtures in aquatic environments, including amphibian habitats. Benzo[a]pyrene (B[a]P) is recognized as the most potent toxicant of PAH mixtures and is the most extensively studied PAH with demonstrated adverse effects on the immune system of many vertebrate species. Understanding how aquatic contaminants, such as B[a]P, can impact the immune system of amphibians is imperative since contaminant-induced immunotoxicity is hypothesized to exacerbate disease-driven amphibian population decline. Thus, the overall goal of this thesis was to gain a better understanding of developmental and contaminant-induced changes in the immune system of amphibians, and ultimately how exposure to B[a]P modulates the response to immune stimulation. Specific research questions were addressed through four studies conducted within the broader goal of this thesis. The objective of the first study was to characterize the expression profiles of various pro-inflammatory cytokines in the model amphibian species, Xenopus laevis, throughout larval developmental stages and determine the impacts of thyroidal modulation on their expression. Results suggest that expression of two cytokines, tumor necrosis factor- (TNF) and interleukin-1β (IL-1β) varied over development, increasing with developmental stage, while interferon- (IFN-) remained relatively unchanged. Exogenous manipulation of thyroidal status was successful, as demonstrated by an altered rate of development and thyroid gland histology; however, thyroidal modulation had negligible effects on basal cytokine expression. The dynamic nature of the tadpole immune system suggested that the immunotoxic impacts of environmental contaminants may depend on the stage of development at the time of exposure. Therefore, the second study aimed to identify the sensitive developmental phases for sub-lethal effects of B[a]P exposure in terms of the development (stage, weight and length) and changes in the expression of immune- and detoxification-related genes. Exposure to B[a]P at all life-stages tested (embryo-larval, pre-metamorphic, and pro-metamorphic tadpoles) resulted in CYP1A7 mRNA induction (43, 53, and 47-fold, respectively) as well as stage-specific modulation of pro-inflammatory cytokine expression. Exposure of pre-metamorphic tadpoles to B[a]P demonstrated the greatest effect on weight, length and stage of development. Taken together, these initial studies indicate that the unique development of the tadpole immune system influences their susceptibility to… Advisors/Committee Members: Hogan, Natacha, Janz, David, Morrissey, Christy, Blakley, Barry, Bollinger, Trent.

Subjects/Keywords: Immunotoxicity; Xenopus laevis; benzo[a]pyrene

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APA · Chicago · MLA · Vancouver · CSE | Export to Zotero / EndNote / Reference Manager

APA (6^th Edition):

Gallant, M. J. 1. (2019). Developmental sensitivity and immunotoxicity of benzo[a]pyrene in the amphibian Xenopus laevis. (Thesis). University of Saskatchewan. Retrieved from http://hdl.handle.net/10388/12517

Note: this citation may be lacking information needed for this citation format:
Not specified: Masters Thesis or Doctoral Dissertation

Chicago Manual of Style (16^th Edition):

Gallant, Melanie J 1991-. “Developmental sensitivity and immunotoxicity of benzo[a]pyrene in the amphibian Xenopus laevis.” 2019. Thesis, University of Saskatchewan. Accessed January 22, 2021. http://hdl.handle.net/10388/12517.

Note: this citation may be lacking information needed for this citation format:
Not specified: Masters Thesis or Doctoral Dissertation

MLA Handbook (7^th Edition):

Gallant, Melanie J 1991-. “Developmental sensitivity and immunotoxicity of benzo[a]pyrene in the amphibian Xenopus laevis.” 2019. Web. 22 Jan 2021.

Vancouver:

Gallant MJ1. Developmental sensitivity and immunotoxicity of benzo[a]pyrene in the amphibian Xenopus laevis. [Internet] [Thesis]. University of Saskatchewan; 2019. [cited 2021 Jan 22]. Available from: http://hdl.handle.net/10388/12517.

Note: this citation may be lacking information needed for this citation format:
Not specified: Masters Thesis or Doctoral Dissertation

Council of Science Editors:

Gallant MJ1. Developmental sensitivity and immunotoxicity of benzo[a]pyrene in the amphibian Xenopus laevis. [Thesis]. University of Saskatchewan; 2019. Available from: http://hdl.handle.net/10388/12517

Note: this citation may be lacking information needed for this citation format:
Not specified: Masters Thesis or Doctoral Dissertation

University of Saskatchewan

27. Masse, Anita. Reproductive and Developmental Effects of Elevated Maternal Dietary Selenium in the Model Amphibian Xenopus laevis.

Degree: 2016, University of Saskatchewan

URL: http://hdl.handle.net/10388/ETD-2016-04-2505

► Selenium (Se) is a contaminant of potential concern in aquatic systems due to its efficient incorporation into food webs, potential for bioaccumulation at higher trophic… (more)

▼ Selenium (Se) is a contaminant of potential concern in aquatic systems due to its efficient incorporation into food webs, potential for bioaccumulation at higher trophic levels, and role as a developmental toxicant in oviparous vertebrates. While the presence of embryonic/larval deformities due to in ovo Se exposure is considered the most sensitive toxicological endpoint, elevated levels of dietary Se have also been associated with alterations to bioenergetic and hormonal status of adult female fishes, which consequently could lead to diminished fitness and impaired reproduction. Adverse reproductive effects in fishes have been the primary focus of Se research thus far, while studies focusing on Se toxicity in amphibians in any regard are severely lacking. The US EPA has recently proposed a new set of criteria for the protection of freshwater aquatic life with regards to acceptable Se tissue threshold levels; however, these values were generated based on effects observed in fishes with negligible existent data on amphibians to assist in this process. Thus, the overall goal of this thesis research was to characterize the reproductive and developmental effects of elevated dietary Se exposure in Xenopus laevis, in order to provide a foundation for amphibian related Se research that may assist in establishing effective regulatory guidelines that protect this highly vulnerable and ecologically valuable taxon. The research presented in this thesis was performed as one large generational bioassay with the analysis of experimental variables divided into three sections in order to evaluate the effects of elevated in ovo Se exposure via maternal transfer on early and late stages of larval development in addition to the overall fitness of adult X. laevis females after a dietary exposure. Adult X. laevis females were fed a diet augmented with L-selenomethionine (SeMet) for 68 days after which they were bred with untreated males. The resultant embryos were incubated up to 5 days post fertilization (dpf) to determine fertilization success, hatchability, mortality and frequency/severity of malformations. Subsamples of 5 dpf tadpoles were selected and raised to completion of metamorphosis for evaluation of mortality, growth and maturation rate. In addition, tissue and blood samples as well as morphometric indices were collected from X. laevis females, upon completion of the exposure period and subsequent breeding, to ascertain Se tissue distribution, triglyceride and glycogen levels, cortisol concentrations and the overall health status of SeMet-treated females. Within the data gathered throughout this research, a foundation of knowledge characterizing Se toxicity in amphibians was established along with the development of an early life stage toxicity threshold for the frequency of teratogenic abnormalities in X. laevis. The bioenergetic and stress status in addition to the overall body condition of adult females after a 68 day dietary exposure showed no significant differences among treatment groups. The concentrations… Advisors/Committee Members: Janz, David M., Hogan, Natacha S., Wickstrom, Mark L..

Subjects/Keywords: selenium; selenomethionine; amphibian; Xenopus laevis; maternal transfer

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APA · Chicago · MLA · Vancouver · CSE | Export to Zotero / EndNote / Reference Manager

APA (6^th Edition):

Masse, A. (2016). Reproductive and Developmental Effects of Elevated Maternal Dietary Selenium in the Model Amphibian Xenopus laevis. (Thesis). University of Saskatchewan. Retrieved from http://hdl.handle.net/10388/ETD-2016-04-2505

Note: this citation may be lacking information needed for this citation format:
Not specified: Masters Thesis or Doctoral Dissertation

Chicago Manual of Style (16^th Edition):

Masse, Anita. “Reproductive and Developmental Effects of Elevated Maternal Dietary Selenium in the Model Amphibian Xenopus laevis.” 2016. Thesis, University of Saskatchewan. Accessed January 22, 2021. http://hdl.handle.net/10388/ETD-2016-04-2505.

Note: this citation may be lacking information needed for this citation format:
Not specified: Masters Thesis or Doctoral Dissertation

MLA Handbook (7^th Edition):

Masse, Anita. “Reproductive and Developmental Effects of Elevated Maternal Dietary Selenium in the Model Amphibian Xenopus laevis.” 2016. Web. 22 Jan 2021.

Vancouver:

Masse A. Reproductive and Developmental Effects of Elevated Maternal Dietary Selenium in the Model Amphibian Xenopus laevis. [Internet] [Thesis]. University of Saskatchewan; 2016. [cited 2021 Jan 22]. Available from: http://hdl.handle.net/10388/ETD-2016-04-2505.

Note: this citation may be lacking information needed for this citation format:
Not specified: Masters Thesis or Doctoral Dissertation

Council of Science Editors:

Masse A. Reproductive and Developmental Effects of Elevated Maternal Dietary Selenium in the Model Amphibian Xenopus laevis. [Thesis]. University of Saskatchewan; 2016. Available from: http://hdl.handle.net/10388/ETD-2016-04-2505

Note: this citation may be lacking information needed for this citation format:
Not specified: Masters Thesis or Doctoral Dissertation

Texas A&M University

28. Mashoof, Sara. Evolution of Mucosal Immunoglobulins: Xenopus Laevis IgX and Thunnus Orientalis IgZ/T.

Degree: PhD, Veterinary Microbiology, 2014, Texas A&M University

URL: http://hdl.handle.net/1969.1/152474

► Despite a large number of studies during the last decade that investigated mucosal immunity in humans, very few works have been done on this immune… (more)

▼ Despite a large number of studies during the last decade that investigated mucosal immunity in humans, very few works have been done on this immune compartment in lower vertebrates. In the following two studies we focused on the mucosal immunoglobulins in two important species of two classes of ectothermic vertebrates: amphibians and bony fishes. Many studies address the influence of the gut microbiome on the immune system, but few dissect the effect of T cells on gut microbiota and mucosal responses. We have employed larval thymectomy in Xenopus to study the gut microbiota with and without the influence of T lymphocytes. Pyrosequencing of 16S ribosomal RNA genes was used to assess the relative abundance of bacterial groups present in the stomach, and the small and large intestine. Clostridiaceae were the most abundant family throughout the gut, while Bacteroidaceae, Enterobacteriaceae, and Flavobacteriaceae also were well represented. Unifrac analysis revealed no differences in microbiota distribution between thymectomized and unoperated frogs. This is consistent with immunization data showing that levels of the mucosal immunoglobulin IgX are not altered significantly by thymectomy. This study in Xenopus represents the oldest organisms that exhibit class switch to a mucosal isotype and is relevant to mammalian immunology, as IgA appears to have evolved from IgX based upon phylogeny, genomic synteny, and function. It is now appreciated that in addition to the immunoglobulin (Ig)M and D isotypes fish also make the mucosal IgT. In this study we sequenced the full length of Ig tau as well as mu in the commercially important Thunnus orientalis (Pacific bluefin tuna), the first analysis of both of these Ig isotypes in a member of the order Perciformes. Tuna IgM and IgT are each composed of four constant (CH) domains. We cloned and sequenced 48 different variable (VH) domain rearrangements of tuna immunoglobulins and grouped the VH gene sequences to four VH gene segment families based on 70% nucleotide identity. Three VH gene families were used by both IgM and IgT but one group was only found to be used by IgM. Most interestingly, both Ig mu and Ig tau clones appear to use the same diversity (DH) segment, unlike what has been described in other species, although they have dedicated IgT and IgM joining (JH) gene segments. We complemented this repertoire study with phylogenetic and tissue expression analysis. In addition to supporting the development of humoral vaccines in this important aquaculture species, these data suggest that the DH-JH recombination rather than the VH-DH recombination may be instructive for IgT versus IgM/D bearing lymphocyte lineages in some fish. Advisors/Committee Members: Criscitiello, Michael (advisor), Tizard, Ian (committee member), Berghman, Luc (committee member), Rivera, Gonzalo (committee member).

Subjects/Keywords: Xenopus Laevis; Immunoglobulin; Tuna; Mucosal Immunity; IgT

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APA · Chicago · MLA · Vancouver · CSE | Export to Zotero / EndNote / Reference Manager

APA (6^th Edition):

Mashoof, S. (2014). Evolution of Mucosal Immunoglobulins: Xenopus Laevis IgX and Thunnus Orientalis IgZ/T. (Doctoral Dissertation). Texas A&M University. Retrieved from http://hdl.handle.net/1969.1/152474

Chicago Manual of Style (16^th Edition):

Mashoof, Sara. “Evolution of Mucosal Immunoglobulins: Xenopus Laevis IgX and Thunnus Orientalis IgZ/T.” 2014. Doctoral Dissertation, Texas A&M University. Accessed January 22, 2021. http://hdl.handle.net/1969.1/152474.

MLA Handbook (7^th Edition):

Mashoof, Sara. “Evolution of Mucosal Immunoglobulins: Xenopus Laevis IgX and Thunnus Orientalis IgZ/T.” 2014. Web. 22 Jan 2021.

Vancouver:

Mashoof S. Evolution of Mucosal Immunoglobulins: Xenopus Laevis IgX and Thunnus Orientalis IgZ/T. [Internet] [Doctoral dissertation]. Texas A&M University; 2014. [cited 2021 Jan 22]. Available from: http://hdl.handle.net/1969.1/152474.

Council of Science Editors:

Mashoof S. Evolution of Mucosal Immunoglobulins: Xenopus Laevis IgX and Thunnus Orientalis IgZ/T. [Doctoral Dissertation]. Texas A&M University; 2014. Available from: http://hdl.handle.net/1969.1/152474

McMaster University

29. Alcock, Brian. Duplicate Gene Evolution in a Tetraploid African Clawed Frog (Silurana).

Degree: MSc, 2015, McMaster University

URL: http://hdl.handle.net/11375/18035

►

By increasing genomic size, whole-genome duplication (WGD) is considered a major source of evolutionary innovation and speciation. We examined sequence evolution and expression divergence following… (more)

▼

By increasing genomic size, whole-genome duplication (WGD) is considered a major source of evolutionary innovation and speciation. We examined sequence evolution and expression divergence following WGD in a tetraploid African clawed frog (it{Silurana}). We hypothesized that the redundancy generated by WGD might allow for sex-specific and/or tissue-specific divergence, contributing to sexual dimorphism in this frog, and that such changes could be detected at both the expression and sequence levels. We investigated this hypothesis with a transcriptome-based approach, comparing both sexes across brain, heart and liver. We compared molecular evolution and expression divergence of duplicate gene homeologs to singleton genes and to an extant diploid relative, and identified genes with evidence for sex-biased expression. In doing so, we provide evidence for an allopolyploid mechanism of WGD and speciation in it{Silurana}. Additionally, we find that female-biased gene expression is more prevalent among duplicate genes than male-biased expression, particularly in brain where expression levels are highest. We similarly identified antagonistically sex-biased homeologs with indication of positive selection. Our results indicate that divergent evolution at both the sequence and expression levels following WGD favors the co-option of female-biased gene expression and may help resolve sexually antagonistic selection in this frog, thereby facilitating the evolution of sexual dimorphism.

Thesis

Master of Science (MSc)

Whole-genome duplication (WGD) is considered a major source of evolutionary innovation and a driver of speciation. By increasing genetic content and introducing redundancy, selective pressures are reduced and paralogous pairs diverge. We investigate how sex and tissue type contribute to duplicate gene divergence following WGD in a tetraploid African clawed frog. We find evidence for sex-dependent variation in sex-biased expression patterns of duplicate genes in brain, heart and liver, and evaluate how molecular evolution of duplicate genes accounts for expression divergence between sexes. This thesis provides a general framework for investigating sex-biased duplicate gene evolution in an amphibious tetrapod.

Advisors/Committee Members: Evans, Ben, Biology.

Subjects/Keywords: duplication; sex-biased gene expression; polyploidization; xenopus

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APA · Chicago · MLA · Vancouver · CSE | Export to Zotero / EndNote / Reference Manager

APA (6^th Edition):

Alcock, B. (2015). Duplicate Gene Evolution in a Tetraploid African Clawed Frog (Silurana). (Masters Thesis). McMaster University. Retrieved from http://hdl.handle.net/11375/18035

Chicago Manual of Style (16^th Edition):

Alcock, Brian. “Duplicate Gene Evolution in a Tetraploid African Clawed Frog (Silurana).” 2015. Masters Thesis, McMaster University. Accessed January 22, 2021. http://hdl.handle.net/11375/18035.

MLA Handbook (7^th Edition):

Alcock, Brian. “Duplicate Gene Evolution in a Tetraploid African Clawed Frog (Silurana).” 2015. Web. 22 Jan 2021.

Vancouver:

Alcock B. Duplicate Gene Evolution in a Tetraploid African Clawed Frog (Silurana). [Internet] [Masters thesis]. McMaster University; 2015. [cited 2021 Jan 22]. Available from: http://hdl.handle.net/11375/18035.

Council of Science Editors:

Alcock B. Duplicate Gene Evolution in a Tetraploid African Clawed Frog (Silurana). [Masters Thesis]. McMaster University; 2015. Available from: http://hdl.handle.net/11375/18035

30. Jesus, Ana Catarina de. Study of XHEP33 during the heart embryonic development of Xenopus laevis.

Degree: 2011, RCAAP

URL: http://www.rcaap.pt/detail.jsp?id=oai:sapientia.ualg.pt:10400.1/2139

►

Dissertação de mest., Engenharia Biológica, Faculdade de Ciências e Tecnologia, Univ. do Algarve, 2011

A necessidade de identificar genes que são expressos distintamente em células… (more)

Subjects/Keywords: Coração; Vertebrados; Xenopus laevis; Genética; Sapo

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APA · Chicago · MLA · Vancouver · CSE | Export to Zotero / EndNote / Reference Manager

APA (6^th Edition):

Jesus, A. C. d. (2011). Study of XHEP33 during the heart embryonic development of Xenopus laevis. (Thesis). RCAAP. Retrieved from http://www.rcaap.pt/detail.jsp?id=oai:sapientia.ualg.pt:10400.1/2139

Note: this citation may be lacking information needed for this citation format:
Not specified: Masters Thesis or Doctoral Dissertation

Chicago Manual of Style (16^th Edition):

Jesus, Ana Catarina de. “Study of XHEP33 during the heart embryonic development of Xenopus laevis.” 2011. Thesis, RCAAP. Accessed January 22, 2021. http://www.rcaap.pt/detail.jsp?id=oai:sapientia.ualg.pt:10400.1/2139.

Note: this citation may be lacking information needed for this citation format:
Not specified: Masters Thesis or Doctoral Dissertation

MLA Handbook (7^th Edition):

Jesus, Ana Catarina de. “Study of XHEP33 during the heart embryonic development of Xenopus laevis.” 2011. Web. 22 Jan 2021.

Vancouver:

Jesus ACd. Study of XHEP33 during the heart embryonic development of Xenopus laevis. [Internet] [Thesis]. RCAAP; 2011. [cited 2021 Jan 22]. Available from: http://www.rcaap.pt/detail.jsp?id=oai:sapientia.ualg.pt:10400.1/2139.

Note: this citation may be lacking information needed for this citation format:
Not specified: Masters Thesis or Doctoral Dissertation

Council of Science Editors:

Jesus ACd. Study of XHEP33 during the heart embryonic development of Xenopus laevis. [Thesis]. RCAAP; 2011. Available from: http://www.rcaap.pt/detail.jsp?id=oai:sapientia.ualg.pt:10400.1/2139

Note: this citation may be lacking information needed for this citation format:
Not specified: Masters Thesis or Doctoral Dissertation

Open Access Theses and Dissertations