+publisher:"Virginia Tech" +contributor:("Tu, Zhijian Jake")

Virginia Tech

1. Miller, Carin R. Regulatory Balance Between the Peptide Trasporter, Pept1, and Amino Acid Transporter Gene Expression in the Enterocyte.

Degree: PhD, Animal and Poultry Sciences, 2012, Virginia Tech

URL: http://hdl.handle.net/10919/77043

► Amino acids are assimilated by membrane-associated transporters into and out of enterocytes either in their free form or in the form of peptides. The peptide… (more)

▼ Amino acids are assimilated by membrane-associated transporters into and out of enterocytes either in their free form or in the form of peptides. The peptide transporter, PepT1, is thought to be the major facilitator of peptide transport in the enterocyte. It is unknown if the peptide transporters and free amino acid transporters operate in a compensatory fashion to regulate the amino acid balance within the enterocyte. Therefore, the objective was to examine the regulatory balance between PepT1 and other peptide and free amino acid transporters in enterocytes. The Mouse Small Intestinal Epithelial (MSIE) cells are conditionally immortalized. It was found that MSIE cells express BoAT1, CAT1, CAT2, LAT1, y+LAT1, and y+LAT2, but not PepT1, EAAT3, Bo,+AT, or LAT2, making this model similar to the basolateral membrane of enterocytes. Growing MSIE cells at high temperatures did not affect the nutrient transporter gene expression profile of these cells. Thus, the human colon carcinoma (Caco-2) cell line was used as a small intestinal in vitro model for this study. These cells express PepT1, HPT1, PTR3 EAAT1, EAAT3, rBAT, Bo,+AT CAT1, LAT1, y+LAT1, y+LAT2, ABCC3, ABCC4, which increased from D0 to D21 post confluency, indicating cell maturation. In Caco-2 cells, PepT1 gene silencing was induced in Caco-2 cells. Despite an reduction of PepT1 gene (82%, P < 0.05) protein (96%), no significant difference in any peptide (HPT1, PTR3, ABCC3, ABCC4) or free amino acid transporters (EAAT1, EAAT3, rBAT, Bo,+AT, BoAT1, CAT1, CAT2, LAT1, LAT2, y+LAT1, y+LAT2) between Caco-2 cells treated with PepT1 siRNA and Caco-2 cells treated with Control siRNA was observed. These results suggest no compensation at the gene expression level of these transporters in response to a reduction of PepT1. To account for the limitations of an in vitro and PepT1 kockout mouse model, transgenic chicken models were pursued. Potential cPepT1 overexpressing, cPepT1 shRNA or control shRNA expressing G0 chickens were generated by embryo injection of pseudolentiviral particles followed by ex ovo egg culture. Overall, 9 potential G0 cPepT1 overexpressing chickens, 15 potential G0 cPepT1 shRNA expressing chickens, and 4 potential G0 control shRNA expressing chickens were generated. Advisors/Committee Members: Gerrard, David E. (committeechair), Tu, Zhijian Jake (committee member), Huckle, William R. (committee member), Jiang, Honglin (committee member), Dalloul, Rami A. (committee member).

Subjects/Keywords: Amino Acid; RNAi; Transgenic; Chicken; PepT1; Enterocyte

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APA (6^th Edition):

Miller, C. R. (2012). Regulatory Balance Between the Peptide Trasporter, Pept1, and Amino Acid Transporter Gene Expression in the Enterocyte. (Doctoral Dissertation). Virginia Tech. Retrieved from http://hdl.handle.net/10919/77043

Chicago Manual of Style (16^th Edition):

Miller, Carin R. “Regulatory Balance Between the Peptide Trasporter, Pept1, and Amino Acid Transporter Gene Expression in the Enterocyte.” 2012. Doctoral Dissertation, Virginia Tech. Accessed April 11, 2021. http://hdl.handle.net/10919/77043.

MLA Handbook (7^th Edition):

Miller, Carin R. “Regulatory Balance Between the Peptide Trasporter, Pept1, and Amino Acid Transporter Gene Expression in the Enterocyte.” 2012. Web. 11 Apr 2021.

Vancouver:

Miller CR. Regulatory Balance Between the Peptide Trasporter, Pept1, and Amino Acid Transporter Gene Expression in the Enterocyte. [Internet] [Doctoral dissertation]. Virginia Tech; 2012. [cited 2021 Apr 11]. Available from: http://hdl.handle.net/10919/77043.

Council of Science Editors:

Miller CR. Regulatory Balance Between the Peptide Trasporter, Pept1, and Amino Acid Transporter Gene Expression in the Enterocyte. [Doctoral Dissertation]. Virginia Tech; 2012. Available from: http://hdl.handle.net/10919/77043

Virginia Tech

2. Criscione Jr, Frank. A mosquito-specific bZIP transcription factor and the influence of a Y-specific gene on sex determination in Anopheles stephensi.

Degree: PhD, Biochemistry, 2013, Virginia Tech

URL: http://hdl.handle.net/10919/51167

► Aside from few model organisms, little is known about early embryonic development or sex determination in insects, in particular mosquitoes which are major vectors of… (more)

▼ Aside from few model organisms, little is known about early embryonic development or sex determination in insects, in particular mosquitoes which are major vectors of worldwide disease. The goals of this work were to investigate a mosquito-specific transcription factor and its intronic miRNA cluster and characterize a novel Y chromosome gene in An. stephensi. The aims of these experiments were to expand on the knowledge of genes involved in embryonic development and sex determination with potential application in vector control strategies. In Ae. aegypti a mosquito-specific bZIP1 transcription factor was demonstrated to be conserved among divergent mosquito species. It was maternally and zygotically-expressed and knock-down of bZIP1 mRNA via siRNA microinjection in the embryo resulted in embryonic death. The expression profile of this gene was determined through the use of RT-PCR and qRT-PCR. Additionally, this gene contains a miRNA cluster that is also relatively conserved amongst members of the Culicidae family suggesting its evolutionary importance. The miRNAs are also maternally and zygotically expressed and are the most abundant embryonic miRNAs as determined by small RNA sequencing and Northern analysis. Promoter activity for bZIP1 was characterized and the promoter was used to direct maternal and zygotic transgene expression in An. stephensi. Y chromosome genes were successfully identified in An. stephensi from Illumina sequencing data. This work focused on a gene unique to the Y 1 (GUY1). It was shown that GUY1 was male specific and linked to the Y chromosome. RT-PCR and single embryo analysis suggested that GUY1 was expressed during the maternal to zygotic transition and was only expressed in male embryos. It was shown in multiple transient and transgenic assays that the ectopic expression of GUY1 can influence the sex of subjected individuals and skew sex distribution to a male bias. There is still much to be investigated before a GUY1-based transgenic line can be tested and implemented for use in vector population control. However, the work in this dissertation represents a major step towards novel mosquito control strategies based on the manipulation of Y chromosome genes. Advisors/Committee Members: Tu, Zhijian Jake (committeechair), Sharakhov, Igor V. (committee member), Zhu, Jinsong (committee member), Winkel, Brenda S. J. (committee member), Li, Jianyong (committee member).

Subjects/Keywords: bZIP1; mosquito; miRNA; sex determination; Y chromosome; vector control; GUY1; female lethal

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APA (6^th Edition):

Criscione Jr, F. (2013). A mosquito-specific bZIP transcription factor and the influence of a Y-specific gene on sex determination in Anopheles stephensi. (Doctoral Dissertation). Virginia Tech. Retrieved from http://hdl.handle.net/10919/51167

Chicago Manual of Style (16^th Edition):

Criscione Jr, Frank. “A mosquito-specific bZIP transcription factor and the influence of a Y-specific gene on sex determination in Anopheles stephensi.” 2013. Doctoral Dissertation, Virginia Tech. Accessed April 11, 2021. http://hdl.handle.net/10919/51167.

MLA Handbook (7^th Edition):

Criscione Jr, Frank. “A mosquito-specific bZIP transcription factor and the influence of a Y-specific gene on sex determination in Anopheles stephensi.” 2013. Web. 11 Apr 2021.

Vancouver:

Criscione Jr F. A mosquito-specific bZIP transcription factor and the influence of a Y-specific gene on sex determination in Anopheles stephensi. [Internet] [Doctoral dissertation]. Virginia Tech; 2013. [cited 2021 Apr 11]. Available from: http://hdl.handle.net/10919/51167.

Council of Science Editors:

Criscione Jr F. A mosquito-specific bZIP transcription factor and the influence of a Y-specific gene on sex determination in Anopheles stephensi. [Doctoral Dissertation]. Virginia Tech; 2013. Available from: http://hdl.handle.net/10919/51167

Virginia Tech

3. Al-Rayyan, Numan A. Transcriptional and Post-transcriptional Control of Nhlh2 with Differing Energy Status.

Degree: PhD, Human Nutrition, Foods, and Exercise, 2011, Virginia Tech

URL: http://hdl.handle.net/10919/77123

► Nescient Helix Loop Helix 2 (Nhlh2) is a member of the basic helix-loop-helix transcription factor family. Mice with a targeted deletion of Nhlh2, called N2KO… (more)

▼ Nescient Helix Loop Helix 2 (Nhlh2) is a member of the basic helix-loop-helix transcription factor family. Mice with a targeted deletion of Nhlh2, called N2KO mice, show adult onset obesity in both males and females. Nhlh2 regulates other genes by binding to the E-box in the promoter region of these genes. This transcription factor regulates many other transcription factors including MC4R and PC1/3 which are associated with human obesity. The Nhlh2 promoter has been analyzed for putative transcription factors binding sites. These putative binding sites have been tested to be the regulators of Nhlh2 by transactivation assays with mutant promoters, Electrophoretic Shift Assay (EMSA), and Chromatin Immunoprecipitation Assay (ChIP) as methods to investigate the DNA-protein binding. The results of these experiments showed that the Nhlh2 promoter has five Signal Transducer and Activator of Transcription 3 (Stat3) binding site motifs at -47, -65, -80, -281, -294 and two Nuclear Factor Kappa-Light-Chain-Enhancer of Activated B Cells (NFκB) binding site motifs at -67 and -135. While NFκB acts as a negative regulator of Nhlh2, this research showed that Stat3 acts as a regulator for the Nhlh2 basal expression and leptin stimulation. The ChIP assay using chromatin from mouse hypothalamus and antibodies against Stat3 and the NFκB subunits P50, P65, and c-Rel demonstrated that all of these antibodies were able to pull down the part of the Nhlh2 promoter containing the binding sites of Stat3 and NFκB. The EMSA results not only demonstrated that NFκB and Stat3 binding site motifs are real binding sites, but also exists the possibility of a relationship between these transcription factors to regulate Nhlh2 expression with leptin stimulation. An effort in analyzing the human NHLH2 3'UTR showed that one of the SNPs located at position 1568 in the NHLH2 mRNA (NHLH2A^1568G) which converts adenosine to guanine might have the potential to decrease the mRNA stability. For more investigation about this SNP, the mouse Nhlh2 tail was cloned into 2 different vectors and these vectors were subjected to site directed mutagenesis to create the 3'UTR SNP that convert A to G. One of these vectors used luciferase as a reporter gene for expression while the other one was used to measure Nhlh2 mRNA stability. These vectors were transfected into hypothalamic cell line N29/2 to test the effect of this SNP on Nhlh2 expression. This study demonstrated that this SNP down regulated luciferase expression and also decreased Nhlh2 mRNA stability. Taken together, this study demonstrated that Nhlh2 could be regulated transcriptionally by both NFκB and Stat3 transcription factors and post-transcripitionally by the 3'UTR SNP that converts adenosine to guanine. Advisors/Committee Members: Good, Deborah J. (committeechair), Tu, Zhijian Jake (committee member), Hulver, Matthew W. (committee member), Wong, Eric A. (committee member).

Subjects/Keywords: NFκB; Stat3; mRNA stability; 3'UTR; SNP; Obesity; Nhlh2; Energy expenditure; Transcription

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APA (6^th Edition):

Al-Rayyan, N. A. (2011). Transcriptional and Post-transcriptional Control of Nhlh2 with Differing Energy Status. (Doctoral Dissertation). Virginia Tech. Retrieved from http://hdl.handle.net/10919/77123

Chicago Manual of Style (16^th Edition):

Al-Rayyan, Numan A. “Transcriptional and Post-transcriptional Control of Nhlh2 with Differing Energy Status.” 2011. Doctoral Dissertation, Virginia Tech. Accessed April 11, 2021. http://hdl.handle.net/10919/77123.

MLA Handbook (7^th Edition):

Al-Rayyan, Numan A. “Transcriptional and Post-transcriptional Control of Nhlh2 with Differing Energy Status.” 2011. Web. 11 Apr 2021.

Vancouver:

Al-Rayyan NA. Transcriptional and Post-transcriptional Control of Nhlh2 with Differing Energy Status. [Internet] [Doctoral dissertation]. Virginia Tech; 2011. [cited 2021 Apr 11]. Available from: http://hdl.handle.net/10919/77123.

Council of Science Editors:

Al-Rayyan NA. Transcriptional and Post-transcriptional Control of Nhlh2 with Differing Energy Status. [Doctoral Dissertation]. Virginia Tech; 2011. Available from: http://hdl.handle.net/10919/77123

Virginia Tech

4. Ahn, Tae-Hyuk. Computational Techniques for the Analysis of Large Scale Biological Systems.

Degree: PhD, Computer Science, 2016, Virginia Tech

URL: http://hdl.handle.net/10919/77162

► An accelerated pace of discovery in biological sciences is made possible by a new generation of computational biology and bioinformatics tools. In this dissertation we… (more)

▼ An accelerated pace of discovery in biological sciences is made possible by a new generation of computational biology and bioinformatics tools. In this dissertation we develop novel computational, analytical, and high performance simulation techniques for biological problems, with applications to the yeast cell division cycle, and to the RNA-Sequencing of the yellow fever mosquito. Cell cycle system evolves stochastic effects when there are a small number of molecules react each other. Consequently, the stochastic effects of the cell cycle are important, and the evolution of cells is best described statistically. Stochastic simulation algorithm (SSA), the standard stochastic method for chemical kinetics, is often slow because it accounts for every individual reaction event. This work develops a stochastic version of a deterministic cell cycle model, in order to capture the stochastic aspects of the evolution of the budding yeast wild-type and mutant strain cells. In order to efficiently run large ensembles to compute statistics of cell evolution, the dissertation investigates parallel simulation strategies, and presents a new probabilistic framework to analyze the performance of dynamic load balancing algorithms. This work also proposes new accelerated stochastic simulation algorithms based on a fully implicit approach and on stochastic Taylor expansions. Next Generation RNA-Sequencing, a high-throughput technology to sequence cDNA in order to get information about a sample's RNA content, is becoming an efficient genomic approach to uncover new genes and to study gene expression and alternative splicing. This dissertation develops efficient algorithms and strategies to find new genes in Aedes aegypti, which is the most important vector of dengue fever and yellow fever. We report the discovery of a large number of new gene transcripts, and the identification and characterization of genes that showed male-biased expression profiles. This basic information may open important avenues to control mosquito borne infectious diseases. Advisors/Committee Members: Sandu, Adrian (committeechair), Zhang, Liqing (committee member), Tu, Zhijian Jake (committee member), Baumann, William T. (committee member), Shaffer, Clifford A. (committee member).

Subjects/Keywords: Stochastic simulation algorithm (SSA); Parallel load balancing; Cell cycle; RNA-Sequencing; Stochastic differential equations (SDEs)

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APA (6^th Edition):

Ahn, T. (2016). Computational Techniques for the Analysis of Large Scale Biological Systems. (Doctoral Dissertation). Virginia Tech. Retrieved from http://hdl.handle.net/10919/77162

Chicago Manual of Style (16^th Edition):

Ahn, Tae-Hyuk. “Computational Techniques for the Analysis of Large Scale Biological Systems.” 2016. Doctoral Dissertation, Virginia Tech. Accessed April 11, 2021. http://hdl.handle.net/10919/77162.

MLA Handbook (7^th Edition):

Ahn, Tae-Hyuk. “Computational Techniques for the Analysis of Large Scale Biological Systems.” 2016. Web. 11 Apr 2021.

Vancouver:

Ahn T. Computational Techniques for the Analysis of Large Scale Biological Systems. [Internet] [Doctoral dissertation]. Virginia Tech; 2016. [cited 2021 Apr 11]. Available from: http://hdl.handle.net/10919/77162.

Council of Science Editors:

Ahn T. Computational Techniques for the Analysis of Large Scale Biological Systems. [Doctoral Dissertation]. Virginia Tech; 2016. Available from: http://hdl.handle.net/10919/77162

Virginia Tech

5. Hu, Wanqi. The early zygotic genes and microRNAs in the yellow fever mosquito Aedes aegypti and the Asian malaria mosquito Anopheles stephensi.

Degree: PhD, Biochemistry, 2014, Virginia Tech

URL: http://hdl.handle.net/10919/70857

► Mosquitoes are notorious vectors for multiple diseases like malaria, yellow fever and dengue fever. To manipulate gene expression in mosquito and spread desired genes among… (more)

▼ Mosquitoes are notorious vectors for multiple diseases like malaria, yellow fever and dengue fever. To manipulate gene expression in mosquito and spread desired genes among natural population for vector control, a thorough understanding of mosquito development and gene regulation is critical. Early embryogenesis is a rapid, complex yet crucial process in the very beginning of development. Previous research in other species indicated genes transcribed that early evolved fast and played essential roles. The study of mosquito early zygotic genes (EZGs) would offer unique insights into mosquito gene evolution as well as potential targets for mosquito control. In this study, I identified 61 pure EZGs (pEZGs) in mosquito Aedes aegypti. These pEZGs were enriched in architectures adapting to the rapid embryonic cell cycles and were over represented by domains or functions related to maternal zygotic transition. Phylogenetic analysis showed that pEZGs originated mainly from duplication, retrotransposition and de novo emergence. The comparison of pEZGs in Ae. aegypti with those in Drosophila revealed an interesting evolutionary paradox where the early zygotic genes turned over fast but the regulatory motif was conserved in two species. Curiously, the motif binding protein in Drosophila (zelda) seemed unable to initiate the earliest zygotic transcription in Ae. aegypti due to late temporal expression. The regulatory motif (VBRGGTA) found in Ae. aegypti pEZGs was shown necessary and sufficient for driving early zygotic gene expression by transient reporter assays and one motif-bearing promoter was tested with success in driving gene expression as early as 2-4h after egg laying in transgenic Ae. aegypti. This was the first characterized promoter with early zygotic but no maternal expression in Ae. aegypti that can be used for future genetic studies and mosquito control strategies. As important gene regulators, miRNAs also play essential roles in early embryogenesis. The genome-wide predictions and systematic analysis of miRNAs in Ae. aegypti and Anopheles stephensi were conducted in this study. The first miRNA profiling in mosquito across all developmental stages was also performed to provide basis for future functional study. Several lineage-specific miRNAs were found highly expressed in embryos, indicating their special roles in the embryogenesis of mosquitoes. Advisors/Committee Members: Tu, Zhijian Jake (committeechair), Zhu, Jinsong (committee member), Zhang, Liqing (committee member), Helm, Richard F. (committee member).

Subjects/Keywords: Aedes aegypti; Anopheles stephensi; early zygotic gene; cis-regulatory motif; early zygotic promoter; transgenic mosquito; microRNA

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APA (6^th Edition):

Hu, W. (2014). The early zygotic genes and microRNAs in the yellow fever mosquito Aedes aegypti and the Asian malaria mosquito Anopheles stephensi. (Doctoral Dissertation). Virginia Tech. Retrieved from http://hdl.handle.net/10919/70857

Chicago Manual of Style (16^th Edition):

Hu, Wanqi. “The early zygotic genes and microRNAs in the yellow fever mosquito Aedes aegypti and the Asian malaria mosquito Anopheles stephensi.” 2014. Doctoral Dissertation, Virginia Tech. Accessed April 11, 2021. http://hdl.handle.net/10919/70857.

MLA Handbook (7^th Edition):

Hu, Wanqi. “The early zygotic genes and microRNAs in the yellow fever mosquito Aedes aegypti and the Asian malaria mosquito Anopheles stephensi.” 2014. Web. 11 Apr 2021.

Vancouver:

Hu W. The early zygotic genes and microRNAs in the yellow fever mosquito Aedes aegypti and the Asian malaria mosquito Anopheles stephensi. [Internet] [Doctoral dissertation]. Virginia Tech; 2014. [cited 2021 Apr 11]. Available from: http://hdl.handle.net/10919/70857.

Council of Science Editors:

Hu W. The early zygotic genes and microRNAs in the yellow fever mosquito Aedes aegypti and the Asian malaria mosquito Anopheles stephensi. [Doctoral Dissertation]. Virginia Tech; 2014. Available from: http://hdl.handle.net/10919/70857

Virginia Tech

6. Hall, Andrew Brantley. Identification and Characterization of Y Chromosome and M Locus Genes in Anopheles and Aedes Mosquitoes Using the Chromosome Quotient Method.

Degree: PhD, Genetics, Bioinformatics, and Computational Biology, 2016, Virginia Tech

URL: http://hdl.handle.net/10919/78883

► In mosquitoes, sex determination is initiated by a dominant male-determining factor located on the Y chromosome in Anopheles mosquitoes or in a small Y-like region… (more)

▼ In mosquitoes, sex determination is initiated by a dominant male-determining factor located on the Y chromosome in Anopheles mosquitoes or in a small Y-like region called the M locus in Aedes mosquitoes. Before my research, not a single gene from the Anopheles Y or Aedes M locus had ever been discovered. During the course of my undergraduate research in the Tu lab, I developed the chromosome quotient (CQ) method which identifies Y chromosome/M locus sequences by comparing the ratio of alignments from separate pools of female and male Illumina sequencing data. The focus of my dissertation is using the CQ method to identify potential male-determining factors in Aedes and Anopheles mosquitoes. First, we identified a novel gene tightly-linked to the M locus in Aedes aegypti called myo-sex. Myo-sex encodes a myosin heavy chain protein that is highly expressed in the pupa and adult male. Myo-sex is generally only found in males, but can sporadically be found in females due to a rare recombination. The fact that myo-sex can be found in females combined with a lack of early-embryonic expression suggests that myo-sex is not the male-determining factor. Next, we identified a gene in Aedes aegypti, Nix, which appeared to be persistently linked to the M locus and was expressed in the early embryo. Nix shows distant similarity at the amino acid level to Transformer2, a gene involved in the sex determination pathway of Drosophila melanogaster. Nix knockout with CRISPR/Cas9 resulted in feminization of genetic males and the production of the female isoforms of doublesex and fruitless, two key regulators of downstream sexual differentiation. Ectopic expression of Nix resulted in masculinization of genetic females. Based on these results, we concluded that Nix is a male-determining factor in Aedes aegypti. We also characterized large portions of the Anopheles gambiae Y chromosome using PacBio sequencing and the CQ method. We discovered that 92.3 percent of predicted Y sequences fell into two classes, the zanzibar amplified region (ZAR) and the satellite amplified region (SAR). This analysis fills in a large piece of the Anopheles gambiae genome missing since 2002. Advisors/Committee Members: Tu, Zhijian Jake (committeechair), Adelman, Zachary N. (committee member), Sharakhov, Igor V. (committee member), Zhang, Liqing (committee member).

Subjects/Keywords: Genetics; Bioinformatics

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APA (6^th Edition):

Hall, A. B. (2016). Identification and Characterization of Y Chromosome and M Locus Genes in Anopheles and Aedes Mosquitoes Using the Chromosome Quotient Method. (Doctoral Dissertation). Virginia Tech. Retrieved from http://hdl.handle.net/10919/78883

Chicago Manual of Style (16^th Edition):

Hall, Andrew Brantley. “Identification and Characterization of Y Chromosome and M Locus Genes in Anopheles and Aedes Mosquitoes Using the Chromosome Quotient Method.” 2016. Doctoral Dissertation, Virginia Tech. Accessed April 11, 2021. http://hdl.handle.net/10919/78883.

MLA Handbook (7^th Edition):

Hall, Andrew Brantley. “Identification and Characterization of Y Chromosome and M Locus Genes in Anopheles and Aedes Mosquitoes Using the Chromosome Quotient Method.” 2016. Web. 11 Apr 2021.

Vancouver:

Hall AB. Identification and Characterization of Y Chromosome and M Locus Genes in Anopheles and Aedes Mosquitoes Using the Chromosome Quotient Method. [Internet] [Doctoral dissertation]. Virginia Tech; 2016. [cited 2021 Apr 11]. Available from: http://hdl.handle.net/10919/78883.

Council of Science Editors:

Hall AB. Identification and Characterization of Y Chromosome and M Locus Genes in Anopheles and Aedes Mosquitoes Using the Chromosome Quotient Method. [Doctoral Dissertation]. Virginia Tech; 2016. Available from: http://hdl.handle.net/10919/78883

Virginia Tech

7. Jiang, Xiaofang. Genomics and Transcriptomics Analysis of the Asian Malaria Mosquito Anopheles stephensi.

Degree: PhD, Genetics, Bioinformatics, and Computational Biology, 2016, Virginia Tech

URL: http://hdl.handle.net/10919/79959

► Anopheles stephensi is a potent vector of malaria throughout the Indian subcontinent and Middle East. An. stephensi is emerging as a model for molecular and… (more)

▼ Anopheles stephensi is a potent vector of malaria throughout the Indian subcontinent and Middle East. An. stephensi is emerging as a model for molecular and genetic studies of mosquito-parasite interactions. Here we conducted a series of genomic and transcriptomic studies to improve the understanding of the biology of Anopheles stephensi and mosquito in general. First we reported the genome sequence and annotation of the Indian strain of the type form of An. stephensi. The 221 Mb genome assembly was produced using a combination of 454, Illumina, and PacBio sequencing. This hybrid assembly method was significantly better than assemblies generated from a single data source. A total of 11,789 protein-encoding genes were annotated using a combination of homology and de novo prediction. Secondly, we demonstrated the presence of complete dosage compensation in An. stephensi by determining that autosomal and X-linked genes have very similar levels of expression in both males and females. The uniformity of average expression levels of autosomal and X-linked genes remained when An. stephensi gene expression was normalized by that of their Ae. aegypti orthologs, strengthening the conclusion of complete dosage compensation in Anopheles. Lastly, we investigated trans-splicing events in Anopheles stephensi. We identified six trans-splicing events and all the trans-splicing sites are conserved and present in Ae. aegypti. The proteins encoded by the trans-spliced mRNAs are also highly conserved and their orthologs are co-linearly transcribed in out-groups of family Culicidae. This finding indicates the need to preserve the intact mRNA and protein function of the broken-up genes by trans-splicing during evolution. In summary, we presented the first genome assembly of Anopheles stephensi and studied two interesting evolution events" dosage compensation and trans-splicing - via transcriptomic analysis. Advisors/Committee Members: Tu, Zhijian Jake (committeechair), Bevan, David R. (committee member), Heath, Lenwood S. (committee member), Zhang, Liqing (committee member), Sharakhov, Igor V. (committee member).

Subjects/Keywords: genomic; comparative transcriptomes; dosage compensation; sex-specific expression Iso-Seq; trans-splicing

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APA (6^th Edition):

Jiang, X. (2016). Genomics and Transcriptomics Analysis of the Asian Malaria Mosquito Anopheles stephensi. (Doctoral Dissertation). Virginia Tech. Retrieved from http://hdl.handle.net/10919/79959

Chicago Manual of Style (16^th Edition):

Jiang, Xiaofang. “Genomics and Transcriptomics Analysis of the Asian Malaria Mosquito Anopheles stephensi.” 2016. Doctoral Dissertation, Virginia Tech. Accessed April 11, 2021. http://hdl.handle.net/10919/79959.

MLA Handbook (7^th Edition):

Jiang, Xiaofang. “Genomics and Transcriptomics Analysis of the Asian Malaria Mosquito Anopheles stephensi.” 2016. Web. 11 Apr 2021.

Vancouver:

Jiang X. Genomics and Transcriptomics Analysis of the Asian Malaria Mosquito Anopheles stephensi. [Internet] [Doctoral dissertation]. Virginia Tech; 2016. [cited 2021 Apr 11]. Available from: http://hdl.handle.net/10919/79959.

Council of Science Editors:

Jiang X. Genomics and Transcriptomics Analysis of the Asian Malaria Mosquito Anopheles stephensi. [Doctoral Dissertation]. Virginia Tech; 2016. Available from: http://hdl.handle.net/10919/79959

Virginia Tech

8. Morazzani, Elaine M. Modulation of Alphaviruses by Small RNAs.

Degree: PhD, Entomology, 2011, Virginia Tech

URL: http://hdl.handle.net/10919/39328

► Mosquito-borne diseases remain a significant burden on global public health. Maintenance of mosquito-borne viruses in nature requires a biological transmission cycle that involves alternating virus… (more)

▼ Mosquito-borne diseases remain a significant burden on global public health. Maintenance of mosquito-borne viruses in nature requires a biological transmission cycle that involves alternating virus replication in a susceptible vertebrate and mosquito host. Although infection of the vertebrate host is acute and often associated with disease, continual transmission of these viruses in nature depends on the establishment of a persistent, nonpathogenic infection in the mosquito vector. It is well known that invertebrates rely on small RNA pathways as an adaptive antiviral defense. The canonical antiviral response in these organisms involves dicer enzymes that cleave viral double-stranded RNA replicative intermediates (RIs) into small interfering RNAs (siRNAs; ~21-24 nucleotides). One strand of the siRNA duplex guides the targeting and destruction of complementary viral RNAs when loaded and retained in a multi-protein complex called the RNA-induced silencing complex. Here, we show that mosquito vectors mount a redundant double defense against virus infection mediated by two different small RNA pathways. Specifically, we demonstrate that in addition to a canonical antiviral response mediated by siRNAs, virus infection of the mosquito soma also triggers an antiviral immune pathway directed by ping-pong-dependent PIWI-interacting RNAs (piRNAs; ~24-30 nucleotides). The complexity of mosquito antiviral immunity has important implications for understanding how viruses both induce and modulate RNA-silencing responses in mosquito vectors. In mammals, viral RIs induce a range of relatively nonspecific antiviral responses. However, it remains unclear if viral RIs also trigger RNA silencing in mammals. Mosquito-borne viruses represent an ideal model for addressing this question as their transmission cycles involve alternating replication in mammalian and invertebrate hosts. Although we report identifying a subset of virus-derived small RNAs that appear to be products of RNA silencing in two mammalian cell lines infected with the mosquito-borne chikungunya virus (CHIKV), our studies suggest these small RNAs have little biological relevance in combating virus infections. Thus, while the accumulation of virus-derived siRNAs is essential to the survival of mosquitoes infected with CHIKV, they appear to have little functional significance in mammalian antiviral immunity. Advisors/Committee Members: Myles, Kevin M. (committeechair), Adelman, Zachary N. (committee member), Bloomquist, Jeffrey R. (committee member), Roberts, Paul Christopher (committee member), Tu, Zhijian Jake (committee member).

Subjects/Keywords: Aedes albopictus; short interfering RNAs; piwi-interacting RNAs; chikungunya virus; antiviral immunity

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APA (6^th Edition):

Morazzani, E. M. (2011). Modulation of Alphaviruses by Small RNAs. (Doctoral Dissertation). Virginia Tech. Retrieved from http://hdl.handle.net/10919/39328

Chicago Manual of Style (16^th Edition):

Morazzani, Elaine M. “Modulation of Alphaviruses by Small RNAs.” 2011. Doctoral Dissertation, Virginia Tech. Accessed April 11, 2021. http://hdl.handle.net/10919/39328.

MLA Handbook (7^th Edition):

Morazzani, Elaine M. “Modulation of Alphaviruses by Small RNAs.” 2011. Web. 11 Apr 2021.

Vancouver:

Morazzani EM. Modulation of Alphaviruses by Small RNAs. [Internet] [Doctoral dissertation]. Virginia Tech; 2011. [cited 2021 Apr 11]. Available from: http://hdl.handle.net/10919/39328.

Council of Science Editors:

Morazzani EM. Modulation of Alphaviruses by Small RNAs. [Doctoral Dissertation]. Virginia Tech; 2011. Available from: http://hdl.handle.net/10919/39328

Virginia Tech

9. Athamneh, Ahmad I. Electronic Nose Evaluation of Grape Maturity.

Degree: MS, Biological Systems Engineering, 2006, Virginia Tech

URL: http://hdl.handle.net/10919/35503

► Grape maturity is a critical attribute impacting potential wine quality. Maturity evaluation is difficult due to the many interrelated factors that impact physicochemical changes and… (more)

Subjects/Keywords: electronic nose; Cabernet Sauvignon; grape maturity; grape volatiles; grape aroma

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APA (6^th Edition):

Athamneh, A. I. (2006). Electronic Nose Evaluation of Grape Maturity. (Masters Thesis). Virginia Tech. Retrieved from http://hdl.handle.net/10919/35503

Chicago Manual of Style (16^th Edition):

Athamneh, Ahmad I. “Electronic Nose Evaluation of Grape Maturity.” 2006. Masters Thesis, Virginia Tech. Accessed April 11, 2021. http://hdl.handle.net/10919/35503.

MLA Handbook (7^th Edition):

Athamneh, Ahmad I. “Electronic Nose Evaluation of Grape Maturity.” 2006. Web. 11 Apr 2021.

Vancouver:

Athamneh AI. Electronic Nose Evaluation of Grape Maturity. [Internet] [Masters thesis]. Virginia Tech; 2006. [cited 2021 Apr 11]. Available from: http://hdl.handle.net/10919/35503.

Council of Science Editors:

Athamneh AI. Electronic Nose Evaluation of Grape Maturity. [Masters Thesis]. Virginia Tech; 2006. Available from: http://hdl.handle.net/10919/35503

Virginia Tech

10. Busche, Jefferson M. Identification of juvenile hormone response genes in newly emerged female Aedes aegypti.

Degree: MSin Life Sciences, Biochemistry, 2009, Virginia Tech

URL: http://hdl.handle.net/10919/34947

► Juvenile hormone (JH) plays pivotal roles in the development and reproduction of insects. Efforts to characterize the mechanisms of JH regulation are complicated due to… (more)

Subjects/Keywords: juvenile hormone; Kr-h1; Aedes aegypti

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APA (6^th Edition):

Busche, J. M. (2009). Identification of juvenile hormone response genes in newly emerged female Aedes aegypti. (Masters Thesis). Virginia Tech. Retrieved from http://hdl.handle.net/10919/34947

Chicago Manual of Style (16^th Edition):

Busche, Jefferson M. “Identification of juvenile hormone response genes in newly emerged female Aedes aegypti.” 2009. Masters Thesis, Virginia Tech. Accessed April 11, 2021. http://hdl.handle.net/10919/34947.

MLA Handbook (7^th Edition):

Busche, Jefferson M. “Identification of juvenile hormone response genes in newly emerged female Aedes aegypti.” 2009. Web. 11 Apr 2021.

Vancouver:

Busche JM. Identification of juvenile hormone response genes in newly emerged female Aedes aegypti. [Internet] [Masters thesis]. Virginia Tech; 2009. [cited 2021 Apr 11]. Available from: http://hdl.handle.net/10919/34947.

Council of Science Editors:

Busche JM. Identification of juvenile hormone response genes in newly emerged female Aedes aegypti. [Masters Thesis]. Virginia Tech; 2009. Available from: http://hdl.handle.net/10919/34947

Virginia Tech

11. Lin, Kuan-chin. Candidate Gene Expression and SNP Analyses of Toxin-Induced Dilated Cardiomyopathy in the Turkey(Meleagris gallopavo).

Degree: MS, Animal and Poultry Sciences, 2006, Virginia Tech

URL: http://hdl.handle.net/10919/42012

► Dilated cardiomyopathy (DCM), a heart disease, affects many vertebrates including humans and poultry. The disease can be either idiopathic (IDCM) or toxin-induced. Idiopathic DCM often… (more)

Subjects/Keywords: Dilated cardiomyopathy; Single nucleotide polymorphism; Turkeys

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APA (6^th Edition):

Lin, K. (2006). Candidate Gene Expression and SNP Analyses of Toxin-Induced Dilated Cardiomyopathy in the Turkey(Meleagris gallopavo). (Masters Thesis). Virginia Tech. Retrieved from http://hdl.handle.net/10919/42012

Chicago Manual of Style (16^th Edition):

Lin, Kuan-chin. “Candidate Gene Expression and SNP Analyses of Toxin-Induced Dilated Cardiomyopathy in the Turkey(Meleagris gallopavo).” 2006. Masters Thesis, Virginia Tech. Accessed April 11, 2021. http://hdl.handle.net/10919/42012.

MLA Handbook (7^th Edition):

Lin, Kuan-chin. “Candidate Gene Expression and SNP Analyses of Toxin-Induced Dilated Cardiomyopathy in the Turkey(Meleagris gallopavo).” 2006. Web. 11 Apr 2021.

Vancouver:

Lin K. Candidate Gene Expression and SNP Analyses of Toxin-Induced Dilated Cardiomyopathy in the Turkey(Meleagris gallopavo). [Internet] [Masters thesis]. Virginia Tech; 2006. [cited 2021 Apr 11]. Available from: http://hdl.handle.net/10919/42012.

Council of Science Editors:

Lin K. Candidate Gene Expression and SNP Analyses of Toxin-Induced Dilated Cardiomyopathy in the Turkey(Meleagris gallopavo). [Masters Thesis]. Virginia Tech; 2006. Available from: http://hdl.handle.net/10919/42012

Virginia Tech

12. Aljabri, Hareb Mohammed. Comparative analysis of Anopheles gambiae L-tyrosine decarboxylase and L-DOPA decarboxylase.

Degree: MSin Life Sciences, Biochemistry, 2010, Virginia Tech

URL: http://hdl.handle.net/10919/34788

► A major pathway of tyramine and dopamine synthesis in insects is through the decarboxylation of tyrosine and DOPA, respectively. Although tyrosine decarboxylase (TDC) has been… (more)

Subjects/Keywords: Tyrosine; DOPA decarboxylase (DDC); Tyrosine decarboxylase (TDC); Tyramine; Dopamine

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APA (6^th Edition):

Aljabri, H. M. (2010). Comparative analysis of Anopheles gambiae L-tyrosine decarboxylase and L-DOPA decarboxylase. (Masters Thesis). Virginia Tech. Retrieved from http://hdl.handle.net/10919/34788

Chicago Manual of Style (16^th Edition):

Aljabri, Hareb Mohammed. “Comparative analysis of Anopheles gambiae L-tyrosine decarboxylase and L-DOPA decarboxylase.” 2010. Masters Thesis, Virginia Tech. Accessed April 11, 2021. http://hdl.handle.net/10919/34788.

MLA Handbook (7^th Edition):

Aljabri, Hareb Mohammed. “Comparative analysis of Anopheles gambiae L-tyrosine decarboxylase and L-DOPA decarboxylase.” 2010. Web. 11 Apr 2021.

Vancouver:

Aljabri HM. Comparative analysis of Anopheles gambiae L-tyrosine decarboxylase and L-DOPA decarboxylase. [Internet] [Masters thesis]. Virginia Tech; 2010. [cited 2021 Apr 11]. Available from: http://hdl.handle.net/10919/34788.

Council of Science Editors:

Aljabri HM. Comparative analysis of Anopheles gambiae L-tyrosine decarboxylase and L-DOPA decarboxylase. [Masters Thesis]. Virginia Tech; 2010. Available from: http://hdl.handle.net/10919/34788

Virginia Tech

13. Shoja, Valia. A Broad Analysis of Tandemly Arrayed Genes in the Genomes of Human, Mouse, and Rat.

Degree: MS, Computer Science, 2006, Virginia Tech

URL: http://hdl.handle.net/10919/35800

► Tandemly arrayed genes (TAG) play an important functional and physiological role in the genome. Most previous studies have focused on individual TAG families in a… (more)

▼ Tandemly arrayed genes (TAG) play an important functional and physiological role in the genome. Most previous studies have focused on individual TAG families in a few species, yet a broad characterization of TAGs is not available. We identified all the TAGs in the genomes of human, chimp, mouse, and rat and performed a comprehensive analysis of TAG distribution, TAG sizes, TAG gene orientations and intergenic distances, and TAG gene functions. TAGs account for about 14-17% of all the genomic genes and nearly one third of all the duplicated genes in the four genomes, highlighting the predominant role that tandem duplication plays in gene duplication. For all species, TAG distribution is highly heterogeneous along chromosomes and some chromosomes are enriched with TAG forests while others are enriched with TAG deserts. The majority of TAGs are of size two for all genomes, similar to the previous findings in C. elegans, A. thaliana, and O. sativa, suggesting that it is a rather general phenomenon in eukaryotes. The comparison with the genome patterns shows that TAG members have a significantly higher proportion of parallel gene orientation in all species, corroborating Graham's claim that parallel orientation is the preferred form of orientation in TAGs. Moreover, TAG members with parallel orientation tend to be closer to each other than all neighboring genes with parallel orientation in the genome. The analysis of GO function indicate that genes with receptor or binding activities are significantly over-represented by TAGs. Simulation reveals that random gene rearrangements have little effect on the statistics of TAGs for all genomes. It is noteworthy to mention that gene family sizes are significantly correlated with the extent of tandem duplication, suggesting that tandem duplication is a preferred form of duplication, especially in large families. There has not been any systematic study of TAG genes' expression patterns in the genome. Taking advantage of recent large-scale microarray data, we were able to study expression divergence of some of the TAGs of size two in human and mouse for which the expression data is available and examine the effect of sequence divergence, gene orientation, and physical proximity on the divergence of gene expression patterns. Our results show that there is a weak negative correlation between sequence divergence and expression similarity between the two members of a TAG, and also a weak negative correlation between physical proximity of two genes and their expression similarity. No significant relationship was detected between gene orientation and expression similarity. Moreover, we compared the expression breadth of upstream and downstream duplicate copies and found that downstream duplicate does not show significantly narrower expression breadth. We also compared TAG gene pairs with their neighboring non-TAG pairs for both physical proximity and expression similarity. Our results show that TAG gene pairs do not show any distinct differences in the two aspects from their neighboring… Advisors/Committee Members: Zhang, Liqing (committeechair), Heath, Lenwood S. (committee member), Tu, Zhijian Jake (committee member).

Subjects/Keywords: Gene Expression; Tandemly Arrayed Genes; Comparative Genomics; Gene Duplication

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

APA (6^th Edition):

Shoja, V. (2006). A Broad Analysis of Tandemly Arrayed Genes in the Genomes of Human, Mouse, and Rat. (Masters Thesis). Virginia Tech. Retrieved from http://hdl.handle.net/10919/35800

Chicago Manual of Style (16^th Edition):

Shoja, Valia. “A Broad Analysis of Tandemly Arrayed Genes in the Genomes of Human, Mouse, and Rat.” 2006. Masters Thesis, Virginia Tech. Accessed April 11, 2021. http://hdl.handle.net/10919/35800.

MLA Handbook (7^th Edition):

Shoja, Valia. “A Broad Analysis of Tandemly Arrayed Genes in the Genomes of Human, Mouse, and Rat.” 2006. Web. 11 Apr 2021.

Vancouver:

Shoja V. A Broad Analysis of Tandemly Arrayed Genes in the Genomes of Human, Mouse, and Rat. [Internet] [Masters thesis]. Virginia Tech; 2006. [cited 2021 Apr 11]. Available from: http://hdl.handle.net/10919/35800.

Council of Science Editors:

Shoja V. A Broad Analysis of Tandemly Arrayed Genes in the Genomes of Human, Mouse, and Rat. [Masters Thesis]. Virginia Tech; 2006. Available from: http://hdl.handle.net/10919/35800

Virginia Tech

14. Flagg, Jeannine K. Cross-Species Translocation of mRNA from Host Plants into the Parasitic Plant Dodder.

Degree: MS, Plant Pathology, Physiology, and Weed Science, 2006, Virginia Tech

URL: http://hdl.handle.net/10919/31909

► Dodders (Cuscuta spp.) are parasitic plants that live by tapping into the vascular tissue of a host plant. Contents of the host phloem translocate readily… (more)

Subjects/Keywords: pumpkin; phloem-mobile mRNA; tomato; Cusucuta pentagona

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APA (6^th Edition):

Flagg, J. K. (2006). Cross-Species Translocation of mRNA from Host Plants into the Parasitic Plant Dodder. (Masters Thesis). Virginia Tech. Retrieved from http://hdl.handle.net/10919/31909

Chicago Manual of Style (16^th Edition):

Flagg, Jeannine K. “Cross-Species Translocation of mRNA from Host Plants into the Parasitic Plant Dodder.” 2006. Masters Thesis, Virginia Tech. Accessed April 11, 2021. http://hdl.handle.net/10919/31909.

MLA Handbook (7^th Edition):

Flagg, Jeannine K. “Cross-Species Translocation of mRNA from Host Plants into the Parasitic Plant Dodder.” 2006. Web. 11 Apr 2021.

Vancouver:

Flagg JK. Cross-Species Translocation of mRNA from Host Plants into the Parasitic Plant Dodder. [Internet] [Masters thesis]. Virginia Tech; 2006. [cited 2021 Apr 11]. Available from: http://hdl.handle.net/10919/31909.

Council of Science Editors:

Flagg JK. Cross-Species Translocation of mRNA from Host Plants into the Parasitic Plant Dodder. [Masters Thesis]. Virginia Tech; 2006. Available from: http://hdl.handle.net/10919/31909

Virginia Tech

15. Sanna, Chaitanya Ramesh. Patterns of Two Types of Overlapping Genes in Five Mammalian Genomes.

Degree: MS, Computer Science, 2006, Virginia Tech

URL: http://hdl.handle.net/10919/43601

► Increasing evidence suggests that overlapping genes is a common phenomenon in eukaryotic genomes too and are not restricted to prokaryotes alone. Here we determined overlapping… (more)

Subjects/Keywords: 3'- UTR; overlapping genes; same strand; different strand; 5'-UTR

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APA (6^th Edition):

Sanna, C. R. (2006). Patterns of Two Types of Overlapping Genes in Five Mammalian Genomes. (Masters Thesis). Virginia Tech. Retrieved from http://hdl.handle.net/10919/43601

Chicago Manual of Style (16^th Edition):

Sanna, Chaitanya Ramesh. “Patterns of Two Types of Overlapping Genes in Five Mammalian Genomes.” 2006. Masters Thesis, Virginia Tech. Accessed April 11, 2021. http://hdl.handle.net/10919/43601.

MLA Handbook (7^th Edition):

Sanna, Chaitanya Ramesh. “Patterns of Two Types of Overlapping Genes in Five Mammalian Genomes.” 2006. Web. 11 Apr 2021.

Vancouver:

Sanna CR. Patterns of Two Types of Overlapping Genes in Five Mammalian Genomes. [Internet] [Masters thesis]. Virginia Tech; 2006. [cited 2021 Apr 11]. Available from: http://hdl.handle.net/10919/43601.

Council of Science Editors:

Sanna CR. Patterns of Two Types of Overlapping Genes in Five Mammalian Genomes. [Masters Thesis]. Virginia Tech; 2006. Available from: http://hdl.handle.net/10919/43601

Virginia Tech

16. Alvarez, Monica A. Mosquito Transposable Elements and piwi Genes.

Degree: MS, Biochemistry, 2008, Virginia Tech

URL: http://hdl.handle.net/10919/33162

► Vector control is an essential and effective approach for controlling transmission of vector-borne diseases. However, increasing resistance to insecticide and drugs suggests that new strategies… (more)

▼ Vector control is an essential and effective approach for controlling transmission of vector-borne diseases. However, increasing resistance to insecticide and drugs suggests that new strategies to control vector-borne diseases are needed. One possible strategy involves replacing mosquito populations with disease-resistant transgenic mosquitoes. Transposable elements (TEs) are an important component in this new strategy due to their ability to integrate exogenous DNA into chromosomes. They could potentially be useful tools in assisting the spread of disease-resistant genes in mosquito populations. This research focuses on two related subjects, TEs and their regulation. The first subject is on a Long Terminal Repeat (LTR) retrotransposon in the African malaria mosquito, Anopheles gambiae, namely Belly. The second subject focuses on the characterization of piwi genes in the dengue and yellow fever mosquito, Aedes aegypti. For the first subject we characterized Belly by identifying the two identical LTRs and one intact open reading frame. We also defined the target site duplications and boundaries of the full-length Belly element. This novel retrotransposon has nine full-length copies in the An. gambiae sequenced genome and their nucleotide similarity suggests that there has been fairly recent retrotransposon. We have shown that Belly is transcribed and translated in An. gambiae. Single LTR circles were recovered from An. gambiae cells, which is consistent with active transposition of Belly. The second subject focuses on the piwi genes of Ae. aegypti. We found nine potential piwi genes in Ae. aegypti and two in An. gambiae. Phylogenetic analysis suggests that these piwis formed two subgroups and gene duplication within each group occurred after the divergence between the two mosquito species. RT-PCR and transcriptome analysis showed Ago3 as well as all the seven tested piwi genes were expressed either in germline tissues or developing embryos. Differential expression patterns were observed. While most piwis were transcribed in the ovaries, testis, and embryos, two piwis appear to have a zygotic expression. Three piwi genes (piwi 3, piwi 4, and Ago3) were also detected in adult somatic tissues of Ae. aegypti. The expansion of the number of piwi genes in Ae. aegypti compared to An. gambiae and D. melanogaster may be correlated with a larger genome size and greater amount of TEs. The finding of piwi expression in adult somatic tissues is intriguing. It is possible that these piwi genes were expressed in the adult stem cells. It is also possible that they may be involved with anti-viral defense. Both of these hypotheses require further testing. Advisors/Committee Members: Tu, Zhijian Jake (committeechair), Dolan, Erin L. (committee member), Klemba, Michael (committee member).

Subjects/Keywords: piwi; Transposable elements; RNAi; Belly

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APA (6^th Edition):

Alvarez, M. A. (2008). Mosquito Transposable Elements and piwi Genes. (Masters Thesis). Virginia Tech. Retrieved from http://hdl.handle.net/10919/33162

Chicago Manual of Style (16^th Edition):

Alvarez, Monica A. “Mosquito Transposable Elements and piwi Genes.” 2008. Masters Thesis, Virginia Tech. Accessed April 11, 2021. http://hdl.handle.net/10919/33162.

MLA Handbook (7^th Edition):

Alvarez, Monica A. “Mosquito Transposable Elements and piwi Genes.” 2008. Web. 11 Apr 2021.

Vancouver:

Alvarez MA. Mosquito Transposable Elements and piwi Genes. [Internet] [Masters thesis]. Virginia Tech; 2008. [cited 2021 Apr 11]. Available from: http://hdl.handle.net/10919/33162.

Council of Science Editors:

Alvarez MA. Mosquito Transposable Elements and piwi Genes. [Masters Thesis]. Virginia Tech; 2008. Available from: http://hdl.handle.net/10919/33162

Virginia Tech

17. Seok, Hee young. A Mosquito DNA Transposon Agh1: Structure, Evolution and Evidence of Activity.

Degree: MS, Biochemistry, 2004, Virginia Tech

URL: http://hdl.handle.net/10919/35028

► Transposable elements (TEs) are mobile genetic elements. They are a significant component of many eukaryotic genomes. They are involved in chromosomal rearrangement by serving… (more)

▼ Transposable elements (TEs) are mobile genetic elements. They are a significant component of many eukaryotic genomes. They are involved in chromosomal rearrangement by serving as substrates for homologous recombination, in creating new genes through a process of TE "domestication", and in modifying and shuffling existing genes by transducing neighboring sequences (Lander et al., 2001). Therefore, both active and inactive TEs are potentially potent agents for genomic change (Kidwell and Lisch, 2001, 2002; Rizzon et al., 2002; Petrov et al., 2003). In the meantime, active TEs are being explored as useful tools for genetic transformation and possible gene drive mechanisms to deliver genes in natural populations (Ashburner et al.,1998; Alphey et al.,2002; Handler and O'Brochta, 2004). My thesis project focuses on AGH1, a novel DNA-mediated TE in Anopheles gambiae and related mosquitoes. I have studied its genomic structure, insertion polymorphism, evolution, and transposition activity. As part of the sequence and structural characterization of AGH1 in the A. gambiae genome, the boundaries of AGH1were determined. The TA target site duplications flanking AGH1 were verified by comparing a genomic sequence that had an AGH1 insertion with the sequence of a corresponding empty site. AGH1 has relatively long, 350bp, TIRs (Terminal inverted repeats). In addition to the transposase ORF (ORF1) that contains a DD34E catalytic motif, it contains an unusual ORF2 with unknown function. Phylogenic analyses clearly suggest that unlike most DD34E transposons that are similar to the Tc1 family, AGH1 belongs to a different clade that is related to the previously characterized fungal TE Ant and protozoan TEC1 and TEC2. Truncated AGH1 and AGH1-related MITE (Miniature inverted-repeat TE) families were also identified. AGH1 insertion polymorphism was studied using 4 natural populations that belong to two molecular forms of A. gambiae, M and S. AGH1 insertions showed considerable differences between M and S forms and the insertions of AGH1 are highly variable in two populations of M. These results are potentially significant in light of the hypothesis that M forms are newly derived incipient species that are only found in West Africa. PCR and sequencing results showed more than 99% sequence identity between AGH1 sequences in A. gambiae, A. arabiensis, and A. melas, which may indicate either purifying selection or recent horizontal transfer. To assess whether AGH1 is currently active, inverse PCR was performed which provided evidence for extrachromosomal circular AGH1 that may be a product of imprecise excision. RT-PCR detected transcripts for both intact and truncated transposase. Preliminary TE display experiments using genomic DNA isolated from different passages of an A. gambiae Sua1B cell line showed possible new insertions and deletions of AGH1 related elements, which may have been mobilized by AGH1. In summary, the structural and genomic characteristics of AGH1 and the phylogenetic relationship between AGH1… Advisors/Committee Members: Tu, Zhijian Jake (committeechair), Larson, Timothy J. (committee member), Luckhart, Shirley (committee member).

Subjects/Keywords: Anopheles; excision; transposon; polymorphism; insertion; mosquito

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

APA (6^th Edition):

Seok, H. y. (2004). A Mosquito DNA Transposon Agh1: Structure, Evolution and Evidence of Activity. (Masters Thesis). Virginia Tech. Retrieved from http://hdl.handle.net/10919/35028

Chicago Manual of Style (16^th Edition):

Seok, Hee young. “A Mosquito DNA Transposon Agh1: Structure, Evolution and Evidence of Activity.” 2004. Masters Thesis, Virginia Tech. Accessed April 11, 2021. http://hdl.handle.net/10919/35028.

MLA Handbook (7^th Edition):

Seok, Hee young. “A Mosquito DNA Transposon Agh1: Structure, Evolution and Evidence of Activity.” 2004. Web. 11 Apr 2021.

Vancouver:

Seok Hy. A Mosquito DNA Transposon Agh1: Structure, Evolution and Evidence of Activity. [Internet] [Masters thesis]. Virginia Tech; 2004. [cited 2021 Apr 11]. Available from: http://hdl.handle.net/10919/35028.

Council of Science Editors:

Seok Hy. A Mosquito DNA Transposon Agh1: Structure, Evolution and Evidence of Activity. [Masters Thesis]. Virginia Tech; 2004. Available from: http://hdl.handle.net/10919/35028

Virginia Tech

18. Eleswarapu, Satyanarayana Venkata. Developmental and Growth Hormone Regulation of the Expression of Liver-Enriched Transcription Factors in Bovine Liver.

Degree: MS, Animal and Poultry Sciences, 2004, Virginia Tech

URL: http://hdl.handle.net/10919/42801

► Liver gene expression changes during development and is affected by growth hormone (GH). These changes in gene expression may be due to the differential expression… (more)

Subjects/Keywords: Growth Hormone; Bovine; Liver; Liver-Enriched Transcription Factors

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APA (6^th Edition):

Eleswarapu, S. V. (2004). Developmental and Growth Hormone Regulation of the Expression of Liver-Enriched Transcription Factors in Bovine Liver. (Masters Thesis). Virginia Tech. Retrieved from http://hdl.handle.net/10919/42801

Chicago Manual of Style (16^th Edition):

Eleswarapu, Satyanarayana Venkata. “Developmental and Growth Hormone Regulation of the Expression of Liver-Enriched Transcription Factors in Bovine Liver.” 2004. Masters Thesis, Virginia Tech. Accessed April 11, 2021. http://hdl.handle.net/10919/42801.

MLA Handbook (7^th Edition):

Eleswarapu, Satyanarayana Venkata. “Developmental and Growth Hormone Regulation of the Expression of Liver-Enriched Transcription Factors in Bovine Liver.” 2004. Web. 11 Apr 2021.

Vancouver:

Eleswarapu SV. Developmental and Growth Hormone Regulation of the Expression of Liver-Enriched Transcription Factors in Bovine Liver. [Internet] [Masters thesis]. Virginia Tech; 2004. [cited 2021 Apr 11]. Available from: http://hdl.handle.net/10919/42801.

Council of Science Editors:

Eleswarapu SV. Developmental and Growth Hormone Regulation of the Expression of Liver-Enriched Transcription Factors in Bovine Liver. [Masters Thesis]. Virginia Tech; 2004. Available from: http://hdl.handle.net/10919/42801

Virginia Tech

19. Haile, January Dendi. The "atypical" protein kinase, SsoPK5, an archaeal member of the piD261/Bud32 subfamily.

Degree: PhD, Biochemistry, 2009, Virginia Tech

URL: http://hdl.handle.net/10919/39127

► Open reading frame (ORF) sso0433 from the archaeon Sulfolobus solfataricus encodes a protein kinase, SsoPK5 that exhibits 33% sequence identity to p53 related protein kinase… (more)

▼ Open reading frame (ORF) sso0433 from the archaeon Sulfolobus solfataricus encodes a protein kinase, SsoPK5 that exhibits 33% sequence identity to p53 related protein kinase (PRPK) from Homo sapiens and 26% sequence identity to piD261/Bud32 from Saccharomyces cerevisiae. Given this high degree of similarity, the objectives of this thesis were to (a) clone and purify recombinant SsoPK5, (b) examine its commonalities and differences with its eukaryotic homologues, and (c) determine if it was regulated by nucleotides or related compounds. Substantial progress was achieved on each objective. After successful cloning of ORF sso0433 and purification of its protein product, SsoPK5, it was determined that SsoPK5 was cold labile and incubation at 4ºC for an extended period of time rendered SsoPK5 incapable of phosphotransferase activity. When stored at room temperature, SsoPK5 was capable of transferring the γ-phosphate from ATP to casein, reduced carboxyamidomethylated and maleylated (RCM) lysozyme,and p53. SsoPK5 phosphotransferase activity required a divalent metal cofactor; like pid261/Bud32, SsoPK5 preferred Mn²⁺ over the more commonly preferred Mg²⁺. SsoPK5 was shown to phosphorylate itself on threonine and serine residues; one of the specific amino acid residues modified is threonine-151. Recombinant SsoPK5 is activated by ADP-ribose and 5′-AMP. Activation was observed when SsoPK5 was stabilized by ATP or a nonhydrolytic analogue, such as β,γ- methylene adenosine 5′-triphosphate (AMP-PCP). Activation was not a result of phosphoryl transfer nor hydrolytic breakdown of ATP or 5′-AMP. This was deduced by the lack of ³²P radioactivity incorporated into SsoPK5 during pre-incubation with [γ-³²P] ATP for 60 min at 65ºC, and activation by adenosine 5′-O-thiomonophosphate (AMPS), a hydrolysis-resistant analog of AMP. These results may indicate that ADP-ribose acts as a pseudochaperone for SsoPK5 thereby facilitating maximal activity. Advisors/Committee Members: Kennelly, Peter J. (committeechair), Mahaney, James M. (committee member), Dolan, Erin L. (committee member), Tu, Zhijian Jake (committee member).

Subjects/Keywords: protein phosphorylation; piD261/Bud32; ADP-ribose; Archaea

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

APA (6^th Edition):

Haile, J. D. (2009). The "atypical" protein kinase, SsoPK5, an archaeal member of the piD261/Bud32 subfamily. (Doctoral Dissertation). Virginia Tech. Retrieved from http://hdl.handle.net/10919/39127

Chicago Manual of Style (16^th Edition):

Haile, January Dendi. “The "atypical" protein kinase, SsoPK5, an archaeal member of the piD261/Bud32 subfamily.” 2009. Doctoral Dissertation, Virginia Tech. Accessed April 11, 2021. http://hdl.handle.net/10919/39127.

MLA Handbook (7^th Edition):

Haile, January Dendi. “The "atypical" protein kinase, SsoPK5, an archaeal member of the piD261/Bud32 subfamily.” 2009. Web. 11 Apr 2021.

Vancouver:

Haile JD. The "atypical" protein kinase, SsoPK5, an archaeal member of the piD261/Bud32 subfamily. [Internet] [Doctoral dissertation]. Virginia Tech; 2009. [cited 2021 Apr 11]. Available from: http://hdl.handle.net/10919/39127.

Council of Science Editors:

Haile JD. The "atypical" protein kinase, SsoPK5, an archaeal member of the piD261/Bud32 subfamily. [Doctoral Dissertation]. Virginia Tech; 2009. Available from: http://hdl.handle.net/10919/39127

Virginia Tech

20. Ananieva-Stoyanova, Elitsa Antonova. Identification and Functional Role of Myo-Inositol Polyphosphate 5-Phosphatase Protein Complexes.

Degree: PhD, Biochemistry, 2009, Virginia Tech

URL: http://hdl.handle.net/10919/28028

► To survive, an organism must constantly adjust its internal state to changes in the environment from which it receives signals. The signals set off a… (more)

▼ To survive, an organism must constantly adjust its internal state to changes in the environment from which it receives signals. The signals set off a chain of events referred to signal transduction. Signal transduction systems are especially important in multicellular organisms, such as plants and animals, because of the need to coordinate the activities of hundreds to trillions of cells. Plants, in particular, have a special need for perceiving signals from their environment because of their static nature. As in the animal cell, the first steps in perception of a signal include signal interaction with a receptor, signal amplification through second messenger production, and signal termination through second messenger hydrolysis. Myo-inositol polyphosphate 5-phosphatases (5PTases) (EC 3.1.3.56) have unique signal terminating abilities toward the second messenger inositol trisphosphate (Ins (1,4,5)P3, InsP3). In Arabidopsis thaliana there are 15 members of the 5PTase family, the majority of which contain a single 5PTase catalytic domain. Four members of the Arabidopsis 5PTase family, however, have a unique protein domain structure, with additional N-terminal WD40 repeats that are implicated in protein-protein interactions. The research presented here focused on the identification of 5PTase interacting proteins and the characterization of their functional role in Arabidopsis. To accomplish this goal, I examined a 5PTase13-interacting protein, the sucrose (Suc) nonfermenting-1-related kinase, SnRK1.1, an important energy sensor that is highly conserved among eukaryotes. My identification of a 5PTase13:SnRK1.1 complex points to the novel interaction of this metabolic modulator and inositol signaling/metabolism. 5PTase13 , however, plays a regulatory role in other plant specific processes as well, since I also identified the Arabidopsis homolog (Atp80) of the human WDR48 (HsWDR48, Hsp80) as a novel protein interactor of 5PTase13. My results indicate that Atp80 is important for leaf emergence, development and senescence likely via a regulatory interaction with 5PTase13 and PINOID â binding protein (PBP1). Advisors/Committee Members: Gillaspy, Glenda E. (committeechair), Tholl, Dorothea (committee member), Tu, Zhijian Jake (committee member), Sitz, Thomas O. (committee member).

Subjects/Keywords: myo-inositol polyphosphate 5-phosphatase; 5)P3]; sucrose nonfermenting-1-related kinase; Arabidopsis thaliana; inositol trisphosphate [Ins(1; arabidopsis homolog of p80

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APA (6^th Edition):

Ananieva-Stoyanova, E. A. (2009). Identification and Functional Role of Myo-Inositol Polyphosphate 5-Phosphatase Protein Complexes. (Doctoral Dissertation). Virginia Tech. Retrieved from http://hdl.handle.net/10919/28028

Chicago Manual of Style (16^th Edition):

Ananieva-Stoyanova, Elitsa Antonova. “Identification and Functional Role of Myo-Inositol Polyphosphate 5-Phosphatase Protein Complexes.” 2009. Doctoral Dissertation, Virginia Tech. Accessed April 11, 2021. http://hdl.handle.net/10919/28028.

MLA Handbook (7^th Edition):

Ananieva-Stoyanova, Elitsa Antonova. “Identification and Functional Role of Myo-Inositol Polyphosphate 5-Phosphatase Protein Complexes.” 2009. Web. 11 Apr 2021.

Vancouver:

Ananieva-Stoyanova EA. Identification and Functional Role of Myo-Inositol Polyphosphate 5-Phosphatase Protein Complexes. [Internet] [Doctoral dissertation]. Virginia Tech; 2009. [cited 2021 Apr 11]. Available from: http://hdl.handle.net/10919/28028.

Council of Science Editors:

Ananieva-Stoyanova EA. Identification and Functional Role of Myo-Inositol Polyphosphate 5-Phosphatase Protein Complexes. [Doctoral Dissertation]. Virginia Tech; 2009. Available from: http://hdl.handle.net/10919/28028

Virginia Tech

21. Traver, Brenna E. Exogenously-introduced Homing Endonucleases Catalyze Double-stranded DNA Breaks in Aedes aegypti.

Degree: MSin Life Sciences, Entomology, 2009, Virginia Tech

URL: http://hdl.handle.net/10919/40967

► Aedes aegypti transmits the viruses which cause yellow fever, dengue fever, and dengue hemorrhagic fever. Homing endonucleases are selfish genetic elements which introduce double-stranded DNA… (more)

Subjects/Keywords: Homing endonuclease; Aedes aegypti; double-strand DNA break repair

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APA (6^th Edition):

Traver, B. E. (2009). Exogenously-introduced Homing Endonucleases Catalyze Double-stranded DNA Breaks in Aedes aegypti. (Masters Thesis). Virginia Tech. Retrieved from http://hdl.handle.net/10919/40967

Chicago Manual of Style (16^th Edition):

Traver, Brenna E. “Exogenously-introduced Homing Endonucleases Catalyze Double-stranded DNA Breaks in Aedes aegypti.” 2009. Masters Thesis, Virginia Tech. Accessed April 11, 2021. http://hdl.handle.net/10919/40967.

MLA Handbook (7^th Edition):

Traver, Brenna E. “Exogenously-introduced Homing Endonucleases Catalyze Double-stranded DNA Breaks in Aedes aegypti.” 2009. Web. 11 Apr 2021.

Vancouver:

Traver BE. Exogenously-introduced Homing Endonucleases Catalyze Double-stranded DNA Breaks in Aedes aegypti. [Internet] [Masters thesis]. Virginia Tech; 2009. [cited 2021 Apr 11]. Available from: http://hdl.handle.net/10919/40967.

Council of Science Editors:

Traver BE. Exogenously-introduced Homing Endonucleases Catalyze Double-stranded DNA Breaks in Aedes aegypti. [Masters Thesis]. Virginia Tech; 2009. Available from: http://hdl.handle.net/10919/40967

Virginia Tech

22. O'Carroll, Ina Puleri. Assembly of Iron-Sulfur Clusters In Vivo.

Degree: PhD, Biochemistry, 2009, Virginia Tech

URL: http://hdl.handle.net/10919/26289

► Iron-sulfur [Fe-S] clusters are protein cofactors that facilitate various life-sustaining biological processes. Their in vivo assembly is accomplished by three different systems known to date.… (more)

▼ Iron-sulfur [Fe-S] clusters are protein cofactors that facilitate various life-sustaining biological processes. Their in vivo assembly is accomplished by three different systems known to date. These are: the NIF system which provides [Fe-S] clusters for nitrogenase and other nitrogen-fixing proteins, the SUF system which is induced during conditions of oxidative stress and iron starvation in E. coli, and the ISC system which serves as the housekeeping assembly apparatus. The latter is the focus of this dissertation and includes the proteins IscR, IscS, IscU, IscA, HscB, HscA, Fdx, and IscX. IscU is purified in its cluster-less (apo) form, but can serve as a scaffold to assemble [Fe-S] clusters in vitro in the presence of excess iron and sulfide. To test the scaffold hypothesis and gain insight into the events that occur during [Fe-S] cluster assembly and delivery, we developed two methods that allow the isolation of IscU and other ISC proteins in vivo. In the first method, Azotobacter vinelandii IscU is isolated from its native host, whereas in the second, it is isolated recombinantly from E. coli using a vector that allows expression of the entire isc operon. We found that IscU exists in vivo in two forms: apo-IscU and [2Fe-2S]2+ cluster-loaded IscU which are believed to be conformationally distinct. Both transient and stable IscU-IscS complexes were identified, indicating that the two proteins interact in vivo in a manner that involves their association and dissociation. The [2Fe-2S]2+-IscU species was present as a single entity, whereas significant amounts of apo-IscU were found associated with IscS, suggesting that IscU-IscS dissociation is triggered by the completion of [2Fe-2S] clusters. Both apo and [2Fe-2S]2+-IscU were predominantly monomeric whereas IscU-IscS complexes were determined to have an Î±2Î²2 composition. IscU was purified in the absence of the chaperones HscA and HscB and was also shown to accommodate a [2Fe-2S]2+ cluster similar to the one bound to IscU isolated from wild type cells. The findings suggest that [2Fe-2S]2+-IscU exists in one conformation in vivo and that any conformational changes on IscU are exerted after [2Fe-2S] cluster formation. In silico studies showed that a flexible loop containing the conserved LPPVK motif, which is responsible for interactions with HscA, may facilitate cluster exposure to either mediate its delivery to acceptor proteins or participation in the construction of [4Fe-4S] clusters. Experiments with NfuA, a protein similar to the C-terminal domain of NifU, demonstrated that NfuA and similar proteins might serve as [Fe-S] cluster carriers to accomplish the efficient delivery of nascent cofactors to the various recipient proteins. Advisors/Committee Members: Dean, Dennis R. (committeechair), Larson, Timothy J. (committee member), Bevan, David R. (committee member), Tu, Zhijian Jake (committee member).

Subjects/Keywords: ISC; [Fe-S] clusters; Azotobacter vinelandii

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

APA (6^th Edition):

O'Carroll, I. P. (2009). Assembly of Iron-Sulfur Clusters In Vivo. (Doctoral Dissertation). Virginia Tech. Retrieved from http://hdl.handle.net/10919/26289

Chicago Manual of Style (16^th Edition):

O'Carroll, Ina Puleri. “Assembly of Iron-Sulfur Clusters In Vivo.” 2009. Doctoral Dissertation, Virginia Tech. Accessed April 11, 2021. http://hdl.handle.net/10919/26289.

MLA Handbook (7^th Edition):

O'Carroll, Ina Puleri. “Assembly of Iron-Sulfur Clusters In Vivo.” 2009. Web. 11 Apr 2021.

Vancouver:

O'Carroll IP. Assembly of Iron-Sulfur Clusters In Vivo. [Internet] [Doctoral dissertation]. Virginia Tech; 2009. [cited 2021 Apr 11]. Available from: http://hdl.handle.net/10919/26289.

Council of Science Editors:

O'Carroll IP. Assembly of Iron-Sulfur Clusters In Vivo. [Doctoral Dissertation]. Virginia Tech; 2009. Available from: http://hdl.handle.net/10919/26289

Virginia Tech

23. Huang, Fang-Fang. Molecular Characterization of Animal Strains of Hepatitis E Virus (HEV): Avian HEV and Swine HEV.

Degree: PhD, Veterinary Medical Sciences, 2004, Virginia Tech

URL: http://hdl.handle.net/10919/29893

► Hepatitis E virus (HEV), the causative agent of hepatitis E, is an important public health concern in many developing countries. It mainly infects young adults… (more)

▼ Hepatitis E virus (HEV), the causative agent of hepatitis E, is an important public health concern in many developing countries. It mainly infects young adults and has a mortality of up to 25% in pregnant women. Although hepatitis E is only sporadic in industrialized countries including the United States, a relative high seroprevalence rate has been reported in healthy individuals. Evidence suggests that there exist animal reservoirs for HEV and HEV transmission is zoonotic. Animal strains of HEV, swine HEV and avian HEV have been identified from a pig and a chicken, respectively, in the United States. Studies showed that swine HEV and avian HEV are genetically and antigenically related to human HEV, and that pigs and chickens are useful animal models to study HEV replication, pathogenesis and cross-species infection. The objectives of this dissertation were to genetically characterize both avian HEV and swine HEV, to determine their serological and molecular epidemiology in the United States, to assess the ability of avian HEV cross-species infection in non-human primates, to determine the full-length genomic sequence and genome organization, and to construct an infectious cDNA clone of avian HEV. The prevalence of swine HEV infections in US swine herds and the heterogeneity of swine HEV isolates from different geographic regions of the United States were determined. We found that 35% pigs and 54% swine herds were positive for swine HEV RNA. Partial capsid gene region of twenty-seven US swine HEV isolates was sequenced and was showed to share 88%-100% nucleotide sequence identity to each other and 89-98% identity with the prototype US swine HEV, but only <79% identity with Taiwanese swine HEV isolates and most known human strains of HEV worldwide. All US swine HEV isolates belong to the same genotype 3 with the prototype US swine HEV and the two US strains of human HEV. Similarly, the prevalence of avian HEV infections in US chicken flocks and the heterogeneity of avian HEV isolates were also determined. Helicase gene region of eleven field isolates of avian HEV from chickens with hepatitis-splenomegaly (HS) syndrome was sequenced and was found to share 78-100% nucleotide sequence identities with each other, 79-88% identities with the prototype avian HEV, 76-80% identities with Australian chicken big liver and spleen disease virus (BLSV), and 56-61% identities with other known strains of mammalian HEV. A relative high prevalence of anti-avian HEV antibodies was found in apparently healthy chicken flocks in 5 states. Like swine HEV, the seropositivity of avian HEV in adult chickens was higher than that in young chickens. To genetically characterize the avian HEV genome, we determined the full-length genomic sequence of avian HEV, which is 6,654 bp in length excluding the poly (A) tail, and 600 bp shorter than that of mammalian HEVs. Avian HEV has similar genomic organization with human and swine HEVs, but shared only about 50% nucleotide sequence identity with mammalian HEVs in the complete genome. Significant… Advisors/Committee Members: Meng, Xiang-Jin (committeechair), Pierson, Frank William (committee member), Ahmed, S. Ansar (committee member), Tu, Zhijian Jake (committee member), Toth, Thomas E. (committee member).

Subjects/Keywords: hepatitis E virus; avian HEV; hepatitis E; swine HEV; zoonotic infection; molecular characterization; HEV

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APA (6^th Edition):

Huang, F. (2004). Molecular Characterization of Animal Strains of Hepatitis E Virus (HEV): Avian HEV and Swine HEV. (Doctoral Dissertation). Virginia Tech. Retrieved from http://hdl.handle.net/10919/29893

Chicago Manual of Style (16^th Edition):

Huang, Fang-Fang. “Molecular Characterization of Animal Strains of Hepatitis E Virus (HEV): Avian HEV and Swine HEV.” 2004. Doctoral Dissertation, Virginia Tech. Accessed April 11, 2021. http://hdl.handle.net/10919/29893.

MLA Handbook (7^th Edition):

Huang, Fang-Fang. “Molecular Characterization of Animal Strains of Hepatitis E Virus (HEV): Avian HEV and Swine HEV.” 2004. Web. 11 Apr 2021.

Vancouver:

Huang F. Molecular Characterization of Animal Strains of Hepatitis E Virus (HEV): Avian HEV and Swine HEV. [Internet] [Doctoral dissertation]. Virginia Tech; 2004. [cited 2021 Apr 11]. Available from: http://hdl.handle.net/10919/29893.

Council of Science Editors:

Huang F. Molecular Characterization of Animal Strains of Hepatitis E Virus (HEV): Avian HEV and Swine HEV. [Doctoral Dissertation]. Virginia Tech; 2004. Available from: http://hdl.handle.net/10919/29893

Virginia Tech

24. Peterson, Tina Marie Loane. Plasmodium-Induced Nitrosative Stress in Anopheles stephensi: The Cost of Host Defense.

Degree: PhD, Biochemistry, 2005, Virginia Tech

URL: http://hdl.handle.net/10919/27943

► Both vertebrates and anopheline mosquitoes inhibit Plasmodium spp. (malaria parasite) development via induction of nitric oxide (â ¢NO) synthase. Expression of Anopheles stephensi â ¢NO… (more)

▼ Both vertebrates and anopheline mosquitoes inhibit Plasmodium spp. (malaria parasite) development via induction of nitric oxide (â ¢NO) synthase. Expression of Anopheles stephensi â ¢NO synthase (AsNOS) is induced in the midgut epithelium beginning at 6 h following a Plasmodium berghei-infected blood meal. â ¢NO reacts readily with other biocompounds forming a variety of reactive nitrogen intermediates (RNIs) that may impose a nitrosative stress. These RNIs are proposed to be responsible for the AsNOS-dependent inhibition of Plasmodium development. In my studies, I identified several RNIs that are induced in the blood-filled midgut in response to Plasmodium infection. Stable end products of â ¢NO (NO₃⁻ and NO₂⁻), measured using a modified Griess assay, are elevated in infected midguts at 24 h post-blood meal (pBM). Further studies using chemical reduction-chemiluminescence with Hg displacement showed that infected midguts contained elevated levels of potentially toxic higher oxides of nitrogen (NO_x), but S-nitrosothiol (SNO) and nitrite levels did not differ between infected and uninfected midguts at 12.5 and 24 h pBM. Thus, nitrates contributed to elevated NO_x levels. SNO-biotin switch westerns indicated that S-nitrosated midgut proteins change over the course of blood meal digestion, but not in response to infection. Photolysis-chemiluminescence was used to release and detect bound â ¢NO from compounds in blood-filled midguts dissected from 0-33 h pBM. Results showed increased â ¢NO levels in Plasmodium-infected midgut lysates beginning at 8 h, with significant increases at 12.5-13.5 h and 24-25.5 h pBM and peak levels at 20-24 h. Photolyzed â ¢NO is derived from SNOs and metal nitrosyls. Since SNO concentrations did not change in response to infection, I proposed that metal nitrosyls, specifically Fe nitrosyl hemoglobin (nitrosylHb) based on the concentration of hemoglobin, were elevated in the infected midgut. At 12-24 h pBM, levels of midgut RNIs in infected mosquitoes were typical of levels measured during mammalian septic inflammation. The inverse relationship between AsNOS activity and parasite abundance indicates that nitrosative stress has a detrimental effect on parasite development. However, nitrosative stress may impact mosquito tissues as well in a manner analogous to mammalian tissue damage during inflammation. Elevated levels of nitrotyrosine (NTYR), a marker for nitrosative stress in many mammalian disease states, were detected in tissues of parasite-infected A. stephensi at 24 h pBM. Greater nitration of tyrosine residues was detected in the blood bolus, midgut epithelium, eggs and fat body. In the midgut, Hb remained in an oxygenated state for the duration of blood digestion. The reaction between â ¢NO and oxyhemoglobin (oxyHb) can result in the formation of nitrate and methemoglobin (metHb). Although nitrate levels were elevated in response to parasite infection, there was little to no metHb present in… Advisors/Committee Members: Luckhart, Shirley (committeechair), Tu, Zhijian Jake (committee member), Larson, Timothy J. (committee member), Gillaspy, Glenda E. (committee member), Kennelly, Peter J. (committee member).

Subjects/Keywords: malaria; nitric oxide; <; i>; Anopheles<; /i>;

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APA (6^th Edition):

Peterson, T. M. L. (2005). Plasmodium-Induced Nitrosative Stress in Anopheles stephensi: The Cost of Host Defense. (Doctoral Dissertation). Virginia Tech. Retrieved from http://hdl.handle.net/10919/27943

Chicago Manual of Style (16^th Edition):

Peterson, Tina Marie Loane. “Plasmodium-Induced Nitrosative Stress in Anopheles stephensi: The Cost of Host Defense.” 2005. Doctoral Dissertation, Virginia Tech. Accessed April 11, 2021. http://hdl.handle.net/10919/27943.

MLA Handbook (7^th Edition):

Peterson, Tina Marie Loane. “Plasmodium-Induced Nitrosative Stress in Anopheles stephensi: The Cost of Host Defense.” 2005. Web. 11 Apr 2021.

Vancouver:

Peterson TML. Plasmodium-Induced Nitrosative Stress in Anopheles stephensi: The Cost of Host Defense. [Internet] [Doctoral dissertation]. Virginia Tech; 2005. [cited 2021 Apr 11]. Available from: http://hdl.handle.net/10919/27943.

Council of Science Editors:

Peterson TML. Plasmodium-Induced Nitrosative Stress in Anopheles stephensi: The Cost of Host Defense. [Doctoral Dissertation]. Virginia Tech; 2005. Available from: http://hdl.handle.net/10919/27943

Virginia Tech

25. Mead, Edward. Discovery, Characterization, and Functional Analysis of micro RNAs in Culicidae.

Degree: PhD, Biochemistry, 2009, Virginia Tech

URL: http://hdl.handle.net/10919/77433

► MicroRNAs (miRNAs) are non-coding RNAs that often play a fundamental role in gene regulation. Currently, hundreds to over a thousand miRNAs are predicted to be… (more)

▼ MicroRNAs (miRNAs) are non-coding RNAs that often play a fundamental role in gene regulation. Currently, hundreds to over a thousand miRNAs are predicted to be present in many eukaryote species, with many to be discovered; the functions of most are unknown. While much attention has gone towards model organisms, a much greater depth of understanding remains to be gained for the miRNAs of many organisms directly important to humans. There are few verified miRNAs for any mosquito species, despite the role of mosquitoes in many of humanity’s worst diseases. Anopheles gambiae and Aedes aegypti, carriers of malaria and dengue, respectively, are responsible for over a million deaths a year. To date, there are sixty-six microRNAs in An. gambiae in miRBase, a central repository for miRNA sequences. Many of these are based on homology to primarily Drosophila miRNAs. While sequence conservation suggests an important function for these miRNAs, expression has not been experimentally verified for most mosquito miRNAs. Using small RNA cloning and northern blots, I discovered and analyzed 27 different microRNAs in aged female An. stephensi mosquitoes, the age group responsible for transmission of malarial parasites. Three of these miRNAs are only found in mosquitoes (miR-1889, -1890, and –1891). Cloning and northern analysis revealed an abundance of a miRNA that is linked to longevity in flies, miR-14, across different life stages of mosquitoes. It was also shown that miR-989 was expressed almost exclusively in the adult ovary and its expression fluctuated in response to bloodfeeding, suggesting a possible role in reproduction, an area of great importance to controlling mosquito populations. Building upon the above cloning experiment, a later high-throughput sequencing effort uncovered 98 miRNA precursors from Ae. aegypti. There are a total of 13 novel miRNAs that have not been found in other organisms by bioinformatic predictions or experiments. These “mosquito-specific” miRNAs may play a role in processes such as blood-feeding or vector-host interactions. A detailed examination of the expression of eight of these miRNAs was conducted in An. gambiae, An. stephensi, Ae. aegypti, and T. amboinensis to determine their expression profile, conservation, and provide hints to their function. My work revealed conserved and sometime stage-specific expression profiles of some of the mosquito-specific miRNAs. I also provided evidence for three lineage-specific miRNAs that may shed light on the divergence of different mosquito lineages. Extending the finding that miR-989 may be involved in mosquito reproduction, we conducted a detailed analysis of its evolution, expression, possible targets and regulation. miR-989 is conserved in holometabolous insects. miR-989 expression in female An. stephensi and Ae. aegypti dramatically rises following pupal emergence until strong signal is observed, until a blood meal is taken. Expression remains quite strong then begins a steep decline in expression at 32-40 hours post blood meal (PBM), and even by 96… Advisors/Committee Members: Tu, Zhijian Jake (committeechair), Jelesko, John G. (committee member), Myles, Kevin M. (committee member), Sitz, Thomas O. (committee member), Gillaspy, Glenda E. (committee member).

Subjects/Keywords: dengue; small RNA; mosquito; malaria; Aedes; Anopheles; microRNA; RNAi

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

APA (6^th Edition):

Mead, E. (2009). Discovery, Characterization, and Functional Analysis of micro RNAs in Culicidae. (Doctoral Dissertation). Virginia Tech. Retrieved from http://hdl.handle.net/10919/77433

Chicago Manual of Style (16^th Edition):

Mead, Edward. “Discovery, Characterization, and Functional Analysis of micro RNAs in Culicidae.” 2009. Doctoral Dissertation, Virginia Tech. Accessed April 11, 2021. http://hdl.handle.net/10919/77433.

MLA Handbook (7^th Edition):

Mead, Edward. “Discovery, Characterization, and Functional Analysis of micro RNAs in Culicidae.” 2009. Web. 11 Apr 2021.

Vancouver:

Mead E. Discovery, Characterization, and Functional Analysis of micro RNAs in Culicidae. [Internet] [Doctoral dissertation]. Virginia Tech; 2009. [cited 2021 Apr 11]. Available from: http://hdl.handle.net/10919/77433.

Council of Science Editors:

Mead E. Discovery, Characterization, and Functional Analysis of micro RNAs in Culicidae. [Doctoral Dissertation]. Virginia Tech; 2009. Available from: http://hdl.handle.net/10919/77433

Virginia Tech

26. Alford, Shannon Recca. Molecular Characterization of Two myo-Inositol Oxygenases in Arabidopsis thaliana.

Degree: PhD, Biochemistry, 2009, Virginia Tech

URL: http://hdl.handle.net/10919/26448

► Understanding how plants respond to stress is of importance, considering the increasing need to feed a growing population and supply its energy. Plants have complex… (more)

▼ Understanding how plants respond to stress is of importance, considering the increasing need to feed a growing population and supply its energy. Plants have complex systems for detecting, and responding to stresses. One stress-responsive system involves myo-inositol (Ins). Ins is a precursor for cell wall components, inositol trisphosphate (Ins(1,4,5)P3) and phosphatidylinositol phosphate signaling molecules, and an alternate ascorbic acid (AsA) synthesis pathway. The enzyme, myo-inositol oxygenase (MIOX) is encoded by four genes in Arabidopsis and catalyzes the first step of Ins catabolism producing D-glucuronic acid (DGlcA). This research focuses on MIOX metabolism of Ins during plant growth and stress responses. I have examined miox mutants for alterations in metabolism and signaling. MIOX2 and MIOX4 expression patterns correlate with miox mutant root growth in varying nutrient conditions, and changes in flowering time. In miox2 mutants, I found an increase in Ins in most tissues, which was accompanied by cold- and abscisic (ABA)- sensitivity; however, miox4 mutants are ABA- insensitive, and have a small increase of Ins in flowers. MIOX2:GFP fusion protein accumulates in the cytoplasm and MIOX4:GFP accumulates in the cytoplasm and nucleus. Overexpresser MIOX4+ plants provide a model system to examine how directing carbon from Ins into DGlcA impacts Ins levels and Ins signaling. I have examined MIOX4+ plants for alterations in MIOX4 RNA and protein, and measured Ins by gas chromatography (GC). My results indicate that MIOX4+ tissues are impacted differently by the MIOX4 transgene, with decreases in Ins after seed imbibition, and increased Ins levels later in development. Ins depletion in seedlings was correlated with a decrease in Ins(1,4,5)P3. To determine the impact of reducing Ins and Ins(1,4,5)P3 in MIOX4+ seedlings, I examined processes known to involve Ins(1,4,5)P3 signaling. MIOX4+ seed have increased seed dormancy, NaCl-sensitivity, and ABA-insensitivity. These results suggest MIOX affects Ins signaling in response to ABA. Together, these data indicate that transcriptional control of MIOX2 and MIOX4 results in distinct roles in plant growth, and that MIOX2 and MIOX4 function in metabolic and signaling processes critical for growth, nutrient sensing, and stress responses. Advisors/Committee Members: Gillaspy, Glenda E. (committeechair), McDowell, John M. (committee member), Grabau, Elizabeth A. (committee member), White, Robert H. (committee member), Tu, Zhijian Jake (committee member).

Subjects/Keywords: inositol trisphosphate; myo-inositol oxygenase; gas chromatography; Arabidopsis thaliana; phosphatidylinositol; ascorbic acid; D-glucuronic acid

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APA (6^th Edition):

Alford, S. R. (2009). Molecular Characterization of Two myo-Inositol Oxygenases in Arabidopsis thaliana. (Doctoral Dissertation). Virginia Tech. Retrieved from http://hdl.handle.net/10919/26448

Chicago Manual of Style (16^th Edition):

Alford, Shannon Recca. “Molecular Characterization of Two myo-Inositol Oxygenases in Arabidopsis thaliana.” 2009. Doctoral Dissertation, Virginia Tech. Accessed April 11, 2021. http://hdl.handle.net/10919/26448.

MLA Handbook (7^th Edition):

Alford, Shannon Recca. “Molecular Characterization of Two myo-Inositol Oxygenases in Arabidopsis thaliana.” 2009. Web. 11 Apr 2021.

Vancouver:

Alford SR. Molecular Characterization of Two myo-Inositol Oxygenases in Arabidopsis thaliana. [Internet] [Doctoral dissertation]. Virginia Tech; 2009. [cited 2021 Apr 11]. Available from: http://hdl.handle.net/10919/26448.

Council of Science Editors:

Alford SR. Molecular Characterization of Two myo-Inositol Oxygenases in Arabidopsis thaliana. [Doctoral Dissertation]. Virginia Tech; 2009. Available from: http://hdl.handle.net/10919/26448

Virginia Tech

27. Burnette, Ryan Nelson. A Physiological, Biochemical and Structural Analysis of Inositol Polyphosphate 5-Phosphatases from Arabidopsis thaliana and Humans.

Degree: PhD, Biochemistry, 2004, Virginia Tech

URL: http://hdl.handle.net/10919/29874

► The complete role of inositol signaling in plants and humans is still elusive. The plant Arabidopsis thaliana contains fifteen predicted inositol polyphosphate 5- phosphatases (5PTases,… (more)

▼ The complete role of inositol signaling in plants and humans is still elusive. The plant Arabidopsis thaliana contains fifteen predicted inositol polyphosphate 5- phosphatases (5PTases, E.C. 3.1.3.36) that have the potential to remove a 5-phosphate from various inositol second messenger substrates. To examine the substrate specificity of one of these Arabidopsis thaliana 5PTases (At5PTases), recombinant At5PTase1 was obtained from a Drosophila melanogaster expression system and analyzed biochemically. This analysis revealed that At5PTase1 has the ability to catalyze the hydrolysis of four potential inositol second messenger substrates. To determine whether At5PTase1 can be used to alter the signal transduction pathway of the major drought-sensing hormone abscisic acid (ABA), plants ectopically expressing At5PTase1 under the control of a constitutive promoter were characterized. This characterization revealed that plants ectopically expressing At5PTase1 had an altered response to ABA. These plants have stomata that are insensitive to ABA, and have lower basal and ABA-induced inositol (1,4,5)-trisphosphate [Ins(1,4,5)P₃] levels. In addition, At5PTase1 mRNA and protein levels are transiently regulated by ABA. These data strongly suggest that At5PTase1 can act as a signal terminator of ABA signal transduction. Like the Arabidopsis At5PTase1, a human 5PTase, Ocrl, has the ability to catalyze the hydrolysis of a 5-phosphate from several inositol-containing substrates. The loss of functional Ocrl protein results in a rare genetic disorder known as Lowe oculocerebrorenal syndrome. To gather information concerning the specificity determinants of the Ocrl protein, a structure-function analysis of Ocrl was conducted using a vibrational technique, difference Fourier transform infrared (FT-IR) spectroscopy. Upon the introduction of Ins(1,4,5)P₃ substrate, structural changes in carboxylic acid and histidine residues were observed. The net result of changes in these residues indicates that upon Ins(1,4,5)P₃ introduction, a carboxylic acid-containing residue is protonated, and a histidine residue is deprotonated. This interpretation supports the idea that the deprotonation of the histidine residue is concomitant with the coordination of a divalent cation upon Ins(1,4,5)P₃ introduction. This work allows for the proposal of a new model for the role of the active site histidine of OCRL. Advisors/Committee Members: Gillaspy, Glenda E. (committeechair), Kim, Sunyoung (committee member), Luckhart, Shirley (committee member), Tu, Zhijian Jake (committee member), Larson, Timothy J. (committee member), McDowell, John M. (committee member).

Subjects/Keywords: 4; inositol (1; 5)-trisphosphate; inositol polyphosphate 5-phosphatase; Arabidopsis thaliana; Lowe syndrome; infrared spectroscopy

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

APA (6^th Edition):

Burnette, R. N. (2004). A Physiological, Biochemical and Structural Analysis of Inositol Polyphosphate 5-Phosphatases from Arabidopsis thaliana and Humans. (Doctoral Dissertation). Virginia Tech. Retrieved from http://hdl.handle.net/10919/29874

Chicago Manual of Style (16^th Edition):

Burnette, Ryan Nelson. “A Physiological, Biochemical and Structural Analysis of Inositol Polyphosphate 5-Phosphatases from Arabidopsis thaliana and Humans.” 2004. Doctoral Dissertation, Virginia Tech. Accessed April 11, 2021. http://hdl.handle.net/10919/29874.

MLA Handbook (7^th Edition):

Burnette, Ryan Nelson. “A Physiological, Biochemical and Structural Analysis of Inositol Polyphosphate 5-Phosphatases from Arabidopsis thaliana and Humans.” 2004. Web. 11 Apr 2021.

Vancouver:

Burnette RN. A Physiological, Biochemical and Structural Analysis of Inositol Polyphosphate 5-Phosphatases from Arabidopsis thaliana and Humans. [Internet] [Doctoral dissertation]. Virginia Tech; 2004. [cited 2021 Apr 11]. Available from: http://hdl.handle.net/10919/29874.

Council of Science Editors:

Burnette RN. A Physiological, Biochemical and Structural Analysis of Inositol Polyphosphate 5-Phosphatases from Arabidopsis thaliana and Humans. [Doctoral Dissertation]. Virginia Tech; 2004. Available from: http://hdl.handle.net/10919/29874

Virginia Tech

28. Zhang, Xing. Biogeography and biosystematics of plum curculio, Conotrachelus nenuphar (Herbst)/Wolbachia interactions.

Degree: PhD, Entomology, 2006, Virginia Tech

URL: http://hdl.handle.net/10919/25948

► This research focused on the reproductive incompatibility and genetic differences between the two strains of plum curculio, Conotrachelus nenuphar (Herbst). Two molecular markers served as… (more)

▼ This research focused on the reproductive incompatibility and genetic differences between the two strains of plum curculio, Conotrachelus nenuphar (Herbst). Two molecular markers served as the basis for the strain distribution analysis of plum curculio and Wolbachia symbiont. One marker is the partial mitochondrial cytochrome oxidase gene subunit I (mtCOI) of plum curculio. Another marker is the Wolbachia Surface Protein (wsp) gene of Wolbachia associated with plum curculio. First, the reproductive compatibility of cross-populations mating in plum curculio was studied during the summers of 2004 and 2006. The results confirmed the reproductive incompatibility among plum curculio geographic populations. A unidirectional incompatibility was revealed in an approximate north and south transect of the range of plum curculio (4 x 4 two factorial design: NY, VA, FL, and WV): there was a significant low fertility in WV males mated with NY (40%) and VA (29%) females. The Florida population showed a different pattern: FL males have a significantly lower fertility with VA (46%) and WV (37%) females while FL females were compatible with all males from the four populations. The results of experiment 2 indicated that within the northern geographic area populations (3 x 3 two factorial design: NY, MA, and NJ) were compatible with each other. An opposite unidirectional reproductive incompatibility was revealed in the combination of NJ males with FL females, which showed a significant low fertility (47%). A bi-directional incompatibility occurred between FL and WV reciprocal cross mating. FL males mated with WV females (26%) and WV males mated with FL females (21%) both have the significant low fertility compared to fertility of within their population matings. The genetic diversity among plum curculio populations from different geographic locations was investigated using the partial mtCOI gene. A total of 50 samples from 10 populations were sequenced. PCR products were 863 bp in length. A total of 23 unique sequence haplotypes were found in the 50 samples tested. Haplotype G (n = 5), L (n = 12) and T (n = 13) comprised 60% of 50 samples. The nucleotide distances between those haplotypes ranged from 0.12% to 4.87%. Genetic distances between northern and southern group plum curculios range from 4.17% to 4.87%. Two distinct major clades were found, using three different phylogenetic analyses: 1) neighbor joining (NJ), 2) maximum-parsimony (MP), and 3) maximum-likelihood (ML). 100% bootstraps support the northern clade and the southern clade was strongly supported (100/100/86, NJ/MP/ML) as well. The mid-southern subclade within the southern clade was also strongly supported (70/82/71, NJ/MP/ML) and the far-southern subclade was supported in NJ tree (81%) but was not resovled in MP and ML trees. The mid-southern subclade included haplotypes from two NJ, Washington, VA (Ra), Blacksburg, VA (BL) and 50% of WV populations and the far-southern subclade included haplotypes from FL, GA, Whitethorne, VA (Ke), Troutville, VA (Bo) and another 50%… Advisors/Committee Members: Pfeiffer, Douglas G. (committeechair), Bergh, J. Christopher (committee member), Leskey, Tracy C. (committee member), Tu, Zhijian Jake (committee member), Youngman, Roger R. (committee member).

Subjects/Keywords: cross-mating; reproductive incompatibility; mtCOI; Conotrachelus nenuphar; strains; wsp; Wolbachia

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

APA (6^th Edition):

Zhang, X. (2006). Biogeography and biosystematics of plum curculio, Conotrachelus nenuphar (Herbst)/Wolbachia interactions. (Doctoral Dissertation). Virginia Tech. Retrieved from http://hdl.handle.net/10919/25948

Chicago Manual of Style (16^th Edition):

Zhang, Xing. “Biogeography and biosystematics of plum curculio, Conotrachelus nenuphar (Herbst)/Wolbachia interactions.” 2006. Doctoral Dissertation, Virginia Tech. Accessed April 11, 2021. http://hdl.handle.net/10919/25948.

MLA Handbook (7^th Edition):

Zhang, Xing. “Biogeography and biosystematics of plum curculio, Conotrachelus nenuphar (Herbst)/Wolbachia interactions.” 2006. Web. 11 Apr 2021.

Vancouver:

Zhang X. Biogeography and biosystematics of plum curculio, Conotrachelus nenuphar (Herbst)/Wolbachia interactions. [Internet] [Doctoral dissertation]. Virginia Tech; 2006. [cited 2021 Apr 11]. Available from: http://hdl.handle.net/10919/25948.

Council of Science Editors:

Zhang X. Biogeography and biosystematics of plum curculio, Conotrachelus nenuphar (Herbst)/Wolbachia interactions. [Doctoral Dissertation]. Virginia Tech; 2006. Available from: http://hdl.handle.net/10919/25948

Virginia Tech

29. Crosby, Kevin C. Macromolecular Organization and Cell Function: A Multi-System Analysis.

Degree: PhD, Biology, 2008, Virginia Tech

URL: http://hdl.handle.net/10919/30259

► The interior of the cell is a densely crowded and complex arena, full of a vast and diverse array of molecules and macromolecules. A fundamental… (more)

▼ The interior of the cell is a densely crowded and complex arena, full of a vast and diverse array of molecules and macromolecules. A fundamental understanding of cellular physiology will depend not only upon a reductionist analysis of the chemistry, structure, and function of individual components and subsystems, but also on a sagacious exegesis of the dynamic and emergent properties that characterize the higher-level system of living cells. Here, we present work on two aspects of the supramolecular organization of the cell: the controlled assembly of the mitotic spindle during cell division and the regulation of cellular metabolism through the formation of multienzyme complexes. During division, the cell undergoes a profound morphological and molecular reorganization that includes the creation of the mitotic spindle, a process that must be highly controlled in order to ensure that accurate segregation of hereditary material. Chapter 2 describes results that implicate the kinase, Zeste-white3/Shaggy (Zw3/Sgg), as having a role in regulating spindle morphology. The congregation of metabolic enzymes into macromolecular complexes is a key feature of cellular physiology. Given the apparent pervasiveness of these assemblies, it seems likely that some of the mechanisms involved in their organization and regulation might be conserved across a range of biosynthetic pathways in diverse organisms. The Winkel laboratory makes use of the flavonoid biosynthetic pathway in Arabidopsis as an experimental model for studying the architecture, dynamics, and functional roles of metabolic complexes. Over the past several years, we have accumulated substantive and compelling evidence indicating that a number of these enzymes directly interact, perhaps as part of a dynamic globular complex involving multiple points of contact between proteins. Chapter 3 describes the functional analysis of a predicted flavonol synthase gene family in Arabidopsis. The first evidence for the interaction of flavonoid enzymes in living cells, using fluorescent lifetime imaging microscopy fluorescent resonance energy transfer analysis (FLIM-FRET), is presented in Chapter 4. Advisors/Committee Members: Winkel, Brenda S. J. (committeechair), Tholl, Dorothea (committee member), Tu, Zhijian Jake (committee member), McDowell, John M. (committee member), Sible, Jill C. (committee member).

Subjects/Keywords: Mitosis.; Metabolic complexes; Fluorescent Resonance Energy Transfer (FRET); Fluorescent Lifetime Imaging Microscopy (FLIM)

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

APA (6^th Edition):

Crosby, K. C. (2008). Macromolecular Organization and Cell Function: A Multi-System Analysis. (Doctoral Dissertation). Virginia Tech. Retrieved from http://hdl.handle.net/10919/30259

Chicago Manual of Style (16^th Edition):

Crosby, Kevin C. “Macromolecular Organization and Cell Function: A Multi-System Analysis.” 2008. Doctoral Dissertation, Virginia Tech. Accessed April 11, 2021. http://hdl.handle.net/10919/30259.

MLA Handbook (7^th Edition):

Crosby, Kevin C. “Macromolecular Organization and Cell Function: A Multi-System Analysis.” 2008. Web. 11 Apr 2021.

Vancouver:

Crosby KC. Macromolecular Organization and Cell Function: A Multi-System Analysis. [Internet] [Doctoral dissertation]. Virginia Tech; 2008. [cited 2021 Apr 11]. Available from: http://hdl.handle.net/10919/30259.

Council of Science Editors:

Crosby KC. Macromolecular Organization and Cell Function: A Multi-System Analysis. [Doctoral Dissertation]. Virginia Tech; 2008. Available from: http://hdl.handle.net/10919/30259

Virginia Tech

30. Biedler, James K. Non-LTR Retrotransposons in Mosquitoes: Diversity, Evolution, and Analysis of Potentially Active Elements.

Degree: PhD, Biochemistry, 2005, Virginia Tech

URL: http://hdl.handle.net/10919/28430

► This research focuses on non-Long Terminal Repeat (non-LTR) retrotransposons in the African malaria mosquito, Anopheles gambiae and other mosquito species. An unprecedented diversity of non-LTRs… (more)

▼ This research focuses on non-Long Terminal Repeat (non-LTR) retrotransposons in the African malaria mosquito, Anopheles gambiae and other mosquito species. An unprecedented diversity of non-LTRs was discovered by genome analysis of the An. gambiae genome assembly. One hundred and four families were found by a reiterative and comprehensive search using the conserved reverse transcriptase domains of known non-LTRs from a number of organisms as the starting queries. These families range in copy number from a few to approximately 2000 and occupy at least 3% of the genome. An. gambiae non-LTRs represent 8 of the 15 previously defined clades, plus two novel clades, Loner and Outcast, raising the total number of known clades to 17. The first invertebrate L1 clade representatives were also found. All clades except one have families with sequence characteristics suggesting recent activity. Juan, a non-LTR of the Jockey clade originally discovered in the mosquito Culex pipiens quinquefasciatus (Mouches et al. 1991), has been implicated in horizontal transfer in three non-sibling species of the Aedes genus (Mouches, Bensaadi, and Salvado 1992). PCR was used to obtain sequences from 18 mosquito species of six genera. Phylogenetic analysis demonstrates predominant vertical inheritance of Juan elements among these species. There is strong evidence from sequence analysis supporting the recent activity of Juan in several divergent species. We hypothesize that the sustained activity (versus quick inactivation) of non-LTRs in mosquitoes may contribute to the diversity we observe in the An. gambiae genome today. Promoter and transcriptional analyses were performed for several families previously identified as potentially active elements based on sequence analysis. RT-PCR results indicate that transcripts are present in An. gambiae cell lines that contain sequences corresponding to 13 of 15 tested non-LTR families. The 5' UTRs of An. gambiae non-LTRs from the I, Jockey, and L1 clades support basal transcription in divergent mosquito cell lines from 3 species. The Jen-1 5'UTR did not support transcription in Ae. aegypti and had low activity in Ae. albopictus. In summary, this research shows that Non-LTRs have been highly successful genomic elements that have flourished in many divergent mosquito species. Advisors/Committee Members: Tu, Zhijian Jake (committeechair), Dean, Dennis R. (committee member), Larson, Timothy J. (committee member), Luckhart, Shirley (committee member), Smith, Edward J. (committee member), McDowell, John M. (committee member).

Subjects/Keywords: Transposable elements; non-LTR retrotransposons; reverse transcriptase; genome evolution

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

APA (6^th Edition):

Biedler, J. K. (2005). Non-LTR Retrotransposons in Mosquitoes: Diversity, Evolution, and Analysis of Potentially Active Elements. (Doctoral Dissertation). Virginia Tech. Retrieved from http://hdl.handle.net/10919/28430

Chicago Manual of Style (16^th Edition):

Biedler, James K. “Non-LTR Retrotransposons in Mosquitoes: Diversity, Evolution, and Analysis of Potentially Active Elements.” 2005. Doctoral Dissertation, Virginia Tech. Accessed April 11, 2021. http://hdl.handle.net/10919/28430.

MLA Handbook (7^th Edition):

Biedler, James K. “Non-LTR Retrotransposons in Mosquitoes: Diversity, Evolution, and Analysis of Potentially Active Elements.” 2005. Web. 11 Apr 2021.

Vancouver:

Biedler JK. Non-LTR Retrotransposons in Mosquitoes: Diversity, Evolution, and Analysis of Potentially Active Elements. [Internet] [Doctoral dissertation]. Virginia Tech; 2005. [cited 2021 Apr 11]. Available from: http://hdl.handle.net/10919/28430.

Council of Science Editors:

Biedler JK. Non-LTR Retrotransposons in Mosquitoes: Diversity, Evolution, and Analysis of Potentially Active Elements. [Doctoral Dissertation]. Virginia Tech; 2005. Available from: http://hdl.handle.net/10919/28430

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