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You searched for subject:(lophotrochozoa). Showing records 1 – 3 of 3 total matches.

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Freie Universität Berlin

1. Zakrzewski, Anne-Christin. Molekulare Charakterisierung der Borstenbildung von Anneliden und anderen Lophotrochozoa.

Degree: 2011, Freie Universität Berlin

Annelida sind eine gut bekannte Gruppe von segmentierten, wurmförmigen Organismen, deren charakteristischste Merkmale ausgeprägte und oft bizarr gestaltete Borsten (Chaetae) sind. Diese Strukturen wurden seit langem als Autapomorphie der Anneliden-Stammart diskutiert, da ähnliche Strukturen anderer Taxa, z.B. Myzostomida und Brachiopoda, als Resultat eines unabhängigen evolutiven Ursprungs interpretiert wurden. Der Prozess der Borstenbildung (Chaetogenese) wurde seit langem auf ultrastruktureller Ebene untersucht, aber viele Aspekte blieben unklar, da Daten anderer Vergleichsebenen fehlen. Das Ziel dieser Studie ist es daher, Borsten- spezifische Zellen auf einer neuen Ebene zu untersuchen, und zwar durch eine kombinierte Strategie aus strukturellen und molekularen Methoden. Im Zuge des Transkriptom- und Genom-Projektes von Platynereis dumerilii wurde eine Reihe an Marker-Kandidaten durch zufällige in-situ-Hybridisierung identifiziert, die die erstmalige Möglichkeit bieten, neue Erkenntnisse über die Chaetogenese zu gewinnen. Die zelluläre Lokalisierung dieser Marker erfolgte durch ultrastrukturelle, immunhistochemische, sowie verschiedenste Verfahren der in- situ-Hybridisierung und lieferte fünfzehn molekulare Marker, die zwei verschiedene in der Chaetogenese involvierte Zelltypen spezifisch charakterisieren, nämlich den Chaetoblasten und die proximalen Follikelzellen. Außerdem ermöglicht dieses Set von hochspezifischen Markern die ersten vergleichenden Analysen von Borsten-bildenden Zellen des Anneliden Capitella teleta, des Myzostomiden Myzostoma cirriferum und des Brachiopoden Macandrevia cranium. Im Fall mehrerer Marker aus P. dumerilii wurden orthologe Sequenzen in den anderen untersuchten Organismen gefunden, wo deren Expression in homologen Zelltypen lokalisiert ist und somit die ersten molekularen Indizien für die Homologie der Borsten der Annelida, Myzostomida und Brachiopoda liefert. Computer-gestützte Analysen der Markersequenzen zeigen eine Reihe an Aminosäure-Motiven und -Domänen, die auf potentielle Funktionen hindeuten könnten. Unter diesen erscheinen vor allem die mit einer Myosin-Motordomäne (MMD) verbundenen Chitinsynthasen von besonderem Interesse, da diese Studie eine unerwartete Diversität dieser Enzyme in den verfügbaren Lophotrochozoen nachweist, wobei die Vertreter von zwei Chitinsynthase-Gruppen anscheinend eine Chaetoblasten-spezifische Expression in den untersuchten Organismen besitzen. Da die evolutiven Analysen der Chitinsynthasen nahelegen, dass der letzte gemeinsame Vorfahr von Annelida, Myzostomida, Brachiopoda und Mollusca drei MMD-gekoppelte Chitinsynthasen besaß, wird hypothetisiert, dass die ursprüngliche Funktion dieser Enzyme die Bildung homologer Borsten und anderer chitinöser Strukturen ist, möglicherweise sogar die Bildung von Schalen. Da die phylogenetischen Beziehungen innerhalb der Lophotrochozoa noch nicht einmal annähernd geklärt sind, ist die Untersuchung aller verbleibenden Subtaxa der Lophotrochozoa unter Verwendung der in dieser Studie etablierten kombinierten… Advisors/Committee Members: w (gender), Prof. Dr. Klaus Hausmann (firstReferee), Prof. Dr. Thomas Bartolomaeus (furtherReferee).

Subjects/Keywords: chaetae; evolution; annelida; lophotrochozoa; development; gene expression; 500 Naturwissenschaften und Mathematik::570 Biowissenschaften; Biologie

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

APA (6th Edition):

Zakrzewski, A. (2011). Molekulare Charakterisierung der Borstenbildung von Anneliden und anderen Lophotrochozoa. (Thesis). Freie Universität Berlin. Retrieved from http://dx.doi.org/10.17169/refubium-12408

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

Chicago Manual of Style (16th Edition):

Zakrzewski, Anne-Christin. “Molekulare Charakterisierung der Borstenbildung von Anneliden und anderen Lophotrochozoa.” 2011. Thesis, Freie Universität Berlin. Accessed April 13, 2021. http://dx.doi.org/10.17169/refubium-12408.

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

MLA Handbook (7th Edition):

Zakrzewski, Anne-Christin. “Molekulare Charakterisierung der Borstenbildung von Anneliden und anderen Lophotrochozoa.” 2011. Web. 13 Apr 2021.

Vancouver:

Zakrzewski A. Molekulare Charakterisierung der Borstenbildung von Anneliden und anderen Lophotrochozoa. [Internet] [Thesis]. Freie Universität Berlin; 2011. [cited 2021 Apr 13]. Available from: http://dx.doi.org/10.17169/refubium-12408.

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

Council of Science Editors:

Zakrzewski A. Molekulare Charakterisierung der Borstenbildung von Anneliden und anderen Lophotrochozoa. [Thesis]. Freie Universität Berlin; 2011. Available from: http://dx.doi.org/10.17169/refubium-12408

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


University of Edinburgh

2. Jones, Martin. Multigene datasets for deep phylogeny.

Degree: PhD, 2007, University of Edinburgh

Though molecular phylogenetics has been very successful in reconstructing the evolutionary history of species, some phylogenies, particularly those involving ancient events, have proven difficult to resolve. One approach to improving the resolution of deep phylogenies is to increase the amount of data by including multiple genes assembled from public sequence databases. Using modern phylogenetic methods and abundant computing power, the vast amount of sequence data available in public databases can be brought to bear on difficult phylogenetic problems. In this thesis I outline the motivation for assembling large multigene datasets and lay out the obstacles associated with doing so. I discuss the various methods by which these obstacles can be overcome and describe a bioinformatics solution, TaxMan, that can be used to rapidly assemble very large datasets of aligned genes in a largely automated fashion. I also explain the design and features of TaxMan from a biological standpoint and present the results of benchmarking studies. I illustrate the use of TaxMan to assemble large multigene datasets for two groups of taxa – the subphylum Chelicerata and the superphylum Lophotrochozoa. Chelicerata is a diverse group of arthropods with an uncertain phylogeny. When a set of mitochondrial genes is used to analyse the relationships between the chelicerate orders, the conclusions are highly dependent upon the evolutionary model used and are affected by the presence of systematic compsitional bias in mitochondrial genomes. Lophotrochozoa is a recently-proposed group of protostome phyla. A number of distinct phylogenetic hypotheses concerning the relationships between lophotrochozoan phyla have been proposed. I compare the phylogenetic conclusions given by analysis of nuclear and mitochondrial protein-coding and rRNA genes to evaluate support for some of these hypotheses.

Subjects/Keywords: 572.8; Biological Science; molecular phylogenetics; Chelicerata; Lophotrochozoa

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

APA (6th Edition):

Jones, M. (2007). Multigene datasets for deep phylogeny. (Doctoral Dissertation). University of Edinburgh. Retrieved from http://hdl.handle.net/1842/2575

Chicago Manual of Style (16th Edition):

Jones, Martin. “Multigene datasets for deep phylogeny.” 2007. Doctoral Dissertation, University of Edinburgh. Accessed April 13, 2021. http://hdl.handle.net/1842/2575.

MLA Handbook (7th Edition):

Jones, Martin. “Multigene datasets for deep phylogeny.” 2007. Web. 13 Apr 2021.

Vancouver:

Jones M. Multigene datasets for deep phylogeny. [Internet] [Doctoral dissertation]. University of Edinburgh; 2007. [cited 2021 Apr 13]. Available from: http://hdl.handle.net/1842/2575.

Council of Science Editors:

Jones M. Multigene datasets for deep phylogeny. [Doctoral Dissertation]. University of Edinburgh; 2007. Available from: http://hdl.handle.net/1842/2575


University of New Mexico

3. Nolan, Journey R. Molecular characterization of the freshwater snail Physella acuta.

Degree: UNM Biology Department, 2013, University of New Mexico

Current insights into general animal biology, including immune function, are derived mostly from a few model organisms, a necessity imposed by effort required for in-depth studies. Modern next-generation sequencing (NGS) enables genomics-level investigations to test whether specific aspects of biology are general or unique across animal phylogeny. Meaningful comparisons require thorough identification of phylogenetically-relevant species. To provide a touchstone for Biomphalaria glabrata, a freshwater snail that is a major study model for invertebrate immunity, physid snails (Physidae; Hygrophila; Panpulmonata; Gastropoda; Mollusca) will be developed as a model for comparative immunogenomics. Chapter 1 introduces current research capabilities and details the rationale behind developing a physid as a comparative model for B. glabrata. Chapter 2, submitted as a manuscript to the Journal of Molluscan Studies, describes the molecular characterization that was performed for species identification and confirms taxonomic placement of physid snails relative to B. glabrata. Comparative mitogenomics revealed high levels of intraspecific sequence divergence between the entire mitochondrial genomes of the two P. acuta isolates, identified a unique gene order, and compared substitutions rates of gene sequences from the mitochondrial genomes of other gastropods. Additional materials are provided in the Appendices; Appendix A provides supplemental information for Chapter 2 and Appendix B provides a report of preliminary results from NGS-based gene discovery for initial characterization of the immune response of P. acuta to bacterial exposure toward comparative immunogenomics. Results from this thesis support continuing efforts to develop P. acuta as a comparative immunogenomic model to B. glabrata. Advisors/Committee Members: Adema, Dr. Coenraad M., Stricker, Dr. Stephen, Takacs-Vesbach, Dr. Cristina.

Subjects/Keywords: gastropod; Physella acuta; Physa acuta; mitochondria; mitogenomics; transcriptomics; 454; next generational sequencing; Biomphalaria glabrata; gene rearrangements; dN/dS; Ka/Ks; intraspecific sequence differences; invertebrate immunology; lophotrochozoa; Mollusca; FREP

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

APA (6th Edition):

Nolan, J. R. (2013). Molecular characterization of the freshwater snail Physella acuta. (Masters Thesis). University of New Mexico. Retrieved from https://digitalrepository.unm.edu/biol_etds/87

Chicago Manual of Style (16th Edition):

Nolan, Journey R. “Molecular characterization of the freshwater snail Physella acuta.” 2013. Masters Thesis, University of New Mexico. Accessed April 13, 2021. https://digitalrepository.unm.edu/biol_etds/87.

MLA Handbook (7th Edition):

Nolan, Journey R. “Molecular characterization of the freshwater snail Physella acuta.” 2013. Web. 13 Apr 2021.

Vancouver:

Nolan JR. Molecular characterization of the freshwater snail Physella acuta. [Internet] [Masters thesis]. University of New Mexico; 2013. [cited 2021 Apr 13]. Available from: https://digitalrepository.unm.edu/biol_etds/87.

Council of Science Editors:

Nolan JR. Molecular characterization of the freshwater snail Physella acuta. [Masters Thesis]. University of New Mexico; 2013. Available from: https://digitalrepository.unm.edu/biol_etds/87

.