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http://hdl.handle.net/11375/25763
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DC Field | Value | Language |
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dc.contributor.advisor | Evans, Ben | - |
dc.contributor.author | Cauret, Caroline | - |
dc.date.accessioned | 2020-09-02T15:51:22Z | - |
dc.date.available | 2020-09-02T15:51:22Z | - |
dc.date.issued | 2020 | - |
dc.identifier.uri | http://hdl.handle.net/11375/25763 | - |
dc.description.abstract | Developmental system drift refers to situations where, in different species, similar traits are controlled by diverged genetic systems. For example, sexual differentiation is crucial for reproduction and survival of species, but is controlled by rapidly evolving genes and genetic interactions. In my PhD thesis, I studied the evolution of triggers for sex determination in order to better understand how developmental systems drift occurs. The second chapter examines the diversity of sex determining systems in the frog family Pipidae (which includes the genus Xenopus). My work provides evidence for seven distinct sex determination systems in this group of frogs. This work also shows that a known trigger for sex determination (dm-w) has not always been efficient in driving female development of frogs that carry this gene. I propose that the inefficiency of a trigger for sex determination might play a major role in the fate of sex chromosomes. In the third chapter, I explore potential mechanisms by which dm-w and the supergene that contains dm-w evolved, and possible effects in its efficiency in driving female sexual differentiation. This work shows that the acquisition and evolution of the last exon of this gene might be associated with the onset of female-specificity. While the specific function of two other female-specific genes in X. laevis (scan-w, ccdc69-w) remains unclear, their origin seems to coincide with the empowerment of dm-w. We also found that an important domain in the function of dmrt1, another transcription factor that is related by gene duplication to dm-w, is often incapacitated by early stop codons. Taken together, this thesis documents dynamic functional evolution of individual components (dm-w, dmrt1, scan-w, ccdc69-w), entire genetic networks (sex chromosomes), and genomic contexts (recombination suppression) that govern an important phenotype (sex determination) in a diverse group of widely studied vertebrates (pipid frogs). | en_US |
dc.language.iso | en | en_US |
dc.title | Sex determination in frogs offer insights into how important things evolve | en_US |
dc.title.alternative | Evolution of sex determination in Pipid frogs | en_US |
dc.type | Thesis | en_US |
dc.contributor.department | Biology | en_US |
dc.description.degreetype | Thesis | en_US |
dc.description.degree | Doctor of Philosophy (PhD) | en_US |
Appears in Collections: | Open Access Dissertations and Theses |
Files in This Item:
File | Description | Size | Format | |
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Cauret_Caroline_MS_finalsubmission2020august_PhD.pdf | 19.25 MB | Adobe PDF | View/Open |
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