Evolution of sex chromosomes in reptiles
| Thesis title in Czech: | Evoluce pohlavních chromozomů u plazů |
|---|---|
| Thesis title in English: | Evolution of sex chromosomes in reptiles |
| Key words: | FISH, chromozom, genom, cytogenetika, karyotyp, pohlavní chromozomy, evoluce, heterochromatin, telomery, rDNA |
| English key words: | FISH, chromosome, genome, cytogenetics, karyotype, sex chromosomes, evolution, heterochromatin, telomeres, rDNA |
| Academic year of topic announcement: | 2016/2017 |
| Thesis type: | dissertation |
| Thesis language: | angličtina |
| Department: | Department of Ecology (31-162) |
| Supervisor: | Michail Rovatsos, Ph.D. |
| Author: | hidden - assigned by the advisor |
| Date of registration: | 17.10.2016 |
| Date of assignment: | 17.10.2016 |
| Date of electronic submission: | 27.06.2020 |
| Date of proceeded defence: | 16.09.2020 |
| Opponents: | RNDr. Magda Zrzavá, Ph.D. |
| Thomas Liehr, Dr. | |
| Advisors: | prof. Mgr. Lukáš Kratochvíl, Ph.D. |
| Preliminary scope of work in English |
| This thesis focuses on the evolution of sex chromosomes in reptiles. Some reptile lineages possess evolutionary stable sex chromosomes, which are homologous across their members, while other groups present higher variability and only limited information is available. Therefore, among reptiles, I focus my attention on two lineages with opposite characteristics: turtles (Testudines), a lineage in which species with TSD, male and female heterogamety are present, and birds (Aves) in which sex chromosomes are extremely stable and homologous across all the phylogeny. In turtles I want to explore the presence of sex chromosomes, considering that many species have questionable sex determination mechanism or have not been tested yet, while in birds I want to investigate the homology of Z chromosomes among species and apply this information to the development of molecular sexing method. More precisely, the main aims of my thesis are to expand our knowledge on:
(i) the sex chromosomes of pleurodiran turtles of the family Chelidae, a lineage previously known to exhibit GSD (ii) the sex chromosomes of cryptodiran turtles, by screening species belonging to two families, Geoemydidae and Emydidae, which include species with either ESD or GSD (iii) the role of constitutive heterochromatin and repetitive elements on karyotype and sex chromosome evolution in turtles (iv) the level of homology of sex chromosomes across birds, and using our current knowledge, to develop an alternative molecular sex identification method which will effectively work across all the avian diversity |