Reptiles mostly reproduce sexually, but cases of facultative parthenogenesis have been recorded in several species and some lineages have even stopped sexual reproduction entirely. In most cases, obligate parthenogenetic lineages have arisen instantly through interspecific hybridization. However, the transition to obligate parthenogenesis could also be continuous, associated with the gradual spread of facultative parthenogenesis, its fixation in the population and the extinction of males. Each of these evolutionary pathways would be tied to a different cytological mechanism of unreduced egg production, which would affect the genetic variability of offspring and, consequently, of the population as a whole. The proposed PhD project is focused on testing the alternative evolutionary pathways to obligate parthenogenesis using molecular and cytogenetic techniques in selected reptile lineages. We offer work combining state-of-the-art methods in the laboratory, experiments with live animals in our facility, and the opportunity to participate in field trips to the tropics. We have been studying reptile sexual reproduction, especially sex determination, for 20 years and it is time to explore parthenogens! We are looking for a motivated PhD student with an interest in reproductive biology and evolution. Previous experience in bioinformatic analyses of genomic data or cytogenetics is advantageous, passion for reptiles essential.
Five relevant publications of the research group:
Dedukh D, Altmanová M, Klíma J, Kratochvíl L. 2022. Premeiotic endoreplication is essential for obligate parthenogenesis in geckos. Development 149: dev200345.
Kratochvíl L, Stöck M, Rovatsos M, Bullejos M, Herpin A, Jeffries DL, Peichel CL, Perrin N, Valenzuela N, Johnson Pokorná M. 2021. Expanding the classical paradigm: what we have learnt from vertebrates about sex chromosome evolution. Philos Trans R Soc Lond B Biol Sci 376: 20200097.
Kratochvíl L, Vukić J, Červenka J, Kubička L, Johnson Pokorná M, Kukačková D, Rovatsos M, Piálek L. 2020. Mixed-sex offspring produced via cryptic parthenogenesis in a lizard. Mol Ecol. 29: 4118-4127.
Nielsen SV, Guzmán-Méndez IA, Gamble T, Blumer M, Pinto BJ, Kratochvíl L, Rovatsos M. 2019. Escaping the evolutionary trap? Sex chromosome turnover in basilisks and related lizards (Corytophanidae: Squamata). Biol Lett. 15: 20190498.
Johnson Pokorná M, Kratochvíl L. 2016. What was the ancestral sex-determining mechanism in amniote vertebrates? Biol Rev. 91: 1-12.Apply to the project