Missions

Develop new theories to understand the dynamics of sex chromosome turnovers.

Activités

Sex chromosomes have evolved independently in a vast number of species and share common features, including recombination suppression, degeneration, and dosage compensation. These features are however not universal and many species have sex chromosomes lack them, or exhibit them only partially. Sex chromosomes are also variable across species with many events of “turnovers”. These turnovers can take different forms (to an autosome, to the same sex chromosome pair, with or without a change in the sex determination system, with or without a ZW-XY transition, etc.) (1, 2). New models developed by our team (3–5) suggest an important role of regulatory changes during early evolution of sex chromosomes. These new theories may also be helpful to understand these turnovers, the stability of some systems and the diversity of sex chromosomes observed in nature.

The project of this postdoc is to develop such theory using existing models as building blocks and further develop them. This work will be based on chromosomal-scale C++ simulations and analytical work if possible. The postdoc will also be involved in several PhD research projects about regulatory evolution, that include similar methods, and that also include genomic data analysis. Hence, ideally, the applicant will have some background in both theoretical population genetics and genomic data analyses.


References
1. T.-L. Ashman, D. Bachtrog, H. Blackmon, E. E. Goldberg, M. W. Hahn, M. Kirkpatrick, J. Kitano, J. E. Mank, I. Mayrose, R. Ming, S. P. Otto, C. L. Peichel, M. W. Pennell, N. Perrin, L. Ross, N. Valenzuela, J. C. Vamosi, Tree of Sex: A database of sexual systems. Scientific Data 1, 140015 (2014).
2. L. W. Beukeboom, N. Perrin, The Evolution of Sex Determination (Oxford University Press, 2014; http://www.oxfordscholarship.com/view/10.1093/acprof:oso/9780199657148.001.0001/acprof-9780199657148).
3. T. Lenormand, F. Fyon, E. Sun, D. Roze, Sex chromosome degeneration by regulatory evolution. Current Biology 30, 3001-3006.e5 (2020).
4. T. Lenormand, D. Roze, Y recombination arrest and degeneration in the absence of sexual dimorphism. Science 375, 663–666 (2022).
5. T. Lenormand, D. Roze, Can mechanistic constraints on recombination reestablishment explain the long-term maintenance of degenerate sex chromosomes? Peer Community Journal 4, e17 (2024).

Compétences

Candidate requirements:
(1) Enthusiasm and genuine curiosity for evolutionary genetics, genomics, and evolutionary biology.
(2) A PhD in the subject area of evolutionary biology. Experience with population genetics, evolutionary theory, genomics is desirable.
(3) Strong quantitative skills. Experience with programming or bioinformatics is desirable.
(4) Strong oral and written communication skills in English (the work language for science at the CEFE is English).

Contexte de travail

The applicant will receive comprehensive training in state-of-the-art theoretical population genetics. He/she will spend most of their time in the Genetic and Evolutionary Ecology group (GEE) at the Centre d'Ecologie Fonctionnelle et Evolutive (CEFE), a large, ecology and evolution-focused research institute in Montpellier, Southern France, with possible visits of project partners elsewhere in France. Montpellier is a lively student town with a beautiful historic center, located about 10 km from the Mediterranean Sea. This postdoc is part of an advanced ERC project ('RegEvol'), addressing novel ideas and theoretical predictions on the role of regulatory evolution for several important fundamental topics in evolutionary biology (sex chromosomes, maintenance of sex, complexity of gene networks, etc.). The postdoc will join the team working on this project.

Contraintes et risques

Rissks associated to computer work