recLandscapes

Meiotic crossovers among homologous chromosomes lie at the heart of the sexual cycle of eukaryotic species, preventing the missegregation of parental chromosomes and generating novel genetic combinations by recombination. While the core molecular mechanisms of crossover formation are very conserved, recombination landscapes (describing the distribution of crossovers along chromosomes) display considerable variation between species, but also between individuals from the same species. To date, the evolutionary processes underlying this diversity of recombination landscapes remain elusive, partly due to theoretical and experimental limitations. Yet, understanding the causes of the evolution of recombination landscapes could shed new light on the evolutionary benefits of recombination, and more generally, of sexual reproduction.

In the recLandscape project, we will develop a combination of theoretical and experimental approaches using  a recombination modifier (rec-1 mutant) in the nematode Caenorhabditis elegans to reach the following objectives:

1. Develop a general theoretical framework to understand the selective forces acting on the evolution of recombination landscapes, under realistic genetic architectures (polygenic basis of fitness and recombination variation, heterogeneous gene densities along chromosomes). 

2. Use this framework to explore how the fate of modifiers affecting recombination landscapes may depend on their local genomic environment and on the population reproductive system.

3. Obtain predictions on the direction of selection on the rec-1 mutant of C. elegans as a function of its genomic localization, and test them using experimental evolution.

4. Use the rec-1 system to test the effect of selfing on the evolution of recombination landscapes.

Members

Henrique Teotónio (ENS Paris)