Which novels factors are involved in the final resolution of recombination intermediates during meiosis? – ResoFIN

DNA double-strand breaks (DSB) can arise accidentally, or be part of programmed developmental processes, such as meiosis. Faithfull DSB repair occurs through the homologous recombination pathway and culminates in crossovers (CO) formation, through joint DNA molecules resolution. Although meiotic recombination has been investigated for decades, many of the underlying molecular processes remain unclear, largely due to the lack of biochemical studies. An important currently unanswered question is which actors are recruited to clean and clear the road for homologs separation by sealing the deal of CO. I propose here by a multidisciplinary approach based on proteomics (TurboID), genomics, genetics, and biochemistry, to answer three central questions: (i) How do DNA synthesis components influence CO resolution? (ii) How do the nicked joint molecules separate to allow chromosome segregation? (iii) Which DNA ligase is implicated in CO resolution? This work will focus on the yeast Saccharomyces cerevisiae, for which the genetics is best understood, and which offers the richest set of tools. Meiotic recombination appears to be conserved across evolution and more generally, the experimental context of meiosis, during which hundreds of programmed DSB form and repair synchronously, makes yeast meiotic cells an ideal model system to study DSBs repair.
Altogether, this proposal will convey crucial insight in recombination mechanisms by allowing us to uncover new proteins involved in the DSB repair process and shed new light on a poorly explored aspect of homologous recombination, with consequences for fertility and the maintenance of genome stability, unregulated in many pathologies such as cancer.