Interspecies genomic introgressions:  origin, evolution and function

13 Décembre 2018 - 14h30

Gianni Liti, Institute for Research on Cancer and Aging (IRCAN), Université Côte d’Azur

Lieu : LCQB Kitchen, Bâtiment C, 4ème étage

Résumé : Genome interspecific introgressions drive evolution across the animal, plant and fungal kingdoms. We use the model system S. cerevisiae to investigate the birth, evolution and function of interspecies introgressions. Sequencing 1011 S. cerevisiae genomes revealed a ubiquitous gene flow with S. paradoxus. Intorgressions are rare in the highly diverged Asian lineages, consistent with secondary contacts with /S. paradoxus/occurring mainly after the out-of-China dispersal and promoted by human driven environments. Introgressions initiate from archaic interspecific admixtures, but near-universal hybrid sterility has made their evolution a mystery. We recently discovered a “living fossil” S. cerevisae / S. pardoxus hybrid that reveals a new role for genomic instability at the onset of introgressions. Finally, we use quantitative genetics to measure the fitness landscape of interspecies introgressions across multiple environments