Objective Sex chromosomes often show extensive areas of suppressed recombination and cytological differentiation, a well-documented phenomenon in animals and plants. Lack of recombination is expected to limit the efficacy of natural selection, leading to degeneration in gene content. Similarly, fungal mating-type chromosomes, which are responsible for controlling compatibility during mating, can display patterns of suppressed recombination encompassing up to 90% of the chromosome length. The mechanisms responsible for lack of recombination and consequent degeneration remain unclear.Here, I propose to use comparative genomics to investigate the patterns and underlying mechanisms involved in recombination suppression and genomic degeneration in Microbotryum, a model fungal system with a range of dimorphic mating-type chromosomes. I will complement the currently available high-quality genome assemblies for twenty species in the genus with three outgroups, which will allow to polarize all genomic data. I will then use the genomic dataset to: 1) test hypotheses on the origin of recombination suppression in fungal mating-type chromosomes; 2) study the evolution of non-recombining regions in fungal mating-type chromosomes, e.g. their size and age, and the existence of evolutionary strata; and 3) study the patterns and mechanisms of genomic degeneration in non-recombining regions, namely non-synonymous substitution accumulation, transposable elements, disrupted genes, and non-optimal codon usage.Results will not only shed light on the origins and consequences of suppressed recombination and genome degradation in fungal mating-type chromosomes, but will also yield unprecedented insights into the dynamics of sexual reproduction in eukaryotes and contribute for a unified view of the evolution of dimorphic chromosomes. Fields of science natural sciencesbiological sciencesbiological morphologycomparative morphologynatural sciencesbiological sciencesmicrobiologymycologynatural sciencesbiological sciencesgeneticschromosomesnatural sciencesbiological sciencesgeneticsgenomes Keywords Sexual reproduction chromosome evolution mating types fungi Programme(s) H2020-EU.1.3. - EXCELLENT SCIENCE - Marie Skłodowska-Curie Actions Main Programme H2020-EU.1.3.2. - Nurturing excellence by means of cross-border and cross-sector mobility Topic(s) MSCA-IF-2015-EF - Marie Skłodowska-Curie Individual Fellowships (IF-EF) Call for proposal H2020-MSCA-IF-2015 See other projects for this call Funding Scheme MSCA-IF - Marie Skłodowska-Curie Individual Fellowships (IF) Coordinator UNIVERSITE PARIS-SACLAY Net EU contribution € 173 076,00 Address Batiment breguet - 3 rue joliot curie 91190 Gif-sur-yvette France See on map Region Ile-de-France Ile-de-France Essonne Activity type Higher or Secondary Education Establishments Links Contact the organisation Opens in new window Participation in EU R&I programmes Opens in new window HORIZON collaboration network Opens in new window Other funding € 0,00
