Multiple convergent supergene evolution events in mating-type chromosomes

Convergent adaptation provides unique insights into the predictability of evolution and ultimately into processes of biological diversification. Supergenes (beneficial gene linkage) are striking examples of adaptation, but little is known about their prevalence or evolution. A recent study on anther-smut fungi documented supergene formation by rearrangements linking two key mating-type loci, controlling pre- and post-mating compatibility. Here further high-quality genome assemblies reveal four additional independent cases of chromosomal rearrangements leading to regions of suppressed recombination linking these mating-type loci in closely related species. Such convergent transitions in genomic architecture of mating-type determination indicate strong selection favoring linkage of mating-type loci into cosegregating supergenes. We find independent evolutionary strata (stepwise recombination suppression) in several species, with extensive rearrangements, gene losses, and transposable element accumulation. We thus show remarkable convergence in mating-type chromosome evolution, recurrent supergene formation, and repeated evolution of similar phenotypes through different genomic changes.

Descrição

the Louis D. foundation award to T.G., the NSF DEB-1115765 and NIH R15GM119092 grants to M.E.H. the Marie Curie European grant PRESTIGE-2016-4-0013 to F.H. and Campus France (PPP 57211753) to T.G. and D. B

Palavras-chave

FUNGUS MICROBOTRYUM-VIOLACEUM SEX-CHROMOSOME MAXIMUM-LIKELIHOOD SMUT FUNGI ADAPTATION PLANT ALIGNMENT INSIGHTS LINKAGE DNA General Chemistry General Biochemistry,Genetics and Molecular Biology General Physics and Astronomy