Evidence for sex and recombination in the choanoflagellate Salpingoeca rosetta.

ABSTRACT: Nearly all animals reproduce sexually through the production and fusion of sperm and egg cells, yet little is known about the ancestry of animal sexual reproduction. Moreover, the sexual cycle of the closest living relatives of animals, the choanoflagellates, remains completely unknown. The choanoflagellate Monosiga brevicollis possesses a "meiotic toolkit" of genes, but the lack of polymorphisms detected during genome sequencing precluded inferences about its ploidy or sexual cycle. Here, we report that a related choanoflagellate, Salpingoeca rosetta, has a sexual life cycle and transitions between haploid and diploid states. Haploid cultures of S. rosetta became diploid in response to nutrient limitation. This ploidy shift coincided with anisogamous mating, during which small flagellated

SUBMITTER: Levin TC 

PROVIDER: S-EPMC3909816 | biostudies-literature | 2013 Nov

REPOSITORIES: biostudies-literature