Recombination shapes the diversification of the wtf meiotic drivers

Meiotic drivers are selfish genetic elements that distort fair segregation. The wtf genes are poison-antidote meiotic drivers that are experiencing rapid diversification in fission yeasts. However, gene duplication alone is insufficient to drive the diversification of wtf genes, given the poison encoded by a newly duplicated wtf gene can be detoxified by the antidote encoded by the original wtf gene. Here, we analyze the evolution of wtf genes across 21 strains of Schizosaccharomyces pombe. Knocking out each of 25 wtf genes in S. pombe strain 972h- separately does not attenuate the yeast growth, indicating that the wtf genes might be largely neutral to their carriers in asexual life cycle. Interestingly, wtf genes underwent recurrent and intricate recombination. As proof-of-principle, we generate a novel meiotic driver through artificial recombination between wtf drivers, and its encoded poison cannot be detoxified by the antidotes encoded by their parental wtf genes but can be detoxified by its own antidote. Therefore, we propose that recombination can generate new meiotic drivers and thus shape the diversification of the wtf drivers.