Atypical meiosis can be adaptive in outcrossedS. pombedue towtfmeiotic drivers

Abstract

AbstractKiller meiotic drivers are genetic parasites that destroy ‘sibling’ gametes lacking the driver allele. The fitness costs of drive can lead to selection of unlinked suppressors. This suppression could involve evolutionary tradeoffs that compromise gametogenesis and contribute to infertility.Schizosaccharomyces pombe, an organism containing numerous gamete-killingwtfdrivers, offers a tractable system to test this hypothesis. Here, we demonstrate that in scenarios analogous to outcrossing,wtfdrivers generate a fitness landscape in which atypical gametes, such as aneuploids and diploids, are advantageous. In this context,wtfdrivers can decrease the fitness cost of mutations that disrupt meiotic fidelity and, in some circumstances, can even make such mutations beneficial. Moreover, we find thatS. pombeisolates vary greatly in their ability to make haploid gametes, with some isolates generating more than 25% aneuploid or diploid gametes. This work empirically demonstrates the potential for meiotic drivers to shape the evolution of gametogenesis.