Combinations ofSpokgenes create multiple meiotic drivers inPodospora

Abstract

AbstractMeiotic drive is the preferential transmission of a particular allele at a given locus during sexual reproduction. The phenomenon is observed as spore killing in a variety of fungal lineages, includingPodospora. In natural populations ofPodospora anserina, seven spore killers (Psks) have been identified through classical genetic analyses. Here we show that theSpokgene family underlie thePskspore killers. The combination of the variousSpokgenes at different chromosomal locations defines the spore killers and creates a killing hierarchy within the same population. We identify two novelSpokhomologs that are located within a complex region (theSpokblock) that reside in different chromosomal locations in given natural strains. We confirm that the individual SPOK proteins perform both the killing and resistance functions and show that these activities are dependent on distinct domains, a nuclease and a kinase domain respectively. Genomic data and phylogenetic analysis across ascomycetes suggest that theSpokgenes disperse via cross-species transfer, and evolve by duplication and diversification within several lineages.