Gene drive by Fusarium SKC1 is dependent on its competing allele

The Fusarium verticillioides SKC1 gene driver is transmitted to offspring in a biased manner through spore killing. The mechanism that allows SKC1 to kill non-SKC1 offspring while sparing others is poorly understood. Here we report that gene drive by SKC1 is dependent on SKC1's competing allele. We propose that SKC1's competing allele influences the ability of a genome defense process to detect SKC1, and we provide evidence that this genome defense process is meiotic silencing by unpaired DNA (MSUD). Our findings suggest that the successful deployment of gene drivers to control pathogenic fungi will require researchers to consider how competing alleles influence the ability of gene drivers to be detected by genome defense processes.