Gene drive by Fusarium SKC1 is dependent on its competing allele

Authors: Lohmar, Jessica; RHOADES, NICHOLAS - Illinois State University; HAMMOND, THOMAS - Illinois State University; Brown, Daren

Submitted to: Fungal Genetics and Biology
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: 10/25/2022
Publication Date: 10/29/2022
Citation: Lohmar, J.M., Rhoades, N.A., Hammond, T.M., Brown, D.W. 2022. Gene drive by Fusarium SKC1 is dependent on its competing allele. Fungal Genetics and Biology. 163. Article 103749. https://doi.org/10.1016/j.fgb.2022.103749.
DOI: https://doi.org/10.1016/j.fgb.2022.103749

Interpretive Summary: Fungi that infect cereal crops can produce chemicals called mycotoxins that pose health risks to humans and domestic animals. Approaches to control these agricultural threats have had limited success. As a result, crops contamination with mycotoxins can cause hundreds of millions of dollars in losses to U.S. agricultural production in a single year. The mycotoxins known as fumonisins are produced by the fungus Fusarium verticillioides and are being detected with increasing frequency in U.S. corn. In order to develop a method to reduce fumonisin contamination in corn, ARS researchers in Peoria, Illinois, and their collaborators at Illinois State University are investigating the mechanism by which a F. verticillioides gene, called Spore Killer, prevents spores of the fungus from developing. The researchers have determined that use of Spore Killer in fumonisin control strategies is affected by a DNA defense process that protects F. verticillioides chromosomes from virus-like genetic elements known as transposons. Knowledge of how the DNA defense process affects Spore Killer should improve the effectiveness of fumonisin control strategies based on Spore Killer. Thus, the results of this research will be of use to plant breeders, plant genetic engineers, plant pathologists, and other researchers seeking to reduce mycotoxin contamination in corn and other crops.

Technical Abstract: 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.