Investigating Sk-3-based spore killing through DNA deletion in Neurospora crassa

Meiotic drive describes a process in which selfish alleles are recovered in more than half of a progeny generation. It is a type of gene drive and it has been discovered in strains of Neurospora, a filamentous fungus, through its spore killing mechanism. One of the most studied meiotic drive elements within N. crassa is Spore killer-3 (Sk-3). Previous studies have indicated that there is a genomic region within Sk-3 that encodes resistance to spore killing and another that encodes an element that is required for spore killing. Sk-3’s resistance gene, rsk, has been identified. However, the exact region that mediates Sk-3’s spore killing mechanism is currently unknown. In a previous study, it was found that a mutation called rfk-2UV disrupts spore killing by Sk-3. To better understand the region of Chromosome III in which rfk-2UV is located (its exact location is unknown), I constructed a deletion vector to replace a DNA interval (v374) with a hygromycin resistance gene marker (hph). Transformants were crossed to produce offspring, and offspring were tested to determine if they possess the ability to kill ascospores. These findings will contribute to future efforts to determine the molecular nature of rfk-2UV and why this mutation disrupts the ability of Sk-3 to kill spores.