DOI

10.30707/1734473226.462803

Document Type

Senior Thesis

Publication Date

Spring 2024

Committee Chair

Thomas Hammond

Committee Member

Kyle Floyd

Abstract

Meiotic drivers are selfish genetic elements that skew transmission in their favor. In the filamentous fungus N. crassa, one such meiotic driver is Spore killer-3 (Sk-3). In a cross between Sk-3 and a spore killer-sensitive mating partner (Sk-S), only half of the ascospores (sexual spores) survive. Nearly all of the survivors inherit the genes for spore killing. Previous studies have established that a gene called rfk-2 (required for spore killing) is essential for the spore killing activity of Sk-3. The rfk-2 gene has been mapped to Chromosome III, but its exact location is unknown. The goal of this study is to help identify the exact location of rfk-2. Towards this goal, I investigated a DNA interval called v378. Preliminary findings suggested that this interval may be important for spore killing. To determine if v378 is required for spore killing, I constructed and used a transformation vector to replace v378 with a hygromycin resistance gene (hph+) in an N. crassa Sk-3 strain. Strains deleted of v378 were then crossed with two spore killing-sensitive tester strains. The spore sacs containing ascospores from these crosses were imaged to analyze the effects of replacement of v378 on Sk-3-based spore killing. My findings demonstrate that v378 is required for spore killing. The potential implications of my findings with respect to our understanding of meiotic drive elements, and their potential applications, is discussed.

Funding Source

This work was supported by the National Science Foundation (Award Number 200595, Elucidating the mechanism of meiotic drive by mRNA editing-mediated spore killing in Neurospora fungi).

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