Sex, success, and resisting extinction: the genetic basis and fitness effects of meiotic drive in two species of the Malaysian stalk-eyed fly.

Across the genome, each allele has a more-or-less equal chance of segregation during meiosis. However, selfish genetic elements can arise that rapidly spread by enhancing their transmission at the expense of surrounding alleles. How, and why the spread of such segregation distorters remain localised is a fundamental question. When sex-linked, such "meiotic drivers" cause a distortion of the 1:1 sex ratio, disrupting all Y-bearing gametes in male carriers and resulting in female-biased broods. Such X-linked drive genes are typically located within chromosomal inversions to prevent from being disrupted through recombination, but as such, accumulate numerous deleterious mutations. Intragenomic conflict exists between the driver gene, which reduces organismal fitness (E.g. fertility), and the rest of the genome, which evolves compensation mechanisms or suppression against it. This PhD project will investigate a well-known X-linked meiotic drive system in the stalk-eyed flies, Teleopsis dalmanni and Teleopsis whitei. This project will determine the genetic basis of meiotic drive, examine variation in drive frequency in natural populations and its impact on mating systems, and use population cage experiments to test under which ecological and demographic conditions drivers spread, potentially causing local population extinction.