Date of this Version
Chambon, C. (2021). Investigating Interactions Between Meiotic Drive Loci and Their Suppressors In Drosophila simulans. Honors Undergraduate Thesis. University of Nebraska-Lincoln.
The fruit fly species Drosophila simulans contains a sex-ratio distorting gene family known as Dxl (Dox-like). The Dxl gene family in D. simulans is a family of four X-linked meiotic drivers (Dox, MDox, UDoxA, and UDoxB) capable of cheating meiosis by destroying Y-bearing sperm, leading to greater than 50% of progeny deriving from X-bearing sperm and the biased sex ratio. To counteract this effect, an autosomal suppressor not much yang (Nmy) suppresses the expression of the Dxl gene family members through an RNAi pathway. Suppression of Dxl genes through wild-type Nmy leads to a normal sex-ratio phenotype (1:1 male-to-female). However, in the presence of mutant loss-of-function nmy alleles, Dxl genes are expressed, leading to a sex-ratio phenotype dependent on that Dxl gene or set of genes. Different X-chromosomes in D. simulans are shown to yield different sex-ratio phenotypes due to Dxl genes. We hypothesize that Dxl genes responsible for sex-ratio phenotypes will show increased expression in the presence of nmy loss-of-function alleles. Dxl gene family mRNA can be measured to analyze which gene(s) are responsible for the sex-ratio. Testing this hypothesis will provide insight into how the Dxl genes and their suppressors evolve and act during spermatogenesis to impair Y-bearing sperm and produce biased progeny sex-ratios.