White, Michelle; Koury, Spencer; Phadnis, Nitin (University of Utah)
Faculty Advisor: Phadnis, Nitin (University of Utah, School of Biological Sciences)
Sex-ratio chromosomes in Drosophila pseudoobscura are of particular interest because they violate not one, but all three of Mendel's laws of genetics. These special X chromosomes distort the ratio of X and Y-bearing sperm, which leads to biased sex-ratios within the offspring. Although such transmission ratio distortions have been observed from as early as 1928, very little is known about the systems of genes responsible for sex-ratio chromosomal drive due to several complications with traditional methods. Here, we perform one part of a three-part experimental series that attempt to dissect and identify not only the genes involved but also its mechanism. Specifically, this approach will use saturation chemical mutagenesis to knock out every gene on sex-ratio (SR) chromosomes. In order to accomplish this task as efficiently and timely as possible, several preliminary experiments were conducted. We provide the natural variability in SR chromosomal drive and the best statistical framework to analyze the actual mutagenesis experiment. Our results further provide an EMS dosage response curve for the D. pseudoobscura species which has only previously existed for D. melanogaster. These findings propose a reconsideration of the traditional methods used for studying SR chromosomal drive and suggest the mechanism behind the genes or systems of genes involved in this process.
With its rich biological history, the field of genetics has truly grown and expanded into all that we know today. With special regard to our very own Nobel Laureate, Dr. Mario Capecchi, The University of Utah has a dynamic relationship with the field of genetics. The Phadnis Lab plays an active role in this remarkable community and has answered several ideas in evolutionary conflict and speciation. Thus, as a student from the University of Utah studying genetics, it would be greatly interesting to be able to present my work at UCUR.