Effects of Sulfur Dioxide on abdA Gene Expression and Larval Development in Drosophila melanogaster

Abstract

In this experiment, we tested the effects sulfur dioxide exposure had on abd-A gene expression and larval development in Drosophila melanogaster. Previous studies have shown that sulfur dioxide exposure inhibits development of gonads in adult flies and increases development time. We hypothesized that the expression of abd-A would decrease in Drosophila when exposed to sulfur dioxide during development. The abd-A gene is in the Hox gene family, which function in the development of the segments of the adult fly body. The abd-A gene is specific to the abdominal region of the fly, and is also important to the development of gonads and fat bodies. To test our hypothesis, we randomly selected three sets of mating pairs and allowed them to lay eggs in larval culture dishes. The experimental group of larvae was subjected to sulfur dioxide continuously for seven days, while the control group was not exposed to sulfur dioxide, but kept under the exact same conditions. After the exposure, fly larvae were extracted from their culture dishes, sorted by developmental stage, and counted. RNA was then extracted from the larvae after counting. Reverse-Transcription Polymerase Chain Reaction (RT-PCR) was performed to determine abd-A expression in experimental and control groups. Due to sulfur dioxide having detrimental effects on gonad and larval development, it was predicted that, in the presence of sulfur dioxide, abd-A gene expression would decrease, and developmental time course of larval development would be delayed.