This summer I am working in the Volkan Lab. There are many exciting projects in the Volkan Lab ranging from behavioral studies to developmental biological studies using the Drosophila as a model. I will be working alongside Chengcheng Du and Shania Appadoo in the following study: How does the social experience regulate gene expression within a neuronal circuit to modulate animal behavior?
This research question has a lot of integral parts that we can briefly break down below.
Social environments modulate animal behaviors in many aspects. Even in humans, social isolation can have negative effects such as psychological distress and increased risk of disease. To investigate the relationship between social experience and animal behaviors, we will use the courtship behavior of Drosophila melanogaster (fruit fly) as a model.
Studies have shown that male flies raised in social isolation performed differently from those raised in groups in the courtship behavior assay, suggesting that the social experience can regulate fly courtship behaviors. However, the mechanism of this phenomenon is unclear. One possibility is that the difference between group-housed and single-housed males is due to the difference in odors like pheromones in different environments since the olfactory system is integral to the normal courtship behavior of flies. In Drosophila, pheromones are detected by receptors expressed in sensory neurons. The olfactory system of the Drosophila has a relatively small amount of olfactory receptor neurons (ORNs) in comparison to mice and is organized in such a way that has allowed researchers to map the complete olfactory receptor neuron connectivity. Two of these ORNs (Or47b ORNs and Or67d ORNs) have been found to be involved in regulating male fly courtship behaviors (Dweck, 2015). Therefore, we desire to study if disturbing the detection of pheromones by removing these two olfactory receptors will influence the courtship behaviors of male flies.
To evaluate the courtship vigor, we will use some parameters that can statistically describe male courtship steps. Male flies have distinct courtship steps: orientation, tapping, singing, licking, attempted copulation, and copulation. These steps allow for the recording of mating using distinct parameters: courtship index and copulation index. The courtship index measures the amount of time spent in the mentioned steps divided by the total time recording. The copulation index measures the amount of time spent in successful copulation, also divided by total time. Through a series of behavioral experiments this summer including isolating flies, group housing flies, and scoring mating behavior, we will explore the aforementioned research question and the impact of social environments on courtship behaviors.
