Dr. Shaun Davis-Department of Entomology

Behavioral genetics is a growing field that seeks to explain how genes and neurons influence the behavior of an organism. Through a multi-disciplinary approach using genetic and neurobiological techniques, my ultimate research goal is to understand how organisms use their behavioral repertoire to enhance their survival, and to learn how these innate behaviors evolved.
 
For my graduate work, I focused on intraspecific aggressive behavior. Males of the same species will fight one another to compete over territory, food, and mates. This trait is found broadly across the animal kingdom, suggesting that it originated very early in the animal lineage and has been maintained and modified throughout evolution, but the underlying genetic factors remains unknown. We used the fruit fly, Drosophila melanogaster, as a model organism due to the numerous genetic tools to alter genes or neuronal function. I found that co-housing aggressive males lead to an accumulation of physical damage to their wings and used this phenotype to perform the first mutagenesis screen for altered aggressive behavior, in which I identified two genes that were previously not associated with aggression. 
 
In my postdoctoral position here at the University of Arizona, I am branching out into the behavioral defenses of interspecific host-parasite interactions. Flies encounters numerous threats to its survival in the wild. One common threat is that from parasitoid wasps. These small insects inject a single egg into a fly larvae which, once hatched, develops within and ultimately consumes the host. However, flies have behavioral defenses to avoid infection from these wasps, and to cure themselves once infected. While adult female flies are not directly attacked by wasps, they do reduce the number of eggs they lay in the presence of wasps, which is thought to limit their offspring to wasp exposure. I am currently investigating the visual and olfactory systems to understand mechanistically how the fly senses the presence of these wasps. The ultimate goal is to identify the neuronal circuits from sensory inputs to behavioral outputs and understand how these circuits interact to regulate egg laying behavior in a complex environment.
 
In my time at the University of Arizona, I have been encouraged to pursue interdisciplinary research questions, not just from my advisor but across the entire campus. This is exemplified when my work on the olfactory system showed that flies not only respond to the presence of parasitoid wasps but also to other Hymenoptera insects such as ants. This lead to an unanticipated collaboration with Greg Chism from the Dornhaus lab to examine the evolutionary response to olfactory signals from the threats of other insects. Furthermore, I have worked closely with Dr. Diana Ferro of the Zarnescu lab to study altered innate behaviors in a fly model of frontotemporal dementia, resulting in a Center for Insect Science seed grant to advance our work. Finally, I have been awarded the BIO5 Postdoctoral Fellowship on my work of behavioral defenses against parasitoid wasps. These opportunities will allow me to broaden the scope of my research and mentor undergraduate students in the pursuit of obtaining a faculty position at a primarily undergraduate institution or a small liberal arts college where teaching and research experiences are passed down directly from professors to students.