Title: Investigating the spatiotemporal regulation of dumpy during posterior lobe development
Abstract:
The evolution of complex new structures, so-called “morphological novelties”, is a topic of intense study in the field of evolutionary developmental biology. Gene regulatory networks that control developmental expression are critical to explaining how new structures deploy genes to achieve their unique morphological features. In particular, we need examples which explain how genes that execute new and essential functions in the new tissue have derived their expression at the molecular level. Here, I use Drosophila melanogaster as a model organism to study a recently evolved novel genital structure called the posterior lobe. Previous work has found that the posterior lobe required the recruitment of apical extracellular matrix (aECM) during its developmental evolution. The protein Dumpy is present in the aECM, and disruption of dumpy causes the posterior lobe to almost disappear completely. In my project, I am investigating how dumpy gained posterior lobe-associated regulation. I have identified candidate enhancers sufficient to drive reporter expression in the cells of the posterior lobe. I will use CRISPR mediated deletions to test the necessity of this enhancer. Moreover, comparing the homologous sequences of this enhancer between lobed species and non-lobed species will reveal whether it was an ancestral enhancer or newly evolved to have posterior lobe activity. Finally, I am interested in exploring whether this enhancer is also functional in other tissues. A shared regulatory role in another tissue would indicate that this enhancer, and potentially an entire genetic network might have been redeployed from a conserved tissue to the posterior lobe, facilitating the origin of this novelty. Thus, Identifying the enhancers of dumpy and their evolutionary history provides a much needed window into how a process involving dozens if not hundreds of genes may have occurred.
Rebeiz Lab
Friday, Spetember 29th, 2023
12:00PM
Langley A219B