University of Pittsburgh Department of Biological Sciences Presents:
Friday Noon Seminar Series 2017-2018
Graduate Student: Sarah Smith
Rebeiz Lab
Signal to shape: how alterations to signaling pathway activity generates newly evolved morphology
The development of anatomical form is multifaceted, involving both the patterning of gene expression and the morphogenesis of tissues at the cellular level. However, our understanding of how these two processes are integrated remains unclear. Studies of rapidly evolving anatomical structures can contribute to the integration of these processes by providing examples of genetic alterations that can be connected to their naturally occurring cellular effects on morphogenesis.We examined the posterior lobe, a recently evolved appendage-like structure on the genitalia of members of the Drosophila melanogaster clade. During posterior lobe development, the ligand of the JAK/STAT pathway encoded by unpaired (upd) is expanded in the genitalia of species that develop this structure. We characterized the regulatory region upd and uncovered an enhancer that drives ancestral and novel patterns of upd expression in the genitalia. To investigate how this change contributed to the posterior lobe’s unique morphology, we characterized the process of its morphogenesis. We find that the lobe forms through elongation of cells along their apico-basal axis and have identified a gene that is highly patterned during posterior lobe development downstream of upd that may directly contribute to this elongation. This work highlights how the expansion of a signaling pathway became associated with a novel morphogenetic process.
Friday, February 16, 2018
A219B Langley Hall
12:00 PM Seminar