MBI PhD Qualifying Exam

Time: 2.30pm
Date: Thursday, 29 March 2018
Venue: MBI, level 5 meeting rooms

Supervisors: Prof Timothy Saunders

Control of cell behavior by FGFR signaling during Drosophila development

by Vaishali YADAV, Saunders Group

 During embryonic development, cells undergo changes in their behavior that are often highly localized in space and time to arrange into tissues and organs. To study such changes in the way cells behave and interact with one another, classical approaches like gene knockdown or overactivation are often insufficient since they work on larger timescales and are not typically cell-specific. In contrast to these approaches, optogenetics provides a high spatiotemporal regulation that can be used to perturb morphogenesis even at a single cell level.

There are two FGFRs known to function in Drosophila: Heartless (htl) (role in mesodermal and glial cell migration) and Breathless (btl) (role in tracheal cell migration ). We have developed an optogenetic tool (termed opto-htl) to spatiotemporally control FGFR activation in Drosophila to study how cell behavior is modulated by differential distribution of FGFR activity in space and time. Constitutive activation of opto-htl under constant light during later stages of Drosophila embryogenesis leads to 100% lethality in the embryos. Embryos expressing opto-htl fail to undergo trachea filling under constant light but behave normally when kept in the dark. This is interesting since a htl -overactivation leads to a btl -phenotype since constitutively active btl is known to disrupt tracheal cell migration. Using this tool, in the future we will explore the role of FGFR in regulating the mechanical properties of cells, such as their migration and interactions with one another. Combined, this project represents an exciting opportunity to understand how FGFR activity can shape tissues.

**Please note the examination following the seminar is closed-door**