Cell fate determination

The Drosophila eye and antenna both develop from a common tissue, the eye-antennal imaginal disc. We found that the boundary between the eye and antennal fields is set by two LIM-homeodomain transcription factors in combination with the cofactor Chip (Roignant et al., 2010). The eye itself is made up of photoreceptor neurons as well as two types of non-neuronal support cells that produce the lens and eye pigments. All these cells arise from a common pool of progenitors, raising the intriguing question of how their distinct fates are specified. The Glass transcription factor was previously thought to determine the photoreceptor identity. However, our recent work shows that it promotes the terminal differentiation not only of photoreceptors, but of all the cell types in the eye (Morrison et al., 2018). We are trying to understand how signaling pathways and other transcription factors enable Glass to activate different target genes in different contexts. In addition, we are investigating the role of its target genes in implementing the program of eye development. We would also like to know what genes EGFR signaling activates to induce different cell fates and how it interacts with Glass to produce each cell type at the appropriate time and place.