Optogenetic modulation of Notch signaling during tissue morphogenesis in Drosophila

Abstract

Precise activation of signaling pathways is essential for the development of a multicellular organism. Signaling systems display a high range of complexity with quantitative differences in levels of activation often leading to altered cellular responses. A thorough quantitative analysis of these signaling modules would require the ability to modulate individual pathway components with high spatial and temporal precision. Here, I have employed optogenetics to manipulate an endogenous Notch signaling component during Drosophila embryogenesis. I have utilised an optogenetically tagged allele of the Notch ligand, Delta (Opto-Delta), which was generated in the host laboratory. I demonstrate that Opto-Delta functions as a light sensitive loss of function allele and characterise the mechanism underlying light mediated inhibition of Notch activation. Combining Opto-Delta with live transcriptional reporters of Notch activity, I further establish a system to regulate Notch signaling with sub-cellular and second scale precision, which can now be used to gain a quantitative understanding of the input-output relationship underlying Notch signaling.