Optogenetic Signaling Activation in Zebrafish Embryos.

Signaling pathways orchestrate fundamental biological processes, including development, regeneration, homeostasis, and disease. Methods to experimentally manipulate signaling are required to understand how signaling is interpreted in these wide-ranging contexts. Molecular optogenetic tools can provide reversible, tunable manipulations of signaling pathway activity with a high degree of spatiotemporal control and have been applied in vitro, ex vivo, and in vivo.