ERK signaling dynamics in the morphogenesis and homeostasis of Drosophila.

Receptor tyrosine kinases (RTK) are transmembrane kinases that receive signals for intercellular communication to help organize body plan and sustain tissue homeostasis. These signals converge into the major signaling module of ERK, which transduces signals to the cytoplasm and nucleus. How this module responds to multiple RTK signals, and specifies unique outcomes in each cell, is still poorly understood. Recent technological advances in the quantitative imaging of ERK activity and its manipulation have yielded significant information on the cellular logic behind ERK activation and its readout in the context of Drosophila development. While in the pregastrulation stage, ERK plays a decisive on/off switch; its role changes to modulatory functions of morphogenesis and tissue quality control in the late embryonic stages.