Analyzing ERK Signal Dynamics During Zebrafish Somitogenesis.

During vertebrate development, Erk is activated and regulates multiple cellular processes such as cell growth, differentiation, migration, and adhesion in a spatiotemporal manner. Whole-mount immunohistochemistry using antibodies against diphosphorylated Erk (p-Erk; active form of Erk) is a very useful method for understanding the spatial and temporal patterns of Erk activity during embryonic development. However, the fixation step of this method stops embryo development at a certain time point, making it very difficult to observe and interpret Erk activity dynamics. In this chapter, we describe a strategy that combines immunohistochemistry and quantitative analyses of multiple fixed embryos to reconstruct Erk activity dynamics during zebrafish somitogenesis.