Fig. 2.

Signaling pathways regulating C&E cell behaviors. (A) Within regions IV and V, non-canonical Wnt/PCP signaling regulates ML cell elongation and ML-biased cell protrusions via a number of downstream modules including JNK, Ca²⁺, and RhoA. (B) Within region V, anteriorly-directed cell migration is regulated by sphingosine-1-phosphate (S1P), Wnt/PCP, and PDGF signaling that ultimately promote directed protrusions via localized Rac1 and RhoA activity. (C) Within region II, cells converge slowly by alternating phases of “tumble”—blebbing induced by loss of membrane-cortical attachment, and “run”—directed protrusion-driven migration requiring Apelin receptor signaling. Black hashes represent the actin cytoskeleton, green hashes represent non-muscle myosin.