Fig. 6

Predicted model for Ras-MAPK pathway controlling the differentiation of workers into neotenic reproductives. When cell surface receptor accepts extracellular signaling from the absence of queen pheromone, a increase in intracellular Ca²⁺ is triggered via Ca²⁺ channels. Ca²⁺ enters the cytoplasm where it binds and activates calmodulin (CaM). Ca²⁺-CaM can act on Ras in the cytoplasmic surface. Ras binds GTP. Activated Ras initiates the Raf-1, and through the MEK/ERK MAPK pathway, triggers signaling to the nucleus