Intracellular calcium integrates complex signaling to control stem cell activity...

A cross section through a fly intestine depicting intestinal stem cells in green and enterocytes, functional gut cells, in red with large blue nuclei. Left: Under normal conditions, stem cells are distributed throughout the basal side of the epithelium and can be activated to regenerate enterocytes. Upon constitutive elevation of cytosolic Ca2+, intestinal stem cells become rapidly activated and can regenerate enterocytes. Right: Shown here is a condition in which Ca2+ was strongly and chronically elevated, resulting in excessive stem cell proliferation and causing tumors. Credit: Akos Gerencser, PhD, Buck Institute