Notch signaling mediates cell-cell interactions in a multitude of animal developmental and physiological processes. These interactions have been shown to be key determinants of cell fate decisions as well as important for tissue homeostasis. In C. elegans the Notch pathway has been most studied in relation to cell fate determination. Core components of the Notch pathway in C. elegans include receptors
lin-12 and
glp-1, which respond to ligands
lag-2,
apx-1,
arg-1 and
dsl-1. The LIN-12 Notch pathway directs somatic cell fate decisions during gonadogenesis, in particular, during vulval development. GLP-1 directs cell fate decisions during germline proliferation. A number of direct and indirect modulators of LIN-12 and GLP-1 have been identified, in one case, the same regulator, HECD-1, has been shown to positively modulate LIN-12 in the somatic gonad while negatively modulating GLP-1 in the germ line.