COMPARATIVE ASPECTS OF NOTCH SIGNALING IN LOWER AND HIGHER EUKARYOTES

The Drosophila melanogaster Notch gene encodes a receptor that is part of a cell-cell signaling mechanism that is used throughout the develo pment of the fly to regulate a wide variety of cell fate decisions, in cluding some neuronal decisions. The Caenorhabditis elegans Notch-like genes lin-12 and glp-1 play roles that are similar to that of Notch, and studies of this signaling pathway in both organisms have led to mo dels of how the pathway might function. Recent developments in the stu dy of Notch signaling include the isolation of Notch homologs from a v ariety of vertebrate species. Here we compare what has been learned fr om studies of Notch-related genes in vertebrates to what is known abou t Notch signaling in invertebrates, and we discuss the implications of these data for existing models of Notch pathway signaling.