Expression patterns of Jagged, Delta1, Notch1, Notch2, and Notch3 genes identify ligand-receptor pairs that may function in neural development.

Notch genes encode receptors for a signaling pathway that regulates neurogenesis. The DSL (Delta/Serrate/lag-2) genes encode ligands that bind and activate Notch. In situ hybridization was used to determine the spatiotemporal expression of Notch1, Notch2, and Notch3, and the DSL ligands, Jagged and Delta 1, in an effort to identify potential ligand-receptor pairs that function during development of the rat nervous system. Here we describe both distinct and overlapping expression patterns for these genes in neural progenitors that form both the central and the peripheral nervous systems. The punctate expression patterns we detected for Jagged and Delta 1 are consistent with their role in mediating lateral inhibition, a process proposed to regulate neural determination. Furthermore, within the ventricular zone of the neural tube and retina, Jagged and Delta 1 were expressed in complementary regions, suggesting that different DSL-Notch combinations may direct the development of distinct neural subtypes.