Practice question

Delta-Notch lateral signaling components are conserved across nematodes, flies, vertebrates. LAG-2 encodes transmembrane DSL ligand homologous to Drosophila Delta with multiple EGF repeats and DSL domain required for Notch binding, expressed in anchor cell and P2 signaling cells. Its extracellular domain binds LIN-12 and GLP-1 Notch receptors triggering metalloprotease S2 and presenilin gamma-secretase S3 cleavage, releasing NICD transcription complex with LAG-1 CSL and SEL-8 Mastermind activating hes homologs. LAG-2 patterning ensures single anchor cell and ABp induction, making canonical Delta equivalent mediating juxtacrine communication.