Practice question

Lateral inhibition generates fine-grained mosaic of alternate cell fates among initially equivalent cells using Delta-Notch juxtacrine feedback. A cell stochastically expressing slightly more Delta ligand activates Notch receptor in neighbors, triggering transcriptional repression of proneural genes and Delta itself, preventing neighbors from adopting same fate while reinforcing signal in the initial cell. This amplification creates checkerboard patterns exemplified by selection of single neuroblast from proneural cluster, spacing of bristles, and hair cell versus support cell choice in inner ear. Although question lists Bicoid as example, classic paradigm is Notch-Delta mediated inhibition.