ESTABLISHING MYOGENIC IDENTITY DURING SOMITOGENESIS

Over the past year, interest has focused on identifying signalling mol ecules - including Wnts, Sonic hedgehog, BMP-4, and noggin - that dive rt semitic mesodermal cells into the muscle lineage, either by inducti on or derepression. New mouse mutants have also provided insights into somite formation and differentiation, as well as pointing to novel di fferences between head, trunk, and limb myogenic programmes. In additi on, recent genetic, embryological, and molecular studies have shed new light on somite formation and the establishment of muscle progenitor cells.