Department of Molecular and Cellular Biology, Harvard University, Cambridge, Massachusetts 02138, USA. yamaguchi@hubio2.harvard.edu
Understanding how muscles and the skeleton develop is essential to understanding how distinct form arises in different vertebrate organisms. The meristic somites give rise to the serially-repeated precursors of the axial skeleton and musculature. Recent studies of somitogenesis have shed light upon the mechanisms of segmentation in vertebrates and the relationship between segmentation and patterning. Significant advances have also been made in connecting signalling molecules that possess somite patterning activity with downstream effector genes.