Fig. 1. Dynamic expression of desmin immunoreactivity during development of the pioneer myotome. Confocal analysis of whole somites of an embryo aged 31-somite pairs. Consecutive panels illustrate somitic levels A, 29; B, 27; C, 25; D, 23; E, 21; and F, 18. Open arrowheads indicate mesenchymal cells that delaminate from the epithelium. Growing fibers are delimited between arrow and white arrowheads. DML, dorsomedial lip; C, caudal; L, lateral; M, medial; R, rostral.