Transition from non-muscle to muscle myosin light chains in chick embryo development.

In chick embryo blastoderm the electrophoretic pattern of myosin light chains changes between the 4-somite and the 19-somite stages (stages 8-13 of Hamburger and Hamilton) from that of non-muscle to muscle myosin. This transition seems to follow the differentiation of the myotomes and to be developmentally regulated.