(A) Expression of myogenin in 19-day-old trout embryos. Transverse section: labelling can be observed at the periphery of the myotome, and, in a scattered pattern, throughout the deep primary myotome-derived muscle mass. (B-C) Representative laser capture microdissection of peripheral (B) and deep domains (C) of the myotome of 19-day-old trout embryos. The areas in red correspond to laser-captured surfaces. SF: slow fibres. Horizontal line, 75 μm.