Expression of myogenic factor genes in vertebrate embryos

Abstract

SYNOPSIS. In situ hybridization analyses of the developmental patterns of expression of the members of the MyoD family of myogenic regulatory factors have been carried out in several vertebrate species. Differences between the temporal sequence of appearance of these gene transcripts seen in mouse embryos and those detected in avian and in Xenopus embryos suggest that these transcription factors may serve overlapping or redundant functions. Targeted inactivation of two myogenic factor genes in the mouse supports this hypothesis. These factors appear to be necessary but may not be sufficient for muscle-specific gene activation during embryogenesis. The distinct spatial and temporal patterns of gene activation and transcript accumulation of the four related factors in mouse embryos as detected by in situ hybridization are reviewed and discussed in the context of the embryological origins and developmental patterning of muscle in somites and in limb buds. These results are compared briefly with those on myogenic factor gene expression patterns in chick, quail and Xenopus embryos ©1994 by the American Society of Zoologists.