Résumé
THE mRNA levels of the acetylcholine receptor α-subunit gene and of four members of the MyoD1 gene family, which code for candidate transcriptional activators of the former gene, were compared in the mouse during postnatal development and after denervation in the adult. During post-natal development, mRNA levels of myogenin, MyoD1, and Myf5 decrease in parallel with α-subunit mRNA whereas MRF4 mRNA level remains nearly constant. After denervation, increases in the levels of mRNAs coding for myogenin, MyoD1 and MRF4 accompany that of α-subunit mRNA, while Myf5 mRNA level varied little. A possible role of these myogenic genes in mediating nerve influence on the state of muscle differentiation and AChR α-subunit gene expression is discussed.