Drs. Chang and Vincent contributed equally to this work.
The A17 enhancer directs expression of Myf5 to muscle satellite cells but Mrf4 to myonuclei
Article first published online: 18 OCT 2007
Copyright © 2007 Wiley-Liss, Inc.
Special Issue: Special Focus on Stem Cells
Volume 236, Issue 12, pages 3419–3426, December 2007
How to Cite
Chang, T. H.-T., Vincent, S. D., Buckingham, M. E. and Zammit, P. S. (2007), The A17 enhancer directs expression of Myf5 to muscle satellite cells but Mrf4 to myonuclei. Dev. Dyn., 236: 3419–3426. doi: 10.1002/dvdy.21356
- Issue published online: 14 NOV 2007
- Article first published online: 18 OCT 2007
- Manuscript Accepted: 29 AUG 2007
- Medical Research Council UK
- Association Française contre les Myopathies
- Muscular Dystrophy Campaign
- MYORES from the European Commission 6th Framework Programme. Grant Number: 511978
- Mrf4/Myf5 locus;
- satellite cell;
- stem cell;
- adult skeletal muscle;
- transcriptional regulation
The myogenic regulatory factors, Myf5 and Mrf4, play key roles in the specification and differentiation of skeletal muscle, respectively. Many cis-acting regulatory elements at the Mrf4/Myf5 locus have been identified, including the A17 enhancer. During development, A17 in conjunction with the Mrf4 or Myf5 promoter, directs transgene expression either to embryonic or fetal muscles. We now show that this enhancer also regulates Mrf4/Myf5 transcription in the adult. A17 linked to the Myf5 promoter drives expression in muscle satellite cells, whereas with the Mrf4 promoter, A17 directs transgene expression to myonuclei. Interestingly, expression of A17-Mrf4-nlacZ transgenes in myonuclei varies between muscles, revealing muscle autonomous transcriptional regulation. During muscle repair, satellite cells are induced to proliferate and differentiate to provide new myonuclei. A17 directs Myf5 expression in satellite cell progeny while it only drives the Mrf4 promoter after differentiation. Importantly, therefore, this promoter-specific activity directed by A17 reflects aspects of the expression profiles of the endogenous Myf5 and Mrf4 genes. Developmental Dynamics 236:3419–3426, 2007. © 2007 Wiley-Liss, Inc.