The initial somitic phase of Myf5 expression requires neither Shh signaling nor Gli regulation.
Myf5, the skeletal muscle determination gene, is first expressed in the dorso-medial aspect of the somite under the control of an element we have called the early epaxial enhancer. It has subsequently been reported that this enhancer is a direct target of Shh signaling mediated by Gli transcription factors (Gustafsson et al. 2002). We here demonstrate that activation of Myf5 expression depends on neither Shh function nor an intact Gli binding site, although the Gli site is necessary for continuation of expression. We suggest that the discrepancy is due to the existence of specific interactions between the enhancer and the Myf5 promoter.
Teboul
Lydia
L
Section of Gene Function and Regulation, The Institute of Cancer Research, Chester Beatty Laboratories, London SW3 6JB, UK.
Summerbell
Dennis
D
Rigby
Peter W J
PW
D000818:Animals; D001665:Binding Sites; D004268:DNA-Binding Proteins; D053823:Hedgehog Proteins; D051379:Mice; D008822:Mice, Transgenic; D009124:Muscle Proteins / Q000235:genetics*; D051787:Myogenic Regulatory Factor 5; D015513:Oncogene Proteins / Q000378:metabolism*; D011401:Promoter Regions, Genetic; D015398:Signal Transduction; D019170:Somites / Q000378:metabolism*; D015534:Trans-Activators / Q000378:metabolism*; D014157:Transcription Factors / Q000378:metabolism*; D000071676:Zinc Finger Protein GLI1
D004268:DNA-Binding Proteins; D053823:Hedgehog Proteins; D009124:Muscle Proteins; C497418:Myf5 protein, mouse; D051787:Myogenic Regulatory Factor 5; D015513:Oncogene Proteins; D015534:Trans-Activators; D014157:Transcription Factors; D000071676:Zinc Finger Protein GLI1