Fig. 1. Schematic representation of Myf5 transgenes. The –58/–48 distal enhancer of the Myf5 gene (Hadchouel et al., 2000) was divided into subfragments indicated by yellow bars and the corresponding coordinates. Each fragment was linked to a SpeI fragment containing 4.8 kb of the proximal Myf5 promoter including the branchial arch enhancer (red), the Myf5 gene body (blue) and the lacZ reporter gene (purple) fused in frame. The reporter fragment was obtained from M5-YAC-95 described previously (Zweigerdt et al., 1997). Dark and light green boxes indicate homology elements H1 and H2, respectively, which are highly conserved in sequence between mouse and human. The various constructs are referred to by roman numerals.