Fig. 5. The transgene Myf5-IV is correctly expressed in the myotomal compartment of somites and in limb muscles. Whole-mount ß-galactosidase histochemistry and sections of transgenic mouse embryos show myotomal expression in all somites including the occipital/cervical somites at E9.5/10.0 (A-C). Somitic expression is maintained at E13.5 in the dorsal and ventral parts but not in the intermediate region of the myotomes at thoracic and lumbar levels (D,E). The transgene is also expressed normally in limb muscles (F). Few cells in neural tube (B) and dorsal root ganglia (E) exhibit ectopic expression.