Fig. 4. Expression of construct 7 during embryogenesis. The nucleotide region from -1.1 kb to +77 bp was fused to hsp68-lacZ and used to create transgenic mice (see Fig. 2). (A) At E9.0, lacZ expression is detected in rostral somites. (B) An E9.5 embryo shows lacZ reporter expression from the most rostral somites, to some somites in the region of the hind limb. (C) At E11.5, transgene expression is evident throughout the somites and in ventral myoblasts. (D) Transverse section through somites at the level of the fore limb shows lacZ expression in the myotome. Neural tube staining is not reproducible. (E) At E16.5, expression of the transgene is seen throughout embryonic musculature, including facial, epaxial, hypaxial and limb muscle. Arrows, somites; arrowheads, ventral myoblasts; d, deltoid; m, myotome; q, quadriceps; t, trapezius.
