Fig. 6. Somatic myoblast enhancer I-E is not activated in lmd mutant embryos. Early stage 13 wild-type and lmd1 mutant embryos, both of which also carry the construct I-E were double-labeled for MEF2 and ß-gal, and analyzed by confocal microscopy. (A,B) Control embryo shows MEF2 expression (A) in somatic myoblasts and cardioblasts at the dorsal margin and lacZ expression (B), directed by enhancer I-E, in somatic (fusion-competent) myoblasts. (C,D) lmd1 mutant embryo shows reduced MEF2 expression (C) in the somatic mesoderm and a complete absence of lacZ expression (D) in somatic myoblasts. Arrow denotes ectopic lacZ expression in non-mesodermal cells.
