Fig. 3. The mutated DPPRE is independent of the activity of the HOX complex. Expression of lab550 (A,B) is compared with the expression of lab550m300 (C,D) both in wild-type (A,C) and lab mutant embryos (B,D). Embryos were double stained for ß-gal activity driven by the enhancers (brown) and LAB protein (blue). The mutated element is strongly active in lab mutants both in ps 7 and in the gastric caeca (arrow). Note that the diagnostic LAB staining in the CNS (arrowheads) is missing in the mutants.