Fig. 2.
Validation of RARE-lacZ as a sensitive RA reporter. RARE-lacZ staining in wild-type (A,C) and Rdh10trex/trex mutant (B,D) embryos cultured for 18h in the absence of RA (control) or presence of a low physiological dose of RA (25nM). RA treatment rescues RA activity in the proximal hindlimb bud and trunk mesoderm of the mutant. This observation demonstrates that RARE-lacZ can detect low levels of RA in limb buds and shows that Rdh10 mutant hindlimbs indeed lack RA signaling. hl, hindlimb bud; lpm, lateral plate mesoderm; n, neural tube; s, somitic mesoderm.