Analysis of retinoids and atRA-responsive genes in wild type and mutant mice. Retinol (A) and retinyl esters (B) were normalized per wet weight of E13.5 embryos. ***, p < 0.0003, mean ± S.D., n = 5. C, qPCR analysis of RNA isolated from WT (white bars) or KO (gray bars) E14.5 embryos. *, p < 0.05; **, p < 0.01, mean ± S.E., n = 3. Stra, stimulated by the retinoic acid gene; Rdh, retinol dehydrogenase; Raldh, retinaldehyde dehydrogenase; Cyp, cytochrome P450; Rar, retinoic acid receptor.