Mice were maintained at IMM or VU University Medical Centre according to national and international guidelines. Bone marrow cells were isolated from 8 week-old C57Bl/6 CD45.1 mice and injected intravenously into 2 week-old lethally irradiated CD45.2 ROSA26-RARa403Het (WT→RarHet) or WT littermate controls (WT→WT). C57Bl/6 female mice received either vitamin A deficient (VAD), with no vitamin A (vitamin free casein), vitamin A high (VAH, 25,000IU/Kg) or vitamin A control (VAC, 4,000IU/kg) diets. Retinoic acid was provided to pregnant mice from E10.5 until sacrifice. Quantitative real time RT-PCR was performed as previously described6 (link),7 (link),10 (link). Computational analysis was performed with TESS. DNA/protein complexes were immunoprecipitated using antibodies against mouse pan-RAR, pan-RXR or control IgG.