Fig. 3. Phenotype of Mll2^–/– embryos up to the last observable stage. Litters were taken from E6.5 to E11.5, as indicated, and stained (A-D) or not (E,F) for ß-galactosidase (E6.5-E9.5). Intensely staining embryos were homozygous and lighter staining embryos were heterozygous for the null allele. Staining seems absent from the extra-embryonic tissues (A,B).