Fig. 7. Distribution of Mab21l1^-/- cells in chimeric embryos. (A) Whole-mount view of an Mab21l1^+/+ chimeric embryo. (B-D) Whole-mount views of Mab21l1^-/- chimeric embryos. (A'-D') Histological sections of embryos identical to those shown in A-D, respectively. (a-d) Higher magnification views of areas within the boxes in A'-D'. In the Mab21l1^+/+ chimeric embryo, ß-galactosidase negative cells are distributed in the retina (A') and lens epithelium (a, arrowheads). No Mab21l1^-/- cells (ß-galactosidase negative cells are white) are present in the lens, whereas both wild-type (ß-galactosidase positive cells are blue) and Mab21l1^-/- cells are present in retina (B',C',b,c). (C') Despite the high contribution of Mab21l1^-/- cells in the retina, the lens is similar in size to that of the chimera in B'. A high contribution of Mab21l1^-/- cells leads to absence of the lens (D,D',d). Scale bars: 100 µm for A'-D', 50 µm for a-d.