Fig. 1. Morphology and ß-catenin expression in Apc^Min/Min embryos. (A-E) Bright-field images of wild-type and mutant embryos at 5.75 (A-C) and 4.75 (D,E) dpc embryos. (F-J) Immunohistochemistry of ß-catenin (red) with YOYO-1 nuclear staining (green) (bottom panels) in 5.75 (F,G) and 4.75 dpc embryos (H-J). Arrowheads indicate nuclei of visceral endoderm cells. Co-expression of ß-catenin and nuclear stain is apparent in the epiblast and visceral endoderm at 5.75 dpc and in the epiblast and PrE at 4.75 dpc. Nuclear ß-catenin is not obviously seen in the trophoblast lineage. Ep, epiblast; ExE, extraembryonic ectoderm; PA, proamniotic cavity; VE, visceral endoderm; PrE, primitive endoderm.