Fig. 2. Dp1-deficient embryos die despite expressing DP2. (A) Dp1^+/+ and Dp1^-/- embryos at E10.5 are shown for comparison. Note the small size and decreased number of somites in this Dp1^-/- embryo, the most-developed of the E10.5 mutants recovered. (B) Dp1^+/- and Dp1^-/- embryos at E9.5 are shown for comparison. Again, note the small size and developmental delay (absence of turning, unfused neural folds) of the Dp1^-/- embryo. Scales bars to the right of A and B: 1 mm. (C) Western blots of manually dissected E9.5 embryo lysates are shown with an anti-DP1 monoclonal antibody (top panel), an anti-DP2 monoclonal antibody (second panel), an anti-PCNA antibody (third panel) and an anti-actin antibody (bottom panel). Lanes marked A-F are E9.5 embryos recovered from a single Dp1^+/- pregnant female. A positive control E9.5 wild-type embryo is shown in the lane marked 9.5. Genotyping of yolk sacs established the genotypes shown at the bottom of the panels. (D) A developmental timecourse is shown of DP1 and DP2 protein expression in manually dissected embryos from E8.5 to E12.5 by western blotting.