FIG. 4.

p53 loss does not rescue NS deficiency; number of nuclei detected by DAPI staining of blastocysts from NS^+/− p53^−/− intercross matings. (A) Representative images of E3.5, p53-null, NS^+/+ or NS^+/− and NS^−/− mutant embryos stained with DAPI (blue) and anti-NS antibody (red). (B) Mean cell number of wild-type and heterozygous embryos combined and of homozygous NS embryos on a p53-deficient background at E3.0. Error bars denote standard errors. There is a significant difference between the mean numbers by Student's t test (P = 0.06). n, number of embryos analyzed. Magnification, ×200.