FIG 9.

Partial rescue of Ola1-null embryos' growth defects by p21 knockout. (A) Genotypic analysis of offspring from Ola1/p21 double heterozygous intercrosses. Listed are theoretical and observed numbers of mice with different genotypes, with the frequencies shown in parentheses. (B) Body weights of p21^+/+/Ola1^+/+, p21^+/+/Ola1^−/−, p21^−/−/Ola1^+/+, and p21^−/−/Ola1^−/− embryos at E18.5. Data are presented as means ± SEMs (n ≥ 4). N.S., no statistical significance. *, P < 0.05; ***, P < 0.001 (Student's t test). (C) Photograph of a litter of E18.5 fetuses from Ola1^+/−/p21^−/− parents. All animals are p21^−/−, however, with three Ola1 genotypes as annotated. (D) Histological analysis of embryonic lung sections prepared from E17.5 fetuses (H&E staining). Scale bars: 100 μm.