Histological evaluation of H&E-stained sections in the labyrinth zone of murine Cdkn2a-/- (n=5 placentas), Cdkn2a-/-;p53-/- (n=5) placentas on day E14.5, compared to WT placentas (n=6). (H) Representative images of SA-β-gal staining in the labyrinth zones of WT, Cdkn2a-/-, and Cdkn2a-/-;p53-/- placentas on day E14.5. (I) SA-β-gal activity, quantified by ImageJ sofware in Cdkn2a-/- and Cdkn2a-/-;p53-/- labyrinths, is significantly reduced relative to those in WT labyrinth (n>=7 fields of view from each genotype). Values are means + SEM. (***) p < 0.001 by a two-tailed unpaired Student's t-test. Data information: Scale bars, 50 µm. 