Fig. 5. p53 activity but not ß-casein is abundant in irradiated early-pregnancy (P4) mammary glands. (A) Immunohistochemistry using CM5 anti-p53 (i,iii) and Ab5 anti-p21/WAF1 (ii,iv) antisera was performed on early-pregnancy (P4) BALB/c-Trp53+/+ mammary tissue before (unirradiated) or 6 hours after (irradiated) treatment with 5 Gy of whole-body 
-radiation. (Magnification 40x). (B) Northern blot analysis of duplicate total RNA samples (10 µg) from fourth inguinal mammary glands of BALB/c-Trp53+/+ mice were hybridized with a cDNA probe of ß-casein (upper panel). Lower panel shows GAPDH expression as loading control.
