Fig. 2.

Low progesterone levels accompanied by ovarian and mammary gland defects in Pact ^−/− mice. (A) Reduced numbers of corpora lutea in the ovaries of Pact^−/− mice. Panels show representative sections of H&E-stained ovaries. CL, corpus luteum. (B) Defective tertiary branching and alveoli formation in mammary glands of Pact^−/− mice. Whole mammary gland mounts of Pact^+/+ and Pact^−/− are shown. (C) Serum progesterone levels in female Pact^+/+ and Pact^−/− mice, measured by RIA. Pact^+/+, n = 3; Pact^−/−, n = 3.