Fig. 3.
Expression of ERα, PR, and cyclin D1 in mice receiving a single dose of E2. Mammary gland tissues were collected at different times from ovariectomized adult WT or ERβ-/- mice that had received a single dose of estradiol (20 μg/kg). In both WT and ERβ-/- mice, ERα expression was down-regulated at 4, 8, and 24 h postinjection, whereas nuclear ERα staining reappeared at 48 h. There were no significant changes in PR expression in either WT or ERβ-/- mice. An increase in the cyclin D1-positive cell population was evident after E2 treatment in both WT and ERβ-/- mice.