The induction of apoptosis in ovaries and uteri ofbcl-2-deficient mice

To elucidate the essential role ofbcl-2 in female reproductive organs,bcl-2-deficient mice (bcl-2−/− mice), heterozygotes (bcl-2+/−), and wild-type (bcl-2+/+) mice were investigated. The ovaries of 4-week-oldbcl-2−/− mice contained only preantral follicles, although follicles in various developmental stages were present in the ovaries of both 7-and 12-week-oldbcl-2−/− mice. The number of apoptotic granulosa cells inbcl-2−/− mice was higher than in both thebcl-2+/− and thebcl-2+/+ mice. The uteri of thebcl-2-deficient mice were characterized by growth retardation, including a lack of bifurcation of the organ and poorly developed lamina propria and myometrium. The most interesting finding was the presence of apoptotic cells in both the glandular epithelium and the myometrium. Therefore,bcl-2 is an essential gene for the survival of ovarian granulosa cells and of both endometrial glandular cells and myometrial smooth muscle cells in the uteri.