Using gene-targeting techniques, transgenic, knock-out (KO) mice, homozygous for the disrupted estrogen receptor α (αERKO) and β gene (βERKO) have been produced. Estrogen receptor (ER) β expression does not appear to be dependent on ER α expression. Progesterone receptor (PR) mRNA is detected in αERKO mice and appears to have both estrogen-independent and -dependent gene regulation. The phenotypic differences in αERKO and βERKO mice are described. Additional studies will further define the specific roles of ER α and ER β in various tissues.
2. Curtis SW, Washburn TF, Sewall C, et al. Physiological coupling of growth factor and steroid signaling pathways: Estrogen receptor knockout mice lack estrogen-like response to EGF. Proc Natl Acad Sci USA1996;93:12626-12630.
3.
3. Lubahn DB, Moyer JS, Golding TS, et al. Alteration of reproductive function but not prenatal sexual development after insertional disruption of the mouse extrogen receptor gene. Proc Natl Acad Sci USA1993;90:11162-11166.
4.
4. Brocchinfuso WP, Hively WP, Couse JF, et al. An MMTV-Wnt-1 transgene induces mammary glad hyperplasia and tumorigenesis in mice lacking estrogen receptor-α. Cancer Res1999;59:1869-1876.
5.
5. Krege JH, Hodgin JB, Couse JF, et al. Generation and characterization of reproductive phenotypes in mice lacking estrogen receptor-β. Proc Natl Acad Sci USA1998;95:15677-15682.
6.
6. Korach KS, ed. Reproductive and developmental toxicology. New York: Marchel Dekker, 1998.
