Porcine ovarian development - days 28, 33, and 40 of gestation
Credit: Sue McCoard
Digital Credit: Sue McCoard
Publisher: USDA/ARS/U.S. Meat Animal Research Center
Rights: Image Gallery user terms
Description: Whole mounts on the left. At day 28 of gestation, gonads of female embryos appear as morphologically undifferentiated ovaries with Gata4 localization in some of the somatic cells. By day 33 of gestation ovarian cords are apparent. By day 40, Gata4 is localized in many somatic cells including follicular cells and stromal cells but not oogonia that are grouped into germ cell nests. In female conceptuses, the absence of anti-Mullerian hormone (AMH) allows Mullerian ducts to develop into Follopian tubes, uterus and upper vagina; the Wolffian ducts regress in the absence of testosterone, and the external genitalia develops into a female phenotype in the absence of dihydrotestosterone. Images at higher magnification and additional information are available in Biol. Reprod. 65:366, 2001 and J. Endocrinology 175:365, 2002.