Porcine testicular development - day 28 of gestation, Leydig cell differentiation
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. In the upper section on the right, staining with anti-Mis (Mullerian Inhibiting Substance, also known as AMH, anti-Mullerian Hormone) identified by the brown color locates functional Sertoli cells within the developing testis. In fetal males Mis causes regression of the Mullerian ducts that would develop into the internal reproductive tract of female fetuses. In the lower section on the right, staining with anti-P450c17 (17-alpha-hydroxylase/17,20-lyase cytochrome P450) identified in brown defines the onset of functionality of developing Leydig cells within the testes. P450c17 catalyses testosterone synthesis; testosterone stimulates Wolffian ducts to develop into the efferent ductules, epididymis and vas deferens. Conversion of testosterone to dihydrotestosterone masculinizes the external genitalia. Additional information is available in J. Endocrinology 175:365, 2002.