Seasonal variation in estrogen receptor ERα, but not ERβ, androgen receptor and aromatase, in the efferent ductules and epididymis of the big fruit-eating bat Artibeus lituratus

► Well defined variations in excurrent duct morphology occur during the annual reproductive cycle of Artibeus lituratus. ► Efferent ductules and epididymis diameter and epithelial height are reduced during the regressive period. ► In the reproductive period, ERα is mostly restricted to the efferent ductules. ► ERα is increased in efferent ductules and epididymis during the regressive period. ► Aromatase, AR and ERβ are expressed throughout the excurrent ducts and do not vary with reproductive status.