Sex-reversal in a pigeon (Columba livia)

Abstract

The pigeon described had a large testis and a well-developed oviduct on the left and an ovotestis on the right. The spermatic tissue was actively growing and in various stages of development, while the ovarian tissue was degenerating, indicating that the gonads were in process of sex-reversal from ovaries into testes. The sex-reversal was not the result of ovarian disease, of which there were no signs. The spermatic tubules originated from sex-cords formed from islet cells of the ovary, which were very numerous. These islet cells have been described as "interstitial" or "luteal" cells. The sex-cords were not derived by proliferation from the peritoneal epithelium. The spermatic tubules exhibited all the typical reduction prophase stages. Spermatozoa were not formed. The ovarian portions of the gonad were covered by a typical ovarian peritoneal epithelium. This was not apparent over the spermatic portions where the tunica albuginea was very thick. Tubules embedded in the tunica albuginea in one region resembled mesonephric tubules and were possibly developing efferent ducts.