The Morphogenesis of the Sexually Indifferent Gonads in the Rabbit

Abstract

The present study aimed to point out the prenatal developmental stages of the indifferent gonads in rabbit. About 50 embryos and fetuses aged 11 to 18 days postcoitum were used in this study. The embryos of 9 days-old up to 13 days-old fetuses were fixed firstly within the uterus by using modified Davidson's fixative and then were transferred with the caudal halves of the fetuses aged from 14 to 18 days postconception into 10% Neutral buffered formalin for 24 to 48 hours. The specimens were prepared using routine histological work. The morphogenesis of the sexually indifferent gonad of the rabbit was studied by high-resolution light microscopy. The results showed that the gonadal ridges were detected at the 12 th day postconception as a cellular thickening covered by coelomic epithelium on either sides of the dorsal mesentery and attached to the developing pronephros. As the development progressed the gonadal ridge increased in size and cellular constituents and became housing blood vessels and germ cells. The current work concluded that the gonads of the rabbit remained indifferent and neither testis nor ovary was observed until the 17 th day postconception.