A histochemical study of follicular atresia in the snake ovary

Abstract By employing histochemical techniques, the follicular atresia and problems of interstitial cells have been worked out in the ovaries of two species of snakes (Naja tripudians and Bungarus coeruleus). Large follicles with a polymorphic granulosa show more atresia from September to November. Details of morphological and histochemical changes in the yolk nucleus substance, mitochondria and lipid bodies of oocyte and granulosa have been described. During atresia the theca interna is greatly hypertrophied and is loaded with lipids consisting of first phospholipids, then phospholipids and triglycetides and finally triglycerides, cholesterol and its ester and little phospholipids. Finally the oocyte, zona pellucida, granulosa cells and most of the cells of theca interna regress and disappear, leaving behind some residual cells of theca interna. The histochemistry of normal and atretic follicle of snakes and lizards has also been compared and contrasted with that in mammals. The “interstitial cells” of snake ovary have been discussed in the light of recent researches carried out on similar cells in the mammalian ovary.