A histochemical study has been made of seasonal fluctuations in the follicular atresia and interstitial gland tissue with the ovarian cycles of the house sparrow (Passer domesticus). The atresia of primordial oocytes forms the predominant feature of the quiescent-winter ovary. The building up of interstitial gland tissue of thecal origin. which precedes the breeding activity, is closely related to the atresia of previtellogenic follicles of variable sizes. Interstitial gland cells which accumulate lipid droplets consisting of cholesterol, and/or its esters, triglycerides and some phospholipids, are the steroid secretors. The possible functional significance of different-sized follicular atresia in relation to follicular growth and breeding activity is discussed.

A morphological and histochemical study has been made of the primordial and early growing oocytes in the ovaries of crow (Corvus splendens) and common myna (Acridotheres tristis). The primordial oocytes in the myna ovary are loosely arranged in groups or nests, whereas in crow they form compact nests surrounded by highly vascularized connective tissue bands or lie in layers beneath the surface epithelium. The primordial oocytes in both the species are surrounded by flat granulosa cells whose number, shape, and cytochemical properties change with the initiation of growth. The oocyte nucleus shows a single basophilic nucleolus and thick diplotene chromosomes. With the initiation of growth, the number of nucleoli increases; simultaneously the chromosomes attain lampbrush configuration. Crescent-shaped Balbiani's vitelline body consists of ribonucleoproteins, lipoproteins, and phospholipids. The amount of these substances increases with the oocyte growth. The nature of proteins and lipids in the ooplasm and follicular epithelium also changes with the oocyte growth. Some randomly distributed protein bodies are also present in the ooplasm of primordial follicles. They disappear with the initiation of oocyte growth. The enzyme activities of acid phosphatase, NADP-diaphorase and NAD-diaphorase, also increase in the Balbiani's vitelline body with the oocyte growth. Alkaline phosphatase and delta 5-3 beta-HSDH activities are not seen. The possible functional significance of these morphological and histochemical changes has been discussed in relation to the initiation of growth in quiescent oocytes.

A histochemical study has been made of the postovulatory follicles of fowl (Gallus domesticus) during their various stages of development and degeneration. The lumen of postovulatory follicle shows granulosa cells at their initial formative stages and both thecal and stromal cells at the later regressive stages. The granulosa and thecal cells develop diffuse lipoproteins, cholesterol-positive lipids and various enzyme activities (delta5-3beta-HSDH, NAD-NADP-diaphorases and alkaline phosphatase), which are indicative of steroidogenesis.

No abstract

No abstract