Spermatogenesis

Spermatogenesis can be studied through histological preparation of tissues (testis) or by squash technique or heat dry Giemsa technique. For histological studies, testis of Albino rat is taken out after chloroforming rat. After fixing testis is 10% formaline, its sections are cut through microtomy process. Stain sections in haematoxylin and eosin, dehydrate, clear in xylol and mount in DPX. Study various stages under the microscope. For spermatogenesis, various changes undertaking in chromosomes, slide can be made by squash technique and heat dry Giemsa technique. Study the slides under microscope for various stages as under.

Rabbit : T. S. Passing Through Testis and Spermatogenesis

Comments

• T. S. Testis shows various stages of spermatogenesis.
• Serosa is a hard cellular layer called on tunica albuginea.
• Each seminiferous tubule is covered by a thin basement membrane and lined germinal epithelium.
• Germinal epithelium has sperm mother cell which undergoes mitotic division to give rise to diploid spermatogonia.
• Each spermatogonium gives rise to two primary spermatocytes.
• Each primary spermatocyte gives rise to two secondary spermatocyte which are haploid after reduction division.
• Each secondary spermatocyte undergoes second meiotic division or mitotic division and gives rise to two spermatids.
• These spermatids again divide and give rise to four spermatozoa.
• In the first reduction division, prophase-I, leptotene, zygotene, pachytene, diplotene and diakinesis occurs followed by anaphase-I and telophase-I.
• Because of above stages this is longest stage.

Identification : Since the section has spermatids, spermatozoa and above feature, hence it is T. S. of testis of rabbit.

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Oogenesis

Oogenesis is the development of fully mature oocytes in females, where one oogonial mother cell produces four oocytes, with three degenerating and one developing into a mature ovum, which is larger and essential for the individual’s development. Oogenesis can be studied histologically using techniques such as the squash technique or heat dry Giemsa method. For histological study, an albino rat’s ovaries are dissected, fixed in 10% formalin, sectioned using microtomy, stained with hematoxylin and eosin, dehydrated, cleared, and mounted in DPX for examination under high and low magnification.

Rabbit : T. S. Passing Through Ovary and Oogenesis

Comments

T. S. through ovary shows serosa, oogonial mother cells and oogonial cells.

• Serosa is outer most layer lined by oogonial mother cells.
• Oogonial mother cells divide mitotically forming oogonial cells which develop into oocytes.
• Oogonial cells pass through growth phase and maturation phase.
• Older oocytes contains yolk platelets, DNA, RNA, E.R. (endoplasmic reticulum), ribosomes, Golgi body and cortical granules.
• Appearance of two polar bodies of maturation indicates ovum.
• In ovary other structures seen are tunica albugines stroma, blood vessels, interstitial cells, oogonic, developing follicles, germinal epithelium, oocytes, Graafian follicles, young follicles and corpus luteum.

Identification : Since the section has Graafian follicle and above features, hence it is T.S. of ovary of rabbit.