PRENATAL STUDY ON THE DEVELOPMENT OF TESTIS AND EPIDIDYMIS OF GADDI SHEEP

The present study was conducted on the testis and epididymis of 68 Gaddi sheep foetii to study gross anatomy, histogenesis, organogenesis and histochemistry in different stages of gestation. The biochemical analysis was done in the foetal fluid. The samples were divided into 4 stages: stage I (31-60 days), stage II (61-90 days), stage III (91-120 days) and stage IV (121 till term) based on their age in days obtained by the formula, Y = 2.74 x X + 30.15, where X is CRL in cm and Y is age in days. The testes were located under the mesonephric kidneys which started descending into the inguinal canal at around 83 rd day of gestation and started entering into the scrotum at around 95 th day of gestation and finally settled into the scrotum at around 140 th day of gestation. All the gross biometrical parameters increased with the increase in age of the fetus. The differentiation of cortex and medulla in the indifferent gonad was observed on 37 th day of gestation. The differentiation of tunica albuginea and seminiferous tubules containing large, small and sertoli cells was observed on 46 th day of gestation. The differentiation of tunica albuginea into tunica fibrosa and tunica vasculosa was evident on 50 th day of gestation. The connective tissue trabeculae divided the testicular parenchyma into lobules which contained developing sex cords on 60 th day of gestation. The testicular capsule and connective tissue trabeculae contained abundant reticular and collagen fibers in stage IV of gestation. The diameter of seminiferous tubules, large, small, sertoli and leydig cells increased with the progression of gestation. The epididymal duct appeared grossly as a straight elongated tubular structure adjacent to the testis on 45 th day of embryonic life. The epididymal duct was distinguishable into caput, corpus and cauda regions on 70 th day of gestation. The gubernaculums appeared as a cylindrical gelatinous mass and was visible in the scrotum on 86 th day of gestation and appeared as a regressed knob like structure on 99 th day of gestation. The gross parameters increased with increase in age of Gaddi sheep foetii. The formation of the tunica albuginea in the epididymis was observed on 65 th day of gestation and its differentiation into tunica fibrosa and tunica vasculosa was evident on 70 th day of gestation. The connective tissue septae originated from the tunica albuginea and divided the epididymis into lobules at 115 th day of gestation. Abundant reticular and collagen fibers were seen in the capsule on 137 th day of gestation. The tubular and luminal diameter increased significantly from stage II to III and thereafter decreased at stage IV of gestation. The lining epithelium of epididymal tubules was tall cuboidal type. Histochemical reactions showed presence of glycogen, sulphated mucosubstances, lipids and proteins mainly in the capsule, seminiferous tubules and interstitial tissue of the testis and in the capsule, peritubular connective tissue layer, basement membrane, lining epithelium and supra nuclear zone of the epididymis in these areas. Normal values of various macro and micro minerals, biochemicals and activity of various enzymes was analysed in foetal fluid of Gaddi sheep. (Parul Shukla) (Rajesh Rajput) Date: 19 th October, 2015 Major Adviser Date: 19 th October, 2015 Head of the Department