Spermatogenesis in goats with and without scrotum bipartition.
The objective of the present research was to quantify the seminiferous epithelium cells, spermatogenesis efficiency and characterize the ultrastrucure of Sertoli cells in goats. Eighteen goats were used and divided into three groups: Group I - goats without bipartition of the scrotum; Group II - animals with bipartition of the scrotum in up to 50% of the testicular length; Group III - goats with bipartition of the scrotum in more than 50% of the testicular length. The goat testes in Group III had a greater number of primary spermatocytes (25.37 ± 4.55 cells per cross sections), spermatids (112 ± 15.12 cells per cross sections), and Sertoli cells (9.46 ± 1.74 cells per cross sections) than the animals in Groups I and II (P<0.05). The spermatogenic mitotic, meiotic, and general efficiency were greater in animals in Group III (1.25 ± 0.28; 5.12 ± 1.63; 6.44 ± 1.96) when compared to those in Groups I and II. Sheet-like processes originated from the Sertoli cell body as simple and smooth structures which involved almost all the surface of germ cells. Slender cord-like processes originated from Sertoli cells and also from the sheet-like processes. The relative frequency of the cycle stages showed differences among the groups of goats studied, and the highest frequency was in Stage 3 (20.68% for goats in Group I, 21.15% for those in Group II, and 16.89% for the animals in Group III). In conclusion, goats with bipartition of the scrotum have a greater number of germ and Sertoli cells per cross section of seminiferous tubule, that indicated a greater sperm production when compared to the other groups, and the ultrastructure of the Sertoli cell process did not present any relationship with bipartition of the scrotum.
ltrastructure of germ cells , Sertoli cells and mitochondria during permatogenesis in mature testis of the Chinese Taihang black goats Capra hircus )
The objective of this study was to describe the ultrastructure of germ cells, Sertoli cells and mitochondria in mature testis of the Chinese Taihang black goat. The characteristics of germ cell nucleus and mitochondria changing during spermatogenesis were investigated by transmission electron microscopy (TEM). The results showed that the spermatogonium was elliptical, and its nucleus was about 4–5 m. The round mitochondria can be observed throughout the cytoplasm around the nucleus. Small patches of heterochromatin were distributed throughout the nucleus. Spermatocyte was oval-shaped with a nucleus of about 4–4.5 m in diameter. The heterochromatin began to attach to the inner surface of the nuclear membrane. Spermatid was about 4 m and oval in shape. Its nucleus was oval or round and approximately 2–3 m in diameter. The borderline between nucleus membrane and karyoplasm was distinct. During spermiogenesis, spermatid nucleus was condensed and elongated, and chromatin reached the highest condensation in the mature spermatozoon. The mid-piece was surrounded by mitochondria at the neck ′′ region. The sperm tail showed the typical “9 + 2 structure, contained axoneme and central singlet microtubules. The nuclei of the Sertoli cells were irregular shaped and showed indentations in the membrane. In the mature testes of goat bucks, abundant mitochondria were around the germ cells and Sertoli cells. The scattered mitochondria were aggregated around the base of the flagellum (axoneme) during the spermatid differentiation stage. In conclusion, the present study showed that the spermatogenic process of Taihang black goat followed the pattern of mammals with some specific.
An ultrastructural study of the Sertoli cell in the Shiba goat.
The ultrastructure of the Shiba goat Sertoli cell was observed using light and transmission electron microscopy. In the basal portion of the Sertoli cell, the nucleus was located near the basement membrane and was irregular in outline. A number of filaments with intermediate width were observed around the nucleus. A multivesicular nuclear body, composed of numerous vesicles of different sizes and ribosome-like structures, was detected within the nucleus. The majority of cell organelles was situated in this basal portion of the cytoplasm. Oval mitochondria were randomly distributed. A well-developed laminated smooth endoplasmic reticulum (sER) was frequently found within the cytoplasm of Sertoli cell. Lysosomes and large lipid droplets were also recognized. While, the outline of the basal lamina was almost straight. No nodular processes were observed in the lamina. The Golgi complex appeared only in the supranuclear region. In the middle and apical portions of the Sertoli cell, elongated mitochondria and microtubules were oriented parallel to the long axis of the cell. The laminated sER was also detected in these portions. The apical head of slightly-elongated spermatids was occasionally surrounded by the laminated sER. The head of maturing spermatids without laminated sER revealed a bleb-like shape. The microfilament bundles at the ectoplasmic specialization site were regularly arranged. Judging from the present observations, we have suggested that only the multivesicular nuclear body and the laminated sER may be the peculiar structures which are commonly found in the Sertoli cell of ruminants.