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.
Pomegranate seed in diet, affects sperm parameters of cloned goats following freezing-thawing.
Semen cryopreservation is affected by individual differences and use of cloned animal from the same source is the main tool to eliminate genetic variation. Pomegranate seed (PS) contains fatty acids and phenolic compounds which have antioxidant properties. Essential fatty acids and antioxidants are vital for production of healthy sperm by improving sperm membrane integrity and protecting sperm from oxidative stress. In this study, the effect of dietary supplementation of PS on some blood metabolites and sperm parameters following freezing-thawing of semen of cloned goats were investigated. 5-6 years cloned male goats (N = 9, 50 ± 2 kg) were randomly assigned to three different isocaloric and isonitogenous diet groups: supplemented with 0 (control), 30 and 60% (g/100 g of barley) replaced with PS for a total of 9 weeks. Sperm collection was carried out within 10-14 weeks. Semen samples were diluted whit cryo-protectant and frozen in liquid nitrogen. Sperm parameters, reactive oxygen species (ROS) as well as, ability to induce fertilization were evaluated following freezing/thawing. According to the results of our study, treatment with PS induce higher plasma cholesterol production compared to control group at 8th week. However, testosterone and MDA (malondialdehyde) level of blood plasma were not significantly affected by PS treatment. In comparison to control group, PS supplementation significantly improved total sperm motility and viability in both 30 and 60% PS groups and reduced ROS production. Cleavage rate and developmental competency to blastocyst stage were similar to fresh sperm. In conclusion, dietary supplementation with PS can improve sperm motility and viability following freezing-thawing and maintain developmental competency.
Role of FSH in the control of testicular function.
Follicle stimulating hormone (FSH) binds to the plasma membranes of Sertoli cells and, apparently, spermatogonia; the hormone may then be taken into the cytoplasm of its target cells and metabolized there. In the immature testis, binding of FSH to Sertoli cells leads to activation of adenylate cyclase, formation of cyclic AMP (cAMP), and activation of a cAMP-dependent protein kinase. There is a subsequent increase in the rates of RNA, protein, and DNA synthesis. Normal adult testis is unresponsive to FSH, one reason being the destruction of cAMP by a phosphodiesterase. After hypophysectomy of adult animals this enzyme disappears and FSH is again able to stimulate RNA and protein synthesis. Other factors contributing to the insen-sitivity of the mature testis are an FSH binding inhibitor, a protein kinase inhibitor, and in-activation of FSH.FSH increases the formation by Sertoli cells of structural proteins and an androgen-binding protein (ABP) that the Sertoli cells secrete into the extracellular fluid su...