Topic:Germ Cells
Germ cells in horses are the reproductive cells responsible for transmitting genetic material to the next generation. These cells differentiate into sperm in stallions and oocytes in mares. The development and function of germ cells are critical for fertility and breeding success in equine species. Research in this area focuses on understanding the processes of germ cell formation, maturation, and the factors influencing their viability and function. Studies also explore the genetic and environmental influences on germ cell health, aiming to improve reproductive efficiency and address fertility issues. This page compiles peer-reviewed research studies and scholarly articles that examine the biology, development, and clinical implications of germ cells in equine reproduction.
Expression pattern of germ cell markers in cryptorchid stallion testes. Cryptorchidism affects spermatogenesis and testis development, often resulting in stallion subfertility/infertility. This study aims to identify the specific germ cells impacted by cryptorchism in stallions. In a previous study, we found that PGP9.5 and VASA are molecular markers expressed in different germ cells within stallions. Herein, we assessed the heat stress-induced response of spermatogonial stem cells (SSCs) in the seminiferous tubules (ST) of cryptorchid stallion testes (CST) and normal stallion testes (NST). This goal was accomplished by comparing PGP9.5 and VASA expression pattern...
Effects of insulin-like growth factor-1 on the proliferation and apoptosis of stallion testicular cells under normal and heat stress culture conditions. This study investigated the effect of heat stress on stallion testicular cells (TCs) and the effect of insulin-like growth factor (IGF)-1 on TC viability, proliferation, and apoptosis, including different stages of germ cells. TCs were divided into control or treatment groups with 0.01, 0.1, 1, 10, and 100 ng/mL of recombinant human IGF-1 (rhIGF-1) for 24 h at 34 °C and 37 °C. The population and viability were measured before and after treatment. The effects of rhIGF-1 on TC viability, proliferation, and apoptosis were determined using RT-qPCR. Proliferating cell nuclear antigen (PCNA) a...
Heat stress and stallion fertility. The threat posed by increased surface temperatures worldwide has attracted the attention of researchers to the reaction of animals to heat stress. Spermatogenesis in animals such as stallions is a temperature-dependent process, ideally occurring at temperatures slightly below the core body temperature. Thus, proper thermoregulation is essential, especially because stallion spermatogenesis and the resulting spermatozoa are negatively affected by increased testicular temperature. Consequently, the failure of thermoregulation resulting in heat stress may diminish sperm quality and increase the li...
Sperm nuclear protamines: A checkpoint to control sperm chromatin quality. Protamines are nuclear proteins which are specifically expressed in haploid male germ cells. Their replacement of histones and binding to DNA is followed by chromatin hypercondensation that protects DNA from negative influences by environmental factors. Mammalian sperm contain two types of protamines: PRM1 and PRM2. While the proportion of the two protamines is highly variable between different species, abnormal ratios within a species are known to be associated with male subfertility. Therefore, it is more than likely that correct protamine expression represents a kind of chromatin checkpoint...
COMPARISON OF THE CYTOTOXIC EFFECTS OF ZEARALENON AND T-2 TOXIN ON THE HORSES AND OXEN GERM CELL IN VITRO BEFORE AND AFTER CRYOPRESERVATION. The article presents the results of the studies of cytotoxic effect of zearalenone and T-2 toxin on sperm of horses and bulls during incubation and after thawing according to the technology of sperm obtaining and cryopreservation in Kharkov. We first have shown in vitro toxic effects of different concentrations of zearalenone and T-2 toxin (from 0.5 to 0.01 mM) on the membrane stability, as well as quantitative and qualitative indicators of semen in stallions and bulls before and after freezing and thawing. It has been found that the biological activity of the native sperm in 1 h after additio...
Acrosin-binding protein (ACRBP) in the testes of stallions. Acrosin Binding Protein (ACRBP) is specifically localized in the acrosome of germ cells of several species, including mice, pigs, guinea pigs, and humans. The main objective of this study was to investigate ACRBP patterns in the germ cells of stallions at different reproductive stages and seminiferous tubule stages using Western blot, immunohistochemistry, and immunocytochemistry techniques. The stallion reproductive stages were classified as follows: pre-pubertal and post-pubertal stages based on the presence/absence of lumen opening in the seminiferous tubules and full spermatogenesis. The p...
The KIT is a putative marker for differentiating spermatogonia in stallions. Putative markers have been discovered and are used to identify and separate certain lineage of spermatogonia. The KIT is a marker for differentiating spermatogonial stem cells in several species including mice and goats. The objectives of this study were (1) to investigate reproductive stage-dependent KIT expression patterns in stallions and (2) to identify spermatogonia subpopulations expressing KIT in stallion testes. To achieve these objectives, testicular samples were obtained during routine field castration of stallions. The reproductive stage of the stallions was classified as pre-pubert...
Immunolocalization of estrogen receptor alpha, estrogen receptor beta and androgen receptor in the pre-, peri- and post-pubertal stallion testis. In various species, androgens and estrogens regulate the function of testicular Leydig, Sertoli, peritubular myoid, and germ cells by binding to their respective receptors and eliciting a cellular response. Androgen receptor (AR) is expressed in Sertoli cells, peritubular myoid cells, Leydig cells and perivascular smooth muscle cells in the testis depending on the species, but its presence in germ cells remains controversial. Two different estrogen receptors have been identified, estrogen receptor alpha (ERα) and estrogen receptor beta (ERβ), and their localization and function in testicular...
Factors affecting spermatogenesis in the stallion. Spermatogenesis is a process of division and differentiation by which spermatozoa are produced in seminiferous tubules. Seminiferous tubules are composed of somatic cells (myoid cells and Sertoli cells) and germ cells (spermatogonia, spermatocytes, and spermatids). Activities of these three germ cells divide spermatogenesis into spermatocytogenesis, meiosis, and spermiogenesis, respectively. Spermatocytogenesis involves mitotic cell division to increase the yield of spermatogenesis and to produce stem cells and primary spermatocytes. Meiosis involves duplication and exchange of genetic materia...
A quantitative study of Sertoli cell and germ cell populations as related to sexual development and aging in the stallion. Testes from 47 stallions, 1-20 yr of age, were used to examine the influence of age on Sertoli and germ cell populations as well as on functional activity of Sertoli cells. For these stallions, the number of Sertoli cells per paired testes declined linearly with age, and was only 41.7% as great at age 20 as at age 2. However, development of reproductive organs proceeded until age 12-13, as evident from increases in paired testes weight and quantitative rates of spermatozoal production. Although the absolute number of Sertoli cells declined during this period of development, individual Sertoli ...
Ultrastructural events in horse gonadal morphogenesis. The establishment and sexual differentiation of the gonads of horse embryos were studied using high-resolution techniques. The most dramatic observation is the early cytodifferentiation of the somatic cells into steroidogenic cells which takes place before sexual differentiation of the gonads. A unique morphogenetic pattern is established during this process: the seminiferous cords of the testis are completely segregated from the steroidogenic tissue by a basal lamina, while in the medulla of the ovary, steroidogenic cells differentiate inside the epithelial cords which contain germ cells. Thi...
Further studies on the cell populations of an intersex horse. An intersex horse exhibiting cell types of different sex chromosome constitution was subjected to further studies in order to determine whether the house was a mosaic or a chimera. Cultures of gonadal tissue and peripheral blood revealed mainly 64/XX and 64/XY cells, the former predominating in both tissues. The frequency of drumstick-bearing poly-morphonuclear neutrophils in the intersex horse was similar to that noted in normal mares. Blood type analysis using 17 naturally occurring agglutinins and hemolysins revealed partial agglutinations with three antibodies for the factors of the A syst...