نتایج جستجو برای: sperm head
تعداد نتایج: 203185 فیلتر نتایج به سال:
The differentiation of the spermatids of Bufo arenarum has been described from a study of electron micrographs of thin sections of testis. The development of the acrosome from the Golgi complex takes place in much the same manner as in mammalian spermatogenesis but no acrosome granule is formed. A perforatorium is described for the first time in this species. It is formed by a convergence of de...
Metal compounds have been associated with male reproductive toxicity in vivo. The aim of the present study was to investigate the in vitro effects of 20 metal compounds using rabbit ejaculated spermatozoa as a study model for spermiotoxicity. Five of the metals tested (arsenic, cadmium, chromium, mercury and vanadium) reduced sperm motility and curvilinear velocity. Ultrastructural analyses rev...
High-resolution two-dimensional polyacrylamide gel electrophoresis analyses have indicated that several major boar sperm plasma membrane polypeptides (PMPs) increased in concentration during maturation in the epididymis. To investigate this further, monoclonal antibodies (MAbs) to two of these PMPs/glycoproteins referenced as 4.85 and 5.0 and polyclonal antisera (PCA) raised against PMP 5.0 wer...
Motile porcine sperms adhere to hydrophilic materials such as glass and plastics. The adsorption of sperms to a hydrophobic poly(dimethylsiloxane) (PDMS) membrane is less compared with that to glass. We investigated the linear velocity (LV) and amplitude of lateral head displacement (ALHD) of motile porcine sperm on glass and PDMS preparations using computer-assisted sperm analysis (CASA). Sign...
The in vivo cytogenetic effects of 2-trans hexenal were evaluated by investigating chromosomal aberrations and sperm head abnormalities in the bone marrow cells of laboratory bred Swiss albino mice. Single intraperitoneal injections of 8, 16 or 32 μl per kg bodyweight resulted in dose-dependent decreases in the mitotic index, significantly so at the higher doses and earlier times. Chromosomal a...
Genotoxic effects of EMS have been assessed in fish, A. testudineus, using widely accepted cytogenetic protocols like chromosome aberrations, nuclear anomalies in red blood cells and abnormal sperm head morphology. In addition, gel electrophoretic protein profiles and total protein contents in nine selected tissues were analysed for evaluating their utility as potential indicators of genotoxici...
Intracytoplasmic sperm injection (ICSI) has increased the potential of the assisted reproductive technologies to propagate mammalian species and has provided an opportunity for research into cell cycle control and the mechanisms involved in sperm-induced oocyte activation. We have investigated the efficacy of ICSI in the rhesus monkey, the mechanism of fertilization following sperm injection an...
Spermatozoa emerging from the testis undergo a maturation process in the epididymis during which they change morphologically, biochemically and physiologically to gain motility and the ability to fertilize ova. We examined mouse epididymal sperm with immunostaining and transmission electron microscopy (EM) and identified a previously unknown structure on the apical hook. The structure has a coi...
background: sperm vitrification is a technique of ice and cryoprotectant free cryopreservation by direct plunging of sperm suspension into liquid nitrogen (ln2). the aim of this study was to investigate the influence of cryoprotectant free-vitrification on human sperm fine structure by msome technology and the fertility potential by zona binding assay (zba). methods: 20 normo-ejaculates were pr...
This, the last of a series of three papers, deals with the final events which lead to the incorporation of the spermatozoon with the egg. The material used consisted of moderately polyspermic eggs of Hydroides hexagonus, osmium-fixed at various times up to five minutes after insemination. The first direct contact of sperm head with egg proper is by means of the acrosomal tubules. These deeply i...
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