Sperm plasma membrane

About: Sperm plasma membrane is a research topic. Over the lifetime, 1016 publications have been published within this topic receiving 49964 citations.

Flow Cytometry Analysis Reveals That Only a Subpopulation of Mouse Sperm Undergoes Hyperpolarization During Capacitation 1 Running title: Flow cytometry analysis of sperm membrane potential.

Abstract: To gain fertilizing capacity, mammalian sperm should reside in the female tract for a period of time. The physiological changes that render the sperm able to fertilize are known as capacitation. Capacitation is associated with an increase in intracellular pH, an increase in intracellular calcium, and phosphorylation of different proteins. This process is also accompanied by the hyperpolarization of the sperm plasma membrane potential. In the present work, we used flow cytometry to analyze changes in sperm membrane potential (Em) during capacitation in individual cells. Our results indicate that a subpopulation of hyperpolarized mice sperm can be clearly distinguished by sperm flow cytometry analysis. Using sperm bearing green fluorescent protein in their acrosomes, we found that this hyperpolarized subpopulation is composed by sperm with intact acrosomes. In addition, we show that the capacitation-associated hyperpolarization is blocked by high extracellular K + , by PKA inhibitors and by SLO3 inhibitors in CD1 mice sperm, and undetectable in Slo3 knock-out mice sperm. On the other hand, in sperm incubated in conditions that do not support capacitation, sperm membrane hyperpolarization can be induced by amiloride, high extracellular NaHCO3 and cAMP agonists. Altogether, our observations are consistent with a model in which sperm Em hyperpolarization is downstream a

Glycosyl Phosphatidyl Inositol (GPI) Anchored Molecules on Mammalian Spermatozoa

Abstract: Sperm cells, like somatic cells, are surrounded by a plasma membrane that participates in early events of fertilization including capacitation, sperm-egg interaction and the acrosome reaction. Thus, an understanding of the composition and organization of sperm membrane is important to ascertain its role in the fertilization process. The sperm plasma membrane is predominantly composed of phospholipids and cholesterol. A change in the relative concentrations of these two components determines the permeability, fluidity, rigidity and functional state of the gamete. A mosaic of other molecules including proteins is scattered and embedded in this structure (1). Spermatozoa require a large number of proteins to become competent and fertilize the egg. Unfortunately, the cells have no known synthetic activity and the number of molecules that can be physically accommodated at any given time is severely restricted by their miniscule size. One strategy by which spermatozoon overcomes this limitation is to choose a type of anchorage/mechanism that economizes on the number of surface molecules.

PERANAN PROTEIN GOAT ZONA PELLUCIDA-3 (gZP3) SEBAGAI RESEPTOR FERTILISASI DAN POTENSINYA SEBAGAI KANDIDAT BAHAN IMUNOKONTRASEPSI PERANAN PROTEIN GOAT ZONA PELLUCIDA-3 (gZP3) SEBAGAI RESEPTOR FERTILISASI DAN POTENSINYA SEBAGAI KANDIDAT BAHAN IMUNOKONTRASEPSI

Abstract: Goat zona pellucida consists of three constituents: gZP1, gZP2 and gZP3, with molecular weight were 120, 94 and 82 kDa, and its composition was 6.93, 29.60 and 63.47 % respectively. Protein of gZP3 was fertilization receptor. Physiologically, ZP3 protein function as an adhesion molecule and as a secretogogue for acrosomal exocytosis. Acrosome reaction occurs upon interaction of the spermatozoon with the zona pellucida protein ZP3. This is followed by liberation of several acrosomal enzymes and other constituents that facilitate penetration of the zona and exposes molecules on the sperm equatorial segment that allows fusion of sperm membrane with the oolemma. The molecular mechanisms and the signal transduction pathways mediating the processes of acrosome reaction are appear to involve modifications of intracellular calcium and other ions, lipid transfer and phospholipid remodelling in sperm plasma membrane as well as changes in protein phosphorylation. Protein of gZP3 was effective as an immunocontraceptive substance on mice as an animal model in vivo and in vitro. Physiologically, the IgG molecules preferentially bind to the surface carbohydrate moieties, and block sperm recognition and initial binding. Additionally, there is an IgG binding to the protein backbone of the zona pellucida glycoproteins, which compounds the infertility effect by inhibiting the acrosome reaction. The aim of this study was to determine the fertilization receptor of goat and its immunocontraceptive potential. It could be concluded that gZP3 was prospective in further research to find immunocontraceptive substance for women.

Effect of different cryoprotectants on sperm plasma membrane integrity of osmanabadi and sirohi buck semen

Abstract: Semen was collected from six Osmanabadi and six Sirohi bucks weekly for six weeks by Artificial Vagina method. Semen was diluted using Tris Egg yolk Glycerol (TYG), Tris Egg yolk Ethylene Glycol (TYE) and Tris -Dimethyl sulphoxide (DMSO) dilutors (TYD) and evaluated for sperm plasma membrane integrity by HOS test at pre (50C) and post freezing (-1960C at 24 and 72 hours) stage. At pre freezing (50C) stage in Osmanabadi buck semen there was no significant difference (P>0.05) across different dilutors with respect to HOS positive sperm percentage but in Sirohi bucks significantly higher sperm plasma membrane integrity was observed in TYD and TYG than TYE dilutor. At 24 hours post freezing stage in Osmanabadi buck semen significantly higher plasma membrane integrity was noted in TYD than TYG and TYE dilutors. In Sirohi buck semen significantly higher plasma membrane integrity was noted in TYD than TYE dilutor, TYG being intermediate. At 72 hrs post freezing stage in osmanabadi bucks semen there was no significant difference (p>0.05) across different dilutors with respect to HOS positive sperm percentage. In Sirohi bucks semen significantly, higher (P<0.05) percentage of plasma membrane integrity was observed in TYD than TYE dilutors. It was concluded that in both the breeds higher plasma membrane integrity was observed in TYD dilutor which indicates that DMSO was more effective cryoprotectant than ethylene glycol and glycerol in preserving sperm membrane integrity during cryopreservation of Osmanabadi and Sirohi bucks semen.

Antioxidants Use and Sperm DNA Damage

Abstract: Infertility is a common clinical condition known to induce significant psychological stress to the couple. Conventional semen analysis is commonly used for the initial evaluation of infertile men. However, this test cannot accurately detect sperm function, therefore, it cannot differentiate infertile from fertile men. Reactive oxygen species (ROS) are known to cause lipid peroxidation of the sperm plasma membrane, which in turn could lead to sperm DNA fragmentation (SDF). This shows the positive relationship between these two distinct entities. Therefore, it is necessary to detect their presence as this will determine one of the possible explanations of male infertility. Elevated SDF has been shown to negatively correlate with semen parameters and reproductive outcomes. Indications for its testing has been well studied by a panel composed of experts in this field. Although not recommended for routine use, it is still a valid test for male infertility assessment. Many surgical and nonsurgical treatment options have been offered to reduce the level of SDF. One of these is the use of antioxidants which are readily available compounds used in the treatment of male infertility. Several studies have demonstrated improved sperm kinetics with antioxidant therapy and subsequently improved reproductive outcomes. However, additional research is needed. Despite this limitation, antioxidant use is still a reasonable option for men suffering from infertility due to elevated SDF.