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Sperm Surface (sperm + surface)
Selected AbstractsReduced fertility of mouse epididymal sperm lacking Prss21/Tesp5 is rescued by sperm exposure to uterine microenvironmentGENES TO CELLS, Issue 10 2008Misuzu Yamashita Although the acrosome reaction and subsequent penetration of sperm through the egg zona pellucida (ZP) are essential for mammalian fertilization, the molecular mechanism is still controversial. We have previously identified serine protease Tesp5 identical to Prss21 on the mouse sperm surface as a candidate enzyme involved in sperm penetration through the ZP. Here we show that despite normal fertility of male mice lacking Prss21/Tesp5, the epididymal sperm penetrates the ZP only at a very low rate in vitro, presumably owing to the reduced ability to bind the ZP and undergo the ZP-induced acrosome reaction. The ability of Prss21-null sperm to fuse with the egg in vitro was also impaired severely. Intriguingly, the reduced fertility of Prss21-null epididymal sperm was rescued by exposure of the sperm to the uterine microenvironment and by in vitro treatment of the sperm with uterine fluids. These data suggest the physiological importance of sperm transport through the uterus. [source] A New Method for the Treatment of Sperm Samples for Ultrastructural Study Based on the Use of Animal Tissues as Biological ContainersMICROSCOPY RESEARCH AND TECHNIQUE, Issue 9 2007Concepción Junquera Abstract The study of the ultrastructure of spematozoa by means of transmission electron microscopy often presents with problems of interpretation according to the method employed, depending on whether samples are either centrifuged previously to the fixation or immersed in viscous gels. The major problems of interpretation are: changes in the location of vesicles originated during the maturation process and modifications in the adsorption of seminal plasma proteins to the sperm membrane surface. The aim of our study is to communicate an original new method for the treatment of spermatozoa for ultrastructural study. Our method is based on the use of animal tissues as biological containers, inside which the spermatic suspensions are included. We developed this method using fresh sperm samples taken from mature Rasa aragonesa rams. As biological container, we used 2.5-cm long segments of the intestine of 1-week-old chickens (Gallus gallus) (diameter around 4 mm). To avoid any influence of digestive enzymes of the mucosa on the sperm surface, we put each intestine fragment inside out by means of microdissection forceps under bifocal optical microscope and cold light. One of the edges was tied with thin suture silk. The sperm suspension was injected in the optimal experimental condition and amount. Finally, the still open edge of the intestine segment was tied with silk in the same way as the other segment edge. By using this technique, we can perform a suitable morphological study at an ultrastructural level. In addition, the functional relationship of the ultrastructural components of the target cells is correctly preserved. Microsc. Res. Tech., 2007. © 2007 Wiley-Liss, Inc. [source] Role of the sperm proteasome during fertilization and gamete interaction in the mouseMOLECULAR REPRODUCTION & DEVELOPMENT, Issue 2 2005Consuelo Pasten Abstract In this work, we have investigated the role of the sperm proteasome during in vitro fertilization (IVF) and gamete interaction in the mouse. Proteasome activity was measured in extract and intact sperm using a specific substrate. In addition, sperm were treated with specific proteasome inhibitors and evaluated during IVF, binding to the zona pellucida, and progesterone- and zona pellucida-induced acrosome reactions. In other experiments, sperm membrane proteins were obtained resuspending them in Triton X-114, shaking vigorously and let standing by 4 hr. Soluble sperm proteins were partitioned in the aqueous phase and sperm membrane proteins in the detergent phase. In both phases, proteasome activity was measured. Labeling of cell surface sperm proteins was carried out with the cell-impermeable NHS-LC biotin, extracted with Triton X-114, and mixing with avidin-agarose beads. Nonpermeabilized sperm were incubated with an anti-proteasome monoclonal antibody and evaluated by indirect immunofluorescence. The results indicate that sperm extracts as well as intact sperm had proteasome activity; the sperm proteasome was involved in IVF, specifically during sperm-zona pellucida binding and the acrosome reaction; soluble sperm membrane proteins exhibited proteasome activity; biotin experiments indicated the presence of proteasomes on the sperm surface, which was corroborated by indirect immunofluorescence experiments. All these observations indicate that the mouse sperm proteasome participates in the binding to the zona pellucida and the acrosome reaction and that there is a pool of proteasomes located on the sperm head. Mol. Reprod. Dev. 71: 209,219, 2005. © 2005 Wiley-Liss, Inc. [source] GPI-anchored aminopeptidase is involved in the acrosome reaction in sperm of the mussel mytilusedulisMOLECULAR REPRODUCTION & DEVELOPMENT, Issue 4 2004Tatsuru Togo Abstract The sperm of the mussel Mytilus had hydrolytic activities against substrates for aminopeptidase. Acrosome reaction (AR) was suppressed in the presence of aminopeptidase substrate, Phe-4-methylcoumaryl-7-amide (MCA), and an aminopeptidase inhibitor, bestatin. Treatment of sperm with phosphatidylinositol-specific phospholipase C (PI-PLC) released aminopeptidase activity from sperm and suppressed AR. These results suggest that the enzyme is located on the sperm surface via glycosylphosphatidylinositol (GPI)-anchor and is involved in the AR. Immunoblot analysis showed that tyrosine residues of 40, 59, 68, and 72 kDa proteins were phosphorylated during induction of the AR. The 40 kDa protein was also recognized by anti-c-Src antibody by immunoblotting. The tyrosine phosphorylation of these proteins was inhibited when sperm were inseminated in the presence of Phe-MCA, and by PI-PLC treatment. Treatment of sperm with tyrosine kinase activator, 9,10-dimethyl-1,2-benzanthracene, induced AR, and its inhibitor, genistein, suppressed AR. These results suggest that tyrosine phosphorylation of 40, 59, 68, and 72 kDa proteins, induced by the interaction of GPI-anchored aminopeptidase with oocyte surface, triggers AR in Mytilus sperm. Mol. Reprod. Dev. 67: 465,471, 2004. © 2004 Wiley-Liss, Inc. [source] Surface of human sperm bears three differently charged CD52 forms, two of which remain stably bound to sperm after capacitationMOLECULAR REPRODUCTION & DEVELOPMENT, Issue 1 2001C. Della Giovampaola Abstract gp20 is a sialoglycoprotein of the human sperm surface with a core peptide homologous to the leukocyte antigen CD52, a GPI-anchored glycosylated protein which is described by the monoclonal antibody CAMPATH-1. Comparative analyses, by means of CAMPATH and anti-gp20, indicated that they describe it in morphologically and functionally different ways, suggesting that the respective epitopes are different but also casting doubt on the immunological identity of the antigen. In the present study, we used immunodepletion to demonstrate that CAMPATH and anti-gp20 interact with the same antigen, but that anti-gp20 has a much higher avidity for the antigen than CAMPATH. Anion exchange fractionation analysis of the antigen revealed three differently charged gp20-CD52 forms, the least charged of which, was largely without a GPI-anchor. All three forms were associated with freshly ejaculated sperm, whereas capacitated sperm only contained the two GPI-anchored, more charged forms, which were also the ones found in the prostasome fraction of seminal plasma and in leukocytes. The two charged, GPI-anchored forms were described as homogeneous by anti-gp20, since they ran as a singlet; the third form ran as a doublet. When tested for insertion into Jurkat T cells, the medium charged form inserted the most readily and the less charged one could not be inserted at all. Mol. Reprod. Dev. 60: 89,96, 2001. © 2001 Wiley-Liss, Inc. [source] Vital Aspects of Fallopian Tube Physiology in PigsREPRODUCTION IN DOMESTIC ANIMALS, Issue 4 2002RHF Hunter Contents This essay reviews four topical aspects of Fallopian tube physiology that bear on either successful fertilization or early development of the zygote. An initial focus is on glycoprotein secretions of the duct that accumulate as a viscous mucus in the caudal isthmus. Because this is the site of the pre-ovulatory sperm reservoir, an involvement of the secretions is considered in: preventing uterine and ampullary tubal fluids from entering the functional sperm reservoir; removing residual male secretions from the sperm surface; deflecting spermatozoa towards endosalpingeal organelles and reducing flagellar beat before ovulation. The subtle prompting of flagellar movement with impending ovulation is examined in terms of potential reactivation mechanisms, with overall control attributed to increasing secretion of progesterone. The site of full capacitation and the acrosome reaction in a fertilizing spermatozoon is then debated, with strong arguments pointing to completion of these processes in the specific fluids at the ampullary-isthmic junction. Finally, the synthetic activity of cumulus cells released at ovulation as a paracrine tissue in the Fallopian tube is highlighted with reference to steroid hormones, peptides and cytokines. Not only does the suspension of granulosa-derived cells influence the process of fertilization, but also it may amplify oocyte or embryonic signals to the endosalpinx and ipsilateral ovary. [source] Identification of Evolutionary Conserved Mouse Sperm Surface Antigens by Human Antisperm Antibodies (ASA) from Infertile PatientsAMERICAN JOURNAL OF REPRODUCTIVE IMMUNOLOGY, Issue 5 2006Agnieszka Paradowska Problem The presence of antisperm antibodies (ASA) in semen may impair sperm function leading to immunological infertility. The aim of the study was to identify the evolutionary conserved antigens on mouse sperm surface that react with human ASA in order to study the mechanism of autoimmune infertility. Methods of study The binding of human ASA to mouse sperm was investigated by means of indirect immunofluorescence. 2D-electrophoresis was applied to separate the biotin-labelled mouse membrane proteins using isoelectric focusing followed by polyacrylamide gel electrophoresis. Cognate antigens of ASA from seminal plasma of infertile patients were analysed by Western blotting. Performing avidin-blots it was detected which of the proteins recognized were sperm surface proteins. The spots of interest were analysed by means of mass spectrometry. Results ASA bound most frequently (36%) to the post-acrosomal region and to the midpiece of mouse spermatozoa. About 30% of ASA recognized apo lactate dehydrogenase (LDHC4) as a cognate antigen, 30% voltage-dependent anion channel (VDAC2). ASA of 20% bound to outer dense fibre protein and 20% of samples recognized glutathione S-transferase mu5. Conclusions Human ASA bound to specific cognate antigens of mouse spermatozoa, offering the possibility to study their functional relevance in the mouse model. [source] Localization of binding sites of naturally occurring antisperm antibodies on human spermatozoa by immunofluorescenceANDROLOGIA, Issue 5 2004C. Bohring Summary. Antisperm antibodies (ASA) may affect sperm motility, acrosome reaction, sperm penetration of cervical mucus, binding to the zona pellucida, and sperm,egg fusion. We investigated the localization of ASA of infertile men or men after vasectomy bound on the sperm surface using an immunofluorescence method. Binding occurred in the acrosomal region, midpiece, and tail. Most of the ASA in both groups of patients bound to the midpiece alone or in combination with other regions of spermatozoa. Only few ASA samples showed binding to all the three sperm regions. A combination of binding to the acrosomal region and to the midpiece was never observed. In infertile patients with ASA, the binding site was compared with sperm parameters. ASA binding to the sperm head influenced the acrosome reaction. Binding of ASA on tail and/or midpiece was not associated with a significant alteration of viability and motility. Immunofluorescence appears to be a valuable tool in the diagnosis of immune infertility, in particular when impairment of the acrosome activity is suggested. [source] Mammalian fertilization: the strange case of sperm protein 56BIOESSAYS, Issue 2 2009Paul M. Wassarman During mammalian fertilization sperm bind to the egg's zona pellucida (ZP) after undergoing capacitation. Capacitated mouse sperm bind to mZP3 (one of three ZP glycoproteins), undergo the acrosome reaction, penetrate the ZP, and fuse with egg plasma membrane. Sperm protein 56 (sp56), a member of the C3/C4 superfamily of binding proteins, was identified nearly 20 years ago as a binding partner for mZP3 by photoaffinity cross-linking of acrosome-intact sperm. However, subsequent research revealed that sp56 is a component of the sperm's acrosomal matrix and, for sperm with an intact acrosome, should be unavailable for binding to mZP3. Recently, this dilemma was resolved when it was recognized that some acrosomal matrix (AM) proteins, including sp56, are released to the sperm surface during capacitation. This may explain why uncapacitated mammalian sperm are unable to bind to the unfertilized egg ZP. [source] | |||||||||||||