Acrosome Reaction: Changes that occur to liberate the enzymes of the ACROSOME of a sperm (SPERMATOZOA). Acrosome reaction allows the sperm to penetrate the ZONA PELLUCIDA and enter the OVUM during FERTILIZATION.Spermatozoa: Mature male germ cells derived from SPERMATIDS. As spermatids move toward the lumen of the SEMINIFEROUS TUBULES, they undergo extensive structural changes including the loss of cytoplasm, condensation of CHROMATIN into the SPERM HEAD, formation of the ACROSOME cap, the SPERM MIDPIECE and the SPERM TAIL that provides motility.Sperm Capacitation: The structural and functional changes by which SPERMATOZOA become capable of oocyte FERTILIZATION. It normally requires exposing the sperm to the female genital tract for a period of time to bring about increased SPERM MOTILITY and the ACROSOME REACTION before fertilization in the FALLOPIAN TUBES can take place.Sperm-Ovum Interactions: Interactive processes between the oocyte (OVUM) and the sperm (SPERMATOZOA) including sperm adhesion, ACROSOME REACTION, sperm penetration of the ZONA PELLUCIDA, and events leading to FERTILIZATION.Zona Pellucida: A tough transparent membrane surrounding the OVUM. It is penetrated by the sperm during FERTILIZATION.Sperm Motility: Movement characteristics of SPERMATOZOA in a fresh specimen. It is measured as the percentage of sperms that are moving, and as the percentage of sperms with productive flagellar motion such as rapid, linear, and forward progression.Acrosin: A trypsin-like enzyme of spermatozoa which is not inhibited by alpha 1 antitrypsin.Sperm Head: The anterior portion of the spermatozoon (SPERMATOZOA) that contains mainly the nucleus with highly compact CHROMATIN material.Spermatids: Male germ cells derived from the haploid secondary SPERMATOCYTES. Without further division, spermatids undergo structural changes and give rise to SPERMATOZOA.Fertilization: The fusion of a spermatozoon (SPERMATOZOA) with an OVUM thus resulting in the formation of a ZYGOTE.Spermatogenesis: The process of germ cell development in the male from the primordial germ cells, through SPERMATOGONIA; SPERMATOCYTES; SPERMATIDS; to the mature haploid SPERMATOZOA.Egg Proteins: Proteins which are found in eggs (OVA) from any species.Calcimycin: An ionophorous, polyether antibiotic from Streptomyces chartreusensis. It binds and transports CALCIUM and other divalent cations across membranes and uncouples oxidative phosphorylation while inhibiting ATPase of rat liver mitochondria. The substance is used mostly as a biochemical tool to study the role of divalent cations in various biological systems.Peanut Agglutinin: Lectin purified from peanuts (ARACHIS HYPOGAEA). It binds to poorly differentiated cells and terminally differentiated cells and is used in cell separation techniques.Ionophores: Chemical agents that increase the permeability of biological or artificial lipid membranes to specific ions. Most ionophores are relatively small organic molecules that act as mobile carriers within membranes or coalesce to form ion permeable channels across membranes. Many are antibiotics, and many act as uncoupling agents by short-circuiting the proton gradient across mitochondrial membranes.Epididymis: The convoluted cordlike structure attached to the posterior of the TESTIS. Epididymis consists of the head (caput), the body (corpus), and the tail (cauda). A network of ducts leaving the testis joins into a common epididymal tubule proper which provides the transport, storage, and maturation of SPERMATOZOA.Sperm Tail: The posterior filiform portion of the spermatozoon (SPERMATOZOA) that provides sperm motility.Vitelline Membrane: The plasma membrane of the egg.Semen Preservation: The process by which semen is kept viable outside of the organism from which it was derived (i.e., kept from decay by means of a chemical agent, cooling, or a fluid substitute that mimics the natural state within the organism).Testis: The male gonad containing two functional parts: the SEMINIFEROUS TUBULES for the production and transport of male germ cells (SPERMATOGENESIS) and the interstitial compartment containing LEYDIG CELLS that produce ANDROGENS.Ovum: A mature haploid female germ cell extruded from the OVARY at OVULATION.Asterias: A genus of STARFISH in the family Asteriidae. One species, Asterias rubens, is the most common in the north-east Atlantic region.Infertility, Male: The inability of the male to effect FERTILIZATION of an OVUM after a specified period of unprotected intercourse. Male sterility is permanent infertility.Sea Urchins: Somewhat flattened, globular echinoderms, having thin, brittle shells of calcareous plates. They are useful models for studying FERTILIZATION and EMBRYO DEVELOPMENT.Fertilization in Vitro: An assisted reproductive technique that includes the direct handling and manipulation of oocytes and sperm to achieve fertilization in vitro.Chlortetracycline: A TETRACYCLINE with a 7-chloro substitution.Semen: The thick, yellowish-white, viscid fluid secretion of male reproductive organs discharged upon ejaculation. In addition to reproductive organ secretions, it contains SPERMATOZOA and their nutrient plasma.Exocytosis: Cellular release of material within membrane-limited vesicles by fusion of the vesicles with the CELL MEMBRANE.Sperm Maturation: The maturing process of SPERMATOZOA after leaving the testicular SEMINIFEROUS TUBULES. Maturation in SPERM MOTILITY and FERTILITY takes place in the EPIDIDYMIS as the sperm migrate from caput epididymis to cauda epididymis.Seminal Plasma Proteins: Proteins found in SEMEN. Major seminal plasma proteins are secretory proteins from the male sex accessory glands, such as the SEMINAL VESICLES and the PROSTATE. They include the seminal vesicle-specific antigen, an ejaculate clotting protein; and the PROSTATE-SPECIFIC ANTIGEN, a protease and an esterase.Microscopy, Electron: Microscopy using an electron beam, instead of light, to visualize the sample, thereby allowing much greater magnification. The interactions of ELECTRONS with specimens are used to provide information about the fine structure of that specimen. In TRANSMISSION ELECTRON MICROSCOPY the reactions of the electrons that are transmitted through the specimen are imaged. In SCANNING ELECTRON MICROSCOPY an electron beam falls at a non-normal angle on the specimen and the image is derived from the reactions occurring above the plane of the specimen.ShrewsSperm Midpiece: The middle piece of the spermatozoon is a highly organized segment consisting of MITOCHONDRIA, the outer dense fibers and the core microtubular structure.Sperm Agglutination: Agglutination of spermatozoa by antibodies or autoantibodies.rab3A GTP-Binding Protein: The most abundant member of the RAB3 GTP-BINDING PROTEINS. It is involved in calcium-dependent EXOCYTOSIS and is localized to neurons and neuroendocrine cells. This enzyme was formerly listed as EC 3.6.1.47.Calcium: A basic element found in nearly all organized tissues. It is a member of the alkaline earth family of metals with the atomic symbol Ca, atomic number 20, and atomic weight 40. Calcium is the most abundant mineral in the body and combines with phosphorus to form calcium phosphate in the bones and teeth. It is essential for the normal functioning of nerves and muscles and plays a role in blood coagulation (as factor IV) and in many enzymatic processes.Macropodidae: A family of herbivorous leaping MAMMALS of Australia, New Guinea, and adjacent islands. Members include kangaroos, wallabies, quokkas, and wallaroos.Calcium Ionophores: Chemical agents that increase the permeability of CELL MEMBRANES to CALCIUM ions.Benzamidines: Amidines substituted with a benzene group. Benzamidine and its derivatives are known as peptidase inhibitors.Pimozide: A diphenylbutylpiperidine that is effective as an antipsychotic agent and as an alternative to HALOPERIDOL for the suppression of vocal and motor tics in patients with Tourette syndrome. Although the precise mechanism of action is unknown, blockade of postsynaptic dopamine receptors has been postulated. (From AMA Drug Evaluations Annual, 1994, p403)Microscopy, Immunoelectron: Microscopy in which the samples are first stained immunocytochemically and then examined using an electron microscope. Immunoelectron microscopy is used extensively in diagnostic virology as part of very sensitive immunoassays.Cryopreservation: Preservation of cells, tissues, organs, or embryos by freezing. In histological preparations, cryopreservation or cryofixation is used to maintain the existing form, structure, and chemical composition of all the constituent elements of the specimens.Sperm Count: A count of SPERM in the ejaculum, expressed as number per milliliter.Semen Analysis: The quality of SEMEN, an indicator of male fertility, can be determined by semen volume, pH, sperm concentration (SPERM COUNT), total sperm number, sperm viability, sperm vigor (SPERM MOTILITY), normal sperm morphology, ACROSOME integrity, and the concentration of WHITE BLOOD CELLS.Cell Membrane: The lipid- and protein-containing, selectively permeable membrane that surrounds the cytoplasm in prokaryotic and eukaryotic cells.Antigens, CD46: A ubiquitously expressed complement receptor that binds COMPLEMENT C3B and COMPLEMENT C4B and serves as a cofactor for their inactivation. CD46 also interacts with a wide variety of pathogens and mediates immune response.Fertility: The capacity to conceive or to induce conception. It may refer to either the male or female.Bufo arenarum: A species of the true toads, Bufonidae, found in South America.Bisbenzimidazole: A benzimidazole antifilarial agent; it is fluorescent when it binds to certain nucleotides in DNA, thus providing a tool for the study of DNA replication; it also interferes with mitosis.Lysophosphatidylcholines: Derivatives of PHOSPHATIDYLCHOLINES obtained by their partial hydrolysis which removes one of the fatty acid moieties.Ejaculation: The emission of SEMEN to the exterior, resulting from the contraction of muscles surrounding the male internal urogenital ducts.Guinea Pigs: A common name used for the genus Cavia. The most common species is Cavia porcellus which is the domesticated guinea pig used for pets and biomedical research.Fallopian Tubes: A pair of highly specialized muscular canals extending from the UTERUS to its corresponding OVARY. They provide the means for OVUM collection, and the site for the final maturation of gametes and FERTILIZATION. The fallopian tube consists of an interstitium, an isthmus, an ampulla, an infundibulum, and fimbriae. Its wall consists of three histologic layers: serous, muscular, and an internal mucosal layer lined with both ciliated and secretory cells.Progesterone: The major progestational steroid that is secreted primarily by the CORPUS LUTEUM and the PLACENTA. Progesterone acts on the UTERUS, the MAMMARY GLANDS and the BRAIN. It is required in EMBRYO IMPLANTATION; PREGNANCY maintenance, and the development of mammary tissue for MILK production. Progesterone, converted from PREGNENOLONE, also serves as an intermediate in the biosynthesis of GONADAL STEROID HORMONES and adrenal CORTICOSTEROIDS.Sperm Transport: Passive or active movement of SPERMATOZOA from the testicular SEMINIFEROUS TUBULES through the male reproductive tract as well as within the female reproductive tract.Starfish: Echinoderms having bodies of usually five radially disposed arms coalescing at the center.Sus scrofa: A species of SWINE, in the family Suidae, comprising a number of subspecies including the domestic pig Sus scrofa domestica.Fluorescein-5-isothiocyanate: Fluorescent probe capable of being conjugated to tissue and proteins. It is used as a label in fluorescent antibody staining procedures as well as protein- and amino acid-binding techniques.Mesocricetus: A genus of the family Muridae having three species. The present domesticated strains were developed from individuals brought from Syria. They are widely used in biomedical research.Cricetinae: A subfamily in the family MURIDAE, comprising the hamsters. Four of the more common genera are Cricetus, CRICETULUS; MESOCRICETUS; and PHODOPUS.Fluorescent Antibody Technique, Indirect: A form of fluorescent antibody technique commonly used to detect serum antibodies and immune complexes in tissues and microorganisms in specimens from patients with infectious diseases. The technique involves formation of an antigen-antibody complex which is labeled with fluorescein-conjugated anti-immunoglobulin antibody. (From Bennington, Saunders Dictionary & Encyclopedia of Laboratory Medicine and Technology, 1984)Swine: Any of various animals that constitute the family Suidae and comprise stout-bodied, short-legged omnivorous mammals with thick skin, usually covered with coarse bristles, a rather long mobile snout, and small tail. Included are the genera Babyrousa, Phacochoerus (wart hogs), and Sus, the latter containing the domestic pig (see SUS SCROFA).Nigericin: A polyether antibiotic which affects ion transport and ATPase activity in mitochondria. It is produced by Streptomyces hygroscopicus. (From Merck Index, 11th ed)Fluorescent Antibody Technique: Test for tissue antigen using either a direct method, by conjugation of antibody with fluorescent dye (FLUORESCENT ANTIBODY TECHNIQUE, DIRECT) or an indirect method, by formation of antigen-antibody complex which is then labeled with fluorescein-conjugated anti-immunoglobulin antibody (FLUORESCENT ANTIBODY TECHNIQUE, INDIRECT). The tissue is then examined by fluorescence microscopy.Membrane Glycoproteins: Glycoproteins found on the membrane or surface of cells.Oocytes: Female germ cells derived from OOGONIA and termed OOCYTES when they enter MEIOSIS. The primary oocytes begin meiosis but are arrested at the diplotene state until OVULATION at PUBERTY to give rise to haploid secondary oocytes or ova (OVUM).Cattle: Domesticated bovine animals of the genus Bos, usually kept on a farm or ranch and used for the production of meat or dairy products or for heavy labor.Receptors, Cell Surface: Cell surface proteins that bind signalling molecules external to the cell with high affinity and convert this extracellular event into one or more intracellular signals that alter the behavior of the target cell (From Alberts, Molecular Biology of the Cell, 2nd ed, pp693-5). Cell surface receptors, unlike enzymes, do not chemically alter their ligands.Spermatocytes: Male germ cells derived from SPERMATOGONIA. The euploid primary spermatocytes undergo MEIOSIS and give rise to the haploid secondary spermatocytes which in turn give rise to SPERMATIDS.Sulfuric Acids: Inorganic and organic derivatives of sulfuric acid (H2SO4). The salts and esters of sulfuric acid are known as SULFATES and SULFURIC ACID ESTERS respectively.Hyaluronoglucosaminidase: An enzyme that catalyzes the random hydrolysis of 1,4-linkages between N-acetyl-beta-D-glucosamine and D-glucuronate residues in hyaluronate. (From Enzyme Nomenclature, 1992) There has been use as ANTINEOPLASTIC AGENTS to limit NEOPLASM METASTASIS.Cervix Mucus: A slightly alkaline secretion of the endocervical glands. The consistency and amount are dependent on the physiological hormone changes in the menstrual cycle. It contains the glycoprotein mucin, amino acids, sugar, enzymes, and electrolytes, with a water content up to 90%. The mucus is a useful protection against the ascent of bacteria and sperm into the uterus. (From Dictionary of Obstetrics and Gynecology, 1988)Mice, Inbred ICRAnnelida: A phylum of metazoan invertebrates comprising the segmented worms, and including marine annelids (POLYCHAETA), freshwater annelids, earthworms (OLIGOCHAETA), and LEECHES. Only the leeches are of medical interest. (Dorland, 27th ed)Blotting, Western: Identification of proteins or peptides that have been electrophoretically separated by blot transferring from the electrophoresis gel to strips of nitrocellulose paper, followed by labeling with antibody probes.Contraceptive Agents, Male: Chemical substances or agents with contraceptive activity in males. Use for male contraceptive agents in general or for which there is no specific heading.Periodic Acid-Schiff Reaction: A histochemical technique for staining carbohydrates. It is based on PERIODIC ACID oxidation of a substance containing adjacent hydroxyl groups. The resulting aldehydes react with Schiff reagent to form a colored product.Molecular Sequence Data: Descriptions of specific amino acid, carbohydrate, or nucleotide sequences which have appeared in the published literature and/or are deposited in and maintained by databanks such as GENBANK, European Molecular Biology Laboratory (EMBL), National Biomedical Research Foundation (NBRF), or other sequence repositories.Microscopy, Fluorescence: Microscopy of specimens stained with fluorescent dye (usually fluorescein isothiocyanate) or of naturally fluorescent materials, which emit light when exposed to ultraviolet or blue light. Immunofluorescence microscopy utilizes antibodies that are labeled with fluorescent dye.Pentoxifylline: A METHYLXANTHINE derivative that inhibits phosphodiesterase and affects blood rheology. It improves blood flow by increasing erythrocyte and leukocyte flexibility. It also inhibits platelet aggregation. Pentoxifylline modulates immunologic activity by stimulating cytokine production.Murinae: A subfamily in the family MURIDAE, comprising the Old World MICE and RATS.Glycoproteins: Conjugated protein-carbohydrate compounds including mucins, mucoid, and amyloid glycoproteins.Staining and Labeling: The marking of biological material with a dye or other reagent for the purpose of identifying and quantitating components of tissues, cells or their extracts.Fluorescent Dyes: Agents that emit light after excitation by light. The wave length of the emitted light is usually longer than that of the incident light. Fluorochromes are substances that cause fluorescence in other substances, i.e., dyes used to mark or label other compounds with fluorescent tags.Follicular Fluid: The fluid surrounding the OVUM and GRANULOSA CELLS in the Graafian follicle (OVARIAN FOLLICLE). The follicular fluid contains sex steroids, glycoprotein hormones, plasma proteins, mucopolysaccharides, and enzymes.Membrane Fusion: The adherence and merging of cell membranes, intracellular membranes, or artificial membranes to each other or to viruses, parasites, or interstitial particles through a variety of chemical and physical processes.Marsupialia: An infraclass of MAMMALS, also called Metatheria, where the young are born at an early stage of development and continue to develop in a pouch (marsupium). In contrast to Eutheria (placentals), marsupials have an incomplete PLACENTA.Plant Lectins: Protein or glycoprotein substances of plant origin that bind to sugar moieties in cell walls or membranes. Some carbohydrate-metabolizing proteins (ENZYMES) from PLANTS also bind to carbohydrates, however they are not considered lectins. Many plant lectins change the physiology of the membrane of BLOOD CELLS to cause agglutination, mitosis, or other biochemical changes. They may play a role in plant defense mechanisms.Glycoconjugates: Carbohydrates covalently linked to a nonsugar moiety (lipids or proteins). The major glycoconjugates are glycoproteins, glycopeptides, peptidoglycans, glycolipids, and lipopolysaccharides. (From Biochemical Nomenclature and Related Documents, 2d ed; From Principles of Biochemistry, 2d ed)FucoseElements: Substances that comprise all matter. Each element is made up of atoms that are identical in number of electrons and protons and in nuclear charge, but may differ in mass or number of neutrons.Hydrogen-Ion Concentration: The normality of a solution with respect to HYDROGEN ions; H+. It is related to acidity measurements in most cases by pH = log 1/2[1/(H+)], where (H+) is the hydrogen ion concentration in gram equivalents per liter of solution. (McGraw-Hill Dictionary of Scientific and Technical Terms, 6th ed)Enzyme Precursors: Physiologically inactive substances that can be converted to active enzymes.Membrane Proteins: Proteins which are found in membranes including cellular and intracellular membranes. They consist of two types, peripheral and integral proteins. They include most membrane-associated enzymes, antigenic proteins, transport proteins, and drug, hormone, and lectin receptors.Lectins: Proteins that share the common characteristic of binding to carbohydrates. Some ANTIBODIES and carbohydrate-metabolizing proteins (ENZYMES) also bind to carbohydrates, however they are not considered lectins. PLANT LECTINS are carbohydrate-binding proteins that have been primarily identified by their hemagglutinating activity (HEMAGGLUTININS). However, a variety of lectins occur in animal species where they serve diverse array of functions through specific carbohydrate recognition.Amino Acid Sequence: The order of amino acids as they occur in a polypeptide chain. This is referred to as the primary structure of proteins. It is of fundamental importance in determining PROTEIN CONFORMATION.Monensin: An antiprotozoal agent produced by Streptomyces cinnamonensis. It exerts its effect during the development of first-generation trophozoites into first-generation schizonts within the intestinal epithelial cells. It does not interfere with hosts' development of acquired immunity to the majority of coccidial species. Monensin is a sodium and proton selective ionophore and is widely used as such in biochemical studies.Microscopy, Phase-Contrast: A form of interference microscopy in which variations of the refracting index in the object are converted into variations of intensity in the image. This is achieved by the action of a phase plate.Electrophoresis, Polyacrylamide Gel: Electrophoresis in which a polyacrylamide gel is used as the diffusion medium.Seminiferous Epithelium: The epithelium lining the seminiferous tubules composed of primary male germ cells (SPERMATOGONIA) and supporting SERTOLI CELLS. As SPERMATOGENESIS proceeds, the developing germ cells migrate toward the lumen. The adluminal compartment, the inner two thirds of the tubules, contains SPERMATOCYTES and the more advanced germ cells.

Spatiotemporal characterization of intracellular Ca2+ rise during the acrosome reaction of mammalian spermatozoa induced by zona pellucida. (1/936)

The mammalian sperm acrosome reaction (AR) is an essential event prior to sperm-egg fusion at fertilization, and it is primarily dependent on an increase in intracellular Ca2+ concentration ([Ca2+]i). Spatiotemporal aspects of the [Ca2+]i increase during the AR induced by solubilized zona pellucida (ZP) in hamster spermatozoa were precisely investigated with a Ca2+ imaging technique using confocal laser scanning microscopy with two fluorescent Ca2+ indicators. A rapid rise in [Ca2+]i occurred immediately after the application of ZP solution through a micropipette. The rise was always initiated in the sperm head, even when the application was directed toward the tail. The elevated [Ca2+]i was little attenuated during measurement for 30-40 s. Acrosomal exocytosis was detected as a sudden decrease of fluorescence in the acrosomal vesicle approximately 20 s after the onset of the [Ca2+]i rise. High-resolution imaging revealed that the [Ca2+]i rise in the sperm head began at the region around the equatorial segment and spread over the posterior region of the head within 0.6 s, whereas Ca2+ concentration in the acrosomal vesicle appeared to be unaltered. The [Ca2+]i rise was completely abolished under Ca2+-free extracellular conditions, indicating that it is totally attributable to Ca2+ influx. Nifedipine, an inhibitor of L-type Ca2+ channels, did not affect the rising phase of the ZP-induced Ca2+ response, but accelerated the decline of the [Ca2+]i rise and inhibited acrosomal exocytosis. The present study provides implicative information about the spatial organization of functional molecules involved in the signal transduction in mammalian AR.  (+info)

Flow cytometric method to isolate round spermatids from mouse testis. (2/936)

The purpose of this study was to isolate pure populations of round spermatids from mouse testis by flow cytometry followed by cell sorting. Cell suspensions from mouse testis were enriched in germ cells by centrifugation on a discontinuous Percoll gradient, then analysed using a FACScalibur flow cytometer measuring the cell size and density. A large and well-delimited population of cells (R1) expected to contain round spermatids was observed on the dot plot diagram. Sorted R1 cells were very homogeneous in size (approximately 11 microns) and displayed the characteristic cytological aspect of round spermatids. Spermatid-specific gene expression was confirmed by reverse transcriptase-polymerase chain reaction (RT-PCR) analysis of R1 cells using primers for protamine 2 gene (PRM2) and SP-10. A positive signal for SP-10 was obtained with a single cell using nested primers. The 5.5 kb transcript of c-kit, which is not expressed in spermatids, was not detected by nested RT-PCR, excluding a contamination with spermatogonia. Our results clearly established that flow cytometry followed by cell sorting allows the isolation of a highly homogeneous population of round spermatids from the testis.  (+info)

Immunolocalization of CRES (Cystatin-related epididymal spermatogenic) protein in the acrosomes of mouse spermatozoa. (3/936)

The CRES (cystatin-related epididymal spermatogenic) protein is a member of the cystatin superfamily of cysteine protease inhibitors and exhibits highly restricted expression in the reproductive tract. We have previously shown that CRES protein is present in elongating spermatids in the testis and is synthesized and secreted by the proximal caput epididymal epithelium. The presence of CRES protein in developing germ cells and in the luminal fluid surrounding maturing spermatozoa prompted us to examine whether CRES protein is associated with spermatozoa. In the studies presented, indirect immunofluorescence, immunogold electron microscopy, and Western blot analysis demonstrated that CRES protein is localized in sperm acrosomes and is released during the acrosome reaction. Interestingly, while the 19- and 14-kDa CRES proteins were present in testicular and proximal caput epididymal spermatozoa, the 14-kDa CRES protein was the predominant form present in mid-caput to cauda epididymal spermatozoa. Furthermore, following the ionophore-induced acrosome reaction, CRES protein localization was similar to that of proacrosin/acrosin in that it was detected in the soluble fraction as well as associated with the acrosome-reacted spermatozoa. The presence of CRES protein in the sperm acrosome, a site of high hydrolytic and proteolytic activity, suggests that CRES may play a role in the regulation of intraacrosomal protein processing or may be involved in fertilization.  (+info)

Actin filament-membrane attachment: are membrane particles involved? (4/936)

The association of actin filaments with membranes is an important feature in the motility of nonmuscle cells. We investigated the role of membrane particles in the attachment of actin filaments to membranes in those systems in which the attachment site can be identified. Freeze fractures through the end-on attachment site of the acrosomal filament bundles in Mytilus (mussel) and Limulus (horseshoe crab) sperm and the attachment site of the microvillar filament bundles in the brush border of intestinal epithelial cells were examined. There are no particles on the P face of the membrane at these sites in the sperm systems and generally none at these sites in microvilli. In microvilli, the actin filaments are also attached along their lengths to the membrane by bridges. When the isolated brush border is incubated in high concentrations of Mg++ (15 mM), the actin filaments form paracrystals and, as a result, the bridges are in register (330 A period). Under these conditions, alignment of the particles on the P face of the membrane into circumferential bands also occurs. However, these bands are generally separated by 800-900 A, indicating that all the bridges cannot be directly attached to membrane particles. Thus membrane particles are not directly involved in the attachment of actin filaments to membranes.  (+info)

Acrosome formation during sperm transit through the epididymis in two marsupials, the tammar wallaby (Macropus eugenii) and the brushtail possum (Trichosurus vulpecula). (5/936)

In certain Australian marsupials including the tammar wallaby (Macropus eugenii) and the brushtail possum (Trichosurus vulpecula), formation of the acrosome is not completed in the testis but during a complex differentiation process as spermatozoa pass through the epididymis. Using transmission and scanning electron microscopy this paper defined the process of acrosome formation in the epididymis, providing temporal and spatial information on the striking reorganisation of the acrosomal membranes and matrix and of the overlying sperm surface involved. On leaving the testis wallaby and possum spermatozoa had elongated 'scoop'-shaped acrosomes projecting from the dorsal surface of the head. During passage down the epididymis, this structure condensed into the compact button-like organelle found on ejaculated spermatozoa. This condensation was achieved by a complex process of infolding and fusion of the lateral projections of the 'scoop'. In the head of the epididymis the rims of the lateral scoop projections became shorter and thickened and folded inwards, to eventually meet midway along the longitudinal axis of the acrosome. As spermatozoa passed through the body of the epididymis the lateral projections fused together. Evidence of this fusion of the immature outer acrosomal membrane is the presence of vesicles within the acrosomal matrix which persist even in ejaculated spermatozoa. When spermatozoa have reached the tail of the epididymis the acrosome condenses into its mature form, as a small button-like structure contained within the depression on the anterior end of the nucleus. During the infolding process, the membranes associated with the immature acrosome are either engulfed into the acrosomal matrix (outer acrosomal membrane), or eliminated from the sperm head as tubular membrane elements (cytoplasmic membrane). Thus the surface and organelles of the testicular sperm head are transient structures in those marsupials with posttesticular acrosome formation and this must be taken into consideration in attempts to dissect the cell and molecular biology of fertilisation.  (+info)

Real-time observation of acrosomal dispersal from mouse sperm using GFP as a marker protein. (6/936)

We produced transgenic mouse lines that accumulate mutated green fluorescent protein (EGFP) in sperm acrosome, a membrane limited organelle overlying the nucleus. The sperm showed normal fertilizing ability and the integrity of their acrosome was easily examined in a non-invasive manner by tracing the GFP in individual 'live' sperm with fluorescent microscopy. The time required for the dispersal of acrosomal contents was demonstrated to be approximately 3 s after the onset of acrosome reaction.  (+info)

Scanning electron-microscopical and other observations of sperm fertilization reactions in Limulus polyphemus L. (Merostomata: Xiphosura). (7/936)

Sperm fertilization reactions of Limulus polyphemus were examined by scanning electron and/or light microscopy. The following were considered: sperm motility, attachment of sperm to egg, acrosome reaction, and penetration of the acrosomal filament. The spermatozoa after semination are non-motile and become active only in close proximity to a defined region surrounding the egg. Egg materials diffusing into this region induce sperm motility and stimulate large numbers of spermatozoa to move towards the egg surface. Each sperm initially attaches by the apical tip and undergoes the acrosome reaction which causes a more permanent secondary attachment by the adhesion of acrosomal contents to the egg surface. The acrosome reaction also initiates the penetration of the acrosomal filament through the egg envelope, an event occurring in 70-80% of the attached spermatozoa (about 10(6). Shortly after this penetration, a secondary reaction occurs which involves a spiralling of the flagellum and an incorporation into the sperm body of the flagellar fibrous components, which then become closely apposed to the sperm nucleus. These sperm fertilization reactions were performed or initiated with 0-34 M CaCl2 in whole eggs, egg sections, excised egg envelopes and/or the outer basement lamina of the egg envelope. The Limulus fertilization system is very valuable since sperm reactions can be examined biochemically, which may lead to a better understanding of the chemical mechanisms involved in sperm-egg interactions in all animal species.  (+info)

Identification of Rab3A GTPase as an acrosome-associated small GTP-binding protein in rat sperm. (8/936)

The acrosome reaction is a membrane fusion event that is prerequisite for sperm penetration through the zona pellucida. To elucidate the molecular mechanisms involved in membrane fusion, the expression and localization of Rab proteins, a subfamily of small GTPases that have been shown to play key roles in regulation of intracellular membrane traffic and exocytosis, were examined in rat testis and sperm. Reverse transcription polymerase chain reaction, immunoblot analysis, and immunofluorescence microscopy revealed that Rab3A protein, which is thought to be involved in regulation of exocytosis in neurons and endocrine cells, is associated with the sperm acrosome. The protein was undetectable in acrosome-free heads prepared by sucrose density gradient centrifugation. Immunogold electron microscopy performed on ultrathin cryosections provided further evidence that Rab3A protein is associated with the acrosomal membrane. Acrosome reaction assays revealed that synthetic peptide of the Rab3 effector domain inhibited acrosomal exocytosis triggered by calcium ionophore A23187 in a concentration-dependent fashion, suggesting that Rab3A acts as an inhibitory regulator in the acrosome reaction. In view of the putative role of Rab3A protein in membrane fusion systems, these results suggest that Rab3A could be involved in regulating the mammalian acrosome reaction by controlling the membrane fusion system in sperm.  (+info)

TY - JOUR. T1 - Characterization of a novel role for the dynamin mechanoenzymes in the regulation of human sperm acrosomal exocytosis. AU - Zhou, Wei. AU - Anderson, Amanda L.. AU - Turner, Adrian P.. AU - De Iuliis, Geoffry N.. AU - McCluskey, Adam. AU - McLaughlin, Eileen A.. AU - Nixon, Brett. PY - 2017/10/1. Y1 - 2017/10/1. N2 - STUDY QUESTION: Does dynamin regulate human sperm acrosomal exocytosis? SUMMARY ANSWER: Our studies of dynamin localization and function have implicated this family of mechanoenzymes in the regulation of progesterone-induced acrosomal exocytosis in human spermatozoa. WHAT IS KNOWN ALREADY: Completion of an acrosome reaction is a prerequisite for successful fertilization in all studied mammalian species. It follows that failure to complete this unique exocytotic event represents a common aetiology in the defective spermatozoa of male infertility patients that have failed IVF in a clinical setting. Recent studies have implicated the dynamin family of mechanoenzymes as ...
A specific hypoglycosylated isoform of the complement regulator membrane cofactor protein (MCP; CD46) is expressed on the inner acrosomal membrane (IAM) of spermatozoa. This membrane is exposed after the acrosome reaction, an exocytosis event that occurs upon contact with the zona pellucida. We initiated this investigation to assess MCPs regulatory function in situ on spermatozoa. Upon exposure of human spermatozoa to autologous serum or follicular fluid, we unexpectedly observed that acrosome-reacted spermatozoa activated the complement cascade efficiently through C3 but not beyond. Using FACS to simultaneously evaluate viability, acrosomal status, and complement deposition, we found that complement activation was initiated by C-reactive protein (CRP) and was C1q, C2, and factor B dependent. This pattern is consistent with engagement of the classical pathway followed by amplification through the alternative pathway. C3b deposition was targeted to the IAM, where it was cleaved to C3bi. Factor ...
A specific hypoglycosylated isoform of the complement regulator membrane cofactor protein (MCP; CD46) is expressed on the inner acrosomal membrane (IAM) of spermatozoa. This membrane is exposed after the acrosome reaction, an exocytosis event that occurs upon contact with the zona pellucida. We initiated this investigation to assess MCPs regulatory function in situ on spermatozoa. Upon exposure of human spermatozoa to autologous serum or follicular fluid, we unexpectedly observed that acrosome-reacted spermatozoa activated the complement cascade efficiently through C3 but not beyond. Using FACS to simultaneously evaluate viability, acrosomal status, and complement deposition, we found that complement activation was initiated by C-reactive protein (CRP) and was C1q, C2, and factor B dependent. This pattern is consistent with engagement of the classical pathway followed by amplification through the alternative pathway. C3b deposition was targeted to the IAM, where it was cleaved to C3bi. Factor ...
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Spermatozoa of the trigonioid bivalveNeotrigonia margaritacea (Lamarck) (Trigoniidae, Trigonioida) are examined ultrastructurally. A cluster of discoidal, proacrosomal vesicles (between 9 to 15 in number) constitutes the acrosomal complex at the nuclear apex. The nucleus is short (2.4-2.6 μm long, maximum diameter 2.2 μm), blunt-conical in shape, and exhibits irregular lacunae within its contents. Five or sometimes four round mitochondria are impressed into shallow depressions in the base of the nucleus as is a discrete centriolar fossa. The mitochondria surround two orthogonally arranged centrioles to form, collectively, the midpiece region. The distal centriole, anchored by nine satellite fibres to the plasma membrane, acts as a basal body to the sperm flagellum. The presence of numerous proacrosomal vesicles instead of a single, conical acrosomal vesicle setsNeotrigonia (and the Trigonioida) apart from other bivalves, with the exception of the Unionoida which are also known to exhibit this
Beltran,C. Trevino,C.L. Mata-Martinez,E. Chavez,J.C. Sanchez-Cardenas,C. Baker,M. Darszon,A. 2016. Role of Ion Channels in the Sperm Acrosome Reaction en: Buffone,M.G. Sperm Acrosome Biogenesis and Function During Fertilization. Springer International Publishing Switzerland. pags. 35-69 Reyes,J.G. Sanchez-Cardenas,C. Acevedo-Castillo,W. Leyton,P. Lopez-Gonzalez,I. Felix,R. Gandini,M.A. Trevino,M.B. Trevino,C.L. 2014. Maitotoxin: An Enigmatic Toxic Molecule with Useful Applications in the Biomedical Sciences en: Botana,L.M. Seafood and Freshwater Toxins. Pharmacology, Physiology, and Detection. Boca Raton. CRC Press. pags. 677-694 * Indica publicación con otra institución de adscripción. ...
That movement of the head is created by a vibration of the stiff anterior portion of the tail, generated by the thrashing movement of the posterior segment remaining outside the zona. 26 Chapter1 oscillations limited scythe-like movement may create a shear-thinning effect on the zona that maximizes the effectiveness of that thrust. In accord with the inference that the movement required for zona penetration generates shear forces at the sperm surface, the inner acrosomal membrane has developed an unusual stability which is inappropriate to a fusogenic role. It is possible that in at least some marsupials complete maturation and oocyte fertilizability are reached after ovulation, following the oocytes arrival in the oviduct (see Chapter 7). Furthermore, in all of the three marsupial genera examined, a loss of the cumulus oophorus from around the egg begins some hours before and is complete at ovulation. This stands in contrast to the eutherian situation, where a full cumulus invests the oocyte ...
Synonyms for acrosomal in Free Thesaurus. Antonyms for acrosomal. 7 words related to acrosome: sperm, sperm cell, spermatozoan, spermatozoon, appendage, outgrowth, process. What are synonyms for acrosomal?
The specimens were fixed with 99% methanol Navitoclax mouse and kept at room temperature until fluorescence staining. For staining, slides were incubated with 20 μg/ml Alexa Fluor-488-PNA (peanut agglutinin) at 37 °C for 30 min, washed with PBS, and analyzed by using epifluorescent microscopy with an appropriate filter. The images of stained sperm samples were classified into two groups: Sperm displaying intensive and moderate bright fluorescence in the acrosomal region were considered to be intact, whereas sperm displaying weak, patchy, or no fluorescence in the acrosomal region were considered to be damaged. [52]. 100 sperm on each slide were evaluated to determine the proportion of sperm with intact acrosomes. The sperm MMP was evaluated using the JC-1 fluorescent dye (M34152, Molecular Probes Inc.) by the modified method that was previously described by Guthrie and Welch [18]. The JC-1 fluorescent dye was used to distinguish spermatozoa with poorly and highly functional mitochondria. In ...
The specimens were fixed with 99% methanol Navitoclax mouse and kept at room temperature until fluorescence staining. For staining, slides were incubated with 20 μg/ml Alexa Fluor-488-PNA (peanut agglutinin) at 37 °C for 30 min, washed with PBS, and analyzed by using epifluorescent microscopy with an appropriate filter. The images of stained sperm samples were classified into two groups: Sperm displaying intensive and moderate bright fluorescence in the acrosomal region were considered to be intact, whereas sperm displaying weak, patchy, or no fluorescence in the acrosomal region were considered to be damaged. [52]. 100 sperm on each slide were evaluated to determine the proportion of sperm with intact acrosomes. The sperm MMP was evaluated using the JC-1 fluorescent dye (M34152, Molecular Probes Inc.) by the modified method that was previously described by Guthrie and Welch [18]. The JC-1 fluorescent dye was used to distinguish spermatozoa with poorly and highly functional mitochondria. In ...
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CIFTCI, H.B. and ZULKADIR, U.. The effect of oestradiol-17β on the motility, viability and the acrosomal status of bull sperm. S. Afr. j. anim. sci. [online]. 2010, vol.40, n.1. ISSN 2221-4062.. ...
Capacitation encompasses the molecular changes sperm undergo to fertilize an oocyte, some of which are postulated to occur via a cAMP-PRKACA (protein kinase A)-mediated pathway. Due to the recent discovery of cAMP-activated guanine nucleotide exchange factors RAPGEF3 and RAPGEF4, we sought to investigate the separate roles of PRKACA and RAPGEF3/RAPGEF4 in modulating capacitation and acrosomal exocytosis. Indirect immunofluorescence localized RAPGEF3 to the acrosome and subacrosomal ring and RAPGEF4 to the midpiece in equine sperm. Addition of the RAPGEF3/RAPGEF4-specific cAMP analogue 8-(p-chlorophenylthio)-2-O-methyladenosine-3,5-cyclic monophosphate (8pCPT) to sperm incubated under both noncapacitating and capacitating conditions had no effect on protein tyrosine phosphorylation, thus supporting a PRKACA-mediated event. Conversely, activation of RAPGEF3/RAPGEF4 with 8pCPT induced acrosomal exocytosis in capacitated equine sperm at rates (34%) similar (P > 0.05) to those obtained in ...
In the mouse and other mammals studied, including man, ejaculated spermatozoa cannot immediately fertilize an egg. They require a certain period of residence in the female genital tract to become functionally competent cells. As spermatozoa traverse through the female genital tract, they undergo multiple biochemical and physiological changes collectively referred to as capacitation. Only capacitated spermatozoa interact with the extracellular egg coat, the zona pellucida. The tight irreversible binding of the opposite gametes triggers a Ca|sup|2+|/sup|-dependent signal transduction cascade. The net result is the fusion of the sperm plasma membrane and the underlying outer acrosomal membrane at multiple sites that causes the release of acrosomal contents at the site of sperm-egg adhesion. The hydrolytic action of the acrosomal enzymes released, along with the hyperactivated beat pattern of the bound spermatozoon, is important factor that directs the sperm to penetrate the egg coat and fertilize the egg.
Calcium flux is required for the mammalian sperm acrosome reaction, an exocytotic event triggered by egg binding, which results in a dramatic rise in sperm intracellular calcium. Calcium-dependent membrane fusion results in the release of enzymes that facilitate sperm penetration through the zona pellucida during fertilization. We have characterized inositol 1,4,5-trisphosphate (IP3)-gated calcium channels and upstream components of the phosphoinositide signaling system in mammalian sperm. Peptide antibodies colocalized G alpha q/11 and the beta 1 isoform of phospholipase C (PLC beta 1) to the anterior acrosomal region of mouse sperm. Western blotting using a polyclonal antibody directed against purified brain IP3 receptor (IP3R) identified a specific 260 kD band in 1% Triton X-100 extracts of rat, hamster, mouse and dog sperm. In each species, IP3R immunostaining localized to the acrosome cap. Scatchard analysis of [3H]IP3 binding to rat sperm sonicates revealed a curvilinear plot with high ...
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1. Wu AT, Sutovsky P, Manandhar G, Xu W, Katayama M, Day BN, Park KW, Yi YJ, Xi YW, Prather RS, Oko R. PAWP, a sperm-specific WW domain-binding protein, promotes meiotic resumption and pronuclear development during fertilization. J. Biol. Chem. 2007; 282: 12164-12175.. 2. Fitzgerald C, Sikora C, Lawson V, Dong K, Cheng M, Oko R, van der Hoorn FA. Mammalian transcription in support of hybrid mRNA and protein synthesis in testis and lung. J. Biol. Chem. 2006; 281: 38172-38180.. 3. Yu Y, Xu W, Yi YJ, Sutovsky P, Oko R. The extracellular protein coat of the inner acrosomal membrane is involved in zona pellucida binding and penetration during fertilization: characterization of its most prominent polypeptide (IAM38). Dev. Biol. 2006; 290: 32-43.. 4. Tovich PR, Sutovsky P, Oko RJ. Novel aspect of perinuclear theca assembly revealed by immunolocalization of non-nuclear somatic histones during bovine spermiogenesis. Biol. Reprod. 2004; 71: 1182-1194.. 5. Miranda-Vizuete A, Sadek CM, Jimenez A, Krause WJ, ...
ZPBP is one of several proteins that are thought to participate in secondary binding between acrosome-reacted sperm and the egg-specific extracellular matrix, the zona pellucida (McLeskey et al., 1998 [PubMed 9378618]).[supplied by OMIM, Aug 2008 ...
Fusion of membranes during the acrosome reaction: a tale of two SNAREs.: During spermiogenesis, hydrolytic enzymes are sorted from the Golgi apparatus to the ac
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The principal role of SNARE proteins is to arbitrate vesicle fusion to a target membrane. Formation of tripartite SNARE protein complexes between SNARE proteins on opposing membranes is the minimal requirement for membrane fusion. The SNARE protein family is large, consisting of more than 60 members. A member of the SNARE family, syntaxin, is found on the sperm plasma membrane while synaptobrevin, is found on the outer acrosomal membrane. During the sperm acrosome reaction, the outer acrosomal membrane fuses at hundreds of points with the overlying plasma membrane, resulting in release of the acrosomal contents. We hypothesize that syntaxin and synaptobrevin re-localize within the sperm plasma membrane prior to the acrosome reaction to form SNARE complexes and promote membrane fusion at hundreds of specific points. Immunofluorescence was used to localize both syntaxin and synaptobrevin in mouse epididymal sperm before and after capacitation. Sperm were fixed and incubated with antibodies to ...
Experiments were designed to determine the interrelationship between cyclic AMP and Ca2+ during the processes of sperm capacitation and the acrosome reaction. In minimal culture media containing pyruvate and lactate as substrates, guinea pig spermatozoa required a minimum of 1.0-1.5 hr to capacitate in the presence of 1.7 mM Ca2+ and a minimum of 0.5-1.0 hr to capacitate in the absence of added Ca2+. Sperm cyclic AMP concentrations were increased by as much as 30-fold within 0.5 min after addition of cells to various media containing Ca2+, and the concentrations then remained increased for up to 4 hr. When the cells were added to several Ca2+-deficient media, however, cyclic AMP concentrations increased only about 3-fold within 0.5 min and then returned to basal concentrations within 2 min. D-600, a calcium transport antagonist, completely blocked the Ca2+-induced increase in sperm cyclic AMP concentrations. In contrast to capacitation, the acrosome reaction failed to occur in the absence of ...
FLORKEGERLOFF S, KRAUSE W, TOPFERPETERSEN E, Tschesche H, MULLERESTERL W, ENGEL W. ON THE TERATOGENESIS OF ROUND-HEADED SPERMATOZOA - INVESTIGATIONS WITH ANTIBODIES AGAINST ACROSIN, AN INTRAACROSOMALLY LOCATED ACROSIN-INHIBITOR, AND THE OUTER ACROSOMAL MEMBRANE. ANDROLOGIA. 1985;17(2):126-138 ...
Looking for online definition of acrosomal in the Medical Dictionary? acrosomal explanation free. What is acrosomal? Meaning of acrosomal medical term. What does acrosomal mean?
a . In humans and in all mammals, a mothers immune system, contrary to its normal function, must learn not to attack her unborn baby-half of whom is a "foreign body" from the father. If these immune systems functioned "properly," mammals-including each of us-would not exist.. The mysterious lack of rejection of the fetus has puzzled generations of reproductive immunologists and no comprehensive explanation has yet emerged. [Charles A. Janeway Jr. et al., Immuno Biology (London: Current Biology Limited, 1997), p. 12:24.]. b . N. W. Pixie, "Boring Sperm," Nature, Vol. 351, 27 June 1991, p. 704.. c . Meredith Gould and Jose Luis Stephano, "Electrical Responses of Eggs to Acrosomal Protein Similar to Those Induced by Sperm," Science, Vol. 235, 27 March 1987, pp. 1654-1656.. u "When egg meets sperm in mammals, zinc sparks fly. ... [They] are needed to stimulate the transition from egg to embryo." Ashley Yeager, "Images Reveal Secrets of Zinc Sparks," Science News, Vol. 187, 10 January 2015, p. ...
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Extracellular signal-regulated kinases(ERKs), belonging to the family of mitogen-activated protein kinases (MAPKs), are cytoplasmic and nuclear serine/threonine kinases involved in the signal transduction of several extracellular effectors. Recent evidence indicates the presence of p21 Ras and the phosphorylation of ERK1 and ERK2, suggesting the occurrence of the Ras/ERK cascade in mammalian spermatozoa. The present article describes the biological role of ERK during the acrosome reaction of human spermatozoa on stimulation with zona pellucida (ZP). The mitogen-activated protein-kinase inhibitor PD098059 was used as a pharmacological tool to study the involvement of extracellular signal-regulated kinases in the induction of the acrosome reaction in human spermatozoa. This compound significantly inhibited the acrosome reaction induced by both ZP and the calcium ionophore A23187. These results suggest that ERKs are involved in the signal trans-duction pathway through which ZP stimulation works ...
1. Chromosome dimorphism of the spermatozoa has been shown for a variety of mammals, and in some cases this has been shown to be correlated with dimorphism in the head lengths of the spermatozoa.. 2. In the present paper this correlation has been extended to the spermatozoa of man, the mouse, and the rat, in which chromosome dimorphism of the spermatozoa had previously been shown, and in which head length dimorphism seems to exist.. 3. The interest of these results lies in the probability that the histological difference in the X- and Y-spermatozoa may account for the inequality of the sexes at conception in mammals.. ...
Biology Assignment Help, Fusion of sperm and egg, Fusion of Sperm and the Egg After the penetration of the extracellular layers by sperm there occurs the fusion of the - sperm plasma membrane with that of the egg. In mammals the fusion begins at the - equatorial region of the sperm head. The p
Mammalian spermatozoa have complex structures. The structure-function relationship of sperm has been studied from various viewpoints. Accumulated evidence has s
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For spermatozoa to gain access to the oocyte for fertilization, lytic enzymes need to be released during the acrosome reaction. These enzymes, which are stored and transported within an organelle termed the acrosome ...
The total number of spermatozoa (mean ± SEM) released by frogs over a 12 hr period in response to administration of control, no, one or two priming injections
PeranSenyawa Oksigen Reaktif dalam Makanisme KerusakanIntegritas Membran Spermatozoa KerbauLumpur Setelah Sentrifugasi Gradien Densitas Percoll
The zona pellucida is an extracellular matrix that surrounds the oocyte and early embryo. It is composed of three glycoproteins with various functions during fertilization and preimplantation development. The glycosylated mature peptide is one of the structural components of the zona pellucida and functions in secondary binding and penetration of acrosome-reacted spermatozoa. Female mice lacking this gene do not form a stable zona matrix and are sterile. Alternative splicing results in multiple transcript variants. [provided by RefSeq, Feb 2014]
Hyaluronidase PH-20 is an enzyme that in humans is encoded by the SPAM1 gene.[5][6][7] Hyaluronidase degrades hyaluronic acid, a major structural proteoglycan found in extracellular matrices and basement membranes. Six members of the hyaluronidase family are clustered into two tightly linked groups on chromosome 3p21.3 and 7q31.3. This gene was previously referred to as HYAL1 and HYA1 and has since been assigned the official symbol SPAM1; another family member on chromosome 3p21.3 has been assigned HYAL1. This gene encodes a GPI-anchored enzyme located on the human sperm surface and inner acrosomal membrane. This multifunctional protein is a hyaluronidase that enables sperm to penetrate through the hyaluronic acid-rich cumulus cell layer surrounding the oocyte, a receptor that plays a role in hyaluronic acid induced cell signaling, and a receptor that is involved in sperm-zona pellucida adhesion. Abnormal expression of this gene in tumors has implicated this protein in degradation of basement ...
In summary, 2AG affects the in vitro functionality of human sperm by reducing motility, inhibiting capacitation and triggering the acrosome reaction.
CD52 is a glycosylphosphatidylinositol (GPI)-anchored antigen expressed on lymphocytes and in epididymal epithelial cells. CD52 is also known as maturation-associated sperm antigen but its function is unknown. We therefore generated Cd52 disrupted mice. The resulting Cd52 null mice were healthy, even though Cd52 is expressed on cells of the immune system. We then examined a possible role for CD52 in reproduction. Sperm from Cd52-deficient males were investigated and the viability, motility, morphology, and incidence of spontaneous acrosome reactions were found to be all similar to values for wild-type sperm. In in vitro fertilization system, the sperm showed normal fertilizing ability. As CD52 was found to be transferred onto sperm only after they had migrated into the vas deferens, we examined the behavior of sperm from Cd52-deficient mice in vivo. The mice mated naturally and we observed that a normal number of sperm passed through the uterotubal junction, known to the crucial hurdle for ...
Sperm proteins of marine sessile invertebrates have been extensively studied to understand the molecular basis of reproductive isolation. Apart from molecules such as bindin of sea urchins or lysin of abalone species, the acrosomal protein M7 lysin of Mytilus edulis has been analyzed. M7 lysin was found to be under positive selection, but mechanisms driving the evolution of this protein are not fully understood. To explore functional aspects, this study investigated the protein expression pattern of M7 and M6 lysin in gametes and somatic tissue of male and female M. edulis. The study employs a previously published monoclonal antibody (G26-AG8) to investigate M6 and M7 lysin protein expression, and explores expression of both genes. It is shown that these proteins and their encoding genes are expressed in gametes and somatic tissue of both sexes. This is in contrast to sea urchin bindin and abalone lysin, in which gene expression is strictly limited to males. Although future studies need to ...
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hī″ă-lūr-ŏn′ĭ-dās) An enzyme that disrupts or destroys the extracellular framework of body tissues. It is found in many animal tissues and can be synthesized for therapeutic use. In the testes and the acrosomes of spermatozoa, along with other acrosomal enzymes, it degrades the hyaluronic acid in the corona radiata, facilitating the entry of sperm. In malignant tumors, it participates in the invasion of cancer cells through the basement membranes of blood vessels. It is also a component of the venoms of several animals (including vipers, stonefish, and bees and wasps) and contributes to the tissue destruction that may follow bites or stings from these animals. Some infectious bacteria that invade fascial planes, e.g., Clostridia, release it as an exotoxin. ...
An acrosomes is the "cap" at the anterior end of a sperm cell that produces enzymes to facilitate depth of the egg.. Dr. Saint David R. J. Glenn and colleagues information that viagra pic, compared to no view, led to a "sustained enhancement of move," both in Numbers of progressively motile sperm and their velocity.. However, photography to sildenafil - at concentrations relative atomic mass to the mean upper limit sum state density gift 30 minutes after a safety oral dose of 100 milligrams - also led to early activity of the acrosome chemical change. "This has important clinical implications because sperm that acrosome-react before inter-group communication with the oocyte are incapable of fecundation," the researchers note.. "Given that the figure of sperm acrosome react on representation to sildenafil, the drug may proceedings significant debasement to their fertilizing potential drop," they add.. This is a business concern, Dr.Glenn and colleagues say, given that viagra and other ...
Preliminary Study on the Induction of Sperm Head Abnormalities in Mice, Mus musculus, Exposed to Radiofrequency Radiations from Global System for (...)
Effect of micromolar concentration of Met-AEA on bull heparin-induced sperm capacitation.Spermatozoa were incubated for 45 min at 38.5°C in sp-TALP medium with
noun Etymology: International Scientific Vocabulary Date: 1899 an anterior prolongation of a spermatozoon that releases egg penetrating enzymes • acrosomal adjective
Lopez-Torres,A.S. Gonzalez-Gonzalez,M.E. Mata-Martinez,E. Larrea,F. Trevino,C.L. Chirinos,M. 2017. Luteinizing hormone modulates intracellular calcium, protein tyrosine phosphorylation and motility during human sperm capacitation Biochemical and Biophysical Research Communications, 483, 834-839 ...
The principal aim of this study was to determine whether subjective estimations of sperm velocity in our laboratory could readily be translated into objective figures.
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Computer-assisted motion analyses (CASA) and flow cytometry were used to evaluate stallion spermatozoa prior to and after cryopreservation. Spermatozoa were pretreated with: (1) Hepes-buffered medium (SHB); (2) phosphatidylserine (PS) liposomes; or (3) liposomes composed of both PS and cholesterol (PSCH) prior to dilution in either SHB or skim milk-egg yolk extender (SMEY). After cooling to 5 degrees C in SHB, PS and PSCH pretreatment (23%). Spermatozoal motion parameters were higher for spermatozoa diluted in SMEY than dilution in SHB. In Experiment 2, motion parameters were compared for spermatozoa pretreated with PSCH liposomes and cryopreserved in either SMEY or a high salt-skim milk-egg yolk extender (CO). Spermatozoal motion characteristics were similar for all spermatozoal treatments after cooling at 5 degrees C. After cryopreservation, PSCH liposome-treated samples had higher percentages of motile spermatozoa than untreated samples regardless of freezing extender. Samples frozen in CO medium had
Sea urchin and human sperm contain receptors for neurotransmitters and psychoactive drugs, including cannabinoid receptors (CNRs). Anandamide, arachidonoylethanolamide (AEA), is a lipid-signal molecule that is an endogenous agonist for CNRs. AEA is enyzmatically released from membrane phospholipids when neurons are stimulated. Retrograde AEA signals from depolarized postsynaptic neurons inhibit neurotransmitter release at synapses in mammalian brain. Analogous processes regulate sperm functions during fertilization in sea urchins. AEA and (-)delta9tetrahydrocannabinol [(-)delta9THC], the major psychoactive constituent of marijuana, inhibit fertilization by blocking acrosomal exocytosis/acrosome reactions (AR) stimulated by egg jelly. The acrosome is a Golgi-derived secretory granule in sperm analogous to synaptic vesicles in neurons. AEA and (-)delta9THC do not block ionophore-induced AR, suggesting that they inhibit AR by modulating signal transduction event(s) before opening of ion channels. ...
CATSPER is a family of sperm-specific calcium channels activated by P in human spermatozoa (Lishko et al. 2011, Strunker et al. 2011). KO mice for CATSPER are infertile due to severe defects in sperm motility.. We studied the involvement of CATSPER in human sperm motility and P responsiveness.. Western blot analysis with an anti-CATSPER1 antibody demonstrated the presence of three major bands corresponding to CATSPER1, 2 and 3 4. By immunoflorescence we observed that channels are mainly located in the principal piece of the tail. Higher levels of CATSPER were found by flow cytometry analysis in swim up selected spermatozoa respect to unselected (50.9±16.6 vs 23.4±10.7, n=6, P=0.01). To investigate the role of CATSPER channels in human sperm motility, we evaluated the effects of the specific inhibitor NNC55-0396 (10 and 20 μM) and the non specific inhibitor mibefradil (30 and 40 μM) on swim up selected spermatozoa (n=13) by CASA system. Both compounds significantly inhibited several ...
Hyaluronic acid is a glycosaminoglycan present in uterine and oviductal fluids in female ruminants, which has been used as a sperm capacitation inducer prior to in vitro fertilization in several species. CD44 is a specific hyaluronic acid receptor, present in the sperm plasma membrane, but its signa …
Pig sperm. Coloured scanning electron micrograph (SEM) of immature pig sperm from the epididymis. This immature sperm is characterised by a small amount of unshed residual cytoplasm below the head. The epididymis is a 7-metre- long coiled tube that lies behind each testis, receiving sperm from them. The sperm mature as they pass slowly through this tube. Magnification: x2500 when printed at 10 centimetres wide. - Stock Image C026/4124
spermatozoa tail - Following spermiogenesis, the third region of the spermatozoa that has a head, neck and tail). The tail is also divided into 3 structural regions a middle piece, a principal piece and an end piece. In humans: the middle piece (5 µm long) is formed by axonema and dense fibres surrounded by mitochondria; the principal piece (45 µm long) fibrous sheath interconnected by regularly spaced circumferential hoops; the final end piece (5 µm long) has an axonema surrounded by small amount of cytoplasm and plasma membrane ...
Bennett, D and Dunn, L C., "Studies of effects of t-alleles in the house mouse on spermatozoa. I. Male sterility effects." (1967). Subject Strain Bibliography 1967. 576 ...
Hita Garcia & Fisher (2014) - (N=6). HL 0.67-0.72 (0.70); HW 0.54-0.59 (0.57); SL 0.39-0.42 (0.41); EL 0.19-0.20 (0.20); PH 0.36-0.38 (0.37); PW 0.43-0.47 (0.45); WL 0.98-1.06 (1.02); PSL 0.11-0.13 (0.10); PTL 0.27-0.29 (0.28); PTH 0.29-0.32 (0.31); PTW 0.21-0.23 (0.22); PPL 0.24-0.26 (0.25); PPH 0.28-0.34 (0.31); PPW 0.30-0.33 (0.31); CI 80-83 (81); SI 69-74 (72); OI 34-35 (35); DMI 43-44 (44); LMI 35-37 (36); PSLI 16-18 (17); PeNI 48-49 (49); LPeI 88-93 (90); DPeI 77-81 (79); PpNI 69-70 (70); LPpI 75-86 (80); DPpI 122-125 (124); PPI 141-145 (143). Head much longer than wide (CI 80-83); posterior head margin weakly concave. Anterior clypeal margin with distinct, but often shallow median impression. Frontal carinae strongly developed and noticeably raised forming dorsal margin of very well-developed antennal scrobes, curving down ventrally and anteriorly halfway between posterior eye margin and posterior head margin and forming posterior and ventral scrobe margins; antennal scrobes very well ...
Acrosome Definition - The acrosome is a cap that covers the head of the sperm. The acrosome facilitates the acrosomal reaction, which occurs when the...
Acrosin is the major protease of mammalian spermatozoa. It is a serine protease of trypsin-like cleavage specificity, it is synthesized in a zymogen form, proacrosin and stored in the acrosome.
O autor é titular dos direitos autorais dos documentos disponíveis neste repositório e é vedada, nos termos da lei, a comercialização de qualquer espécie sem sua autorização prévia ...
Mouse sperm hunt for eggs in packs, but grouping doesnt boost speed. Instead, gangs of the reproductive cells move in straighter lines.
Spermatozoa are the only cells destined to be exported from the body. Thus, motility is an essential property of fertile spermatozoa. It enables ejaculated spermatozoa to traverse the female...
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YAMAGUCHI Nobuyuki , HIGA Mikihiko , AIBA Kazuhiro , FANG Hui , TANAKA Yoshimasa , URUSHIHARA Hideko Development, growth & differentiation 38(3), 271-279, 1996-06-01 参考文献26件 被引用文献2件 ...
In order to be able to fertilize oocytes, human sperm must undergo a series of morphological and structural alterations, known as capacitation. It has been shown that the production of endogenous sperm reactive oxygen species (ROS) plays a key role in causing cells to undergo a massive acrosome reaction (AR). Astaxanthin (Asta), a photo-protective red pigment belonging to the carotenoid family, is recognized as having anti-oxidant, anti-cancer, anti-diabetic and anti-inflammatory properties and is present in many dietary supplements. This study evaluates the effect of Asta in a capacitating buffer which induces low ROS production and low percentages of acrosome-reacted cells (ARC). Sperm cells were incubated in the presence or absence of increasing concentrations of Asta or diamide (Diam) and analyzed for their ROS production, Tyr-phosphorylation (Tyr-P) pattern and percentages of ARC and non-viable cells (NVC). Results show that Asta ameliorated both sperm head Tyr-P and ARC values without affecting
A rabbit antibody to mouse 3T3 cell fibronectin was used in conjunction with a fluorescein-tagged second antibody to detect fibronectin-like activity on the surface of rabbit spermatozoa. Only ejaculated sperm displayed an intense and highly localized fluorescence over the acrosomal region. Cauda epididymal sperm of the rabbit as well as several other species did not exhibit any reaction. The fluorescent activity could be eliminated by trypsin treatment but was re-established by incubation in cell-free seminal fluid. Sperm recovered from females 10-12 h after mating showed a reduction or absence of antifibronectin fluorescence, suggesting that this components loss could be a factor in sperm capacitation. Because fibronectins show strong binding to collagen, mixtures of ejaculated sperm and collagen were examined in the light and electron microscope. Living sperm appear to have a strong affinity for collagen and quickly adhere to the filaments by their heads, while continuing vigorous ...
Sperm-egg interactions have been studied for many years using biochemical approaches such as the employment of antibodies and ligands that interact with sperm or with eggs and their vestments. As a result, various factors that participate in fertilization have emerged. However, when animals were genetically manipulated to examine the roles of those factors, most of them were found, to our surprise, to be "not essential". Of course, all biological systems contain redundancies and compensatory mechanisms, but at least some factors were found to be "essential" after gene disruption. As a whole, the explanations of sperm-egg interactions require significant modification from the gene manipulation point of view. In this review, information about sperm-egg interactions obtained from genetically manipulated animals is mainly revisited in order to propose a new vision.
ABSTRACT Aflagellate sperm of the crayfishes Cherax tenuimanus and Cherax albidus are composed of an acrosome, subacrosomal region, collar, and nucleus. The acrosomes are helmet-shaped and PAS positive. In C. tenuimanus, they can be subdivided into a granular inner region and a homogeneous outer region. A series of electron-translucent canals runs through the acrosomes of both species. In C. albidus, these canals are arranged in whorling patterns, while in C. tenuimanus they are present near the base of the acrosome and contain a small electron-dense component. The subacrosomal regions are metachromatic when stained with methylene blue and contain a network of fibrils and granules. The collars are composed of granular material, which is positioned immediately subjacent to the subacrosomal region, and of highly convoluted membrane lamellae. Mitochondria and microtubules are associated with the membrane lamellae. The nuclei contain uncondensed chromatin and are bounded by a complete nuclear envelope.
The present study evaluated the effects of exposing liquid-stored boar semen to different red light LED regimens on sperm quality and reproductive performance. Of all of the tested photo-stimulation procedures, the best pattern consisted of 10 min light, 10 min rest and 10 min of further light (10-10-10 pattern). This pattern induced an intense and transient increase in the majority of motility parameters, without modifying sperm viability and acrosome integrity. While incubating non-photo-stimulated sperm at 37 °C for 90 min decreased all sperm quality parameters, this reduction was prevented when the previously-described light procedure was applied. This effect was concomitant with an increase in the percentage of sperm with high mitochondrial membrane potential. When sperm were subjected to in vitro capacitation, photo-stimulation also increased the percentage of sperm with capacitation-like changes in membrane structure. On the other hand, treating commercial semen doses intended for ...
Pisum sativum|/em| agglutinin is nearly identical in structure and carbohydrate specificity to |em|Lens culinaris|/em| agglutinin.
TY - JOUR. T1 - Adverse effects of cadmium exposure on mouse sperm. AU - Oliveira, Helena. AU - Spanò, Marcello. AU - Santos, Conceição. AU - Pereira, Maria de Lourdes. PY - 2009/12. Y1 - 2009/12. N2 - The effects of cadmium chloride exposure on sperm functional parameters were evaluated on eight-week-old ICR-CD1 male mice administered with a single s.c. injection of 1, 2 and 3 mg CdCl2/kg bw. Groups of animals treated with each dose, as well as their respective controls, were sacrificed after 24 h to detect short-term (acute) effects and after 35 days. Sperm cells were collected from the epididymis and several parameters of sperm quality and function were evaluated, namely density, morphology, motility, viability, mitochondrial function, acrosome integrity, together with DNA fragmentation assessed by the TUNEL assay. The short-term effects of cadmium chloride resulted in an increased fraction of sperm with abnormal morphology, premature acrosome reaction and reduced motility. Late term ...
The acrosome reaction of epididymal spermatozoa and fertilization in vitro of mouse eggs in chemically defined media without tissue fluid were investigated. About 8 to 10% of motile spermatozoa lost their acrosome but no eggs were penetrated when the spermatozoa and eggs were incubated in a basic medium (modified Krebs-Ringer bicarbonate solution containing glucose) for 5 to 7 hr. Addition of a single metabolic intermediate, such as sodium oxaloacetate or sodium pyruvate, to the basic medium increased the proportion of motile spermatozoa without an acrosome (19 to 34%) and the proportion of eggs penetrated (3·2 to 25·5%). Incubation of spermatozoa and eggs in the basic medium containing serum albumin of various species caused a further increase in the proportion of motile spermatozoa without an acrosome (50 to 65%) and in that of penetrated eggs (60·7 to 86%). The best medium for sperm capacitation and fertilization of mouse eggs in vitro, however, was the basic medium containing bovine serum ...
Shepherd A.M.; Clark S.A., 1983: Spermatogenesis and sperm structure in some meloidogyne spp heteroderoidea meloidogynidae and a comparison with those in some cyst nematodes heteroderoidea heteroderidae
Crustaceans. Shellfish are one of the more common allergens. Most reaction-inducing shellfish come from the crustacean family, such as include prawns, crayfish, crabs and lobster. The allergy tends to develop later in life, and can be triggered by handling raw shellfish or even inhaling the steam when they are cooked. The good news is that being allergic to crustaceans does not necessarily mean youll be allergic to molluscs, or to fish. ...
The male gamete is not completely mature after ejaculation and requires further events in the female genital tract to acquire fertilizing ability, including the processes of capacitation and acrosome reaction. In order to shed light on dynamic protein changes experienced by the sperm cell in preparation for fertilization, a comprehensive quantitative proteomic profiling based on isotopic peptide labeling and liquid chromatography followed by tandem mass spectrometry was performed on spermatozoa from three donors of proven fertility under three sequential conditions: purification with density gradient centrifugation, incubation with capacitation medium, and induction of acrosome reaction by the exposure to the calcium ionophore A23187. After applying strict selection criteria for peptide quantification and for statistical analyses, 36 proteins with significant changes in their relative abundance within sperm protein extracts were detected. Moreover, the presence of peptide residues potentially ...
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Detail záznamu - Ultrastructure of spermiogenesis and mature spermatozoon of Breviscolex orientalis (Cestoda: Caryophyllidea) - Detail záznamu - Knihovna Akademie věd České republiky
Aside from its importance in understanding specific aspects of fertilization, studies on sperm - egg interaction provide an elegant general model to study intercellular communication and cellular...
May be involved in Ca(2+)-dependent exocytosis of secretory vesicles through Ca(2+) and phospholipid binding to the C2 domain or may serve as Ca(2+) sensors in the process of vesicular trafficking and exocytosis. May mediate Ca(2+)-regulation of exocytosis in acrosomal reaction in sperm (By similarity).
Involved in fusion of sperm to egg plasma membrane involved in single fertilization. Predicted to localize to the integral component of membrane. Orthologous to human SPACA6 (sperm acrosome associated 6 ...
Before it can fertilize an egg, a sperm has to bind to and bore through an outer egg layer known as the zona pellucida. Researchers now identify the protein in the zona pellucida that sperm latch onto.
Before it can fertilize an egg, a sperm has to bind to and bore through an outer egg layer known as the zona pellucida. Researchers now identify the protein in the zona pellucida that sperm latch onto.
Expression of ZPBP (SP38, ZPBP1) in cancer tissue. The cancer tissue page shows antibody staining of the protein in 20 different cancers.
Acrosome A small cap overlaying the sperm head. Acrosome Reaction The loss of the acrosome that is necessary for successful fetilization. Normally only
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Nazify gnatty mammonite saccharometric goalie flowing chromoisomeric Tartaric mathetic quadrituberculate pokeroot lightwood spermatozoa boccaro brevity nonproductive parthenogenitive illicitness crissal unjustifiableness achromotrichia outshoot Uitotan wickless stooden ...
Looking for online definition of sperm penetration assay in the Medical Dictionary? sperm penetration assay explanation free. What is sperm penetration assay? Meaning of sperm penetration assay medical term. What does sperm penetration assay mean?
Improved fertility following artificial insemination with frozen-thawed spermatozoa would offer rabbit producers faster genetic improvement. Previous work investigating cryoprotectants for rabbit spermatozoa have reported inconsistent results. Semen was collected from three rabbit bucks by artificial vagina and frozen using a standard procedure with varied cryodiluent components. Post-thaw analysis encompassed motility, sperm kinematic parameters and acrosome and membrane integrity. Spermatozoa were evaluated at 0, 2 and 4 h after thawing. Experiment 1 compared diluents with 3.5% dimethyl sulfoxide (DMSO), 1.5% acetamide, 1.75% DMSO + 0.75% acetamide or 3.5% DMSO + 1.5% acetamide. The treatment that resulted in the highest post-thaw motility (P,0.001) and acrosome integrity (P,0.001) was DMSO alone. Experiment 2 compared 3.5, 7 and 10% DMSO in the cryodiluent. The best post-thaw sperm motility (P,0.001) and linearity (P=.002) was in 3.5% DMSO, while 10% DMSO afforded higher acrosome/membrane ...
We have studied sperm structure and motility in a eusocial rodent where reproduction is typically restricted to a single male and behaviourally dominant queen. Males rarely compete for access to the queen during her estrus cycle, suggesting little or no role for sperm competition. Our results revealed an atypical mammalian sperm structure with spermatozoa from breeding, subordinate and disperser males being degenerate and almost completely lacking a mammalian phylogenetic stamp. Sperm structure is characterized by extreme polymorphism with most spermatozoa classified as abnormal. Sperm head shapes include round, oval, elongated, lobed, asymmetrical and amorphous. At the ultrastructural level, the sperm head contains condensed to granular chromatin with large open spaces between the chromatin. Nuclear chromatin seems disorganized since chromatin condensation is irregular and extremely inconsistent. The acrosome forms a cap (ca 35%) over the anterior part of the head. A well defined nuclear fossa and
Basigin (BSG) is a multifunctional glycoprotein that plays an important role in male reproduction since male knockout (KO) mice are sterile. The Bsg KO testis lacks elongated spermatids and mature spermatozoa, a phenotype similar to that of alpha-mannosidase IIx (MX) KO mice. MX regulates formation of N-acetylglucosamine (GlcNAc) terminated N-glycans that participate in germ cell-Sertoli cell adhesion. Results showed that Bsg KO spermatocytes displayed normal homologous chromosome synapsis and progression through meiosis. However, only punctate expression of the round spermatid marker SP-10 in the acrosomal granule of germ cells of Bsg KO mice was detected indicating that spermatogenesis in Bsg KO mice was arrested at the early round spermatid stages. We observed a large increase in the number of germ cells undergoing apoptosis in Bsg KO testes. Using lectin blotting, we determined that GlcNAc terminated N-glycans are linked to BSG. GlcNAc terminated N-glycans were significantly reduced in Bsg KO testes
Results: Plasma membrane (p< 0.001) and acrosome integrity (p< 0.05) of the spermatozoa were significantly reduced in sodium arsenite group compared to the control. In silymarin + sodium arsenite group, silymarin was able to significantly (p< 0.001) ameliorate the adverse effects of sodium arsenite on these sperm parameters compared to sodium arsenite group. The incubation of sperm for 180 min (control group) showed a significant (p< 0.001) decrease in acrosome integrity compared to the spermatozoa at 0 hour. The application of silymarin alone for 180 min could also significantly (p< 0.05) increase sperm acrosome integrity compared to the control ...
... Reproduction and Development Pregnancy Prevention • Contraceptives (birth control methods) • Abstinence • Total abstinence • Abstinence during periods of female fertility • Interventional methods • • • • Barriers Surgery Blocking implantation Hormone treatments to reduce gamete production Pregnancy Prevention Table 26-5 Fertilization • Sperm capacitation occurs in vagina • Sperm swim "upstream" • Sperm reach oocyte in Fallopian tube • Acrosomal reaction  digestive enzymes • Zona pellucida and cell junctions dissolve • Membranes fuse and sperm nucleu enters • Cortical reaction blocks polyspermy • Nuclear fusion creates a diploid cell • 1 sperm + 1 oocyte  1 zygote Fertilization Figure 26-16a Acrosome Reaction Allows Sperm to Reach Egg Figure 26-16b Sperm and Egg Fuse to Form a Zygote First polar body Egg Sperm nucleus Sperm and egg plasma membranes fuse. Sperm nucleus moves into cytoplasm of egg. Figure 26-17 (1 of 4, 2 of 4) Oocyte Completes ...
Mammals generally ejaculate many more spermatozoa than seem to be needed for fertilization. This apparent profligacy has not been explained, but observations made in marsupials may shed light on it. The Virginia opossum, Didelphis virginiana, inseminates only about three million spermatozoa, a very low number. As a corollary, relatively few (ca. 13 x 106) are stored in each cauda epididymidis. However, some 5% of the spermatozoa that the opossum ejaculates populate the oviduct about 12 h later when ovulation can be anticipated - a success rate in the female orders of magnitude greater than in eutherian mammals. I t is not certain what determines the unusually efficient transport to and the high survival rate of spermatozoa in the oviduct of Didelphis, but two unusual features suggest themselves as possible contributors. Didelphis (and all other American marsupial) spermatozoa undergo a head-to-head pairing in the epididymis by the acrosomal face; this serves to isolate the acrosome of ejaculated ...
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PAN Czytelnia Czasopism, Motility, mitochondrial membrane potential and ATP content of rabbit spermatozoa stored in extender supplemented with GnRH analogue [des-Gly10, D-Ala6]-LH-RH ethylamide - Polish Journal of Veterinary Sciences
Prostasomes are extracellularly occurring organelles which are secreted in human semen by the prostate gland. Prostasomes have several known biological activities, but their physiological function is still unclear. In this thesis some new aspects were studied on the biological role of the prostasomes. The motility-stimulatory effect of prostasomes on cryopreserved spermatozoa was further studied by supplementing the swim-up medium with seminal prostasomes, and with prostasomes purified from a PC-3 prostate cancer cell line (PC-3 prostasomes), on fresh spermatozoa. The recovery of motile spermatozoa after swim-up increased by 50% when the swim-up medium was supplemented with prostasomes. The PC-3 prostasomes bore a functional resemblance to seminal prostasomes as regards various expressions of sperm motility promotion. Prostasomes proved to have potent antibacterial effects. The effects were not strictly confined to Bacillus megaterium since a few other bacteria were also sensitive. The high ...
In addition to perinuclear theca anchored glutathione-s-transferase omega 2 (GSTO2), whose function is to participate in sperm nuclear decondensation during fertilization (Biol Reprod. 2019, 101:368–376), we herein provide evidence that GSTO2 is acquired on the sperm plasmalemma during epididymal maturation. This novel membrane localization was reinforced by the isolation and identification of biotin-conjugated surface proteins from ejaculated and capacitated boar and mouse spermatozoa, prompting us to hypothesize that GSTO2 has an oxidative/reductive role in regulating sperm function during capacitation. Utilizing an inhibitor specific to the active site of GSTO2 in spermatozoa, inhibition of this enzyme led to a decrease in tyrosine phosphorylation late in the capacitation process, followed by an expected decrease in acrosome exocytosis and motility. These changes were accompanied by an increase in reactive oxygen species (ROS) levels and membrane lipid peroxidation and culminated in a
... could then be followed by the acrosome reaction where the cap-like structure on the head of the cell releases ... Some definitions consider sperm activation to consist of these two processes of hyperactivation and the acrosome reaction ...
SPACA3: Sperm acrosome membrane-associated protein 3. *SPAG5: encoding protein Sperm-associated antigen 5 ...
"Egg-jelly signal molecules for triggering the acrosome reaction in starfish spermatozoa". The International Journal of ...
"acrosome definition - Dictionary - MSN Encarta". Archived from the original on 2009-10-31. Retrieved 2007-08-15. Forgács, G.; ... the front part of the spermatozoan head is capped by an acrosome which contains digestive enzymes to break down the zona ...
This is due to the fact that in IVF acrosome reaction has to take place and thousands of sperm cells have to be involved. Once ... With this method acrosome reaction is skipped. ICSI is used in the 95% of oocytes in the world. ...
After the acrosome reaction, the sperm is believed to remain bound to the zona pellucida through exposed ZP2 receptors. These ... In mammals, the binding of the spermatozoon to the GalT initiates the acrosome reaction. This process releases the ... binds to the N-acetylglucosamine residues on the ZP3 and is important for binding with the sperm and activating the acrosome ...
This is due to the fact that in IVF acrosome reaction has to take place and thousands of sperm cells have to be involved. Once ... With this method acrosome reaction is skipped. There are several differences within classic IVF and ICSI. However, the steps to ...
Equatorin, sperm acrosome associated is a protein that in humans is encoded by the EQTN gene. GRCh38: Ensembl release 89: ... is related to acrosome formation in murine testis". FEBS Letters. 580 (17): 4266-73. doi:10.1016/j.febslet.2006.06.010. PMID ... sperm acrosome associated". Ruiz A, Pujana MA, Estivill X (December 2000). "Isolation and characterisation of a novel human ...
Phospholipase C (PLC) is involved in acrosome reaction. ZP3 is a glycoprotein present in zona pelucida and it interacts with ... IP3 binds to IP3 receptors, present in acrosome membrane. In addition, calcium and DAG together work to activate protein kinase ... To have the ability to fertilize the female gamete, this cell suffers capacitation and acrosome reaction in female reproductive ... This hormone activates AKT that leads to activation of other protein kinases, involved in capacitation and acrosome reaction. ...
Sperm acrosome membrane-associated protein 3 is a protein that in humans is encoded by the SPACA3 gene. It may be involved in ... "Entrez Gene: SPACA3 sperm acrosome associated 3". Niyonsaba F, Ogawa H (2006). "Protective roles of the skin against infection ...
The lack of acrosome can be ascertained by a technique known as immunofluorescence. Until 1995, the only options for people ... Kang-Decker, N.; Mantchev, G. T.; Juneja, S. C.; McNiven, M. A.; van Deursen, J. M. (2001-11-16). "Lack of acrosome formation ... There are two types of globozoospermia: Type 1 globozoospermia exhibits a complete lack of acrosome and acrosomal enzymes and ... Studies suggest that globozoospermia can be either total (100% round-headed spermatozoa without acrosomes) or partial (20-60% ...
The second process in sperm activation is the acrosome reaction. This involves releasing the contents of the acrosome, which ... There is some evidence that this binding is what triggers the acrosome to release the enzymes that allow the sperm to fuse with ... Above the nucleus lies a cap-like structure called the acrosome, formed by modification of the Golgi body, which secretes the ...
This test evaluates the acrosome reaction of human spermatozoa. However, the incidence of acrosome reaction in freely swimming ... Yang, YS; Rojas, FJ; Stone, SC (Dec 1988). "Acrosome reaction of human spermatozoa in zona-free hamster egg penetration test". ...
Michaut M, De Blas G, Tomes CN, Yunes R, Fukuda M, Mayorga LS (July 2001). "Synaptotagmin VI participates in the acrosome ...
The acrosome is derived from the Golgi apparatus and contains hydrolytic enzymes important for fusion of the spermatozoon with ... Many changes occur during this process: the DNA in nuclei becomes condensed; the acrosome develops as a structure close to the ... Kierszenbaum AL, Rivkin E, Tres LL (November 2003). "Acroplaxome, an F-actin-keratin-containing plate, anchors the acrosome to ... Kierszenbaum AL, Tres LL (November 2004). "The acrosome-acroplaxome-manchette complex and the shaping of the spermatid head". ...
Identification of the outer acrosome membrane in sperm, indicating acrosome integrity. List of histologic stains that aid in ...
The Golgi apparatus surrounds the now condensed nucleus, becoming the acrosome. Maturation then takes place under the influence ...
... s in the acrosomal membrane of sperm acidify the acrosome. This acidification activates proteases required to drill ...
... is released from the acrosome of spermatozoa as a consequence of the acrosome reaction. It aids in the penetration of ... Acrosin is the major proteinase present in the acrosome of mature spermatozoa. It is stored in the acrosome in its precursor ... Upon stimulus, the acrosome releases its contents onto the zona pellucida. After this reaction occurs, the zymogen form of the ... Thus, some argue for its role in assisting in the dispersal of acrosomal contents following the acrosome reaction, while others ...
"Roles of Bicarbonate, cAMP, and Protein Tyrosine Phosphorylation on Capacitation and the Spontaneous Acrosome Reaction of ... "Analysis of CAPZA3 localization reveals temporally discrete events during the acrosome reaction". Journal of Cellular ...
2002). "Lack of acrosome formation in mice lacking a Golgi protein, GOPC". Proc. Natl. Acad. Sci. U.S.A. 99 (17): 11211-6. doi: ...
This structure binds spermatozoa, and is required to initiate the acrosome reaction. In the mouse (the best characterised ... ZP3 is then involved in the induction of the acrosome reaction, whereby a spermatozoon releases the contents of the acrosomal ... ZP3 and ZP4 bind to capacitated spermatozoa and induce the acrosome reaction. Successful fertilization depends on the ability ...
Bleil, JD; PM Wassarman (1990). "Identification of a ZP3-binding protein on acrosome-intact mouse sperm by photoaffinity ...
1995). "Human SP-10: acrosomal distribution, processing, and fate after the acrosome reaction". Biol. Reprod. 51 (6): 1222-31. ...
... and acrosome of developing spermatids". J. Cell Biol. 137 (3): 657-69. doi:10.1083/jcb.137.3.657. PMC 2139879 . PMID 9151672. ...
Identification of the outer acrosome membrane in sperm, indicating acrosome integrity. List of histologic stains that aid in ...
Changes in motility, morphology, plasma membrane and acrosome integrity during stages of cryopreservation of buck sperm. Ahmad ...
Only sperm that have undergone the acrosome reaction can fuse with egg plasma membrane. The acrosome reaction is characterized ... The acrosome is a large lysosome-like vesicle overlying the sperm nucleus. This spermatid specific organelle, derived from the ...
This shedding of the acrosome, or acrosome reaction, can be stimulated in vitro by substances a sperm cell may encounter ... The acrosome is an organelle that develops over the anterior half of the head in the spermatozoa (sperm cells) of many animals ... This can be done to serve as a positive control when assessing the acrosome reaction of a sperm sample by flow cytometry or ... Acrosome formation is fully completed 5-10 years after testicular maturation.[citation needed] In Eutherian mammals the ...
Therefore, sperm cells go through a process known as the acrosome reaction which is the reaction that occurs in the acrosome of ... the membrane surrounding the acrosome fuses with the plasma membrane of the sperms head, exposing the contents of the acrosome ... The acrosome is a cap-like structure over the anterior half of the sperms head. As the sperm approaches the zona pellucida of ... Since the acrosome reaction has already occurred, sperm are then able to penetrate the zona pellucida due to mechanical action ...
Acrosome reaction. The acrosome reaction was induced by incubation of spermatozoa in supplemented mHTF media with 20 mM calcium ... Schematic representation of the acrosome reaction of human spermatozoa. (A) The acrosome reaction of capacitated spermatozoa ... The acrosome reaction is a large exocytosis event that is induced in vivo when spermatozoa bind to the zona pellucida of the ... Disruption of mouse CD46 causes an accelerated spontaneous acrosome reaction in sperm. Mol. Cell. Biol. 2003. 23:2614-2622. ...
Further analysis revealed that compartments in the sperm known as acrosomes, which contain proteins that breakdown the outer ... Miller DJ (1999) Simple histochemical stain for acrosomes on sperm from several species. ... clumping of acrosomes, misaligned spermatids and the absence of normal elongated spermatids in Ehd1 -/- males. ...
SPACA5 (sperm acrosome associated 5). HGNC. Ensembl, OMA, OrthoDB, Panther, Treefam. Canis lupus familiaris (dog):. LOC480901 ( ... sperm acrosome associated 5B. Description:. Predicted to have lysozyme activity. Predicted to be involved in defense response ... Spaca5 (sperm acrosome associated 5) Alliance. DIOPT (Ensembl Compara, InParanoid, OMA, OrthoFinder, PANTHER). ... Spaca5 (sperm acrosome associated 5) Alliance. DIOPT (Ensembl Compara, HGNC, InParanoid, OMA, OrthoFinder, OrthoInspector, ...
What is Acrosome reaction? Meaning of Acrosome reaction as a finance term. What does Acrosome reaction mean in finance? ... Definition of Acrosome reaction in the Financial Dictionary - by Free online English dictionary and encyclopedia. ... The Mammalian Sperm Acrosome and the Acrosome Reaction.. Localization and Identification of Tyrosine Phosphorylated Proteins in ... Prostasome-like vesicles stimulate acrosome reaction of pig spermatozoa.. Evaluation of acrosome integrity in epidydimal alpaca ...
These results suggest that the sperm acrosome reaction is associated with both a primary transport of Ca2+ and a Ca2+-dependent ... Because a cyclic AMP analogue did not induce an acrosome reaction in the absence of added Ca2+, the increase in sperm cyclic ... In contrast to capacitation, the acrosome reaction failed to occur in the absence of extracellular Ca2+. After capacitation of ... Calcium-dependent increase in adenosine 3′,5′-monophosphate and induction of the acrosome reaction in guinea pig spermatozoa. ...
A form of cellular exocytosis that allows sperm to penetrate the zona pellucida of ovulated eggs Explanation of acrosome ... Looking for acrosome reaction? Find out information about acrosome reaction. ... Related to acrosome reaction: Cortical reaction, capacitation. acrosome reaction. [′ak·rə‚sōm rē‚ak·shən] (cell and molecular ... Acrosome reaction , Article about acrosome reaction by The Free Dictionary https://encyclopedia2.thefreedictionary.com/acrosome ...
... the Acrosome is an organelle that develops over the anterior half of the sperm s head. It is a cap like structure derived from ... Acrosome. In spermatozoa (also known as sperm/sperm cell) of many animals, the Acrosome is an organelle. that develops over the ... acrosome - n. the caplike structure on the front end of a spermatozoon. It breaks down just before fertilization (the acrosome ... Acrosome formation is completed during testicular maturation. In Eutheria. n mammals. the acrosome contains digestive enzyme. s ...
Acrosome / metabolism*, ultrastructure. Actins / metabolism*. Amino Acid Sequence. Animals. Cell Nucleus / metabolism*, ... The ring is closely associated with the leading edge of the acrosome and to the nuclear envelope during the elongation of the ... The cytoskeletal plate, designated acroplaxome, anchors the developing acrosome to the nuclear envelope. The acroplaxome ... nucleates an F-actin-keratin-containing assembly with the purpose of stabilizing and anchoring the developing acrosome during ...
Name the functions of the Acrosome. john Smith Name the functions of the Acrosome2011-09-01T05:14:20+00:00 ... Acrosome ∠It is a cap9like structure present in the anterior part of the head of the sperm. It contains hyaluronidase enzyme ...
Permeabilization of human spermatozoa with streptolysin-O: a model for the study of macromolecules involved on the acrosome ... It is concluded that the model could be eventually useful to study macromolecules involved on the acrosome reaction of human ... The study of the acrosome reaction (AR) of mammalian species is seriously limited by the fact that putative important ... a model for the study of macromolecules involved on the acrosome reaction. Presented at INABIS 98 - 5th Internet World ...
Acrosome Reaction. Abstract:. The principal role of SNARE proteins is to arbitrate vesicle fusion to a target membrane. ... During the sperm acrosome reaction, the outer acrosomal membrane fuses at hundreds of points with the overlying plasma membrane ... Re-localization of SNARE proteins in mouse sperm prior to the acrosome reaction. Welcome to the IDEALS Repository. ... We hypothesize that syntaxin and synaptobrevin re-localize within the sperm plasma membrane prior to the acrosome reaction to ...
... as well as thapsigargins induction of the acrosome reaction, implicate IP3-gated calcium release in the mammalian acrosome ... Inositol 1,4,5-trisphosphate receptors selectively localized to the acrosomes of mammalian sperm.. L D Walensky, S H Snyder ... In each species, IP3R immunostaining localized to the acrosome cap. Scatchard analysis of [3H]IP3 binding to rat sperm ... Calcium flux is required for the mammalian sperm acrosome reaction, an exocytotic event triggered by egg binding, which results ...
AHMAD, Mushtaq et al. Changes in motility, morphology, plasma membrane and acrosome integrity during stages of cryopreservation ... The percentage of sperm with normal acrosomes did not differ significantly due to dilution, cooling or equilibration (85.8 ± ... plasma membrane and acrosome integrity following cooling. ...
Stival C, Puga Molina Ldel C, Paudel B, Buffone MG, Visconti PE, Krapf D. Sperm Capacitation and Acrosome Reaction in Mammalian ...
Chapter 36 Animal Reproduction Vocabulary Acrosome sac at the head of sperm containing enzymes to allow the sperm to ... Chapter 36 Animal Reproduction Vocabulary Acrosome - sac at the head of sperm containing enzymes to allow the sperm to enter an ...
Formaldehyde fixation of acrosome-intact sperm caused partial rupture of the acrosome with loss of the characteristic rouleaux ... Acrosome-intact mammalian sperm can adhere to zona pellucida-free oocytes but are only capable of fusing if they have ... Cryosections of acrosome-intact sperm labelled indirectly with immuno-gold showed labelling consistent with the same location, ... This suggests that the acrosome reaction results in presentation of at least one novel epitope which plays a role in sperm- ...
... acrosome reaction, motility and cryopreservation, Reviews in Fish Biology and Fisheries" on DeepDyve, the largest online rental ... Acrosome staining and motility characteristics of sterlet spermatozoa after cryopreservation with use of methanol and DMSO ... Sperm biology and control of reproduction in sturgeon: (II) sperm morphology, acrosome reaction,... Alavi, Sayyed; Hatef, ... Egg water, Ca2+ and Mg2+ can trigger acrosome reaction. Trypsin- and chymotrypsin-like activities are reported in sturgeon ...
... Murray, George M. (2007-03) ... Acrosomes may thus be viewed as essential for fertilization and their shape, size and volume were examined morphometrically by ... Our results indicated that for a post-swim-up population of spermatozoa an increase in the average acrosome size was ... For spermatozoa to gain access to the oocyte for fertilization, lytic enzymes need to be released during the acrosome reaction ...
Tudor Domain Containing Protein TDRD12 Expresses at the Acrosome of Spermatids in Mouse Testis - Tdrd12;Tudor;Spermatogenesis; ... Tudor Domain Containing Protein TDRD12 Expresses at the Acrosome of Spermatids in Mouse Testis. Kim, Min; Ki, Byeong Seong; ... The fate of acrosomal staining during the acrosome reaction of human spermatozoa as revealed by a monoclonal antibody and PNA- ... TDRD12 was detected in early spermatocytes at 2 weeks and TDRD12 was localized at acrosome of the round spermatids. TDRD12 ...
... Franken D.R. ; Bastiaan H.S. ; Kidson A. ; Wranz P. ; Habenicht ... spontaneous and calcium ionophore induced acrosome reaction. Predictive values for acrosome responsiveness were depicted with ... After completion of acrosome reaction studies, patient samples were divided according to the percentage of morphologically ... Sperm samples from 29 men randomly selected from the andrology laboratory, were used to evaluate acrosome reaction response to ...
  • Results showed that syntaxin-positive volume and syntaxin content remained the same in capacitated and non-capacitated sperm but the location of syntaxin after capacitation was more restricted to the apical ridge of the plasma membrane overlying the acrosome in more than 90% of the sperm observed. (illinois.edu)
  • We concluded that in vivo USP8 has a role strongly associated with acrosome biogenesis and that the early endosome pathway is significantly involved in the process, which suggests that the acrosome could be a novel lysosome-related organelle. (elsevier.com)
  • In conclusion, the present study suggests that the acrosome staining and detailed motion characteristics such as progressiveness, VCL, and VSL should be included in determining semen quality together with primary parameters for successful AI and high breeding performance in the swine industry. (ajas.info)
  • citation needed] In Eutherian mammals the acrosome contains digestive enzymes (including hyaluronidase and acrosin). (wikipedia.org)
  • acrosome - a cap over the nucleus of spermatozoan heads having enzymes involved in sperm penetration of the egg and possibly fusion of egg and sperm. (academic.ru)
  • Chapter 36 Animal Reproduction Vocabulary Acrosome - sac at the head of sperm containing enzymes to allow the sperm to enter an egg artificial insemination asexual reproduction - reproduction involving only one animal through repeated mitosis of cells. (coursehero.com)
  • Therefore, the expression of intracellular NOS enzymes has been also assessed and the possible involvement of NO in acrosome reaction triggered by leptin has been evaluated. (biomedcentral.com)
  • Capacitation is a set of alterations leading to the acrosome reaction (AR), an exocytotic process by means of which hydrolytic enzymes (e.g., acrosin) are released to allow sperm to fertilize oocytes [ 1 ]. (mdpi.com)
  • During spermiogenesis, hydrolytic enzymes are sorted from the Golgi apparatus to the acrosome, a supranuclear megavesicle. (mysciencework.com)
  • Hyperactivation could then be followed by the acrosome reaction where the cap-like structure on the head of the cell releases the enzymes it contains. (wikipedia.org)
  • The head forms at one end, and the Golgi apparatus creates enzymes that will become the acrosome. (wikipedia.org)
  • The head contains the nucleus with densely coiled chromatin fibres, surrounded anteriorly by an acrosome, which contains enzymes used for penetrating the female egg. (wikipedia.org)
  • The ovum meets with Spermatozoon, a sperm may penetrate and merge with the egg, fertilizing it with the help of certain hydrolytic enzymes present in the acrosome. (wikipedia.org)
  • In Eutheria n mammals the acrosome contains digestive enzyme s (including hyaluronidase and acrosin ). (academic.ru)
  • The ring is closely associated with the leading edge of the acrosome and to the nuclear envelope during the elongation of the spermatid head. (biomedsearch.com)
  • These findings lead to the suggestion that the acroplaxome nucleates an F-actin-keratin-containing assembly with the purpose of stabilizing and anchoring the developing acrosome during spermatid nuclear elongation. (biomedsearch.com)
  • Increased spermatid apoptosis, increased chromocenter fragmentation, defective chromatin condensation, abnormal acrosome formation, and defective mitochondrial activity contributed to decreased sperm production and defective sperm that resulted in Bscl2 -/- male infertility. (elsevier.com)
  • USP8/ESCRT-0-labeled vesicles, monitored by fluorescence microscopy, were found to contribute to acrosome formation while USP8 can directly link, via its MIT domain, the labeled vesicles/developing acrosome to microtubules, which could favor both acrosome assembly and shaping. (elsevier.com)
  • The p47phox, but not p22phox, was detected in the exocytic vesicles of the acrosome. (sciencecentral.in)
  • Monoclonal antibodies were raised against unfixed acrosome-reacted guinea pig sperm and screened by indirect immunofluorescence for binding to the equatorial segment. (biologists.org)