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.
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.
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.
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.
A tough transparent membrane surrounding the OVUM. It is penetrated by the sperm during FERTILIZATION.
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.
A trypsin-like enzyme of spermatozoa which is not inhibited by alpha 1 antitrypsin.
The anterior portion of the spermatozoon (SPERMATOZOA) that contains mainly the nucleus with highly compact CHROMATIN material.
Male germ cells derived from the haploid secondary SPERMATOCYTES. Without further division, spermatids undergo structural changes and give rise to SPERMATOZOA.
The fusion of a spermatozoon (SPERMATOZOA) with an OVUM thus resulting in the formation of a ZYGOTE.
The process of germ cell development in the male from the primordial germ cells, through SPERMATOGONIA; SPERMATOCYTES; SPERMATIDS; to the mature haploid SPERMATOZOA.
Proteins which are found in eggs (OVA) from any species.
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.
Lectin purified from peanuts (ARACHIS HYPOGAEA). It binds to poorly differentiated cells and terminally differentiated cells and is used in cell separation techniques.
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.
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.
The posterior filiform portion of the spermatozoon (SPERMATOZOA) that provides sperm motility.
The plasma membrane of the egg.
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).
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.
A mature haploid female germ cell extruded from the OVARY at OVULATION.
A genus of STARFISH in the family Asteriidae. One species, Asterias rubens, is the most common in the north-east Atlantic region.
The inability of the male to effect FERTILIZATION of an OVUM after a specified period of unprotected intercourse. Male sterility is permanent infertility.
Somewhat flattened, globular echinoderms, having thin, brittle shells of calcareous plates. They are useful models for studying FERTILIZATION and EMBRYO DEVELOPMENT.
An assisted reproductive technique that includes the direct handling and manipulation of oocytes and sperm to achieve fertilization in vitro.
A TETRACYCLINE with a 7-chloro substitution.
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.
Cellular release of material within membrane-limited vesicles by fusion of the vesicles with the CELL MEMBRANE.
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.
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 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.
The middle piece of the spermatozoon is a highly organized segment consisting of MITOCHONDRIA, the outer dense fibers and the core microtubular structure.
Agglutination of spermatozoa by antibodies or autoantibodies.
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
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.
A family of herbivorous leaping MAMMALS of Australia, New Guinea, and adjacent islands. Members include kangaroos, wallabies, quokkas, and wallaroos.
Chemical agents that increase the permeability of CELL MEMBRANES to CALCIUM ions.
Amidines substituted with a benzene group. Benzamidine and its derivatives are known as peptidase inhibitors.
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 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.
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.
A count of SPERM in the ejaculum, expressed as number per milliliter.
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.
The lipid- and protein-containing, selectively permeable membrane that surrounds the cytoplasm in prokaryotic and eukaryotic cells.
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.
The capacity to conceive or to induce conception. It may refer to either the male or female.
A species of the true toads, Bufonidae, found in South America.
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.
Derivatives of PHOSPHATIDYLCHOLINES obtained by their partial hydrolysis which removes one of the fatty acid moieties.
The emission of SEMEN to the exterior, resulting from the contraction of muscles surrounding the male internal urogenital ducts.
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.
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.
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.
Passive or active movement of SPERMATOZOA from the testicular SEMINIFEROUS TUBULES through the male reproductive tract as well as within the female reproductive tract.
Echinoderms having bodies of usually five radially disposed arms coalescing at the center.
A species of SWINE, in the family Suidae, comprising a number of subspecies including the domestic pig Sus scrofa domestica.
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.
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.
A subfamily in the family MURIDAE, comprising the hamsters. Four of the more common genera are Cricetus, CRICETULUS; MESOCRICETUS; and PHODOPUS.
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)
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).
A polyether antibiotic which affects ion transport and ATPase activity in mitochondria. It is produced by Streptomyces hygroscopicus. (From Merck Index, 11th ed)
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.
Glycoproteins found on the membrane or surface of cells.
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).
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.
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.
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.
Inorganic and organic derivatives of sulfuric acid (H2SO4). The salts and esters of sulfuric acid are known as SULFATES and SULFURIC ACID ESTERS respectively.
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.
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)
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)
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.
Chemical substances or agents with contraceptive activity in males. Use for male contraceptive agents in general or for which there is no specific heading.
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.
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 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.
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.
A subfamily in the family MURIDAE, comprising the Old World MICE and RATS.
Conjugated protein-carbohydrate compounds including mucins, mucoid, and amyloid glycoproteins.
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.
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.
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.
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.
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.
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.
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)
Fucose is a monosaccharide that is commonly found in the cell walls of bacteria and is involved in the formation of glycoproteins and glycolipids.
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.
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)
Physiologically inactive substances that can be converted to active enzymes.
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.
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.
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.
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.
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 in which a polyacrylamide gel is used as the diffusion medium.
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)

Acrosin is an enzyme that is produced by sperm cells and is responsible for the penetration of the zona pellucida, the outer layer of the egg, during fertilization. It is a serine protease that cleaves the zona pellucida glycoproteins, allowing the sperm to penetrate and fertilize the egg. Acrosin is essential for successful fertilization and is therefore an important factor in male fertility.

Egg proteins are the proteins found in eggs. They are a rich source of essential amino acids, which are the building blocks of proteins in the body. Egg proteins are commonly used in the medical field as a dietary supplement for people who are unable to consume enough protein through their regular diet, such as people with certain medical conditions or athletes who engage in strenuous physical activity. Egg proteins are also used in the production of medical products such as vaccines and antibodies.

Calcimycin, also known as FK506, is a medication that belongs to a class of drugs called immunosuppressants. It is primarily used to prevent organ rejection in people who have received a transplant, such as a kidney or liver transplant. Calcimycin works by inhibiting the activity of a protein called calcineurin, which plays a key role in the activation of T-cells, a type of white blood cell that is involved in the immune response. By inhibiting calcineurin, calcimycin helps to suppress the immune system and reduce the risk of organ rejection. Calcimycin is usually given as an oral tablet or as an injection. It can cause side effects such as headache, nausea, and diarrhea, and it may interact with other medications.

Peanut agglutinin (PNA) is a lectin, which is a type of protein that binds to specific carbohydrate structures on the surface of cells. It is derived from the seeds of the peanut plant (Arachis hypogaea) and has been used in medical research and diagnostics for several purposes. One of the main uses of PNA is in the diagnosis of certain types of cancer, particularly leukemia and lymphoma. PNA binds to specific carbohydrate structures on the surface of cancer cells, allowing them to be identified and distinguished from normal cells. This can be useful in identifying the type and stage of cancer, as well as monitoring the effectiveness of treatment. PNA has also been used in the diagnosis of other conditions, such as autoimmune diseases and infectious diseases. In these cases, PNA is used to identify specific types of immune cells or pathogens that are present in the body. In addition to its diagnostic uses, PNA has been studied for its potential therapeutic applications. For example, it has been shown to have anti-inflammatory properties and may be useful in treating conditions such as inflammatory bowel disease and rheumatoid arthritis. Overall, peanut agglutinin is a valuable tool in the medical field, with a wide range of potential applications in research and diagnostics.

Infertility, male refers to the inability of a man to produce viable sperm or to deliver them to his partner in a way that can result in pregnancy. This can be caused by a variety of factors, including genetic abnormalities, hormonal imbalances, infections, injuries to the reproductive organs, or certain medications or environmental factors. Male infertility can be diagnosed through a series of tests, including semen analysis, hormone testing, and imaging studies. Treatment options for male infertility may include medications, surgery, or assisted reproductive technologies such as in vitro fertilization (IVF).

Chlortetracycline is an antibiotic medication that is used to treat a variety of bacterial infections, including respiratory tract infections, urinary tract infections, skin infections, and sexually transmitted infections. It works by inhibiting the growth of bacteria and is often used in combination with other medications to treat more severe infections. Chlortetracycline is available in both oral and injectable forms and is typically prescribed for short-term use. It is important to follow the dosage instructions provided by your healthcare provider and to complete the full course of treatment, even if you start to feel better before the medication is finished. Like all medications, chlortetracycline can cause side effects, including nausea, vomiting, diarrhea, and an allergic reaction. It is important to talk to your healthcare provider if you experience any side effects while taking this medication.

Seminal plasma proteins are proteins found in the fluid portion of semen. They are produced by various cells within the male reproductive system, including the prostate gland, seminal vesicles, and epididymis. These proteins play a number of important roles in the reproductive process, including protecting and nourishing sperm cells, facilitating sperm movement, and contributing to the viscosity of semen. Some of the most well-known seminal plasma proteins include prostate-specific antigen (PSA), fructose, and citrate. Abnormal levels of seminal plasma proteins can sometimes be an indication of certain medical conditions, such as prostate cancer or infections of the reproductive system.

Rab3A GTP-Binding Protein is a small GTPase protein that plays a crucial role in regulating the transport of synaptic vesicles to the presynaptic membrane in neurons. It is involved in the exocytosis of neurotransmitters, which is the process by which neurons communicate with each other and with other cells in the body. Rab3A is expressed in a wide range of tissues, including the brain, spinal cord, heart, and pancreas, and is involved in a variety of cellular processes beyond neurotransmitter release. It has been implicated in the regulation of insulin secretion, the development of cancer, and the pathogenesis of neurodegenerative diseases such as Alzheimer's and Parkinson's disease. Mutations in the RAB3A gene have been associated with several inherited disorders, including Charcot-Marie-Tooth disease type 2A (CMT2A), a peripheral neuropathy characterized by weakness and wasting of the muscles in the legs and feet.

Calcium is a chemical element with the symbol Ca and atomic number 20. It is a vital mineral for the human body and is essential for many bodily functions, including bone health, muscle function, nerve transmission, and blood clotting. In the medical field, calcium is often used to diagnose and treat conditions related to calcium deficiency or excess. For example, low levels of calcium in the blood (hypocalcemia) can cause muscle cramps, numbness, and tingling, while high levels (hypercalcemia) can lead to kidney stones, bone loss, and other complications. Calcium supplements are often prescribed to people who are at risk of developing calcium deficiency, such as older adults, vegetarians, and people with certain medical conditions. However, it is important to note that excessive calcium intake can also be harmful, and it is important to follow recommended dosages and consult with a healthcare provider before taking any supplements.

Benzamidines are a class of chemical compounds that contain a benzene ring with an amide functional group. They are commonly used as inhibitors of serine proteases, which are enzymes that play important roles in various physiological processes, including blood clotting, inflammation, and digestion. In the medical field, benzamidines are used as anti-inflammatory agents and anticoagulants. They are also used to treat conditions such as peptic ulcers, pancreatitis, and inflammatory bowel disease. Some benzamidines are also used as antiviral agents to treat viral infections such as hepatitis B and C. Benzamidines work by binding to the active site of serine proteases, thereby inhibiting their activity. This inhibition can help to reduce inflammation, prevent blood clotting, and treat various conditions associated with excessive protease activity. However, benzamidines can also have side effects, including nausea, vomiting, and diarrhea, and they may interact with other medications.

Pimozide is a medication that is primarily used to treat schizophrenia and other psychotic disorders. It works by blocking the action of dopamine, a neurotransmitter that is involved in the regulation of mood, movement, and other cognitive functions. Pimozide is typically administered orally in tablet form and is usually taken once or twice a day. It can cause side effects such as drowsiness, dizziness, constipation, and dry mouth, and it may also increase the risk of developing movement disorders such as Parkinson's disease.

CD46 is a protein found on the surface of many different types of cells in the body, including immune cells, epithelial cells, and endothelial cells. It is a member of the complement regulatory protein family and plays a role in regulating the immune system's response to infections and other stimuli. Antigens, CD46 refers to molecules that bind to the CD46 protein on the surface of cells. These antigens can be recognized by the immune system as foreign and trigger an immune response. In some cases, the immune system may mistakenly attack cells that express CD46, leading to autoimmune diseases such as lupus or Goodpasture's syndrome. CD46 is also a target for certain viruses, such as measles virus, which uses it to enter and infect cells. Vaccines against measles virus often contain a small amount of inactivated or weakened measles virus that binds to CD46 on cells, triggering an immune response without causing the disease. Overall, CD46 plays an important role in regulating the immune system and is a target for both the immune system and certain viruses.

Bisbenzimidazole is a class of organic compounds that are commonly used as antifungal agents. They are structurally related to benzimidazole, a heterocyclic compound with a six-membered ring containing one nitrogen atom and one sulfur atom. Bisbenzimidazoles are characterized by the presence of two benzimidazole rings joined by a linker group. In the medical field, bisbenzimidazoles are used to treat a variety of fungal infections, including dermatophytosis (ringworm), candidiasis (yeast infection), and aspergillosis (fungal pneumonia). They work by inhibiting the growth and reproduction of fungi by interfering with their cell division and metabolism. The most commonly used bisbenzimidazole in medicine is miconazole, which is available in various forms, including creams, ointments, and tablets. Other bisbenzimidazoles, such as ketoconazole and itraconazole, are also used to treat fungal infections, but they are typically used for more severe or resistant infections.

Lysophosphatidylcholines (LPCs) are a type of phospholipid that are found in cell membranes and are involved in various cellular processes. They are characterized by the presence of a fatty acid chain attached to a glycerol backbone with a phosphate group and a choline head group. In the medical field, LPCs have been studied for their potential role in various diseases, including cancer, cardiovascular disease, and neurodegenerative disorders. They have been shown to modulate cell signaling pathways, affect cell proliferation and migration, and contribute to inflammation and oxidative stress. LPCs have also been used as a tool in diagnostic imaging and as a therapeutic agent in the treatment of certain diseases. For example, LPCs have been used as a contrast agent in magnetic resonance imaging (MRI) to visualize the blood-brain barrier and to detect brain tumors. They have also been investigated as a potential treatment for Alzheimer's disease, as they have been shown to improve cognitive function in animal models of the disease.

Progesterone is a hormone that plays a crucial role in the female reproductive system. It is produced by the ovaries and the placenta during pregnancy and is responsible for preparing the uterus for pregnancy and maintaining the pregnancy. Progesterone also helps to regulate the menstrual cycle and can be used as a contraceptive. In addition to its reproductive functions, progesterone has a number of other effects on the body. It can help to reduce inflammation, promote bone density, and regulate mood. Progesterone is also used in medical treatment for a variety of conditions, including menopause, osteoporosis, and certain types of breast cancer. Progesterone is available as a medication in a variety of forms, including oral tablets, injections, and creams. It is important to note that progesterone can have side effects, including nausea, dizziness, and mood changes. It is important to discuss the potential risks and benefits of using progesterone with a healthcare provider before starting treatment.

Fluorescein-5-isothiocyanate (FITC) is a fluorescent dye that is commonly used in the medical field for various diagnostic and research purposes. It is a water-soluble, yellow-green fluorescent dye that is highly sensitive to light and can be easily excited by ultraviolet light. In medical applications, FITC is often used as a fluorescent marker to label cells, proteins, and other molecules. It can be conjugated to antibodies, nucleic acids, and other molecules to enable visualization and analysis of these molecules in cells and tissues. FITC is also used in diagnostic tests, such as flow cytometry and immunofluorescence microscopy, to detect and quantify specific cells or molecules in biological samples. It is also used in research to study cell biology, immunology, and other areas of biomedical science. Overall, FITC is a valuable tool in the medical field due to its high sensitivity, specificity, and ease of use.

Nigericin is a natural antibiotic produced by the bacterium Streptomyces niger. It is a polypeptide antibiotic that has a broad spectrum of activity against gram-positive bacteria, including methicillin-resistant Staphylococcus aureus (MRSA) and vancomycin-resistant Enterococcus (VRE). Nigericin is also effective against gram-negative bacteria, fungi, and viruses. In the medical field, nigericin is used as an antiseptic and disinfectant, particularly in the treatment of skin and wound infections. It is also used as an antifungal agent to treat fungal infections such as candidiasis and aspergillosis. Nigericin has also been studied for its potential use in cancer therapy, as it has been shown to selectively kill cancer cells while sparing healthy cells. However, nigericin is not commonly used in clinical practice due to its potential toxicity and side effects, including skin irritation, nausea, vomiting, and diarrhea. It is also not approved by regulatory agencies for use in humans.

Membrane glycoproteins are proteins that are attached to the cell membrane through a glycosyl group, which is a complex carbohydrate. These proteins play important roles in cell signaling, cell adhesion, and cell recognition. They are involved in a wide range of biological processes, including immune response, cell growth and differentiation, and nerve transmission. Membrane glycoproteins can be classified into two main types: transmembrane glycoproteins, which span the entire cell membrane, and peripheral glycoproteins, which are located on one side of the membrane.

Receptors, cell surface are proteins that are located on the surface of cells and are responsible for receiving signals from the environment. These signals can be chemical, electrical, or mechanical in nature and can trigger a variety of cellular responses. There are many different types of cell surface receptors, including ion channels, G-protein coupled receptors, and enzyme-linked receptors. These receptors play a critical role in many physiological processes, including sensation, communication, and regulation of cellular activity. In the medical field, understanding the function and regulation of cell surface receptors is important for developing new treatments for a wide range of diseases and conditions.

Sulfuric acid is a strong acid that is commonly used in the medical field for various purposes. It is a colorless, odorless, and corrosive liquid that is highly soluble in water. In the medical field, sulfuric acid is used as a chemical reagent in various laboratory procedures, such as the preparation of buffers, the extraction of proteins, and the analysis of biological samples. It is also used as a component in some medications, such as certain antacids and laxatives. However, sulfuric acid is highly caustic and can cause severe burns and tissue damage if it comes into contact with the skin or eyes. Therefore, it is important to handle sulfuric acid with extreme caution and to follow proper safety protocols when working with it.

Hyaluronoglucosaminidase (also known as hyaluronidase) is an enzyme that breaks down hyaluronic acid, a complex carbohydrate found in the extracellular matrix of connective tissue. It is primarily produced by cells in the immune system, such as neutrophils and macrophages, and is involved in the process of inflammation. In the medical field, hyaluronoglucosaminidase is used as a diagnostic tool to detect and monitor certain diseases, such as cancer, rheumatoid arthritis, and osteoarthritis. It is also used in certain medical procedures, such as tissue repair and wound healing, to break down hyaluronic acid and facilitate the migration of cells to the site of injury. In addition, hyaluronoglucosaminidase has been studied for its potential therapeutic applications in various diseases, including cancer, cardiovascular disease, and neurodegenerative disorders. However, more research is needed to fully understand its role in these conditions and to develop effective treatments.

Pentoxifylline is a medication that is used to improve blood flow in the body. It is primarily used to treat conditions such as intermittent claudication (a condition in which the muscles cramp and become painful when walking due to poor blood flow), and to reduce the risk of blood clots after surgery. Pentoxifylline works by relaxing the muscles in the blood vessels, which allows blood to flow more easily. It is usually taken by mouth in the form of tablets.

Glycoproteins are a type of protein that contains one or more carbohydrate chains covalently attached to the protein molecule. These carbohydrate chains are made up of sugars and are often referred to as glycans. Glycoproteins play important roles in many biological processes, including cell signaling, cell adhesion, and immune response. They are found in many different types of cells and tissues throughout the body, and are often used as markers for various diseases and conditions. In the medical field, glycoproteins are often studied as potential targets for the development of new drugs and therapies.

Plant lectins are a class of proteins found in many plants that have a specific affinity for binding to carbohydrates. They are known to have a wide range of biological activities, including antiviral, antibacterial, antifungal, and antitumor properties. In the medical field, plant lectins are being studied for their potential use in the treatment of various diseases, including cancer, viral infections, and autoimmune disorders. They are also being investigated as adjuvants in vaccines to enhance the immune response. Some plant lectins have been approved for use as drugs, such as concanavalin A, which is used to diagnose hepatitis B and C infections.

Glycoconjugates are complex molecules that consist of carbohydrates (sugars) covalently attached to other molecules, such as proteins, lipids, or nucleic acids. In the medical field, glycoconjugates play important roles in various biological processes, including cell signaling, immune response, and disease pathogenesis. Glycoconjugates are found on the surface of cells and in the extracellular matrix, and they can be modified in response to various stimuli. For example, changes in the glycosylation patterns of proteins can affect their function and stability, and altered glycosylation has been implicated in many diseases, including cancer, autoimmune disorders, and infectious diseases. In addition to their biological functions, glycoconjugates are also important targets for drug discovery and development. Many drugs and vaccines target specific glycoconjugates on the surface of cells or viruses, and the development of glycoconjugate-based therapies is an active area of research in the medical field.

Fucose is a monosaccharide that is commonly found in the cell walls of bacteria, fungi, and plants. In the medical field, fucose is often used as a diagnostic tool to identify certain types of bacteria and fungi. It is also used in the production of certain types of vaccines and antibiotics. Additionally, fucose has been shown to have potential therapeutic applications, such as in the treatment of cancer and inflammatory diseases.

In the medical field, the term "elements" typically refers to the basic building blocks of matter that make up the human body. These elements include: 1. Hydrogen: The most abundant element in the human body, found in water, proteins, and carbohydrates. 2. Carbon: The second most abundant element in the body, found in carbohydrates, proteins, and fats. 3. Oxygen: Essential for respiration and energy production, found in the air we breathe and in water. 4. Nitrogen: Found in proteins and nucleic acids. 5. Calcium: Essential for bone health and nerve function, found in dairy products, leafy greens, and seafood. 6. Phosphorus: Essential for bone health and energy production, found in dairy products, meat, and whole grains. 7. Sodium: Regulates fluid balance and nerve function, found in table salt and many processed foods. 8. Potassium: Regulates fluid balance and nerve function, found in fruits, vegetables, and dairy products. 9. Chlorine: Regulates fluid balance and helps with digestion, found in table salt and many processed foods. 10. Magnesium: Essential for muscle and nerve function, found in leafy greens, nuts, and whole grains. These elements are essential for the proper functioning of the human body and are obtained through a balanced diet and proper hydration.

Enzyme precursors are the inactive forms of enzymes that are synthesized in the body and need to be activated before they can perform their specific functions. Enzymes are proteins that catalyze chemical reactions in the body, and they play a crucial role in various physiological processes such as digestion, metabolism, and energy production. Enzyme precursors are usually synthesized in the liver and other organs and are transported to the cells where they are needed. Once inside the cells, they are activated by a process called proteolysis, which involves the cleavage of specific amino acid bonds in the enzyme precursor molecule. Enzyme precursors are important for maintaining proper enzyme function and activity in the body. Deficiencies in enzyme precursors can lead to enzyme deficiencies, which can cause a range of health problems. For example, a deficiency in the enzyme precursor for the enzyme lactase can lead to lactose intolerance, a condition in which the body is unable to digest lactose, a sugar found in milk and other dairy products.

Membrane proteins are proteins that are embedded within the lipid bilayer of a cell membrane. They play a crucial role in regulating the movement of substances across the membrane, as well as in cell signaling and communication. There are several types of membrane proteins, including integral membrane proteins, which span the entire membrane, and peripheral membrane proteins, which are only in contact with one or both sides of the membrane. Membrane proteins can be classified based on their function, such as transporters, receptors, channels, and enzymes. They are important for many physiological processes, including nutrient uptake, waste elimination, and cell growth and division.

Lectins are a class of proteins that are found in many plants, animals, and microorganisms. They are characterized by their ability to bind to specific carbohydrates, such as sugars and starches, on the surface of cells. In the medical field, lectins have been studied for their potential therapeutic applications. For example, some lectins have been shown to have antiviral, antibacterial, and antifungal properties, and may be useful in the development of new drugs to treat infections. Lectins have also been used as research tools to study cell-cell interactions and to identify specific cell surface markers. In addition, some lectins have been used in diagnostic tests to detect specific diseases or conditions, such as cancer or diabetes. However, it is important to note that not all lectins are safe or effective for medical use, and some may even be toxic. Therefore, the use of lectins in medicine requires careful consideration and testing to ensure their safety and efficacy.

Monensin is a polyether antibiotic that is used in veterinary medicine to treat various infections caused by gram-positive and gram-negative bacteria, as well as protozoa. It works by inhibiting the growth and reproduction of these microorganisms by disrupting their cell membranes. In the medical field, monensin is primarily used to treat cattle and other livestock, particularly for respiratory and digestive infections caused by bacteria such as Mycoplasma bovis, Mannheimia haemolytica, and Escherichia coli. It is also used to treat protozoal infections such as coccidiosis in poultry and sheep. Monensin is available in various forms, including oral drenches, injectable solutions, and feed additives. It is generally well-tolerated by animals, although some may experience mild side effects such as diarrhea, decreased appetite, and weight loss. As with any medication, it is important to follow the recommended dosage and administration guidelines provided by a veterinarian.

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 (front) half of the head in the spermatozoa (sperm cells) of ... This can be done to serve as a positive control when assessing the acrosome reaction of a sperm sample by flow cytometry or ... Acroplaxome "acrosome definition - Dictionary - MSN Encarta". Archived from the original on 2009-02-14. Retrieved 2007-08-15. ...
Therefore, sperm cells go through a process known as the acrosome reaction, which is the reaction that occurs in the acrosome ... At least 200 cells are considered arbitrarily and classified as either acrosome intact (fluorescing bright green), or acrosome ... the membrane surrounding the acrosome fuses with the plasma membrane of the sperm's head, exposing the contents of the acrosome ... The acrosome is a membrane-bound organelle of Golgi apparatus origin, commonly located at the tip of the head of mature ...
Equatorin, sperm acrosome associated is a protein that in humans is encoded by the EQTN gene. GRCm38: Ensembl release 89: ... "Entrez Gene: Equatorin, sperm acrosome associated". Ruiz A, Pujana MA, Estivill X (December 2000). "Isolation and ... is related to acrosome formation in murine testis". FEBS Letters. 580 (17): 4266-73. doi:10.1016/j.febslet.2006.06.010. PMID ...
Sperm guidance Acrosome reaction Oocyte Wessel, GM; Brooks, JM; Green, E; Haley, S; Voronina, E; Wong, J; Zaydfudim, V; Conner ... "Egg-jelly signal molecules for triggering the acrosome reaction in starfish spermatozoa". The International Journal of ...
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. ... Abou-haila, A; Tulsiani, DR (1 May 2009). "Signal transduction pathways that regulate sperm capacitation and the acrosome ...
Both of Jean's Studies on the Acrosome (the second being published in 1954) pioneered the use of the electron microscope and ... Sperm Acrosome Biogenesis and Function During Fertilization. Springer. ISBN 978-3-319-30567-7. Mohri, Hideo (2019-03-26). ...
... can be used to fluorescently tag the acrosome of sperm cells, which can be then used to assess the status of the acrosome using ... Lu HY, Lu JC, Hu YA, Wang YM, Huang YF (2002). "[Detection of human sperm morphology and acrosome reaction with Coomassie ... Ozaki T, Takahashi K, Kanasaki H, Miyazaki K (2002). "Evaluation of acrosome reaction and viability of human sperm with two ... These media can be supplemented with other chemicals to induce hyperactivated sperm motility and/or the acrosome reaction. For ...
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 ...
This is because the acrosome reaction has to take place and thousands of sperm cells have to be involved in IVF. Once ... With this method, the acrosome reaction is skipped. There are several differences between classic IVF and ICSI. However, the ...
They have parental care.[unreliable source?] It has an acrosome shaped like a beaker. They reproduce by iteroparous.[unreliable ...
The lack of acrosome can be ascertained by either morphology staining or immunofluorescence. Until 1995, the only options for ... Kang-Decker, N.; Mantchev, G. T.; Juneja, S. C.; McNiven, M. A.; van Deursen, J. M. (2001-11-16). "Lack of acrosome formation ... Given the absence of the acrosome, these sperm are unable to penetrate the oocyte and are unable to achieve fertilization ... There are two types of globozoospermia: Type 1 globozoospermia exhibits a complete lack of acrosome and acrosomal enzymes and ...
This test evaluates the acrosome reaction of human spermatozoa. However, the incidence of acrosome reaction in freely swimming ... "Acrosome reaction of human spermatozoa in zona-free hamster egg penetration test". Fertility and Sterility. 50 (6): 954-9. doi: ...
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". ...
The second process in sperm activation is the acrosome reaction. This involves releasing the contents of the acrosome, which ... As the spermatozoon approaches the egg, it undergoes the acrosome reaction in which the membrane surrounding the acrosome fuses ... 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 ...
ZP3 is then involved in the induction of the acrosome reaction, whereby a spermatozoon releases the contents of the acrosomal ... This structure binds spermatozoa, and is required to initiate the acrosome reaction. In the mouse (the best characterised ... They bind to capacitated spermatozoa and induce the acrosome reaction. Successful fertilization depends on the ability of sperm ... and enable the acrosome reaction for the successful adhesion and penetration by the sperm cell. Also allows correct embryo ...
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 ...
... F is thereby important to prevent a premature acrosome reaction. Found in Cumulus Oophorus, stimulates binding of ... thereby inhibiting acrosome reaction and sperm-egg binding. Upon de-glycosilation, glycodelin F dissociates from the sperm and ...
The acrosome ideally should occupy between the 40-70% of the head. The IMSI may be used in cases with high levels of DNA ...
... and Protein Tyrosine Phosphorylation on Capacitation and the Spontaneous Acrosome Reaction of Hamster Sperm". Biology 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. ...
1995). "Human SP-10: acrosomal distribution, processing, and fate after the acrosome reaction". Biol. Reprod. 51 (6): 1222-31. ...
Bleil JD, Wassarman PM (July 1990). "Identification of a ZP3-binding protein on acrosome-intact mouse sperm by photoaffinity ...
NYD-SP27 is a unique DF as it is intrinsic to the sperm acrosome and inhibits the action of phospholipase C that is necessary ... However, some DFs have been identified that are located on the acrosome of sperm. Normally, capacitation is initiated through ...
Acrosome reaction, cortical reaction and sperm-egg fusion". Zoomorphology. 108 (4): 229-243. doi:10.1007/BF00312223. ISSN 0720- ...
... and acrosome of developing spermatids". J. Cell Biol. 137 (3): 657-69. doi:10.1083/jcb.137.3.657. PMC 2139879. PMID 9151672. ...
... lacking flagella and acrosomes. When self-inseminated, the wild-type worm lays about 300 eggs. When inseminated by a male, the ...
Involvement of zinc in the regulation of pHi, motility, and acrosome reactions in sea urchin sperm. D L Clapper, D L Clapper ... D L Clapper, J A Davis, P J Lamothe, C Patton, D Epel; Involvement of zinc in the regulation of pHi, motility, and acrosome ... Since both sperm motility and acrosome reactions are in part regulated by intracellular pH (pHi), the effect of chelators on ... Regulatory mechanisms of the acrosome reaction revealed by multiview microscopy of single starfish sperm. ...
Please do not hesitate to contact us should you have any queries. You can do so using our chat system on the website, by email to [email protected] or by phone on 087 797 5058. ...
As a result, sperm cells have no acrosome and do not elongate properly. Without an acrosome, the abnormal sperm are unable to ... Normal sperm cells have an oval-shaped head with a cap-like covering called the acrosome. The acrosome contains enzymes that ... The sperm cells of males with globozoospermia, however, have a round head and no acrosome. The abnormal sperm are unable to ... The DPY19L2 protein is involved in the development of the acrosome and elongation of the sperm head, which are integral steps ...
The acrosome, a derivative of the Golgi process, surrounds the nucleus anteriorly and contains enzymes necessary to penetrate ... undergo capacitation and the acrosome reaction to digest the zona pellucida of the oocyte, attach to the inner membrane, and ... the formation of the acrosome and flagella, and the migration of cytoplasmic organelles to their final cellular location. ...
Taken together, we conclude that viability and acrosome integrity could serve as fertility biomarkers in the field and, when ... According to the results, acrosome integrity and viability were the only sperm attributes that were significantly different ... Interestingly, although spermatozoa from low-fertility bulls, on average, had reduced viability and acrosome integrity, this ... Comprehensive functional analysis reveals that acrosome integrity and viability are key variables distinguishing artificial ...
Acrosome , Chloroplast , Cilium/Flagellum , Centriole , Endoplasmic reticulum , Golgi apparatus , Lysosome , Melanosome , ...
... localization of PLC zeta in non-capacitated and capacitated sperm and in sperm treated with ionophore to induce the acrosome ... C zeta is localized to acrosomal and post-acrosomal regions and undergoes dynamic changes during capacitation and the acrosome ... Acrosome, Acrosome Reaction, Animals, Blotting, Northern, Cloning, Molecular, Cricetinae, DNA Primers, Immunoblotting, Male, ... Phospholipase C zeta undergoes dynamic changes in its pattern of localization in sperm during capacitation and the acrosome ...
Sperm from Hyh mice carrying a point mutation in αSNAP have a defect in acrosome reaction. In: PLoS ONE. 2009 ; Vol. 4, No. 3. ... Sperm from Hyh mice carrying a point mutation in αSNAP have a defect in acrosome reaction. PLoS ONE. 2009 Mar 23;4(3):e4963. ... Sperm from Hyh mice carrying a point mutation in αSNAP have a defect in acrosome reaction. / Bátiz, Luis Federico; De Blas, ... Dive into the research topics of Sperm from Hyh mice carrying a point mutation in αSNAP have a defect in acrosome reaction. ...
These Ca2+ and K+ channels are involved in early events of acrosome reactions. Ca2+ channel are susceptible to Cd2+ poisoning ... In both forms of male infertility the ability to undergo an acrosome reaction decreases. Reverse transcriptase-polymerase chain ... acrosome reaction; cadmium; ion channels; lead; male infertility ...
Simons, J.; Fauci, L. A model for the acrosome reaction in mammalian sperm. Bull. Math. Biol. 2018, 80, 2481-2501. [Google ...
MeSH Terms: Acrosome/chemistry; Acrosome/metabolism*; Animals; Female; Fertilization/physiology*; Gene Expression Regulation; ... specific activities that affect acrosome biogenesis during spermatogenesis or interfere with acrosome function in mature sperm ... Abstract: The acrosome, a single exocytotic vesicle on the head of sperm, has an essential role in fertilization, but the exact ... The acrosome contains dozens of secretory proteins that are packaged into the forming structure during spermatogenesis; many of ...
PRKRA was stained in region adjacent to the acrosome of step 17 spermatids (arrows). No PRKRA staining was noted in control ... This staining was visible in the region surrounding the acrosome of step 10 spermatids and expanded to whole head and finally ...
2008) Regulating the acrosome reaction The International Journal of Developmental Biology 52:503-510. ...
2022). A Genetically-targeted sensor reveals spatial and temporal dynamics of acrosomal calcium and sperm acrosome exocytosis. ...
Insulin and leptin enhance human sperm motility, acrosome reaction and nitric oxide production FREE Fanuel Lampiao and Stefan S ...
Electron transmission microscopy of outer sperm membranes showed higher (P,0,05) percentage of sperm with lost acrosomes in ... This could be attributed to a better acrosome exocytosis, associated to the absence of certain membrane proteins. ...
18 It is responsible for initiating the acrosome reaction in capacitated sperm.19 ...
DHA is a component of the acrosome, an enzyme present in the head of sperm cells. This enzyme is essential for the sperms ... The amount of DHA required to form the acrosome is minute, and the body can produce enough of the fatty acid using EPA to ...
... the process by which spermatozoa in the ampullary portion of a uterine tube become capable of going through the acrosome ...
acrosome. November 12, 2018 * undying. November 21, 2018 * neem. November 15, 2018 ...
This portion is called acrosome . Tail is long cylindrical process attached to posterior end of head and it arises from ...
Instead, may protect sperm from premature acrosome reaction in the epididymis by binding to lipid peroxides, which might ...
1. Bindin in acrosomes and bindin receptors on egg vitelline membrane. 2. Bindin in egg membrane and bindin receptors in ... acrosomes. 3. Resact on egg jelly and bindin on sperm membrane. 4. Proteasomes on egg membranes and complex sugars on sperm ...
How sperm prepares to fertilize: SNARE mediated acrosome docking and priming to the plasma membrane ...
The tip of the sperm head is the portion called the acrosome, which enables the sperm to penetrate the egg. The midpiece ... The tip of the sperm head is the portion called the acrosome, which enables the sperm to penetrate the egg. The midpiece ...
Lax Y, Grossman S, Rubinstein S, Magid N, Breitbart H: Role of lipoxygenase in the mechanism of acrosome reaction in mammalian ... Human Sperm Acrosome Reaction. Edited by: Fénichel P, Parinaud J. 1995, John Libbey Eurotext, Collioure, 348- ... It has functional significance and is involved in hyperactivation, capacitation, and the acrosome reaction. An abnormally large ... Both are implicated in calcium level oscillations during hyperactivation and the acrosome reaction. Ropporin is yet another ...
Assertion (A) - Head of the sperm consists of acrosome and mitochondria. Reason (R) - Acrosome contains spiral rows of ...
  • Involvement of zinc in the regulation of pHi, motility, and acrosome reactions in sea urchin sperm. (
  • Since both sperm motility and acrosome reactions are in part regulated by intracellular pH (pHi), the effect of chelators on the sperm pHi was examined by using the fluorescent pH sensitive probe, 9-aminoacridine, EDTA depresses sperm pHi in both species, and 0.1 microM free Zn+2 reverses this pHi depression. (
  • When sperm are diluted into media that contain chelators, both NH4Cl and monensin (a Na+/H+ ionophore) increase the sperm pHi and reverse the chelator inhibition of sperm motility and acrosome reactions. (
  • The results of this study are consistent with the involvement of a trace metal (probably zinc) in the pHi regulation of sea urchin sperm and indicate a likely mechanism for the previously observed effects of chelators on sperm motility and acrosome reactions. (
  • Normal sperm cells have an oval-shaped head with a cap-like covering called the acrosome. (
  • The acrosome contains enzymes that break down the outer membrane of an egg cell, allowing the sperm to fertilize the egg. (
  • The sperm cells of males with globozoospermia, however, have a round head and no acrosome. (
  • The DPY19L2 protein is involved in the development of the acrosome and elongation of the sperm head, which are integral steps in sperm cell maturation. (
  • As a result, sperm cells have no acrosome and do not elongate properly. (
  • Without an acrosome, the abnormal sperm are unable to get through the outer membrane of an egg cell to fertilize it, leading to infertility in affected men. (
  • A recurrent deletion of DPY19L2 causes infertility in man by blocking sperm head elongation and acrosome formation. (
  • According to the results, acrosome integrity and viability were the only sperm attributes that were significantly different between high- and low-fertility bulls. (
  • Taken together, we conclude that viability and acrosome integrity could serve as fertility biomarkers in the field and, when used alongside other sperm attributes, may be useful in detecting low-fertility bulls. (
  • Phospholipase C zeta undergoes dynamic changes in its pattern of localization in sperm during capacitation and the acrosome reaction. (
  • Next, we used hamster and mouse models to investigate the localization of PLC zeta in non-capacitated and capacitated sperm and in sperm treated with ionophore to induce the acrosome reaction. (
  • CONCLUSION(S): Phospholipase C zeta is localized to acrosomal and post-acrosomal regions and undergoes dynamic changes during capacitation and the acrosome reaction, indicating a potential role regulating not only egg activation but other sperm functions. (
  • When stimulated with progesterone or A23187 (a calcium ionophore), sperm from these animals had a defective acrosome reaction. (
  • The acrosome, a single exocytotic vesicle on the head of sperm, has an essential role in fertilization, but the exact mechanisms by which it facilitates sperm-egg interactions remain unresolved. (
  • This review focuses on recent findings using genetically modified mice (gene knockouts and transgenic 'green acrosome' mice) to study the effects of eliminating acrosomal matrix-associated proteins on sperm structure and function. (
  • Some gene knockouts produce infertile phenotypes with obviously missing, specific activities that affect acrosome biogenesis during spermatogenesis or interfere with acrosome function in mature sperm. (
  • 0,05) percentage of sperm with lost acrosomes in Percoll® treated samples compared to Swim up. (
  • Instead, may protect sperm from premature acrosome reaction in the epididymis by binding to lipid peroxides, which might otherwise interact with phospholipase A2 and induce the acrosome reaction. (
  • and when exposed to egg jelly, an acrosome reaction is induced. (
  • In the presence of a variety of structurally different metal chelators (0.1-1 mM EDTA, EGTA, phenanthroline, dipyridyl, cysteine, or dithiothreitol), motility initiation is delayed and the acrosome reaction is inhibited. (
  • In both forms of male infertility the ability to undergo an acrosome reaction decreases. (
  • AZP-Ab and its association with ASA in quired to activate the acrosome reaction [ 1 ]. (
  • Vps13b is required for acrosome biogenesis through functions in Golgi dynamic and membrane trafficking. (
  • This could be attributed to a better acrosome exocytosis, associated to the absence of certain membrane proteins. (
  • These Ca2+ and K+ channels are involved in early events of acrosome reactions. (
  • Interestingly, although spermatozoa from low-fertility bulls, on average, had reduced viability and acrosome integrity, this response varied considerably from bull to bull. (
  • In general, these studies enable the reassessment of paradigms to explain acrosome formation and function and provide novel, objective insights into the roles of acrosomal matrix proteins in fertilization. (
  • Incubation of epididymal spermatozoa in medium containing 1 microgram/ml and 10 micrograms/ml progesterone significantly increased the acrosome reaction as monitored by a chlortetracycline fluorescence assay. (
  • Here we show that spermatozoa in gene-edited mice lacking a BTBD18 targeted pachytene piRNA cluster on Chr18 have severe sperm head dysmorphology, poor motility, impaired acrosome exocytosis, zona pellucida penetration and are sterile. (
  • Sperm was collected from the epididymis and several parameters of sperm function, such as sperm density, motility, viability, mitochondrial function, acrosome integrity and morphology, were evaluated. (
  • Thus, the results obtained indicate that, together with impaired motility, the effect of lead toxicity on acrosome integrity, leading to premature reaction, may compromise the ability of sperm to fertilize the oocyte. (
  • Calcium regulation is highly important for fertility and can influence motility, capacitation, and acrosome reaction. (
  • In adjusted models, semen quality parameters were associated with significantly shorter TTP as measured by FORs >1: percent motility, strict and traditional morphology, sperm head width, elongation factor, and acrosome area. (
  • In many animals, the acrosome is a secretory vesicle with exocytosis essential for sperm penetration through the egg coats. (
  • We provide evidence that the acrosome induces changes in sperm plasma membrane, exclusive of exocytosis and through the action of the acrosomal membrane protein Snky. (
  • The recent observation that human sperm bind to the mouse zona pellucida only when huZP2 replaces the endogenous mouse protein contradicts long-standing models of ZP3 acting as the primary mediator of gametes recognition and inducer of sperm acrosome exocytosis. (
  • Sperm from transgenic mice in which nuclear protamines are tagged with EGFP and soluble mCherry is released upon acrosome exocytosis were imaged by time-lapse microscopy. (
  • We conclude that the N-terminus of ZP2 is the ligand for gamete recognition and acrosome exocytosis is induced by the zona matrix during sperm penetration. (
  • Inhibition of the influx by three inhibitors of the zona pellucida induced acrosome reaction: tyrphostin A48, pertussis toxin, and 3-quinuclidinyl benzilate. (
  • 7. Differential sensitivity of progesterone- and zona pellucida-induced acrosome reactions to pertussis toxin. (
  • 10. Solubilization and partial purification from mouse sperm membranes of the specific binding activity for 3-quinuclidinyl benzilate, a potent inhibitor of the zona pellucida-induced acrosome reaction. (
  • Only acrosome-intact sperm bind to the surface of the zona pellucida and only acrosome-reacted sperm are present in the perivitelline space after penetration of the zona pellucida. (
  • Intriguingly, in the absence of ZP1, a looser zona matrix is formed to which acrosome-intact sperm bind and penetrate, but remain acrosome-intact. (
  • The zona pellucida (ZP) is a glycoprotein membrane surrounding the oocyte and is required to activate the acrosome reaction [1]. (
  • The acrosome contains enzymes that break down the outer membrane of an egg cell, allowing the sperm to fertilize the egg. (
  • Enzymes are released and the plamsa membrane over the acrosome is dissolved. (
  • Acrosome, derived from LYSOSOMES , is a membrane-bound organelle that contains the required hydrolytic and proteolytic enzymes necessary for sperm penetration of the egg in FERTILIZATION . (
  • The DPY19L2 protein is involved in the development of the acrosome and elongation of the sperm head, which are integral steps in sperm cell maturation. (
  • A recurrent deletion of DPY19L2 causes infertility in man by blocking sperm head elongation and acrosome formation. (
  • The mutant phenotype arises from aberrant formation of proacrosomal vesicles, distortion of the trans-Golgi network, and up-regulation of GOLGA2 transcripts and protein associated with acrosome dysgenesis. (
  • Using a transgene that expresses an active Snky-Green fluorescent protein fusion (Snky-GFP), we show that the protein is localized to the acrosome, a membrane-bound vesicle located at the apical tip of sperm. (
  • Snky-GFP also allowed us to follow the fate of the protein and the acrosome during fertilization. (
  • VAMP3 is a membrane protein that helps dock the sperm acrosome to the plasma membrane-an important process for the acrosome reaction. (
  • 20. [Acrosome reaction and fertilization]. (
  • 13. Calcium channel antagonists inhibit the acrosome reaction and bind to plasma membranes of sea urchin sperm. (
  • VAMP3 is regulated by calcium ions, therefore, disruption of calcium ion channels may inhibit proper acrosome reaction which may impact the sperm's ability to fertilize the egg. (
  • Included in these are failure of the basal body to make normal attachment to the nucleus, failure of acrosomes to develop, and lack of a normal pupulation of perinuclear microtubules. (
  • The sperm cells of males with globozoospermia, however, have a round head and no acrosome. (
  • 17 alpha-OH-progesterone, however, failed to show any effect on the acrosome reaction. (
  • Without an acrosome, the abnormal sperm are unable to get through the outer membrane of an egg cell to fertilize it, leading to infertility in affected men. (
  • In both forms of male infertility the ability to undergo an acrosome reaction decreases. (
  • Normal sperm cells have an oval-shaped head with a cap-like covering called the acrosome. (
  • As a result, sperm cells have no acrosome and do not elongate properly. (
  • 9. An influx of extracellular calcium is required for initiation of the human sperm acrosome reaction induced by human follicular fluid. (
  • 17. Initiation of the human sperm acrosome reaction by thapsigargin. (
  • The VAMP3 gene is important for human sperm acrosome reaction. (
  • We relate the characteristics of Drosophila Snky, acrosome function and sperm PMBD to membrane fusion events that occur in other systems. (
  • 19. ERK1/2 mediates sperm acrosome reaction through elevation of intracellular calcium concentration. (
  • However, a decrease in the percentage of intact acrosomes was also observed, mirroring a lead-induced premature acrosome reaction. (