SNARE Proteins: A superfamily of small proteins which are involved in the MEMBRANE FUSION events, intracellular protein trafficking and secretory processes. They share a homologous SNARE motif. The SNARE proteins are divided into subfamilies: QA-SNARES; QB-SNARES; QC-SNARES; and R-SNARES. The formation of a SNARE complex (composed of one each of the four different types SNARE domains (Qa, Qb, Qc, and R)) mediates MEMBRANE FUSION. Following membrane fusion SNARE complexes are dissociated by the NSFs (N-ETHYLMALEIMIDE-SENSITIVE FACTORS), in conjunction with SOLUBLE NSF ATTACHMENT PROTEIN, i.e., SNAPs (no relation to SNAP 25.)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.Acrosome: The cap-like structure covering the anterior portion of SPERM HEAD. 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.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.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.R-SNARE Proteins: SNARE proteins where the central amino acid residue of the SNARE motif is an ARGININE. They are classified separately from the Q-SNARE PROTEINS where the central amino acid residue of the SNARE motif is a GLUTAMINE. This subfamily contains the vesicle associated membrane proteins (VAMPs) based on similarity to the prototype for the R-SNAREs, VAMP2 (synaptobrevin 2).IllinoisSyntaxin 1: A neuronal cell membrane protein that combines with SNAP-25 and SYNAPTOBREVIN 2 to form a SNARE complex that leads to EXOCYTOSIS.Qa-SNARE Proteins: A subfamily of Q-SNARE PROTEINS which occupy the same position as syntaxin 1A in the SNARE complex and which also are most similar to syntaxin 1A in their AMINO ACID SEQUENCE. This subfamily is also known as the syntaxins, although a few so called syntaxins are Qc-SNARES.Annexin A7: An annexin family member that plays a role in MEMBRANE FUSION and signaling via VOLTAGE-DEPENDENT CALCIUM CHANNELS.Acrosome: The cap-like structure covering the anterior portion of SPERM HEAD. 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.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.Zona Pellucida: A tough transparent membrane surrounding the OVUM. It is penetrated by the sperm during FERTILIZATION.Inositol 1,4,5-Trisphosphate Receptors: Intracellular receptors that bind to INOSITOL 1,4,5-TRISPHOSPHATE and play an important role in its intracellular signaling. Inositol 1,4,5-trisphosphate receptors are calcium channels that release CALCIUM in response to increased levels of inositol 1,4,5-trisphosphate in the CYTOPLASM.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.Sperm Head: The anterior portion of the spermatozoon (SPERMATOZOA) that contains mainly the nucleus with highly compact CHROMATIN material.Inositol 1,4,5-Trisphosphate: Intracellular messenger formed by the action of phospholipase C on phosphatidylinositol 4,5-bisphosphate, which is one of the phospholipids that make up the cell membrane. Inositol 1,4,5-trisphosphate is released into the cytoplasm where it releases calcium ions from internal stores within the cell's endoplasmic reticulum. These calcium ions stimulate the activity of B kinase or calmodulin.Dictionaries, MedicalSpermatozoa: 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.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.Dictionaries as Topic: Lists of words, usually in alphabetical order, giving information about form, pronunciation, etymology, grammar, and meaning.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.Arteriovenous Malformations: Abnormal formation of blood vessels that shunt arterial blood directly into veins without passing through the CAPILLARIES. They usually are crooked, dilated, and with thick vessel walls. A common type is the congenital arteriovenous fistula. The lack of blood flow and oxygen in the capillaries can lead to tissue damage in the affected areas.Sperm Head: The anterior portion of the spermatozoon (SPERMATOZOA) that contains mainly the nucleus with highly compact CHROMATIN material.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).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.Dictionaries, ChemicalPsychoses, Substance-Induced: Psychotic organic mental disorders resulting from the toxic effect of drugs and chemicals or other harmful substance.Reproduction: The total process by which organisms produce offspring. (Stedman, 25th ed)Financing, Government: Federal, state, or local government organized methods of financial assistance.VirginiaYolk Sac: The first of four extra-embryonic membranes to form during EMBRYOGENESIS. In REPTILES and BIRDS, it arises from endoderm and mesoderm to incorporate the EGG YOLK into the DIGESTIVE TRACT for nourishing the embryo. In placental MAMMALS, its nutritional function is vestigial; however, it is the source of INTESTINAL MUCOSA; BLOOD CELLS; and GERM CELLS. It is sometimes called the vitelline sac, which should not be confused with the VITELLINE MEMBRANE of the egg.Vocabulary: The sum or the stock of words used by a language, a group, or an individual. (From Webster, 3d ed)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.Vocabulary, Controlled: A specified list of terms with a fixed and unalterable meaning, and from which a selection is made when CATALOGING; ABSTRACTING AND INDEXING; or searching BOOKS; JOURNALS AS TOPIC; and other documents. The control is intended to avoid the scattering of related subjects under different headings (SUBJECT HEADINGS). The list may be altered or extended only by the publisher or issuing agency. (From Harrod's Librarians' Glossary, 7th ed, p163)West VirginiaSperm 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.Exocytosis: Cellular release of material within membrane-limited vesicles by fusion of the vesicles with the CELL MEMBRANE.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.Fertilization: The fusion of a spermatozoon (SPERMATOZOA) with an OVUM thus resulting in the formation of a ZYGOTE.Sterols: Steroids with a hydroxyl group at C-3 and most of the skeleton of cholestane. Additional carbon atoms may be present in the side chain. (IUPAC Steroid Nomenclature, 1987)Lipids: A generic term for fats and lipoids, the alcohol-ether-soluble constituents of protoplasm, which are insoluble in water. They comprise the fats, fatty oils, essential oils, waxes, phospholipids, glycolipids, sulfolipids, aminolipids, chromolipids (lipochromes), and fatty acids. (Grant & Hackh's Chemical Dictionary, 5th ed)Fertilization in Vitro: An assisted reproductive technique that includes the direct handling and manipulation of oocytes and sperm to achieve fertilization in vitro.Signal Transduction: The intracellular transfer of information (biological activation/inhibition) through a signal pathway. In each signal transduction system, an activation/inhibition signal from a biologically active molecule (hormone, neurotransmitter) is mediated via the coupling of a receptor/enzyme to a second messenger system or to an ion channel. Signal transduction plays an important role in activating cellular functions, cell differentiation, and cell proliferation. Examples of signal transduction systems are the GAMMA-AMINOBUTYRIC ACID-postsynaptic receptor-calcium ion channel system, the receptor-mediated T-cell activation pathway, and the receptor-mediated activation of phospholipases. Those coupled to membrane depolarization or intracellular release of calcium include the receptor-mediated activation of cytotoxic functions in granulocytes and the synaptic potentiation of protein kinase activation. Some signal transduction pathways may be part of larger signal transduction pathways; for example, protein kinase activation is part of the platelet activation signal pathway.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.G(M1) Ganglioside: A specific monosialoganglioside that accumulates abnormally within the nervous system due to a deficiency of GM1-b-galactosidase, resulting in GM1 gangliosidosis.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 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.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.Chlortetracycline: A TETRACYCLINE with a 7-chloro substitution.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.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.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.Acrosome: The cap-like structure covering the anterior portion of SPERM HEAD. 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.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).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.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.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.Echinodermata: A phylum of the most familiar marine invertebrates. Its class Stelleroidea contains two subclasses, the Asteroidea (the STARFISH or sea stars) and the Ophiuroidea (the brittle stars, also called basket stars and serpent stars). There are 1500 described species of STARFISH found throughout the world. The second class, Echinoidea, contains about 950 species of SEA URCHINS, heart urchins, and sand dollars. A third class, Holothuroidea, comprises about 900 echinoderms known as SEA CUCUMBERS. Echinoderms are used extensively in biological research. (From Barnes, Invertebrate Zoology, 5th ed, pp773-826)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 Head: The anterior portion of the spermatozoon (SPERMATOZOA) that contains mainly the nucleus with highly compact CHROMATIN material.Acrosome: The cap-like structure covering the anterior portion of SPERM HEAD. 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.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.Sea Cucumbers: A class of Echinodermata characterized by long, slender bodies.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.
(1/936) Spatiotemporal characterization of intracellular Ca2+ rise during the acrosome reaction of mammalian spermatozoa induced by zona pellucida.

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)

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

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)

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

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)

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

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)

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

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)

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

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)

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

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)

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

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)

*  Sperm-associated antigen 8
2007). "Inhibition of mouse acrosome reaction and sperm-zona pellucida binding by anti-human sperm membrane protein 1 antibody ...
*  Acrosome
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 ...
*  Acrosome reaction
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 sperm's head, exposing the contents of the acrosome ... The acrosome is a cap-like structure over the anterior half of the sperm's 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 ...
*  Hyperactivation
... 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 ...
*  Egg jelly
"Egg-jelly signal molecules for triggering the acrosome reaction in starfish spermatozoa". The International Journal of ...
*  Human embryogenesis
"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 ...
*  EQTN
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 ...
*  Biochemical cascade
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. ...
*  SPACA3
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 ...
*  Intracytoplasmic sperm injection
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 ...
*  Globozoospermia
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% ...
*  Hamster zona-free ovum test
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". ...
*  SYT6
Michaut M, De Blas G, Tomes CN, Yunes R, Fukuda M, Mayorga LS (July 2001). "Synaptotagmin VI participates in the acrosome ...
*  Acroplaxome
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". ...
*  Spermatozoon
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 and which secretes ...
*  Peanut agglutinin
Identification of the outer acrosome membrane in sperm, indicating acrosome integrity. List of histologic stains that aid in ...
*  Spermatogenesis
The Golgi apparatus surrounds the now condensed nucleus, becoming the acrosome. Maturation then takes place under the influence ...
*  V-ATPase
... s in the acrosomal membrane of sperm acidify the acrosome. This acidification activates proteases required to drill ...
*  Acrosin
... 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 ...
*  Pablo Visconti
"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 ...
*  GOPC
2002). "Lack of acrosome formation in mice lacking a Golgi protein, GOPC". Proc. Natl. Acad. Sci. U.S.A. 99 (17): 11211-6. doi: ...
*  Zona pellucida
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 ...
*  ACRV1
1995). "Human SP-10: acrosomal distribution, processing, and fate after the acrosome reaction". Biol. Reprod. 51 (6): 1222-31. ...
*  Immunocontraception
Bleil, JD; PM Wassarman (1990). "Identification of a ZP3-binding protein on acrosome-intact mouse sperm by photoaffinity ...
*  Fertilisation
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 ...
acrosomes - definition and meaning  acrosomes - definition and meaning
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. ...
more infohttps://www.wordnik.com/words/acrosomes
Acrosome reaction financial definition of Acrosome reaction  Acrosome reaction financial definition of Acrosome reaction
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 ...
more infohttps://financial-dictionary.thefreedictionary.com/Acrosome+reaction
Acrosome - Wikipedia  Acrosome - Wikipedia
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 ...
more infohttps://en.wikipedia.org/wiki/Acrosome
Acrosome reaction | Article about acrosome reaction by The Free Dictionary  Acrosome reaction | Article about acrosome reaction by The Free Dictionary
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 ...
more infohttps://encyclopedia2.thefreedictionary.com/acrosome+reaction
Acrosome reaction - Wikipedia  Acrosome reaction - Wikipedia
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 sperm's head, exposing the contents of the acrosome ... The acrosome is a cap-like structure over the anterior half of the sperm's 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 ...
more infohttps://en.wikipedia.org/wiki/Acrosome_reaction
Re: Name the functions of the Acrosome  Re: Name the functions of the Acrosome
Name the functions of the Acrosome. john Smith Name the functions of the Acrosome2011-09-01T05:14:20+00:00 ... Acrosome âˆ' It is a cap9like structure present in the anterior part of the head of the sperm. It contains hyaluronidase enzyme ...
more infohttps://www.assignmenthelp.net/forum/topic/name-the-functions-of-the-acrosome/
Acrosome size and kinematics of human spermatozoa  Acrosome size and kinematics of human spermatozoa
... 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 ...
more infohttp://scholar.sun.ac.za/handle/10019.1/2663
IDEALS @ Illinois: Re-localization of SNARE proteins in mouse sperm prior to the acrosome reaction  IDEALS @ Illinois: Re-localization of SNARE proteins in mouse sperm prior to the acrosome reaction
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 ...
more infohttps://www.ideals.illinois.edu/handle/2142/78670
Zona pellucida mediated acrosome reaction and sperm morphology  Zona pellucida mediated acrosome reaction and sperm morphology
... 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 ...
more infohttp://scholar.sun.ac.za/handle/10019.1/13342
Acroplaxome, an F-actin-keratin-containing plate, anchors the acrosome to the nucleus during shaping of the spermatid head.  Acroplaxome, an F-actin-keratin-containing plate, anchors the acrosome to the nucleus during shaping of the spermatid head.
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 ...
more infohttp://www.biomedsearch.com/nih/Acroplaxome-F-actin-keratin-containing/14551252.html
Changes in motility, morphology, plasma membrane and acrosome integrity during stages of cryopreservation of buck sperm  Changes in motility, morphology, plasma membrane and acrosome integrity during stages of cryopreservation of buck sperm
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. ...
more infohttp://www.scielo.org.za/scielo.php?script=sci_abstract&pid=S1019-91282014000100006&lng=en&nrm=iso
SUE - Acrosome Reaction  SUE - Acrosome Reaction
ACROSOME REACTION The red receptors on the sperm come into contact with the egg jelly, yellow. This induces the acrosome ... reaction causing the acrosome in green to fuse with the plasma membrane of the sperm. The actin in pink goes from a globular ...
more infohttps://web.stanford.edu/group/Urchin/acrosome.htm
Inositol 1,4,5-trisphosphate receptors selectively localized to the acrosomes of mammalian sperm. | JCB  Inositol 1,4,5-trisphosphate receptors selectively localized to the acrosomes of mammalian sperm. | JCB
... as well as thapsigargin's 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 ...
more infohttp://jcb.rupress.org/content/130/4/857
INABIS 98 -  Permeabilization of human spermatozoa with streptolysin-O: a model for the study of macromolecules involved on...  INABIS '98 - Permeabilization of human spermatozoa with streptolysin-O: a model for the study of macromolecules involved on...
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 ...
more infohttps://www.mcmaster.ca/inabis98/cellbio/yunes0152/index.html
Acrosome malformation of spermatozoa | definition of acrosome malformation of spermatozoa by Medical dictionary  Acrosome malformation of spermatozoa | definition of acrosome malformation of spermatozoa by Medical dictionary
What is acrosome malformation of spermatozoa? Meaning of acrosome malformation of spermatozoa medical term. What does acrosome ... Looking for online definition of acrosome malformation of spermatozoa in the Medical Dictionary? acrosome malformation of ... redirected from acrosome malformation of spermatozoa) spermatogenic failure type 6. An autosomal recessive infertility disorder ... Acrosome malformation of spermatozoa , definition of acrosome malformation of spermatozoa by Medical dictionary https://medical ...
more infohttps://medical-dictionary.thefreedictionary.com/acrosome+malformation+of+spermatozoa
Tudor Domain Containing Protein TDRD12 Expresses at the Acrosome of Spermatids in Mouse Testis | Korea Science  Tudor Domain Containing Protein TDRD12 Expresses at the Acrosome of Spermatids in Mouse Testis | Korea Science
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 ...
more infohttp://www.koreascience.or.kr/article/ArticleFullRecord.jsp?cn=E1DMBP_2016_v29n7_944
Sperm acrosome membrane-associated protein 6  Sperm acrosome membrane-associated protein 6
Build: Sat Nov 17 23:53:08 EST 2018 (commit: a759bb7). National Center for Advancing Translational Sciences (NCATS), 6701 Democracy Boulevard, Bethesda MD 20892-4874 • 301-435-0888. ...
more infohttps://pharos.nih.gov/idg/targets/SPACA6
Sperm biology and control of reproduction in sturgeon: (II) sperm morphology, acrosome reaction, motility and cryopreservation,...  Sperm biology and control of reproduction in sturgeon: (II) sperm morphology, acrosome reaction, motility and cryopreservation,...
... 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 ...
more infohttps://www.deepdyve.com/lp/springer_journal/sperm-biology-and-control-of-reproduction-in-sturgeon-ii-sperm-LFMPeeh14n
Monoclonal antibodies which recognize equatorial segment epitopes presented de novo following the A23187-induced acrosome...  Monoclonal antibodies which recognize equatorial segment epitopes presented de novo following the A23187-induced acrosome...
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- ...
more infohttp://jcs.biologists.org/content/108/2/767
Chapter 36 Animal Reproduction - Chapter 36 Animal Reproduction Vocabulary Acrosome sac at the head of sperm containing enzymes...  Chapter 36 Animal Reproduction - Chapter 36 Animal Reproduction Vocabulary Acrosome sac at the head of sperm containing enzymes...
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 ...
more infohttps://www.coursehero.com/file/66149/Chapter-36-Animal-Reproduction/
Welcome to CDC stacks | Lipid Modulation of Calcium Flux through CaV2.3 Regulates Acrosome Exocytosis and Fertilization - 29876...  Welcome to CDC stacks | Lipid Modulation of Calcium Flux through CaV2.3 Regulates Acrosome Exocytosis and Fertilization - 29876...
Acrosome Animals Article Calcium Calcium Channels, R-Type Cation Transport Proteins Cells, Cultured Exocytosis Fertilization G( ... In early development, sterol efflux and the ganglioside GM1 regulate sperm acrosome exocytosis (AE) and fertilization ... Lipid Modulation of Calcium Flux through CaV2.3 Regulates Acrosome Exocytosis and Fertilization ...
more infohttps://stacks.cdc.gov/view/cdc/29876
Progesterone in mare follicular fluid induces the acrosome reaction in stallion spermatozoa and enhances in vitro binding to...  Progesterone in mare follicular fluid induces the acrosome reaction in stallion spermatozoa and enhances in vitro binding to...
Viable spermatozoa without the outer acrosomal membrane were considered as physiologically acrosome-reacted. Results showed ... induces the acrosome reaction (AR) in stallion spermatozoa and, if so, to identify the component in FF responsible for it. ... The aim of this study was to investigate whether mare follicular fluid (FF) induces the acrosome reaction (AR) in stallion ... Flow Cytometric Evaluation of Acrosome Function/dysfunction in the Stallion. *Tegan S. Bosard ...
more infohttps://www.semanticscholar.org/paper/Progesterone-in-mare-follicular-fluid-induces-the-Cheng-Fazeli/d69692be6dccbcbd20582be6a791e1c119a7aa72
EMF-Portal | The effect of pulsed 900-MHz GSM mobile phone radiation on the acrosome reaction, head morphometry and zona...  EMF-Portal | The effect of pulsed 900-MHz GSM mobile phone radiation on the acrosome reaction, head morphometry and zona...
2012): RE:'The effect of pulsed 900-MHz GSM mobile phone radiation on the acrosome reaction, head morphometry and zona binding ... Lerchl A (2012): Letter on 'The effect of pulsed 900-MHz GSM mobile phone radiation on the acrosome reaction, head morphometry ... The effect of pulsed 900-MHz GSM mobile phone radiation on the acrosome reaction, head morphometry and zona binding of human ... The irradiation did not affect the acrosome reaction. The analysis of morphometric parameters revealed a statistically ...
more infohttps://www.emf-portal.org/en/article/18046
Sperm acrosome membrane-associated protein 3  Sperm acrosome membrane-associated protein 3
The protein encoded by this gene is a sperm surface protein that may be involved in adhesion to the egg prior to fertilization. While the encoded protein has significant similarity to lysozyme at the amino acid level, it has no detectable bacteriocidal activity. Several transcript variants encoding different isoforms have been found for this gene. [provided by RefSeq, Nov 2015 ...
more infohttps://pharos.nih.gov/idg/targets/Q8IXA5
Effects of pentoxifylline and progesterone on human sperm capacitation and acrosome reaction. - Semantic Scholar  Effects of pentoxifylline and progesterone on human sperm capacitation and acrosome reaction. - Semantic Scholar
After exposure to pentoxifylline (1 mg/ml; 30 min), the fluorescent 'B' pattern, characteristic of capacitated, acrosome-intact ... Stimulation of both capacitation and acrosome reaction resulted from sequential exposure to pentoxifylline and progesterone. ... acrosome loss and hyperactivation. Sperm viability was not affected in any treatment group. These observations suggest that ... cells, increased significantly (P , 0.01), though no increase in 'AR' pattern, characteristic of acrosome-reacted cells, was ...
more infohttps://www.semanticscholar.org/paper/Effects-of-pentoxifylline-and-progesterone-on-huma-Kay-Coutts/8d9644b160b41d3a5a85b5d8ec358bb34870a517
  • The mean percentage (±SE) ZP mediated acrosome reacted sperm among teratozoospermic and severely teratozoospermic cases was 25.8% ± 0.9 and 19.0% ± 0.9 (P= 0.001), compared to 36.8%±0.9 for the donor controls. (sun.ac.za)
  • It is highly expressed in testis, and is required for sperm head elongation and acrosome formation during spermatogenesis. (wikipedia.org)
  • Acroplaxome, an F-actin-keratin-containing plate, anchors the acrosome to the nucleus during shaping of the spermatid head. (biomedsearch.com)
  • 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)
  • 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)
  • Some definitions consider sperm activation to consist of these two processes of hyperactivation and the acrosome reaction Hyperactivation is a term also used to express an X chromosome gene dosage compensation mechanism and is seen in Drosophila. (wikipedia.org)
  • Seminiferous tubules showed disruption of the normal spermatogenic cycle with abnormal acrosomal development on round spermatids, clumping of acrosomes , misaligned spermatids and the absence of normal elongated spermatids in Ehd1 -/- males. (wordnik.com)
  • TDRD12 was detected in early spermatocytes at 2 weeks and TDRD12 was localized at acrosome of the round spermatids. (koreascience.or.kr)
  • Monoclonal antibodies were raised against unfixed acrosome-reacted guinea pig sperm and screened by indirect immunofluorescence for binding to the equatorial segment. (biologists.org)
  • Formaldehyde fixation of acrosome-intact sperm caused partial rupture of the acrosome with loss of the characteristic rouleaux (stacks) of guinea pig sperm. (biologists.org)
  • Thapsigargin, a sequiterpene lactone inhibitor of the microsomal Ca(2+)-ATPase, stimulated the acrosome reaction of mouse sperm to the same extent as the Ca2+ ionophore, A23187. (rupress.org)
  • The cytoskeletal plate, designated acroplaxome, anchors the developing acrosome to the nuclear envelope. (biomedsearch.com)
  • Cryosections of acrosome-intact sperm labelled indirectly with immuno-gold showed labelling consistent with the same location, as well as sporadic labelling at other intracellular sites overlying the acrosome. (biologists.org)