Female sperm storage is a biological process and often a type of sexual selection in which sperm cells transferred to a female during mating are temporarily retained within a specific part of the reproductive tract before the oocyte, or egg, is fertilized. The site of storage is variable among different animal taxa and ranges from structures that appear to function solely for sperm retention, such as insect spermatheca and bird sperm storage tubules (bird anatomy), to more general regions of the reproductive tract enriched with receptors to which sperm associate before fertilization, such as the caudal portion of the cow oviduct containing sperm-associating annexins. Female sperm storage is an integral stage in the reproductive process for many animals with internal fertilization. It has several documented biological functions including: Supporting the sperm by: a.) enabling sperm to undergo biochemical transitions, called capacitation and motility hyperactivation, in which they become ...
Induction of human sperm chemotaxis is an established phenomenon, though signaling systems physiologically involved have not been identified. Recently, it has been demonstrated that RANTES is present in the follicular fluid and that this molecule is a chemoactractant for human spermatozoa. However, the presence of beta-chemokine receptors on human spermatozoa has never been reported. By cytometric, Western blotting and immunofluorescence analysis, we demonstrate the presence of CCR5 and CCR3 on ejaculated spermatozoa from healthy subjects. CCR5 was detected in the periacrosomal region of the sperm surface, whereas CCR3 was also present in the postacrosomal cap. Individual variability was observed on CCR5 and CCR3 positive sperm percentages. Presence of Delta32+/-) mutation was demonstrated in two subjects expressing CCR5 in half of the ejaculated spermatozoa. Our findings represent the missing information in favor of the possibility that beta-chemokines and their receptors are involved in sperm
Lipid peroxidation (LPO) of stallion spermatozoa was assessed in fresh semen and in samples of the same ejaculates after freezing and thawing. Particular attention was paid to individual differences in the susceptibility to LPO and its possible relationship with freezability. Innate levels of LPO were very low in fresh spermatozoa but increased after thawing, a change that was largely stallion-dependent. The level of LPO in fresh spermatozoa was not correlated with that of the thawed spermatozoa. Negative correlations existed between LPO and intact membranes post-thaw (r= -0.789, Pless than0.001), and also between LPO and spermatozoa with high mitochondrial membrane potential (Delta psi m) post-thaw (r= -0.689, Pless than0.001). LPO was also highly and significantly correlated with caspase activity. The correlation between caspase activity in ethidium positive cells and LPO was r=0.772, Pless than0.001. This LPO is unlikely to represent, per se, a sign of cryopreservation-induced injury, but it ...
Even relatively minor errors in chromatin remodeling during spermiogenesis are associated with sperm DNA damage and infertility, yet little is known about the etiology. Mice with severe NPYq deletions are infertile due to severe sperm differentiation defects (Ward and Burgoyne, 2006; Yamauchi et al., 2009). We have recently observed that sperm from these mice presented abnormal chromatin packaging and DNA damage. Moreover, when these sperm were injected into the oocytes, a significant increase of oocyte arrest at pronuclei stage and of chromosome aberrations in the fertilized eggs were noted (Yamauchi et al., 2010). Here we provide evidence that the deficiency of NPYq encoded gene Sly is associated with sperm DNA damage and poor sperm chromatin condensation, and propose that SLY plays a role in spermatid-specific chromatin remodeling.. How can Sly/SLY be involved in sperm DNA damage phenotype? SLY protein has been shown to control the postmeiotic expression of ,100 genes, the majority of which ...
In the mouse and other mammals studied, including man, ejaculated spermatozoa cannot immediately fertilize an egg. They require a certain period of residence in the female genital tract to become functionally competent cells. As spermatozoa traverse through the female genital tract, they undergo multiple biochemical and physiological changes collectively referred to as capacitation. Only capacitated spermatozoa interact with the extracellular egg coat, the zona pellucida. The tight irreversible binding of the opposite gametes triggers a Ca|sup|2+|/sup|-dependent signal transduction cascade. The net result is the fusion of the sperm plasma membrane and the underlying outer acrosomal membrane at multiple sites that causes the release of acrosomal contents at the site of sperm-egg adhesion. The hydrolytic action of the acrosomal enzymes released, along with the hyperactivated beat pattern of the bound spermatozoon, is important factor that directs the sperm to penetrate the egg coat and fertilize the egg.
Sperm-associated antigen 8 is a protein that in humans is encoded by the SPAG8 gene. The correlation of anti-sperm antibodies with cases of unexplained infertility implicates a role for these antibodies in blocking fertilization. Improved diagnosis and treatment of immunologic infertility, as well as identification of proteins for targeted contraception, are dependent on the identification and characterization of relevant sperm antigens. The protein encoded by this gene is recognized by sperm agglutinating antibodies from an infertile woman. This protein is localized in germ cells of the testis at all stages of spermatogenesis and is localized to the acrosomal region of mature spermatozoa. Alternatively spliced variants that encode different protein isoforms have been described but the full-length sequences of only two have been determined. GRCh38: Ensembl release 89: ENSG00000137098 - Ensembl, May 2017 GRCm38: Ensembl release 89: ENSMUSG00000066196 - Ensembl, May 2017 "Human PubMed Reference:". ...
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In mammals, after coitus a small number of spermatozoa enter the uterine tube and following attachment to uterine tube epithelium are arrested in a non-capacitated state until peri-ovulatory signalling induces their detachment. Whilst awaiting release low numbers of spermatozoa continually detach from the epithelium and the uterine tube reservoir risks depletion. There is evidence of attachment of spermatozoa to uterine epithelium in several species which might form a potential pre-uterine tube reservoir. In this study we demonstrate that: (1) dog spermatozoa attach to uterine epithelium and maintain flagellar activity, (2) in non-capacitating conditions spermatozoa progressively detach with a variety of motility characteristics, (3) attachment is not influenced by epithelial changes occurring around ovulation, (4) attachment to uterine epithelium slows capacitation, (5) capacitated spermatozoa have reduced ability to attach to uterine epithelium, (6) under capacitating conditions increased ...
Improved fertility following artificial insemination with frozen-thawed spermatozoa would offer rabbit producers faster genetic improvement. Previous work investigating cryoprotectants for rabbit spermatozoa have reported inconsistent results. Semen was collected from three rabbit bucks by artificial vagina and frozen using a standard procedure with varied cryodiluent components. Post-thaw analysis encompassed motility, sperm kinematic parameters and acrosome and membrane integrity. Spermatozoa were evaluated at 0, 2 and 4 h after thawing. Experiment 1 compared diluents with 3.5% dimethyl sulfoxide (DMSO), 1.5% acetamide, 1.75% DMSO + 0.75% acetamide or 3.5% DMSO + 1.5% acetamide. The treatment that resulted in the highest post-thaw motility (P,0.001) and acrosome integrity (P,0.001) was DMSO alone. Experiment 2 compared 3.5, 7 and 10% DMSO in the cryodiluent. The best post-thaw sperm motility (P,0.001) and linearity (P=.002) was in 3.5% DMSO, while 10% DMSO afforded higher acrosome/membrane ...
Reactive oxygen species (ROS), particularly hydrogen peroxide (H2O2), cause oxidative cell damage and inhibit sperm function. In most oviparous fishes that spawn in seawater (SW), spermatozoa may be exposed to harmful ROS loads associated with the hyperosmotic stress of axonemal activation and ATP synthesis from mitochondrial oxidative phosphorylation. However, it is not known how marine spermatozoa can cope with the increased ROS levels to maintain flagellar motility. Here, we show that a marine teleost orthologue of human aquaporin-8, termed Aqp8b, is rapidly phosphorylated and inserted into the inner mitochondrial membrane of SW-activated spermatozoa, where it facilitates H2O2 efflux from this compartment. When Aqp8b intracellular trafficking and mitochondrial channel activity are immunologically blocked in activated spermatozoa, ROS levels accumulate in the mitochondria leading to mitochondrial membrane depolarisation, the reduction of ATP production, and the progressive arrest of sperm ...
In order to reach fertilization in the context of IVF, the presence of high concentrations of spermatozoa is associated with a higher degree of sperm metabolism and a higher concentration of sperm degradation products, which may adversely affect not only sperm and oocyte viability and the fertilization rate. The effect of a high concentration of sperm used for oocyte insemination appears also to be negative on embryo development (Dumoulin et al 1992*). If that is true, lowering the sperm concentration for oocyte insemination might improve embryo quality and result in a higher implantation rate per embryo. Therefore, we tested the hypothesis that the percentage of 8 cell-embryos on day 3 after IVF is significantly higher (40%) after insemination with a low sperm concentration (150 000/ml spermatozoa) than after insemination with a higher sperm concentration (30%; group 600 000/ml spermatozoa ...
BACKGROUND: Previous results from our laboratory have led us to propose heparan sulfate (HS) as a putative protamine acceptor during human sperm decondensation in vivo. The aim of this paper was to investigate the presence of glycosaminoglycans in the mammalian oocyte in an effort to better support this contention. METHODS: Two experimental approaches are used: oocyte labeling to identify the presence of HS and analysis of sperm decondensing ability of fresh oocytes in the presence or absence of specific glycosidases. RESULTS: Staining of mouse zona-intact oocytes with the fluorescent cationic dye, Rubipy, at pH 1.5 allowed for the detection of sulfate residues in the ooplasm by confocal microscopy. HS was detected in the ooplasm by immunocytochemistry. A sperm decondensation microassay using heparin and glutathione was successfully developed. The same level of sperm decondensation could be attained when heparin was replaced by mouse zona-free oocytes. Addition of heparinase to the ...
The spermiogenesis process in Wardula capitellata begins with the formation of a differentiation zone containing two centrioles associated with striated rootlets and an intercentriolar body. Each centriole develops into a free flagellum orthogonal to a median cytoplasmic process. Later these flagella rotate and become parallel to the median cytoplasmic process, which already exhibits two electron-dense areas and spinelike bodies before its proximodistal fusion with the flagella. The final stage of the spermiogenesis is characterized by the constriction of the ring of arched membranes, giving rise to the young spermatozoon, which detaches from the residual cytoplasm. The mature spermatozoon of W. capitellata presents most of the classical characters reported in digenean spermatozoa such as two axonemes of different lengths of the 9 + 1 trepaxonematan pattern, nucleus, mitochondrion, two bundles of parallel cortical microtubules and granules of glycogen. However, some peculiarities such as two ...
Our clinical catamnestic studies on cases of sterility with a proven sensitization against spermatozoa revealed a statistically significant decrease of pregnancies only in patients with positive spermantibody tests over a period longer than 3 years. A direct spermimunological etiology of sterility can not yet be derived. In the investigated 759 cases a sensitization against spermatozoa was detected in 93 cases. In 11 patients the spermantibodies proved to be positive longer than 3 years. Washed spermatozoa were used as antigen in the applied test methods. It may very well be possible, that the results point in a different direction once we are applying a particular fertility diminishing spermatozoa antigen.
1. Chromosome dimorphism of the spermatozoa has been shown for a variety of mammals, and in some cases this has been shown to be correlated with dimorphism in the head lengths of the spermatozoa.. 2. In the present paper this correlation has been extended to the spermatozoa of man, the mouse, and the rat, in which chromosome dimorphism of the spermatozoa had previously been shown, and in which head length dimorphism seems to exist.. 3. The interest of these results lies in the probability that the histological difference in the X- and Y-spermatozoa may account for the inequality of the sexes at conception in mammals.. ...
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This study evaluated the effects of cooling, freezing and thawing on the plasma membrane integrity, kinetics and expression of two sugar transporters glucose transporter-3 and -5 (GLUT-3 and GLUT-5) in spermatozoa from Iberian boars. Semen samples were collected twice weekly from eight young, fertile Iberian boars of the Entrepelado and Lampiño breeds. The samples were suspended in a commercial extender and refrigerated to 17 degrees C for transport to the laboratory (step A), where they were further extended with a lactose-egg yolk-based extender and chilled to 5 degrees C (step B) prior to freezing in the presence of glycerol (3%). Spermatozoa were assessed for plasma membrane integrity and sperm motility at each of the steps, including post-thaw (step C). Aliquots were also prepared for immunocytochemical localisation of the sugar transporters (fixed and thin smears for transmission and scanning electron microscopy levels respectively) and for SDS-PAGE electrophoresis and subsequent western
The acrosome reaction of epididymal spermatozoa and fertilization in vitro of mouse eggs in chemically defined media without tissue fluid were investigated. About 8 to 10% of motile spermatozoa lost their acrosome but no eggs were penetrated when the spermatozoa and eggs were incubated in a basic medium (modified Krebs-Ringer bicarbonate solution containing glucose) for 5 to 7 hr. Addition of a single metabolic intermediate, such as sodium oxaloacetate or sodium pyruvate, to the basic medium increased the proportion of motile spermatozoa without an acrosome (19 to 34%) and the proportion of eggs penetrated (3·2 to 25·5%). Incubation of spermatozoa and eggs in the basic medium containing serum albumin of various species caused a further increase in the proportion of motile spermatozoa without an acrosome (50 to 65%) and in that of penetrated eggs (60·7 to 86%). The best medium for sperm capacitation and fertilization of mouse eggs in vitro, however, was the basic medium containing bovine serum ...
Membrane fluidity refers to the viscosity of the lipid bilayer. When the temperature decreases, interactions between phospholipids appear and the membrane becomes more rigid and can be described as a "glass state". Some components, such as the cholesterol rate, could help the membrane to better stand the temperature drop.. Contrary to other mammalian spermatozoa, swine spermatozoa are characterized by a high content of polyunsaturated fatty acids and a low concentration of cholesterol. Due to this particular composition, the cold shock point is quite high, thus making boar spermatozoa more sensitive to temperature drops. During semen processing, the temperature goes down from 37°C just after collection to 17°C for the storage. ...
The SCSA®is one of the most widely utilized tests of sperm DNA damage. There are now a number of commercial kits available for testing of sperm DNA fragmentation in which great variations of...
View Notes - Chapter 9 from HEALTH SCI HLTHST101 at Boise State. Medical Terminology Chapter 9 Male Reproductive System Spermatozoon Spermatozoon Sperm cell Flagellum Flagellum Tail of the sperm
Purpose: Sperm nuclear proteins and DNA integrity have been implicated in infertility and treatment failures. High stallion to stallion variability is observed in sperm cryopreservation protocols. The cells are destroyed with harsh chemicals prior to using biochemical assays to test sperm DNA quality. The feasibility of using Raman spectrometry in combination with a laser trap for non-destructive micromanipulation and characterization of DNA damage in motile stallion and human sperm is experimentally investigated in this thesis. Methods: Live stallion sperms were subjected to controlled cellular damage: (a) four grades of chemically induced oxidative stress using Xanthine - Xanthine Oxidase (b) three grades of osmotic stress using PBS and (c) membrane damage using thermal shock. Live human sperm DNA disintegration with time and oxidative stress were explored on fresh, cryopreserved and swim-up categories. The specimens ranged from sub-fertile patients to fertile donors in a limited study. ...
A rabbit antibody to mouse 3T3 cell fibronectin was used in conjunction with a fluorescein-tagged second antibody to detect fibronectin-like activity on the surface of rabbit spermatozoa. Only ejaculated sperm displayed an intense and highly localized fluorescence over the acrosomal region. Cauda epididymal sperm of the rabbit as well as several other species did not exhibit any reaction. The fluorescent activity could be eliminated by trypsin treatment but was re-established by incubation in cell-free seminal fluid. Sperm recovered from females 10-12 h after mating showed a reduction or absence of antifibronectin fluorescence, suggesting that this components loss could be a factor in sperm capacitation. Because fibronectins show strong binding to collagen, mixtures of ejaculated sperm and collagen were examined in the light and electron microscope. Living sperm appear to have a strong affinity for collagen and quickly adhere to the filaments by their heads, while continuing vigorous ...
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The mature spermatozoa are released from the protective Sertoli cells into the lumen of the seminiferous tubule and a process called spermiation then takes place, which removes the remaining unnecessary cytoplasm and organelles. The resulting spermatozoa are now mature but lack motility, rendering them sterile. The non-motile spermatozoa are transported to the epididymis in testicular fluid secreted by the Sertoli cells with the aid of peristaltic contraction. Whilst in the epididymis they acquire motility and become capable of fertilisation. However, transport of the mature spermatozoa through the remainder of the male reproductive system is achieved via muscle contraction rather than the spermatozoons recently acquired motility. ...
spermatozoa tail - Following spermiogenesis, the third region of the spermatozoa that has a head, neck and tail). The tail is also divided into 3 structural regions a middle piece, a principal piece and an end piece. In humans: the middle piece (5 µm long) is formed by axonema and dense fibres surrounded by mitochondria; the principal piece (45 µm long) fibrous sheath interconnected by regularly spaced circumferential hoops; the final end piece (5 µm long) has an axonema surrounded by small amount of cytoplasm and plasma membrane ...
In a situation where technology allows for the simultaneous measurement of numerous parameters of a single sperm cell, it becomes crucial to choose those parameters which may be useful in estimating in vivo fertility. Sperm membrane destabilization is believed to occur during chilling of semen, although its effect on the post-thaw (PT) fertility of the spermatozoa has not yet been fully assessed. For this reason, we tested a new combination of fluorophores, Merocyanine 540 (M540)/Yo-Pro 1/Hoechst 33342 (H33342), to detect sperm plasma membrane destabilization in bull spermatozoa conventionally processed for artificial insemination (AI). The samples were tested by flow cytometry (FC), both immediately PT and following an in vitro swimup (SU) technique, and results were thereafter compared with conventional sperm quality Measurements (of concentration, motility, morphology, and membrane integrity), including in vivo fertility. Semen samples from six Estonian Holstein (EHF) AI bulls, frozen when ...
In addition to perinuclear theca anchored glutathione-s-transferase omega 2 (GSTO2), whose function is to participate in sperm nuclear decondensation during fertilization (Biol Reprod. 2019, 101:368–376), we herein provide evidence that GSTO2 is acquired on the sperm plasmalemma during epididymal maturation. This novel membrane localization was reinforced by the isolation and identification of biotin-conjugated surface proteins from ejaculated and capacitated boar and mouse spermatozoa, prompting us to hypothesize that GSTO2 has an oxidative/reductive role in regulating sperm function during capacitation. Utilizing an inhibitor specific to the active site of GSTO2 in spermatozoa, inhibition of this enzyme led to a decrease in tyrosine phosphorylation late in the capacitation process, followed by an expected decrease in acrosome exocytosis and motility. These changes were accompanied by an increase in reactive oxygen species (ROS) levels and membrane lipid peroxidation and culminated in a
We now have the sperm proteome of a primate. In a paper just out in Molecular & Cellular Proteomics, researchers describe the sperm proteome of the rhesus macaque, the first primate to have its sperm proteome analyzed.. Sperm proteomes from non-primate species, such as rat, mouse and fruit fly, already have been determined. "For comparative evolutionary and functional genomics studies, a primate sperm proteome was highly desirable to include in this growing list of sperm proteomes," explains Tim Karr at Arizona State University.. Rhesus monkeys bear many genetic and physiological similarities to humans, so they are used regularly as a nonhuman primate model system in biomedical research, including human reproduction research. "Knowing the rhesus sperm proteome will greatly expand the possibility for targeted molecular studies of spermatogenesis and fertilization in a commonly used model species for human infertility," explains Karr. (I wrote about sperm and male infertility earlier this ...
This research line is funded by a project of the National R&D Plan (Ministry of Science and Innovation), led by Dr. Felipe Martínez-Pastor.. Sperm work has improved animal breeding and allowed semen banks to preserving species and breeds. However, many factors affect the integrity of the genetic material of the spermatozoon, reducing fertility, causing abortions and affecting offspring fitness. In this research line, we are studying ruminant spermatozoa, a group of great economical importance. Whereas artificial reproductive techniques are routine in cattle, they are still developing for most species. In either cases, it is crucial to maintain sperm DNA integrity during manipulation, storage or in vitro techniques. Sperm DNA assessment has been carried out for more than 30 years, but few studies have dealt on fine analysis of DNA damage. DNA in mammal sperm is associated to protamines (PDNA) and histones (HDNA), an organization with likely epigenetic effects. HDNA include important sequences ...
This chapter focuses specifically on how apoptosis affects sperm quality and function, and the implications of this process for both embryonic development and the health and well-being of the offspring. DNA damage in human spermatozoa has been correlated with poor fertilization and impaired embryonic development to the blastocyst stage as well as with the incidence of subsequent miscarriage. Human infertility is a complex multifactorial condition that is strongly impacted by genetic factors that assisted reproductive technology (ART) will ensure are passed onto the progeny. Spermiogenesis is a key event in the etiology of DNA damage in the male germ line. DNA damage in human spermatozoa appears to have its origins in the testes and is associated with oxidative stress. Spermatozoa possess several variants of the prolactin receptor and respond to the presence of this hormone with the stimulation of PI3 kinase/Akt phosphorylation and the prolongation of sperm survival ...
The association between semen quality and male infertility has been known for more than 40 years.. Having reviewed the literature, it seems clear that strict morphology has a clinical relevance, being an excellent biomarker of sperm fertilizing capacity, in vivo and in vitro, independent of motility and concentration (27).. Sperm morphology evaluation is considered to be a highly subjective procedure because, unlike the haematopoietic cells for example, the difficulty in classifying human sperm morphology is caused by the large variety of abnormal forms found in the semen of infertile and fertile men. Only certain types of abnormality can be quantitated objectively (11).. Normal sperm morphology needs to consider two points. The first one is the proportion of spermatozoa with normal morphology in semen and the second is the definition and the characterization of the normal spermatozoa.. According to WHO criteria, a normal ejaculate must have at least 30% normal sperm.(36). For the stricter ...
Our team in Birmingham has shown that sperm DNA damage more than doubles the risk of miscarriage.. This is a crucial finding; until now, miscarriage has generally been considered an exclusively female problem, with investigations and management targeting only women.. Yet the role of sperm DNA damage in miscarriage is not surprising. This is because while most cell types are able to repair damaged DNA, sperm lose this ability during development and have to rely on repair mechanisms in the egg. As the level of damage in the sperm DNA increases it also becomes increasingly likely that any repairs by the egg may create genetic mutations that could increase the risk of miscarriage.. Most existing tests for sperm DNA damage are insufficiently sensitive to be clinically useful; we are developing a more accurate combined assay system and therapies to achieve repair. One potential cause of sperm DNA damage is exposure to Reactive Oxygen Species (ROS) during production and transit. We are investigating ...
Detail záznamu - Ultrastructure of spermiogenesis and mature spermatozoon of Breviscolex orientalis (Cestoda: Caryophyllidea) - Detail záznamu - Knihovna Akademie věd České republiky
PAN Czytelnia Czasopism, Motility, mitochondrial membrane potential and ATP content of rabbit spermatozoa stored in extender supplemented with GnRH analogue [des-Gly10, D-Ala6]-LH-RH ethylamide - Polish Journal of Veterinary Sciences
Health,According to Researchers Men produce more mutant sperm as they get old...The deformed sperm increase the risk of disease in the mens offspri...Researchers were looking for two mutations that cause virtually all ...The researchers studied sperm from 148 men aged 21 to 80. Most of th...In men with Apert children the younger men were more likely to have...,Mutant,sperm,beat,out,healthy,brethren,in,study,medicine,medical news today,latest medical news,medical newsletters,current medical news,latest medicine news
Bennett, D and Dunn, L C., "Studies of effects of t-alleles in the house mouse on spermatozoa. I. Male sterility effects." (1967). Subject Strain Bibliography 1967. 576 ...
There are several gonadal hormones involved in spermatogenesis or the formation of spermatozoa. The gonadal-releasing hormone or factor in the hypothalamus is responsible for stimulating the anterior pituitary to increase the secretion of androgens and Follicle Stimulating Hormone or FSH. The FSH, in return, will enhance the production of testosterone. During puberty, the testosterone blood levels of men increase. This true male gonadal hormone then stimulates spermatogenesis or the formation of spermatozoa or sperm cells in the testes.. ...
Normal sperm count, as defined by the World Health Organisation, is characterised by: the concentration of spermatozoa, which should be at least 20 million per ml; the total volume of semen should be at least 2ml; the total number of spermatozoa in the semen should be at least 40 million; at least 75 per cent of the spermatozoa should be alive; at least 30 per cent of the spermatozoa should be of normal shape and form; at least 25 per cent of the spermatozoa should be swimming with rapid forward movement; at least 50 per cent of the spermatozoa should be swimming forward, even if only sluggishly ...
Castagnoli, E. and Salo, J. and Toivonen, M. S. and Marik, Tamás and Mikkola, R. and Kredics, László (2018) An Evaluation of Boar Spermatozoa as a Biosensor for the Detection of Sublethal and Lethal Toxicity. TOXINS, 10 (11). ISSN 2072-6651 ...
MACS technique eliminates apoptotic sperms and may be indicated prior to ICSI, in order to guarantee that the injected spermatozoa are not damaged at a molecular level. Alternatively it could be combined with PICSI.. The externalization of the phospholipid phosphatidylserine (PS) to the sperm plasma membrane is a characteristic feature of the apoptotic phenomenon that occurs early during the process of sperm cell death. This basic knowledge has prompted investigators to develop a magnetic-based selection system for sperm cells that can separate early apoptotic from non-apoptotic germ cells (MACS).. Human sperm quality is defined by the classical parameters, concentration, motility and morphology, according to standard WHO diagnostic semen analysis. Nevertheless, hidden anomalies affecting spermatozoa membranes and causing apoptosis are present. Such features are not routinely detected in ejaculated spermatozoa but they have been proven to have a negative impact on ART outcome. Indeed, successful ...
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Illustration of a human sperm fertilising an egg. The picture shows the size difference between the egg, or ovum, & the spermatozoon. Human spermatozoa are extremely elongated single cells about 65 micrometres long, divided into 3 main regions: a head, neck, & tail. The head, which contains the male nucleus, is about 7 micrometres long. Here, the head appears buried in the follicular cells, which form the corona radia that surrounds the ovum. Beneath the corona radiata is a glycoprotein membrane, the zona pellucida, which the sperm must penetrate to reach the female nucleus. This version on black background. Version on white background is P648 010.. Thanks for installing the Bottom of every post plugin by Corey Salzano. Contact me if you need custom WordPress plugins or website design. ...
Sp17 is present in the head and tail of spermatozoa, in the tail it is in the fibrous sheath, which contains AKAP3 and AKAP4. Recombinant AKAP3 and AKAP4 RII binding domains were synthesized as glutathione S-transferase (GST) fusion proteins immobilized on glutathione-agarose resin and added to CHAPS extracts of human spermatozoa. Western blots of bound and eluted proteins probed with anti-Sp17 revealed that AKAP3 bound and precipitated a significant level of Sp17 while AKAP4 did not. AKAP4 binds AKAP3 and expression of AKAP3 is reduced in AKAP4 knockout sperm, therefore we tested AKAP4 knockout spermatozoa for Sp17 and found that there was a reduction in the amount of Sp17 expressed when compared to wild type spermatozoa. Co-localization of AKAP3 and Sp17 by immunofluorescence was demonstrated along the length of the principal piece of the flagella.. ...
2015 by the Society for the Study of Reproduction, Inc. The spermatozoa of many stallions do not tolerate being cooled, restricting the commercial viability of these animals and necessitating the development of a chemically defined room temperature (RT) storage medium. This study examined the impact of two major modulators of oxidative phosphorylation, pyruvate (Pyr) and L-carnitine (L-C), on the storage of stallion spermatozoa at RT. Optimal concentrations of Pyr (10 mM) and L-C (50 mM) were first identified and these concentrations were then used to investigate the effects of these compounds on sperm functionality and oxidative stress at RT. Mitochondrial and cytosolic reactive oxygen species, along with lipid peroxidation, were all significantly suppressed by the addition of L-C (48 h MitoSOX Red negative: 46.2% vs. 26.1%; 48 and 72 h dihydroethidium negative: 61.6% vs. 43.1% and 64.4% vs. 46.9%, respectively; 48 and 72 h 4-hydroxynonenal negative: 37.1% vs. 23.8% and 41.6% vs. 25.7%, ...
Spermatological characters of the liver fluke Mediogonimus jourdanei Mas-Coma et Rocamora, 1978 were studied by means of transmission and scanning electron microscopy. Spermiogenesis begins with the formation of the differentiation zone containing two centrioles associated with striated rootlets and an intercentriolar body. These two centrioles originate two free flagella that undergo a 90 degrees rotation before fusing with the median cytoplasmic process. Both nuclear and mitochondrial migrations toward the median cytoplasmic process occur before the proximodistal fusion of flagella. Finally, the constriction of the ring of arched membranes gives rise to the young spermatozoon. The mature sperm of M. jourdanei measures about 260 microm and presents two axonemes of different lengths with the typical pattern of the Trepaxonemata, two bundles of parallel cortical microtubules, one mitochondrion, a nucleus and granules of glycogen. An analysis of all the microphalloidean species studied to date ...
The capacitation of mammalian spermatozoa involves the activation of a cAMP-mediated signal transduction pathway that drives tyrosine phosphorylation via mechanisms that are unique to this cell type. Controversy surrounds the impact of extracellular calcium on this process, with positive and negative effects being recorded in independent publications. We clearly demonstrate that the presence of calcium in the external medium decreases tyrosine phosphorylation in both human and mouse spermatozoa. Under these conditions, a rise in intracellular pH was recorded, however, this event was not responsible for the observed changes in phosphotyrosine expression. Rather, the impact of calcium on tyrosine phosphorylation in these cells was associated with an unexpected change in the intracellular availability of ATP. Thus, the ATP content of both human and mouse spermatozoa fell significantly when these cells were incubated in the presence of external calcium. Furthermore, the removal of glucose, or addition of 2
Internal fertilization occurs in birds and eutherian mammals. Foetal development, however, is either extra- respectively intra-corpore (egg vs uterus). In these animal classes, the female genital tract stores ejaculated spermatozoa into a restricted oviductal segment; the functional pre-ovulatory sperm reservoir, where they survive until ovulation/s occur. Paradoxically, this immunologically foreign sperm suspension in seminal fluid/plasma, often microbiologically contaminated, ought to be promptly eliminated by the female local immune defence which, instead, tolerates its presence. The female immune tolerance is presumably signalled via a biochemical interplay of spermatozoa, as well as the peptides and proteins of the extracellular seminal fluid, with female epithelial and immune cells. Such interplay can result in gene expression shifts in the sperm reservoir in relation to variations in fertility. To further aid our understanding of the underlying mechanisms, this thesis studied the proteome ...
Internal fertilization occurs in birds and eutherian mammals. Foetal development, however, is either extra- respectively intra-corpore (egg vs uterus). In these animal classes, the female genital tract stores ejaculated spermatozoa into a restricted oviductal segment; the functional pre-ovulatory sperm reservoir, where they survive until ovulation/s occur. Paradoxically, this immunologically foreign sperm suspension in seminal fluid/plasma, often microbiologically contaminated, ought to be promptly eliminated by the female local immune defence which, instead, tolerates its presence. The female immune tolerance is presumably signalled via a biochemical interplay of spermatozoa, as well as the peptides and proteins of the extracellular seminal fluid, with female epithelial and immune cells. Such interplay can result in gene expression shifts in the sperm reservoir in relation to variations in fertility. To further aid our understanding of the underlying mechanisms, this thesis studied the proteome ...
Azoospermic patients (no presence of spermatozoa in the ejaculate) have the option to undergo semen surgical collection procedure, a technique for collecting spermatozoa directly from the vas deferens, epididymis or testis. Sperm retrieval may be performed under local or general anesthetic.. The samples can then be prepared for use on the same day after egg collection, cryopreserved for future use, or do both. Once the spermatozoa have been collected and isolated, fertilization can be achieved through ICSI procedure. ...