Showing papers on "Sperm plasma membrane published in 2017"

Oxidative stress: Major executioner in disease pathology, role in sperm DNA damage and preventive strategies.

Abstract: Oxidative stress (OS) has been implicated in a wide array of diseases such as neurodegenerative disorders, autoimmune diseases, complex lifestyle diseases and cancer. OS is caused by an imbalance in production of Reactive Oxygen Species (ROS) and antioxidant defenses in the cell which results in the damage of cellular components, inactivate essential metabolic enzymes and disrupt signal transduction pathways. OS induces peroxidative damage to the sperm plasma membrane, DNA fragmentation in sperm nuclear/mitochondrial genome and causes dysregulation in levels of mRNAs/transcripts. OS induced sperm DNA damage is associated with male infertility, recurrent pregnancy loss (RPL), congenital malformations and high frequency of childhood disorders. OS induced pathologies are caused by endogenous and exogenous factors, majority of which, are modifiable. Antioxidant supplementation could help in relieving OS, however, its long-term usage may disrupt the intricate oxidation-reduction balance and can lead to "Reductive Stress". Adoption of simple lifestyle interventions may relieve OS and can also aid in its management. This may improve overall quality of life (QOL) and can reduce prevalence of OS induced diseases.

Fatty acid content in epididymal fluid and spermatozoa during sperm maturation in dogs.

Abstract: During sperm maturation, there is a reorganization of fatty acids from plasmatic membrane of the spermatozoa, which allows higher membrane integrity and acquisition of sperm motility. However, the fatty acid profile during sperm maturation remains unclear in dogs. Thus, the aim of this study was to identify the fatty acids from the epididymal spermatozoa and plasma during the sperm maturation, and observed changes in the motility and plasmatic membrane parameters. Twenty one adult dogs were used, subsequently to bilateral orchiectomy and epididymal storage, sperm samples were collected from the different segments of the epididymis. Samples were evaluated for conventional microscopy, computer-assisted motility analysis, sperm plasma membrane permeability and the fatty acid analysis (lipids were extracted, transmethylated and analyzed by chromatography). Caput and corpus sperm showed lower values for the motility variables evaluated and plasmatic membrane integrity, indicating different levels of the fatty acids organization. Saturated, monounsaturated and polyunsaturated fatty acids were in higher concentrations in the spermatozoa from epididymis cauda. Highlighting the presence of caprylic, stearic and docosahexaenoic acids. These findings demonstrate the influence of the fatty acid profile during sperm maturation, assigning physical and chemical changes in sperm cells, essential for fertilization.

Lipid composition of the canine sperm plasma membrane as markers of sperm motility.

Abstract: The fatty acid composition of the sperm membrane is an important factor involved in the overall sperm quality, including motility. However, in the canine species, the exact composition of the plasma membrane is still unknown. Therefore, the purpose of this study was to evaluate the plasma membrane lipid composition of motile sperm cells and to compare it with asthenospermic samples, as an attempt to determine possible involvements of membrane lipids in dog sperm cell motility. The sperm-rich fraction of ten mature dogs was collected, and samples were subjected to density gradient centrifugation by Percoll® , in order to separate motile and asthenospermic samples. Processed semen samples were evaluated for sperm motility, plasma and acrosome membrane integrity, mitochondrial activity and susceptibility to oxidative stress. Lipid plasma membrane composition was identified by mass spectrometry (MALDI-MS). The motile sperm samples presented the following phospholipids in a high frequency in the plasma membrane: phosphatidylcholine 38:4 (composed of stearic and arachidonic fatty acids), phosphatidylcholine 36:1 (stearic and oleic fatty acids), phosphatidylethanolamine 34:4 (myristic and arachidonic fatty acids), glycerophosphatidic acid 36:4 (palmitic and arachidonic fatty acids), phosphatidylcholine 40:4 plasmanyl and phosphatidylcholine 40:5 plasmenyl. Furthermore, no lipid markers were found in the asthenospermic samples. Results also indicate that differences on plasma membrane composition between motile and asthenospermic samples are crucial factors for determining sperm motility, sperm functionality and susceptibility to oxidative stress. In conclusion, plasma membrane lipid composition varies considerable between motile and asthenospermic samples. Therefore, lipid markers of sperm motility can be considered, such as phosphatidylcholine, phosphatidylethanolamine, phosphatidylcholine plasmanyl, phosphatidylcholine plasmenyl and phosphatidic acid.

Effect of inbreeding depression on bull sperm quality and field fertility.

Abstract: The present study investigated the effect of inbreeding depression on sperm quality using automated and objective methods and subsequent effects on beef bull field fertility. Individual inbreeding coefficient (F) values and field fertility data were determined using a dataset of AI bulls belonging to the Spanish Retinta Breeders Association (Asociacion Nacional de Criadores de Ganado Vacuno Selecto de Raza Retinta (ANCRE)). Animals were clustered in two groups according to the F values as follows: (1) a high inbreeding group (HI; F≥13.5%, mean 16.3); and (2) a non-inbreeding group (NI; F=0%). In total, 17 different assessments were performed in both experimental groups, including evaluation of sperm morphology, acrosomal and DNA status, sperm plasma membrane integrity and function (hypo-osmotic swelling test), 10 kinetic parameters and the structure of sperm subpopulations. Sperm morphology, acrosomal and DNA status and osmotic tolerance were similar in both groups. Three velocity parameters (curvilinear velocity, straight line velocity and average path velocity) and the amplitude of lateral head displacement were higher in HI (P<0.05). Cluster analysis of kinematic parameters revealed three different sperm subpopulations (sP1, sP2 and sP3), with the proportion of the sP1 population (highly active but non-progressive spermatozoa) being significantly (P<0.05) higher in the HI group. Field fertility was assessed using two calving record datasets. In a smaller database including only bulls evaluated in the present study, there was a significant increase in the calving interval of cows sired with HI bulls. Conversely, in an extended genetic analysis of the ANCRE database, inbreeding only explained a small part of the variation in calving interval, and the results of regression analysis were not significant among bulls. The findings of the present study suggest that high inbreeding levels have a moderate effect on bull semen quality, with an increased percentage of highly active but non-progressive spermatozoa, but only when F values reached a certain threshold. This motility pattern could explain, in part, the higher calving interval produced by inbred bulls under field conditions.

Na/K-ATPase regulates bovine sperm capacitation through raft- and non-raft-mediated signaling mechanisms

Abstract: Highly dynamic lipid microdomains (rafts) in the sperm plasma membrane contain several signaling proteins that regulate sperm capacitation. Na/K-ATPase isoforms (testis-specific isoform ATP1A4 and ubiquitous isoform ATP1A1) are abundant in bovine sperm plasma membrane. We previously reported that incubation of bovine sperm with ouabain, a specific Na/K-ATPase ligand, induced tyrosine phosphorylation of several sperm proteins during capacitation. The objective of this study was to investigate the roles of lipid rafts and non-rafts in Na/K-ATPase enzyme activity and signaling during bovine sperm capacitation. Content of ATP1A4 and, to a lesser extent, ATP1A1 was increased in raft and non-raft fractions of capacitated sperm, although non-raft enzyme activities of both isoforms were higher than the corresponding activities in rafts from capacitated sperm. Yet, ATP1A4 was the predominant isoform responsible for total Na/K-ATPase activity in both rafts and non-rafts. A comparative increase in phosphorylation of signaling molecules was observed in both raft (CAV1) and non-raft (EGFR and ERK1/2) membrane fractions during capacitation. Although SRC was phosphorylated in both membrane fractions, the non-raft fraction possessed more of this activated form. We also inferred, by immunoprecipitation, that ATP1A4 interacted with CAV1 and EGFR in the raft fraction, whereas interactions of ATP1A4 with SRC, EGFR, and ERK1/2 occurred in the non-raft fraction of ouabain-capacitated sperm; conversely, ATP1A1 interacted only with CAV1 in both fractions of uncapacitated and capacitated sperm. In conclusion, both raft and non-raft cohorts of Na/K-ATPase isoforms contributed to phosphorylation of signaling molecules during bovine sperm capacitation. This article is protected by copyright. All rights reserved

Content of testis-specific isoform of Na/K-ATPase (ATP1A4) is increased during bovine sperm capacitation through translation in mitochondrial ribosomes

Abstract: Capacitation comprises a series of structural and functional modifications of sperm that confer fertilizing ability. We previously reported that the testis-specific isoform of Na/K-ATPase (ATP1A4) regulated bovine sperm capacitation through signaling mechanisms involving kinases. During subsequent investigations to elucidate mechanisms by which ATP1A4 regulates sperm capacitation, we observed that ATP1A4 was localised in both raft and non-raft fractions of the sperm plasma membrane and that its total content was increased in both membrane fractions during capacitation. The objective of the present study was to investigate mechanism(s) of capacitation-associated increase in the content of ATP1A4. Despite the widely accepted dogma of transcriptional/translational quiescence, incubation of sperm with either ouabain (specific ligand for ATP1A4) or heparin increased ATP1A4 content in raft and non-raft sperm membrane fractions, total sperm protein extracts (immunoblotting) and fixed sperm (flow cytometry), with a concurrent increase in Na/K-ATPase enzyme activity. This capacitation-associated increase in ATP1A4 content was partially decreased by chloramphenicol (mitochondrial translation inhibitor) but not affected by actinomycin D (transcription inhibitor). To demonstrate de novo ATP1A4 synthesis, we evaluated incorporation of bodipy conjugated lysine in this protein during capacitation. A partial decrease in bodipy-lysine incorporation occurred in ATP1A4 from sperm capacitated in the presence of chloramphenicol. Therefore, increased ATP1A4 content during capacitation was attributed to mitochondrial translation of ATP1A4 mRNA present in ejaculated sperm, rather than gene transcription. To our knowledge, this is the first report demonstrating ATP1A4 synthesis during bovine sperm capacitation.

The roles of protein disulphide isomerase family A, member 3 (ERp57) and surface thiol/disulphide exchange in human spermatozoa-zona pellucida binding

Abstract: Study question Are multimeric sperm plasma membrane protein complexes, ERp57 and sperm surface thiol content involved in human spermatozoa-zona pellucida (ZP) interaction? Summary answer ERp57 is a component of a multimeric spermatozoa-ZP receptor complex involved in regulation of human spermatozoa-ZP binding via up-regulation of sperm surface thiol content. What is known already A spermatozoon acquires its fertilization capacity within the female reproductive tract by capacitation. Spermatozoa-ZP receptor is suggested to be a composite structure that is assembled into a functional complex during capacitation. Sperm surface thiol content is elevated during capacitation. ERp57 is a protein disulphide isomerase that modulates the thiol-disulphide status of proteins. Study design, size, duration The binding ability and components of protein complexes in extracted membrane protein fractions of spermatozoa were studied. The roles of capacitation, thiol-disulphide reagent treatments and ERp57 on sperm functions and sperm surface thiol content were assessed. Participants/materials, setting, methods Spermatozoa were obtained from semen samples from normozoospermic men. Human oocytes were obtained from an assisted reproduction programme. Blue native polyacrylamide gel electrophoresis, western ligand blotting and mass spectrometry were used to identify the components of solubilized ZP/ZP3-binding complexes. The localization and expression of sperm surface thiol and ERp57 were studied by immunostaining and sperm surface protein biotinylation followed by western blotting. Sperm functions were assessed by standard assays. Main results and the role of chance Several ZP-binding complexes were isolated from the cell membrane of capacitated spermatozoa. ERp57 was a component of one of these complexes. Capacitation significantly increased the sperm surface thiol content, acrosomal thiol distribution and ERp57 expression on sperm surface. Sperm surface thiol and ERp57 immunoreactivity were localized to the acrosomal region of spermatozoa, a region responsible for ZP-binding. Up-regulation of the surface thiol content or ERp57 surface expression in vitro stimulated ZP-binding capacity of human spermatozoa. Blocking of ERp57 function by specific antibody or inhibitors against ERp57 reduced the surface thiol content and ZP-binding capacity of human spermatozoa. Large scale data N/A. Limitations, reasons for caution The mechanisms by which up-regulation of surface thiol content stimulates spermatozoa-ZP binding have not been depicted. Wider implications of the findings Thiol-disulphide exchange is a crucial event in capacitation. ERp57 modulates the event and the subsequent fertilization process. Modulation of the surface thiol content of the spermatozoa of subfertile men may help to increase fertilization rate in assisted reproduction. Study funding/competing interest(s) This work was supported by The Hong Kong Research Grant Council Grant HKU764611 and HKU764512M to P.C.N.C. The authors have no competing interests.

Effects of freezing and activation on membrane quality and DNA damage in Xenopus tropicalis and Xenopus laevis spermatozoa.

Abstract: There is growing concern over the effect of sperm cryopreservation on DNA integrity and the subsequent development of offspring generated from this cryopreserved material. In the present study, membrane integrity and DNA stability of Xenopus laevis and Xenopus tropicalis spermatozoa were evaluated in response to cryopreservation with or without activation, a process that happens upon exposure to water to spermatozoa of some aquatic species. A dye exclusion assay revealed that sperm plasma membrane integrity in both species decreased after freezing, more so for X. laevis than X. tropicalis spermatozoa. The sperm chromatin dispersion (SCD) test showed that for both X. tropicalis and X. laevis, activated frozen spermatozoa produced the highest levels of DNA fragmentation compared with all fresh samples and frozen non-activated samples (P<0.05). Understanding the nature of DNA and membrane damage that occurs in cryopreserved spermatozoa from Xenopus species represents the first step in exploiting these powerful model organisms to understand the developmental consequences of fertilising with cryopreservation-damaged spermatozoa.

Sperm Surface Proteomics

Abstract: This contribution will focus exclusively on the total (global) protein composition (the proteome) of the sperm surface. Immune responses directed towards sperm surface proteins may cause infertility since functionally intact sperm are under immune attack. The immune attack can be achieved directly by deteriorating sperm or by antibody blocking of a sperm surface protein with a specific function in the fertilization process. Antibodies that bind to the sperm surface proteins could also impair the fertilization potential of sperm more indirectly by causing lateral redistribution of the sperm surface proteins and/or by hindrance of the assemblage of functional membrane protein complexes involved in fertilization. Currently the information about the sperm plasma membrane proteome is increasing but has only led to limited understanding of the functionality that is related to the complex ordering and processing of this specific cell surface. New proteomic data and new strategies designed for complete coverage of the surface proteome of mammalian sperm will significantly increase our understanding of how fertilization is accomplished but also how immune responses may frustrate this process. This information will become highly relevant for studying immune infertility. An overview is provided about the current knowledge of the sperm surface and how this structure should experimentally be approached for proteomic studies. Comparative analysis of different mammalian species is covered as this will provide better understanding for the possibilities and limitations of analyzing the surface proteome of human sperm.

Seminal coagulation and sperm quality in different social contexts in captive tufted capuchin monkeys (Sapajus apella).

Abstract: In the present study, we aimed to assess the influence of different social contexts on the seminal coagulation and sperm quality in captive tufted capuchin monkeys. For this, males were housed either individually, in mixed-sex groups (with females), or in male-only groups. Monkeys were housed in cages and each cage type (i.e., individual or group cage) was placed in a different room. Forty-one males were subjected to semen collection by rectal electroejaculation. The degree of seminal coagulation was determined on a scale of I-IV. Seminal volume, sperm concentration, sperm motility, vigor, and plasma membrane integrity were evaluated for all ejaculate samples. All ejaculates collected showed degrees of coagulation between II and IV, where the majority presented coagulation degree IV, when collected from animals housed in groups. No statistical differences among percentages of coagula degree when samples were collected from males housed individually. Animals housed in group cages (male-only groups and mixed-sex groups) showed a significantly higher percentage of ejaculates at degree IV than males housed individually. Seminal volume was not affected by the coagula degree but by the housing system, where animals housed individually showed the highest volume (543 μl) when compared with those animals from male (273 μl) and mixed-sex (318 μl) groups. No differences were observed in semen volume when comparing male-only groups with mixed-sex groups. Sperm motility was affected by both housing system and coagula degree. Samples with coagula degree IV from animals housed individually showed the highest (72%) sperm motility percentages. Sperm plasma membrane integrity was lower when samples were presenting coagula degree II + III and collected from male- (17%) or mixed-sex (23%) groups. However, this housing system effect was not observed when sperm was obtained from coagula degree IV semen. Sperm vigor was neither affect by housing system or coagula degree.

Redistribution of soluble N-ethylmaleimide-sensitive-factor attachment protein receptors in mouse sperm membranes prior to the acrosome reaction.

Abstract: Formation of complexes between soluble N-ethylmaleimide-sensitive-factor attachment protein receptor (SNARE) proteins on opposing membranes is the minimal requirement for intracellular membrane fusion. The SNARE, syntaxin 2, is found on the sperm plasma membrane and a second SNARE, vesicle associated membrane protein 2 (VAMP2, also known as synaptobrevin 2, SYB2), is on the apposing outer acrosomal membrane. During the acrosome reaction, the outer acrosomal membrane fuses at hundreds of points with the plasma membrane. We hypothesized that syntaxin 2 and VAMP2 redistribute within their respective membranes prior to the acrosome reaction to form trans-SNARE complexes and promote membrane fusion. Immunofluorescence and superresolution structured illumination microscopy were used to localize syntaxin 2 and VAMP2 in mouse sperm during capacitation. Initially, syntaxin 2 was found in puncta throughout the acrosomal region. At 60 and 120 min of capacitation, syntaxin 2 was localized in puncta primarily in the apical ridge. Although deletion of bicarbonate during incubation had no effect, syntaxin 2 puncta were relocated in the restricted region in less than 20% of sperm incubated without albumin. In contrast, VAMP2 was already found in puncta within the apical ridge prior to capacitation. The puncta containing syntaxin 2 and VAMP2 did not precisely co-localize at 0 or 60 min of capacitation time. In summary, syntaxin 2 shifted its location to the apical ridge on the plasma membrane during capacitation in an albumin-dependent manner but VAMP2 was already localized to the apical ridge. Puncta containing VAMP2 did not co-localize with those containing syntaxin 2 during capacitation; therefore, formation of trans-SNARE complexes containing these SNAREs does not occur until after capacitation, immediately prior to acrosomal exocytosis.

In vitro evidence for the participation of Drosophila melanogaster sperm β-N-acetylglucosaminidases in the interactions with glycans carrying terminal N-acetylglucosamine residues on the egg's envelopes.

Abstract: Fertilization is a complex and multiphasic process, consisting of several steps, where egg-coating envelope's glycoproteins and sperm surface receptors play a critical role. Sperm-associated β-N-acetylglucosaminidases, also known as hexosaminidases, have been identified in a variety of organisms. Previously, two isoforms of hexosaminidases, named here DmHEXA and DmHEXB, were found as intrinsic proteins in the sperm plasma membrane of Drosophila melanogaster. In the present work, we carried out different approaches using solid-phase assays in order to analyze the oligosaccharide recognition ability of D. melanogaster sperm hexosaminidases to interact with well-defined carbohydrate chains that might functionally mimic egg glycoconjugates. Our results showed that Drosophila hexosaminidases prefer glycans carrying terminal β-N-acetylglucosamine, but not core β-N-acetylglucosamine residues. The capacity of sperm β-N-acetylhexosaminidases to bind micropylar chorion and vitelline envelope was examined in vitro assays. Binding was completely blocked when β-N-acetylhexosaminidases were preincubated with the glycoproteins ovalbumin and transferrin, and the monosaccharide β-N-acetylglucosamine. Overall, these data support the hypothesis of the potential role of these glycosidases in sperm–egg interactions in Drosophila.

Relationship between sperm plasma membrane integrity and morphology and fertility following artificial insemination

Abstract: Sperm quality plays an important role in determining fertility. The aim of the study was to examine the relationship between sperm plasma membrane integrity and morphology, and fertility following artificial insemination (AI). A total of 16 ejaculates were collected from three Large White boars using the gloved hand technique. The semen was extended with a commercial extender. The AI dose contained 80 mL semen sample (3 × 10 9 sperm/mL). Aliquots of diluted semen were assessed for sperm plasma membrane integrity (synthetic binding CD-14 (SYBR+)/propidium iodide (PI-) and sperm morphology (eosin nigrosin). A total of 73 Duroc-type, Large White and nondescript multiparous sows from smallholder farms were inseminated with extended semen samples. Boar sperm plasma membrane integrity and morphology were subjected to one-way analysis of variance (ANOVA). The average boar sperm plasma membrane integrity and normal sperm morphology were 78.6% and 77.2%, respectively. The average conception and farrowing rates following artificial insemination (AI) were 78.1 and 57.5%, respectively. A negative correlation was observed between sperm plasma membrane integrity and fertility. There was a weak positive correlation between normal sperm morphology and conception rate (r = 0.11). Additionally, a relationship was observed between normal sperm morphology and litter size (r = 0.37) and total number born alive (r = 0.03), although relatively low. In conclusion, a negative relationship was found between sperm plasma membrane integrity and fertility. Moreover, there was a relationship between morphologically normal sperm and litter size, as well as number of piglets born alive, although relatively low. Keywords : Boar, Eosin Nigrosin, Semen quality, SYBR14/PI

Extender supplementation with catalase maintains the integrity of sperm plasma membrane after freezing–thawing of semen from capuchin monkey

Abstract: We aimed to evaluate the effect of supplementation of ACP-118® extender with the antioxidant catalase (10 and 50 µg/ml) on Sapajus apella sperm motility, vigour, and plasma membrane integrity during the processes of seminal liquefaction, cooling, and freezing. Catalase did not affect any of the evaluated parameters after semen dilution or cooling. Cryopreserved sperm in the presence of 50 µg/ml catalase presented a plasma membrane integrity similar to that fresh sperm, however.

Bovine sperm capacitation solution and in vitro sperm capacitation method

Abstract: Belonging to the technical field of livestock breeding, the invention discloses a bovine sperm capacitation solution and an in vitro sperm capacitation method. The bovine sperm capacitation solution mainly consists of the following components: 6.7500mg/mL NaCl, 0.3000mg/mL KCl, 2.5000mg/mL NaHCO3, 0.0620mg/mL NaH2PO4.2H2O, 0.2960mg/mL CaCl2.2H2O, 0.1000mg/mL MgCl2.6H2O, 0.1120mg/mL sodium pyruvate, 0.0186mg/mL EDTA-Na, 0.0100mg/mL phenol red, 6.0000mg/mL BSA, 1.0000mg/mL glucose, 0.4800mg/mL caffeine, 0.0500mg/mL heparin, and 0.025-0.05mg/mL Nisin. The capacitation solution provided by the invention can effectively ensure the sperm motility, sperm plasma membrane integrity rate, acrosomal integrity rate and mitochondrial activity, and maintains the in vitro sperm capacitation effect.

Role of oxidative stress and vitamin c, e on male fertility: mini review

Abstract: Exposure to reactive oxygen intermediates or free radicals cause oxidative stress. These free radicals cause damage to proteins, nucleic acids and cell membranes. Increasing evidence suggests that the cumulative damage caused by reactive oxygen species contribute to numerous diseases. Recently many stressful conditions reported to disturb the prooxidant and antioxidant balance of the cells by generating reactive oxygen species and oxygen free radicals thereby inducing oxidative stress. Accumulating evidence has implied that the production of free radical plays a critical role in male reproduction and many studies reported that stress play important role in etiology of male infertility. Chronic psychological and physical stresses induce erectile dysfunction, possibly resulting from neurotransmission changes in various erectile response pathways and a reduced blood flow in male genital organs. Due to high PUFAs content in sperm plasma membrane which results vulnerable to oxidative stress, low membrane fluidity and loss of sperm oocyte interaction. After molecular biology, pharmacology and therapeutics became active for finding the molecules for quenching free radicals. The recent growth in the knowledge of free radicals or ROS is producing a medical revolution and that promises a new age of health disease management. Supplementation of antioxidants improve the sperm quality and reduces oxidative stress induced infertility.

Effect of season on semen quality parameters in Murrah buffalo.

Abstract: Seasonal influence on frozen semen quality in Murrah buffalo breeding bulls was determined. Frozen semen samples of 6 Murrah buffalo bulls were collected and semen frozen in 4 different seasons, viz. winter (Dec-Feb), spring (mid Feb-Apr), summer (May-Jun) and rainy (Jul-Aug) were assessed. Samples (12) of each bull, in a season, were evaluated for sperm motility, viability and acrosome integrity. Motility and other kinematics of spermatozoa during incubation (37°C) at 0, 30, 60, 90 and 120 min of thawing were assessed with computer assisted semen analyzer. Post-thaw sperm total motility and viability differed significantly among the seasons, the highest was in winter. Sperm plasma membrane integrity, acrosome integrity, progressive motility, rapid motility and other CASA evaluated parameters did not differ significantly among the seasons. Higher values of plasma membrane integrity (PMI), progressive motility, rapid motility, average path velocity (VAP), straight line velocity (VSL), curvilinear velocity (VCL), beat cross frequency (BCF), linearity (LIN) and straightness (STR) were obtained in winter season as compared to other seasons. Post-thaw motility at 0 min and 60 min of post-thaw incubation varied significantly between seasons and higher sperm motility was sustained for a longer period in semen cryopreserved in winter followed by rainy season, summer and spring. It can be concluded from this study that buffalo bull semen produced and frozen during winter season resulted in higher sperm motility, viability and postthaw longer survivability in comparison to other seasons.

Experimental method for preserving diluent of sheep semen under room temperature

Abstract: The invention discloses an experimental method for preserving a diluent of sheep semen under a room temperature. The experimental method comprises the following specific steps: 1) extracting the fresh sheep semen; 2) putting a semen collecting cup into a thermal insulation barrel and returning the semen collecting cup to a laboratory; 4) preparing four diluents; 5) putting the diluents into a 37-DEG C water-bath pot; 6) diluting the fresh semen; 7), storing diluted semen I, II, III and IV obtained in the step 6), tightly covering a centrifugal tube cover, putting the centrifugal tube on a foamed centrifugal tube rack, and placing and storing under the room temperature; 8), measuring a sperm motility rate in diluted semen; and 10), detecting a sperm plasma membrane integrity rate in the diluted semen. According to the experimental method for preserving the diluent of the sheep semen under the room temperature, disclosed by the invention, the semen with a relatively high survival rate is extracted, and influences, on experimental results, of a low sperm survival rate are reduced; and survival rates of sheep sperms are separately detected through the four groups of diluents with different proportions, and the measured diluent proportion of the diluent III is more beneficial for survival of the sperms.

Methods for improvement of semen quality

Abstract: A method for improving quality of a mammalian semen sample includes providing an insoluble carrier carrying at least one ligand that binds to an indicator of impaired sperm membrane integrity and/or motility, or the insoluble carrier carrying at least one molecule capable of binding to the at least one ligand, and contacting the semen sample and the insoluble carrier to provide a bound sperm cell population and an unbound sperm cell population, The insoluble carrier may be a plurality of beads each carrying the at least one ligand or the at least one molecule. The indicator may be associated with one or both of impaired sperm acrosome and impaired sperm plasma membrane integrity. The ligand may be an antibody. The molecule may be one of streptavidin, protein A, and an anti-ligand antibody. Kits for performing the method are provided.

Penambahan l – arginin dalam pengencertris kuning telur setelah ekuilibrasi 2jam terhadap motilitas dan membranplasma utuh spermatozoadomba sapudi

Abstract: This research was aimed to determine the addition of L-arginine on motility and sperm plasma membrane of Sapudi sheep after two hour equilibration time in egg yolk tris diluent. This research used fresh samples of sheep Sapudi semen collected by artificial vagina, then were devided into 4 treatments and 6 replications. Analysis of the data using Analysis of Variance (ANOVA) then proceed to the Duncan Test to determine significant differences between treatments. The first treatment P0 was no L – Arginine added as control. P1 was treated with 0,004 M L – Arginine. P2 was treated with 0,005 M L – Arginine, P3 was treated with 0,006 M L – Arginine. Result of two hour equilibration time for the sperm motility showed: (P0) 46,67a ± 5,16 , (P1) 49,16ab ± 5,84 , (P2) 55,00bc ± 7,74 , (P3) 58,33c ± 6,83. Result of two hour equilibration time for the sperm plasm membrane were: (P0) 39,33 a ± 4,92 , (P1) 43,33 ab ± 4,22 , (P2) 46,50 bc ± 3,44 , (P3) 50,83 c ± 3,48. The addition of L-arginine with a concentration as much as 0.006 M, shows the highest result in sperm motility and sperm plasm membrane intact of Sapudi semen.