Showing papers on "Sperm motility published in 2007"
TL;DR: In this article, the authors discuss the need of ROS in normal sperm physiology, the mechanism of production of ROS and its pathophysiology in relation to male reproductive system and highlight the emerging concept of utilizing ROS as a method of contraception and the potential problems associated with it.
Abstract: Male factor has been considered a major contributory factor to infertility. Along with the conventional causes for male infertility such as varicocele, cryptorchidism, infections, obstructive lesions, cystic fibrosis, trauma, and tumors, a new, yet important cause has been identified: oxidative stress. Oxidative stress (OS) is a result of the imbalance between reactive oxygen species (ROS) and antioxidants in the body, which can lead to sperm damage, deformity and eventually male infertility. This involves peroxidative damage to sperm membrane and DNA fragmentation at both nuclear and mitochondrial levels. OS has been implicated as the major etiological factor leading to sperm DNA damage. OS-induced DNA damage can lead to abnormalities in the offspring including childhood cancer and achondroplasia. In this article, we discuss the need of ROS in normal sperm physiology, the mechanism of production of ROS and its pathophysiology in relation to male reproductive system. The benefits of incorporating antioxidants in clinical and experimental settings have been enumerated. We also highlight the emerging concept of utilizing OS as a method of contraception and the potential problems associated with it.
644 citations
TL;DR: Direct protein interactions among CatSpers, the sperm specificity of these proteins, and loss of ICatSper in each of the four CatSper−/− mice indicate that CatSper are highly specialized flagellar proteins.
Abstract: Mammalian spermatozoa become motile at ejaculation, but before they can fertilize the egg, they must acquire more thrust to penetrate the cumulus and zona pellucida. The forceful asymmetric motion of hyperactivated spermatozoa requires Ca2+ entry into the sperm tail by an alkalinization-activated voltage-sensitive Ca2+-selective current (ICatSper). Hyperactivation requires CatSper1 and CatSper2 putative ion channel genes, but the function of two other related genes (CatSper3 and CatSper4) is not known. Here we show that targeted disruption of murine CatSper3 or CatSper4 also abrogated ICatSper, sperm cell hyperactivated motility and male fertility but did not affect spermatogenesis or initial motility. Direct protein interactions among CatSpers, the sperm specificity of these proteins, and loss of ICatSper in each of the four CatSper−/− mice indicate that CatSpers are highly specialized flagellar proteins.
479 citations
TL;DR: This study has written and validated a free CASA software primarily for analysis of fish sperm, and improved upon the traditional velocity straight line (VSL) algorithm, eliminating inaccurate characterization of highly curved fish sperm paths.
392 citations
TL;DR: It is shown that both ZPBP proteins play an earlier structural role during spermiogenesis, and molecular phylogenetic analysis of ZPBPs from amphibians, birds, and mammals suggests that these paralogous genes coevolved to play cooperative roles during sPermiogenesis.
Abstract: Zona pellucida binding protein 1 (ZPBP1), a spermatid and spermatozoon protein that localizes to the acrosome, was originally identified in pigs and named for its binding to the oocyte zona pellucida. In an in silico search for germ cell-specific genes, Zpbp1 and its novel paralog, Zpbp2, were discovered and confirmed to be expressed only in the testes in both mice and humans. To study the in vivo functions of both ZPBP proteins, we disrupted Zpbp1 and Zpbp2 in mice. Males lacking ZPBP1 were sterile, with abnormal round-headed sperm morphology and no forward sperm motility. Ultrastructural studies demonstrated that absence of ZPBP1 prevents proper acrosome compaction, resulting in acrosome fragmentation and disruption of the Sertoli-spermatid junctions. Males null for ZPBP2 were subfertile, demonstrated aberrant acrosomal membrane invaginations, and produced dysmorphic sperm with reduced ability to penetrate zona pellucida. Molecular phylogenetic analysis of ZPBPs from amphibians, birds, and mammals suggests that these paralogous genes coevolved to play cooperative roles during spermiogenesis. Whereas ZPBP1 was discovered for an in vitro role in sperm-egg interactions, we have shown that both ZPBP proteins play an earlier structural role during spermiogenesis.
205 citations
TL;DR: The results suggest that catalase had the most pronounced effect in improving post-thaw quality of canine spermatozoa and none of the reactive oxygen species were significantly reduced post-Thaw in antioxidant treated semen.
193 citations
TL;DR: CFTR in sperm may be involved in the transport of HCO3− important for sperm capacitation and that CFTR mutations with impaired CFTR function may lead to reduced sperm fertilizing capacity and male infertility other than CBAVD.
Abstract: Cystic fibrosis transmembrane conductance regulator (CFTR) is an anion channel, mutations of which cause cystic fibrosis, a disease characterized by defective Cl− and HCO3− transport. Although >95% of all CF male patients are infertile because of congenital bilateral absence of the vas deferens (CBAVD), the question whether CFTR mutations are involved in other forms of male infertility is under intense debates. Here we report that CFTR is detected in both human and mouse sperm. CFTR inhibitor or antibody significantly reduces the sperm capacitation, and the associated HCO3−-dependent events, including increases in intracellular pH, cAMP production and membrane hyperpolarization. The fertilizing capacity of the sperm obtained from heterozygous CFTR mutant mice is also significantly lower compared with that of the wild-type. These results suggest that CFTR in sperm may be involved in the transport of HCO3− important for sperm capacitation and that CFTR mutations with impaired CFTR function may lead to reduced sperm fertilizing capacity and male infertility other than CBAVD.
189 citations
TL;DR: The results of this study provide a new approach to the cryopreservation of sperm from rams and related breeds, and thereby contribute to the improvement of these breeds for the world sheep industry.
Abstract: Uysal O., M. N. Bucak: Effects of Oxidized Glutathione, Bovine Serum Albumin, Cysteine and Lycopene on the Quality of Frozen-Thawed Ram Semen. Acta Vet. Brno 2007, 76: 383-390. Free radicals are known to be involved in lipid peroxidation as well as DNA and sperm membrane damages that may lead to decreased sperm motility or cell death. The balance between free radical production and their detoxifi cation may be an important factor in sperm survival and function before, during and after cryopreservation. The aim of this study was to determine the effects of the addition of the antioxidants of oxidized glutathione (GSSG), bovine serum albumin (BSA), cysteine and lycopene to freezing media on the post-thawing sperm characteristics, including motility, morphology, acrosome integrity, viability and membrane integrity. A total number of 42 ejaculates were collected using the artifi cial vagina from 4 Akkaraman rams and 10 replicates of the ejaculates were diluted with a Tris-based extender containing additives and no additives as control. GSSG (5 mM), BSA (20 mg/ml), cysteine (10 mM) and lycopene (800 μg) showed more positive effects than other concentrations of the supplements and controls in protecting sperm characteristics after the freezing-thawing process (P < 0.001). Many aspects of sperm protection, e.g. sperm motility, viability and membrane stabilisation of the sperm cells during relative cryopreservation, are the key factors in determining the preservation of sperm function. The results of this study provide a new approach to the cryopreservation of sperm from rams and related breeds, and thereby contribute to the improvement of these breeds for the world sheep industry. Antioxidants, ram semen, freezing, extender
187 citations
TL;DR: Cryopreservation and H2O2 promote DNA instability in ram sperm, though motility is a more sensitive indicator of oxidative stress than the other parameters investigated.
Abstract: Assisted reproduction using frozen-thawed semen has practical advantages, although cryopreservation is detrimental to sperm fertility in most mammals We examined the influence of cryopreservation and reactive oxygen species (ROS) on ram sperm DNA stability (using SCSA), lipid peroxidation (LPO), chlortetracycline fluorescence (CTC) patterns, motility and viability In Experiment 1, DNA integrity, LPO, CTC, motility and viability tests were performed on fresh and cryopreserved sperm after 0, 6, and 24 hr in synthetic oviductal fluid (SOF) In Experiment 2, fresh sperm were incubated in serum-free SOF (SOF-S; 1, 4, and 24 hr) with 0, 50, 150, or 300 microM H2O2 then assayed Cryopreservation increased the percentage of sperm with a high DNA fragmentation index (%DFI), decreased the percentages of motile and viable sperm at thawing (0 hr), but did not affect LPO H2O2 (150 or 300 microM) increased %DFI after 24 hr LPO or sperm viability were not affected by H2O2, although most motility parameters decreased H2O2 decreased the percentage of chlortetracycline pattern F sperm at 4 hr and increased the percentage of acrosome-reacted sperm (pattern AR) after 1 hr Pooled data of Experiment 2 showed LPO was positively correlated with SCSA (r = 029 to r = 059; P < 005 to P < 001), while most motility parameters and the percentage of viable sperm were negatively correlated with LPO (r = -030 to r = -038; P < 005 to P < 001) LPO was positively correlated with the percentage of pattern AR sperm (r = 033; P < 001) Cryopreservation and H2O2 promote DNA instability in ram sperm, though motility is a more sensitive indicator of oxidative stress than the other parameters investigated
178 citations
TL;DR: Potential targets for S‐nitrosylation in human sperm include physiologically significant proteins not previously reported in other cells and will provide novel insight into the mechanism of action of NO in spermatozoa.
Abstract: Nitric oxide (NO) enhances human sperm motility and capacitation associated with increased protein phosphorylation. NO activates soluble guanylyl cyclase, but can also modify protein function covalently via S-nitrosylation of cysteine. Remarkably, this mechanism remains unexplored in sperm although they depend on post-translational protein modification to achieve changes in function required for fertilisation. Our objective was to identify targets for S-nitrosylation in human sperm. Spermatozoa were incubated with NO donors and S-nitrosylated proteins were identified using the biotin switch assay and a proteomic approach using MS/MS. 240 S-nitrosylated proteins were detected in sperm incubated with S-nitroso-glutathione. Minimal levels were observed in glutathione or untreated samples. Proteins identified consistently based on multiple peptides included established targets for S-nitrosylation in other cells e.g. tubulin, GST and HSPs but also novel targets including A-kinase anchoring protein (AKAP) types 3 and 4, voltage-dependent anion-selective channel protein 3 and semenogelin 1 and 2. In situ localisation revealed S-nitrosylated targets on the postacrosomal region of the head and throughout the flagellum. Potential targets for S-nitrosylation in human sperm include physiologically significant proteins not previously reported in other cells. Their identification will provide novel insight into the mechanism of action of NO in spermatozoa.
163 citations
01 Jan 2007
TL;DR: Despite different preferences for energy substrates and metabolic pathways between species, analysis of knockout mice revealed that glycolysis is indispensable for mouse sperm function and that oxidative phosphorylation is not essential for male fertility, suggesting that gly colysis could compensate for the lack of oxidative phosphate and recover most sperm function.
Abstract: Energy metabolism is a key factor supporting sperm function. Sustaining sperm motility and active protein modifications such as phosphorylation could be the reason why sperm require exceptionally more ATP than other cells. Many methods have been used to understand the relationship between energy metabolism and sperm function. These approaches have identified critical metabolic pathways that support specific processes during germ cell development and fertilisation. In round spermatids, lactate and pyruvate are the preferred substrates and the use of glucose is limited, however, during epididymal maturation sperm expand to use glycolysis. While the acrosome reaction requires lactate or pyruvate for ATP production by oxidative phosphorylation, gamete fusion requires glucose to produce NADPH by the pentose phosphate pathway. Sperm motility appears to be supported by relatively low ATP levels, but achievement of high ATP levels are essential for tyrosine phosphorylation linked to hyperactivation. Thus, each individual process and event requires a different substrate and metabolic pathway. Despite different preferences for energy substrates and metabolic pathways between species, analysis of knockout mice revealed that glycolysis is indispensable for mouse sperm function and that oxidative phosphorylation is not essential for male fertility. This suggests that glycolysis could compensate for the lack of oxidative phosphorylation and recover most sperm function. Spermatogenic cell-specific glycolytic enzymes may confer flexible use of substrates and adapt to unexpected conditions for substrates in the female reproductive tract.
161 citations
TL;DR: Proteomic technology was used to compare sperm protein expression profiles in asthenozoospermic patients with that of normozoosPermic donors and 10 differentially expressed proteins were identified.
TL;DR: The results suggest that carrying cell phones near reproductive organs could negatively affect male fertility, and this work is concerned with male fertility in rats exposed to cellular phone emissions.
TL;DR: It is reported that Catsper3 and Catsper4 knockout male mice are completely infertile due to a quick loss of motility and a lack of hyperactivated motility under capacitating conditions.
Abstract: Catsper3 and Catsper4 are two recently identified testis-specific genes homologous to Catsper1 and Catsper2 that have been shown to play an essential role in sperm hyperactivated motility and male fertility in mice. Here we report that Catsper3 and Catsper4 knockout male mice are completely infertile due to a quick loss of motility and a lack of hyperactivated motility under capacitating conditions. Our data demonstrate that both CATSPER3 and CATSPER4 are required for hyperactivated sperm motility during capacitation and for male fertility. The present study also demands a revisit to the idiopathic male infertility patients who show normal sperm counts and normal initial motility for defects in sperm hyperactivated motility and for potential CATSPER gene mutations. The CATSPER channel also may be an excellent drug target for male contraceptives.
TL;DR: It is proposed that the formation of this complex efficiently modulates intracellular pH and bicarbonate levels through the rapid and effective control of sAC and sNHE activities to facilitate sperm motility regulation.
Abstract: We previously identified a sperm-specific Na+/H+ exchanger (sNHE) principally localized to the flagellum. Disruption of the sNHE gene in mice resulted in absolute male infertility associated with a complete loss of sperm motility. Here, we show that the sNHE-null spermatozoa fail to develop the cAMP-dependent protein tyrosine phosphorylation that coincides with the functional maturation occurring upon incubation in capacitating conditions in vitro. Both the sperm motility defect and the lack of induced protein tyrosine phosphorylation are rescued by the addition of cell-permeable cAMP analogs, suggesting that cAMP metabolism is impaired in spermatozoa lacking sNHE. Our analyses of the bicarbonate-dependent soluble adenylyl cyclase (sAC) signaling pathway in sNHE-null sperm cells reveal that sNHE is required for the expression of full-length sAC, and that it is important for the bicarbonate stimulation of sAC activity in spermatozoa. Furthermore, both codependent expression and coimmunoprecipitation experiments indicate that sNHE and sAC associate with each other. Thus, these two proteins appear to be components of a signaling complex at the sperm flagellar plasma membrane. We propose that the formation of this complex efficiently modulates intracellular pH and bicarbonate levels through the rapid and effective control of sAC and sNHE activities to facilitate sperm motility regulation.
TL;DR: The aim of this study was to determine the effects of the addition of the anti-oxidants taurine and glutathione, and the membrane structure stabiliser, trehalose, on sperm viability during low temperature liquid storage.
TL;DR: In this paper, the effects of methyl parathion on the testes of rats were investigated at the end of 24 h, 4th and 7th weeks compared with a control group.
TL;DR: Decreasing seminal plasma antioxidants levels, especially catalase and TAC, could have significant role in etiology of impaired sperm function and measurement of 8-Isoprostane may be used as a specific biomarker for assessing oxidative stress on sperm.
Abstract: There is growing evidence that damage to spermatozoa by reactive oxygen species (ROS) play a key role in male infertility. The aim of the present study was to assess seminal plasma levels of total antioxidant capacity (TAC), free 8-Isoprostane and activities of catalase and superoxide dismutase (SOD) in men with asthenozoospermia, asthenoteratozoospermia and oligoasthenoteratozoospermia compared with normozoospermic males. The patients consisted of 46 men with seminal parameters abnormalities. The patients were grouped into asthenozoospermic (n = 15), asthenoteratozoospermic (n = 16) and oligoasthenoteratozoospermic (n = 15). The control group consisted of 16 healthy males with normozoospermia. Catalase activity was measured by Aebi spectrophotometeric method. Levels of TAC and SOD were measured by commercially available colorimetric assays. Level of free 8-Isoprostane was assessed by commercially available enzyme immunoassay (EIA) method. Differences between groups were assessed using Mann-Whitney U test and Kruskal-Wallis test. Coefficients of correlation were calculated using Spearman's correlation analysis. All hypothesis tests were two-tailed with statistical significance assessed at the p value < 0.05 level with 95% confidence intervals Levels of catalase and TAC were significantly lower in patients than the control group. No significant changes were seen in SOD activities. Levels of free 8-Isoprostane were significantly higher in patients than the control group. Furthermore, asthenozoospermic, asthenoteratozoospermic and oligoasthenoteratozoospermic groups had significantly lower values of catalase activity and TAC when compared to normozoospermic males. Levels of free 8-Isoprostane were significantly higher in all patients subgroups than the control group. Levels of catalase and TAC were positively correlated with sperm motility and morphology. Free 8-Isoprostane levels showed an inverse correlation with sperm motility and morphology. Decreasing seminal plasma antioxidants levels, especially catalase and TAC, could have significant role in etiology of impaired sperm function. Measurement of 8-Isoprostane may be used as a specific biomarker for assessing oxidative stress on sperm.
TL;DR: Findings may explain the reduction of fertility, secondary to upregulated production of TNF-α, in men with urogenital infections.
Abstract: The aim of this study was to evaluate the effects of tumour necrosis factor-alpha (TNF-alpha) on sperm motility, mitochondrial membrane potential (DeltaPsi), phosphatidylserine (PS) externalization, sperm chromatin packaging quality, and DNA fragmentation. Motile spermatozoa, obtained from 10 normozoospermic men, were incubated with increasing concentrations of TNF-alpha and analyzed 1, 3, 6, and 24 h after incubation by flow cytometry. TNF-alpha decreased total motility 24 h after incubation at 10 ng/mL and progressive motility 3 h after incubation. Accordingly, TNF-alpha reduced sperm DeltaPsi in a concentration- and time-dependent manner. TNF-alpha increased the percentage of spermatozoa with PS externalization from the concentration of 1 ng/mL 1 h after incubation. TNF-alpha produced sperm chromatin and DNA damage in a concentration- and time-dependent manner. In conclusion, these findings may explain the reduction of fertility, secondary to upregulated production of TNF-alpha, in men with urogenital infections.
TL;DR: It is demonstrated that a febrile episode can have marked effects on semen parameters and sperm DNA integrity and is particularly important for the counseling of infertile couples and in relation to assisted reproductive techniques (ART).
TL;DR: Results indicate that extracellular Ca( 2+) is required to supplement store-released Ca(2+) to produce maximal and sustained hyperactivation and that CatSper1 and CatSar2 are key elements of the major Ca(1+) entry pathways that support not only hyperactivated motility but possibly also normal pre-hyper activated motility.
TL;DR: The results suggest that the insecticide permethrin may cause mitochondrial membrane impairment in Leydig cells and disrupt testosterone biosynthesis by diminishing the delivery of cholesterol into the mitochondria and decreasing the conversion of cholesterol to pregnenolone in the cells, thus reducing subsequent testosterone production.
Abstract: Permethrin, a popular synthetic pyrethroid insecticide used to control noxious insects in agriculture, forestry, households, horticulture, and public health throughout the world, poses risks of environmental exposure. Here we evaluate the reproductive toxicity of cis-permethrin in adult male ICR mice that were orally administered cis-permethrin (0, 35, or 70 mg/kg d) for 6 wk. Caudal epididymal sperm count and sperm motility in the treated groups were statistically reduced in a dose-dependent manner. Testicular testosterone production and plasma testosterone concentration were significantly and dose-dependently decreased with an increase in LH, and a significant regression was observed between testosterone levels and cis-permethrin residues in individual mice testes after exposure. However, no significant changes were observed in body weight, reproductive organ absolute and relative weights, sperm morphology, and plasma FSH concentration after cis-permethrin treatment. Moreover, cis-permethrin exposure significantly diminished the testicular mitochondrial mRNA expression levels of peripheral benzodiazepine receptor (PBR), steroidogenic acute regulatory protein (StAR), and cytochrome P450 side-chain cleavage (P450scc) and enzyme and protein expression levels of StAR and P450scc. At the electron microscopic level, mitochondrial membrane damage was found in Leydig cells of the exposed mouse testis. Our results suggest that the insecticide permethrin may cause mitochondrial membrane impairment in Leydig cells and disrupt testosterone biosynthesis by diminishing the delivery of cholesterol into the mitochondria and decreasing the conversion of cholesterol to pregnenolone in the cells, thus reducing subsequent testosterone production.
TL;DR: The addition of SP from good sperm freezers improved the motility and viability of thawed spermatozoa without any influence on MDA production and increased the percentage of penetrated (SP3) and polyspermic oocytes (SP4) with respect to the control.
Abstract: The study evaluated the protective effect of seminal plasma (SP) added to freezing extender against cryopreservation injuries to boar spermatozoa. Pooled sperm-rich fractions collected from 9 fertile boars were frozen in 0.5-mL straws after being extended in a conventional freezing extender either alone or supplemented with 5% of SPs (SP1-SP4) collected from the sperm-rich fractions (diluted 1:1, vol/vol, in Beltsville Thawing Solution extender) from 4 boars (1-4) with known sperm cryosurvival (poor, moderate, and good sperm freezers). Cryopreservation injuries were assessed in terms of postthaw sperm motility (assessed by computer-assisted sperm analysis), viability (plasma membrane and acrosome integrity assessed simultaneously by flow cytometry), membrane lipid peroxidation (malondialdehyde [MDA] production), and the ability of thawed spermatozoa to fertilize in vitro-matured homologous oocytes. The addition of SP from good sperm freezers (SP3 and SP4) improved (P < .01) the motility and viability of thawed spermatozoa without any influence on MDA production. Moreover, SP from good sperm freezers also increased (P < .05) the percentage of penetrated (SP3) and polyspermic oocytes (SP4) with respect to the control. Neither the total amount of SP proteins, protein profiles, nor antioxidant capacity of the different SPs were related to the various cryosurvival/fertilizing capacities of the processed spermatozoa.
TL;DR: It is indicated that a rise in pH increases intracellular Ca2+ and promotes hyperactivation primarily by stimulating Ca2- influx, but also by other mechanisms.
Abstract: Sperm hyperactivated motility is characterized by high flagellar bend amplitude and asymmetrical beating, which are detected by computer-assisted sperm motility analysis as increased curvilinear velocity and lateral head movement. It is required for sperm penetration of the oocyte zona pellucida during fertilization and is induced by an increase in flagellar Ca(2+). Our objective was to determine whether pH plays a role in promoting Ca signaling of hyperactivated motility. The cell-permeant weak base NH(4)Cl increased curvilinear velocity and amplitude of lateral head movement of bovine sperm, indicative of hyperactivation. Fluorometric recordings of sperm loaded with BCECF-AM or fluo3-AM, revealed that NH(4)Cl evoked elevations of intracellular pH and Ca(2+), respectively, with the rise in pH occurring more rapidly than that of Ca(2+). Single-cell image analysis showed increased Ca(2+) levels in the flagellum in response to NH(4)Cl. When extracellular Ca(2+) was lowered with BAPTA (1,2-bis(2-aminophenoxy)ethane-N,N,N',N'-tetraacetic acid) prior to treatment with NH(4)Cl, intracellular pH was increased, but elevation of Ca(2+) and hyperactivation were diminished. This suggests that the rise in intracellular pH precedes an influx of Ca(2+). The Ca(2+) channel blocker Ni(2+) also diminished NH(4)Cl stimulation of hyperactivation, demonstrating that Ca(2+) entry is required for maximal expression of hyperactivation. Ca(2+) ionophore produced an increase in Ca(2+) that was 3-fold greater than that produced by NH(4)Cl; however, it produced a weaker hyperactivation response. These results indicate that a rise in pH increases intracellular Ca(2+)and promotes hyperactivation primarily by stimulating Ca(2+) influx, but also by other mechanisms.
TL;DR: Experimental evidence demonstrates that prostate-specific antigen (PSA) rapidly cleaves Sg, an event temporally associated with semen liquefaction and initiation of sperm motility, which could play important role in preventing premature capacitation.
Abstract: Semenogelin (Sg), the main component of the human semen coagulum, is an important and versatile protein acting on several sperm parameters, both as intact or degraded Sg. Sg originates mostly from seminal vesicle and probably is responsible for sperm immobilization in the seminal coagulum. Purified Sg can be cross-linked by transglutaminase or phosphorylated by kinases, but the actual occurrence of these reactions in reproductive physiology is not clear. Experimental evidence demonstrates that prostate-specific antigen (PSA) rapidly cleaves Sg, an event temporally associated with semen liquefaction and initiation of sperm motility. Sg and its degradation peptides participate in various processes including Zn +2 shuttling, antibacterial activity, hyaluronidase activation, and so on. Sg inhibits sperm motility at the concentration found in the coagulum, but the rapid processing by PSA allows initiation of movement. The mechanism of Sg action and its targets are not known, but improper Sg degradation decreases fertility. Sg and its degradation peptides block sperm capacitation and associated events at concentrations much lower than those of seminal plasma and could play important role in preventing premature capacitation. The effects of Sg are dependent on time and proteolysis due to PSA, and any imbalance may affect sperm physiology and fertility.
TL;DR: Overall, this study simplified and standardized sperm cryopreservation, and established a protocol using French straws as a freezing container and an extender without powdered milk that can be readily adapted for high-throughput application using automated equipment.
TL;DR: The generation of Taf7l mutant mice by homologous recombination in embryonic stem cells by using the Cre-loxP strategy is reported and mouse studies suggest that mutations in the human TAF7L gene might be implicated in X-linked oligozoospermia in men.
Abstract: TFIID is a general transcription factor required for transcription of most protein-coding genes by RNA polymerase II. TAF7L is an X-linked germ cell-specific paralogue of TAF7, which is a generally expressed component of TFIID. Here, we report the generation of Taf7l mutant mice by homologous recombination in embryonic stem cells by using the Cre-loxP strategy. While spermatogenesis was completed in Taf7l−/Y mice, the weight of Taf7l−/Y testis decreased and the amount of sperm in the epididymides was sharply reduced. Mutant epididymal sperm exhibited abnormal morphology, including folded tails. Sperm motility was significantly reduced, and Taf7l−/Y males were fertile with reduced litter size. Microarray profiling revealed that the abundance of six gene transcripts (including Fscn1) in Taf7l−/Y testes decreased more than twofold. In particular, FSCN1 is an F-action-bundling protein and thus may be critical for normal sperm morphology and sperm motility. Although deficiency of Taf7l may be compensated in part by Taf7, Taf7l has apparently evolved new specialized functions in the gene-selective transcription in male germ cell differentiation. Our mouse studies suggest that mutations in the human TAF7L gene might be implicated in X-linked oligozoospermia in men.
TL;DR: It is shown that sperm quality fluctuates within males both before and after a social challenge, and these rapid within-male fluctuations may help explain the recent findings of trade-offs between male social and gametic competitive abilities and may help maintain phenotypic variability in these traits.
Abstract: When females copulate with multiple males, paternity is determined by the competitive ability of a male to access females and by the ability of its ejaculates to out-compete those of other males over fertilization. The relationship between the social competitiveness of a male and the fertilizing quality of its sperm has therefore crucial implications for the evolution of male reproductive strategies in response to sexual selection. Here, we present a longitudinal experimental study of the relationship between social status and sperm quality. We monitored sperm quality in socially naive male domestic fowl, Gallus gallus domesticus, before and after exposure to a social challenge which comprised two stages. In the first stage, social dominance was established in male pairs divergent in sperm quality, and in the second, social status was experimentally manipulated by re-shuffling males across pairs. We show that sperm quality fluctuates within males both before and after a social challenge. Importantly, such fluctuations followed consistently different patterns in males that displayed different levels of social competitiveness in the social challenge. In particular, following the social challenge, sperm quality dropped in males that won both contests while the sperm quality of males that lost both contests remained constant. Together, these results indicate that males of different social competitiveness are predisposed to specific patterns of fluctuations in sperm quality. These rapid within-male fluctuations may help explain the recent findings of trade-offs between male social and gametic competitive abilities and may help maintain phenotypic variability in these traits.
TL;DR: The administration of LC and/or LAC may be effective in improving pregnancy rate and sperm kinetic features in patients affected by male infertility, however, the exact efficacy of carnitines on male infertility needs to be confirmed by further investigations.
Abstract: The aim of this systematic review was to quantify the efficacy of L-carnitine (LC) and/or L-acetyl-carnitine (LAC) in nutrition treatment for male infertility according to present clinical evidence. Biomedical databases were searched to collect related clinical trials and nine relevant randomized controlled trials (RCTs) were included. The quality of the RCTs was assessed based on their performance in randomization, blinding, and allocation concealment. The meta-analysis compared LC and /or LAC therapy to placebo treatment found significant improvement in pregnancy rate (OR = 4.10, 95% CI (2.08, 8.08), p< 0.0001), total sperm motility (WMD = 7.43, 95% CI (1.72, 13.14), p = 0.04, forward sperm motility (WMD = 11.83, 95% CI (0.49, 23.16), p = 0.04) and atypical sperm cell (WMD = -5.72, 95% CI (-7.89, -3.56), p< 0.00001). However, no significant difference was found in the sperm concentration (WMD = 5.69, 95% CI (-4.47, 15.84), p = 0.27) and semen volume (WMD = 0.28, 95% CI (-0.02, 0.58), p = 0.07). In conclusion, the administration of LC and/or LAC may be effective in improving pregnancy rate and sperm kinetic features in patients affected by male infertility. However, the exact efficacy of carnitines on male infertility needs to be confirmed by further investigations.
TL;DR: While slight variations in pH did not significantly modify sperm swimming performance, changes in osmolality affected all the measured motility variables.
Abstract: Computer assisted sperm analysis (CASA) was used to characterize the motility of sea bass Dicentrarchus labrax spermatozoa and to study the effect of several physicochemical variables and heavy metals on sperm swimming performance Duration of sperm motility in sea bass was very short (<50 s) During the first 20 s all the motility variables measured remained approximately constant, the velocity and linearity of the movement being maximum during this period, while both variables decreased sharply later While slight variations in pH did not significantly modify sperm swimming performance, changes in osmolality affected all the measured motility variables Two of the heavy metals tested, Cu
TL;DR: Results indicate that Tat1 is a critical component of the sperm annulus that is essential for proper sperm tail differentiation and motility.
Abstract: The Slc26 family is a conserved family of anion transporters. In the human, their physiological relevance was highlighted with the discovery of pathogenic mutations in several Slc26 transporters that lead to distinctive clinical disorders (Pendred syndrome, deafness, diastrophic dysplasia, congenital chloride diarrhoea) that are related to the specific distribution of these genes. We previously identified TAT1 as a new family member (Slc26A8), very specifically expressed in male germ cells in both the human and the mouse. To investigate Tat1 function in the male germline, we generated mice with a targeted disruption of the Tat1 gene. Heterozygous and homozygous Tat1 mutant mice were indistinguishable from wild-type littermates concerning survival rate, general appearance and gross behaviour; however, Tat1 null males were sterile due to complete lack of sperm motility and reduced sperm fertilization potential. Ultra-structural analysis revealed defects in flagellar differentiation leading to an abnormal annulus, disorganization of the midpiece-principal piece junction, hairpin bending of the sperm tail with disruption of the axial structures, and abnormal mitochondrial sheath assembly. While ATP levels were normal, ATP consumption was strongly reduced in Tat1 null spermatozoa. Interestingly, Tat1 is located at the annulus, a septin-based circular structure connecting the midpiece to the principal piece. Altogether, our results indicate that Tat1 is a critical component of the sperm annulus that is essential for proper sperm tail differentiation and motility.