Development of methods for cryopreservation of rooster sperm from the endangered breed "Gallina Valenciana de Chulilla" using low glycerol concentrations.

PubMed

Blanch, E; Tomás, C; Casares, L; Gómez, E A; Sansano, S; Giménez, I; Mocé, E

2014-06-01

Glycerol (11%; v:v) is the cryoprotectant most often used for the cryopreservation of rooster sperm. However, chicken breeds differ in the resistance of their sperm to the cryopreservation process and endangered or local breeds usually present low fertilizing ability when conventional sperm cryopreservation protocols are used. The objective of this study was to optimize the protocol for the cryopreservation of the sperm from the endangered breed "Gallina Valenciana de Chulilla". For this purpose, 10 pools of semen from 43 roosters of this breed were cryopreserved using 8%, 7%, 6%, or 4% glycerol, and the sperm quality was determined immediately after thawing and in the insemination doses. Lohmann Brown Classic laying hens (n = 40) were used for the insemination trials. The sperm quality after cryopreservation progressively decreased as the glycerol concentration was reduced (P < 0.01); samples frozen using 4% glycerol exhibited the lowest quality (38% total motile sperm and 49% live sperm), and samples frozen using 8% glycerol exhibited the highest quality (67% total motile sperm and 66% live sperm). These differences were also observed after the glycerol was removed (P < 0.01). However, the sperm fertilizing ability was similar for all the treatments (23%-30% fertilized eggs), and increased as the glycerol concentration decreased. In conclusion, semen from roosters frozen using 4% glycerol exhibited lower sperm quality but similar fertilizing ability compared with samples processed using higher glycerol concentrations. These results may provide useful information for developing cryopreservation protocols for other breeds. Copyright © 2014 Elsevier Inc. All rights reserved.

CRISP1 as a novel CatSper regulator that modulates sperm motility and orientation during fertilization

PubMed Central

Ernesto, Juan I.; Weigel Muñoz, Mariana; Battistone, María A.; Vasen, Gustavo; Martínez-López, Pablo; Orta, Gerardo; Figueiras-Fierro, Dulce; De la Vega-Beltran, José L.; Moreno, Ignacio A.; Guidobaldi, Héctor A.; Giojalas, Laura; Darszon, Alberto; Cohen, Débora J.

2015-01-01

Ca2+-dependent mechanisms are critical for successful completion of fertilization. Here, we demonstrate that CRISP1, a sperm protein involved in mammalian fertilization, is also present in the female gamete and capable of modulating key sperm Ca2+ channels. Specifically, we show that CRISP1 is expressed by the cumulus cells that surround the egg and that fertilization of cumulus–oocyte complexes from CRISP1 knockout females is impaired because of a failure of sperm to penetrate the cumulus. We provide evidence that CRISP1 stimulates sperm orientation by modulating sperm hyperactivation, a vigorous motility required for penetration of the egg vestments. Moreover, patch clamping of sperm revealed that CRISP1 has the ability to regulate CatSper, the principal sperm Ca2+ channel involved in hyperactivation and essential for fertility. Given the critical role of Ca2+ for sperm motility, we propose a novel CRISP1-mediated fine-tuning mechanism to regulate sperm hyperactivation and orientation for successful penetration of the cumulus during fertilization. PMID:26416967

Importance of sperm morphology during sperm transport and fertilization in mammals.

PubMed

García-Vázquez, Francisco A; Gadea, Joaquín; Matás, Carmen; Holt, William V

2016-01-01

After natural or artificial insemination, the spermatozoon starts a journey from the site of deposition to the place of fertilization. However, only a small subset of the spermatozoa deposited achieves their goal: to reach and fertilize the egg. Factors involved in controlling sperm transport and fertilization include the female reproductive tract environment, cell-cell interactions, gene expression, and phenotypic sperm traits. Some of the significant determinants of fertilization are known (i.e., motility or DNA status), but many sperm traits are still indecipherable. One example is the influence of sperm dimensions and shape upon transport within the female genital tract towards the oocyte. Biophysical associations between sperm size and motility may influence the progression of spermatozoa through the female reproductive tract, but uncertainties remain concerning how sperm morphology influences the fertilization process, and whether only the sperm dimensions per se are involved. Moreover, such explanations do not allow the possibility that the female tract is capable of distinguishing fertile spermatozoa on the basis of their morphology, as seems to be the case with biochemical, molecular, and genetic properties. This review focuses on the influence of sperm size and shape in evolution and their putative role in sperm transport and selection within the uterus and the ability to fertilize the oocyte.

Importance of sperm morphology during sperm transport and fertilization in mammals

PubMed Central

García-Vázquez, Francisco A; Gadea, Joaquín; Matás, Carmen; Holt, William V

2016-01-01

After natural or artificial insemination, the spermatozoon starts a journey from the site of deposition to the place of fertilization. However, only a small subset of the spermatozoa deposited achieves their goal: to reach and fertilize the egg. Factors involved in controlling sperm transport and fertilization include the female reproductive tract environment, cell-cell interactions, gene expression, and phenotypic sperm traits. Some of the significant determinants of fertilization are known (i.e., motility or DNA status), but many sperm traits are still indecipherable. One example is the influence of sperm dimensions and shape upon transport within the female genital tract towards the oocyte. Biophysical associations between sperm size and motility may influence the progression of spermatozoa through the female reproductive tract, but uncertainties remain concerning how sperm morphology influences the fertilization process, and whether only the sperm dimensions per se are involved. Moreover, such explanations do not allow the possibility that the female tract is capable of distinguishing fertile spermatozoa on the basis of their morphology, as seems to be the case with biochemical, molecular, and genetic properties. This review focuses on the influence of sperm size and shape in evolution and their putative role in sperm transport and selection within the uterus and the ability to fertilize the oocyte. PMID:27624988

Prophase I Mouse Oocytes Are Deficient in the Ability to Respond to Fertilization by Decreasing Membrane Receptivity to Sperm and Establishing a Membrane Block to Polyspermy1

PubMed Central

Kryzak, Cassie A.; Moraine, Maia M.; Kyle, Diane D.; Lee, Hyo J.; Cubeñas-Potts, Caelin; Robinson, Douglas N.; Evans, Janice P.

2013-01-01

ABSTRACT Changes occurring as the prophase I oocyte matures to metaphase II are critical for the acquisition of competence for normal egg activation and early embryogenesis. A prophase I oocyte cannot respond to a fertilizing sperm as a metaphase II egg does, including the ability to prevent polyspermic fertilization. Studies here demonstrate that the competence for the membrane block to polyspermy is deficient in prophase I mouse oocytes. In vitro fertilization experiments using identical insemination conditions result in monospermy in 87% of zona pellucida (ZP)-free metaphase II eggs, while 92% of ZP-free prophase I oocytes have four or more fused sperm. The membrane block is associated with a postfertilization reduction in the capacity to support sperm binding, but this reduction in sperm-binding capacity is both less robust and slower to develop in fertilized prophase I oocytes. Fertilization of oocytes is dependent on the tetraspanin CD9, but little to no release of CD9 from the oocyte membrane is detected, suggesting that release of CD9-containing vesicles is not essential for fertilization. The deficiency in membrane block establishment in prophase I oocytes correlates with abnormalities in two postfertilization cytoskeletal changes: sperm-induced cortical remodeling that results in fertilization cone formation and a postfertilization increase in effective cortical tension. These data indicate that cortical maturation is a component of cytoplasmic maturation during the oocyte-to-egg transition and that the egg cortex has to be appropriately primed and tuned to be responsive to a fertilizing sperm. PMID:23863404

Egg water from the amphibian Bufo arenarum induces capacitation-like changes in homologous spermatozoa.

PubMed

Krapf, Darío; Visconti, Pablo E; Arranz, Silvia E; Cabada, Marcelo O

2007-06-15

Mammalian sperm acquire fertilizing capacity after residing in the female tract, where physiological changes named capacitation take place. In animals with external fertilization as amphibians, gamete interactions are first established between sperm and molecules of the egg jelly coat released into the medium. Since dejellied oocytes are not normally fertilized, the aim of this study was to determine if the jelly coat of the toad Bufo arenarum promotes a "capacitating" activity on homologous sperm. We found that sperm incubation in diffusible substances of the jelly coat (egg water) for 90-180 s is sufficient to render sperm transiently capable of fertilizing dejellied oocytes. The fertilizing state was correlated with an increase of protein tyrosine phosphorylation and a decrease of sperm cholesterol content. Inhibition of either the increase in tyrosine phosphorylation or cholesterol efflux affected the acquisition of fertilizing capacity. Phosphorylation and fertilization could be promoted with NaHCO(3) and also by addition of beta cyclodextrin. Moreover, sperm could gain the ability to fertilize dejellied oocytes in the presence of these compounds. These data indicate that sperm should undergo a series of molecular changes to gain fertilizing capacity; these changes are reminiscent of mammalian sperm capacitation and take place before the acrosome reaction.

Egg water from the amphibian Bufo arenarum induces capacitation-like changes in homologous spermatozoa

PubMed Central

Krapf, Darío; Visconti, Pablo E.; Arranz, Silvia E; Cabada, Marcelo O

2007-01-01

Mammalian sperm acquire fertilizing capacity after residing in the female tract, where physiological changes named capacitation take place. In animals with external fertilization as amphibians, gamete interactions are first established between sperm and molecules of the egg jelly coat released into the medium. Since dejellied oocytes are not normally fertilized, the aim of this study was to determine if the jelly coat of the toad Bufo arenarum promotes a “capacitating” activity on homologous sperm. We found that sperm incubation in diffusible substances of the jelly coat (Egg Water) for 90–180 sec is sufficient to render sperm transiently capable of fertilizing dejellied oocytes. The fertilizing state was correlated with an increase of protein tyrosine phosphorylation and a decrease of sperm cholesterol content. Inhibition of either the increase in tyrosine phosphorylation or cholesterol efflux affected the acquisition of fertilizing capacity. Phosphorylation and fertilization could be promoted with NaHCO3, and also by addition of beta cyclodextrin. Moreover, sperm could gain the ability to fertilize dejellied oocytes in the presence of these compounds. These data indicate that sperm should undergo a series of molecular changes to gain fertilizing capacity; these changes are reminiscent of mammalian sperm capacitation and take place before the acrosome reaction. PMID:17459363

Pig Spermatozoa Defect in Acrosome Formation Caused Poor Motion Parameters and Fertilization Failure through Artificial Insemination and In vitro Fertilization.

PubMed

Lee, Won Young; Lee, Ran; Kim, Hee Chan; Lee, Kyung Hoon; Cui, Xiang Shun; Kim, Nam Hyung; Kim, Sang Hyun; Lee, Il Joo; Uhm, Sang Jun; Yoon, Min Jung; Song, Hyuk

2014-10-01

The selection of morphologically normal spermatozoa is critical to obtain high breeding performances in boar breeding farms and artificial insemination (AI) centers. Parameters for the selection of semen mainly include total sperm motility, concentration, and morphology. However, these primary parameters are often not reliable for discriminating between normal and abnormal, non-fertilizable spermatozoa. The present study was designed to compare the motion characteristics, fertilization ability using in vitro fertilization (IVF), and acrosome formation of the semen from boars having low (boar number 2012) and normal (boar number 2004 and 2023) breeding performances. The ultimate goal was to identify additional simple and easy criteria for the selection of normal sperm. There was no significant difference between boar 2004 and boar 2023 sperm total motility in computer assisted sperm analysis. However, boar number 2012 semen presented a significantly reduced population of rapid moving spermatozoa and an increased population of slow moving spermatozoa compared to boar numbers 2004 and 2023. Analysis of detailed motion characteristics revealed that sperm from boar number 2012 had significantly reduced motility in progressiveness, average path velocity, straight-line velocity (VSL), curvilinear velocity (VCL), straightness, and linearity. The assessment of the fertilizing ability by IVF also showed that sperm from boar number 2012 showed a fertility rate of 3.4%, whereas sperm from boar number 2023 had a fertility rate of 75.45%. Interestingly, most of the sperm nuclei were found on the peripheral area of the oocytes, suggesting that the sperm from boar number 2012 lacked penetration ability into the oocyte zonapellucida. The acrosome formation analysis using Pisum sativum agglutinin staining demonstrated that the sperm from boar number 2012 had a defect in acrosome formation. Consequently, primary parameters for selecting semen before AI such as motility are not sufficient to select normal and fertilizable spermatozoa. In conclusion, the present study suggests that the acrosome staining and detailed motion characteristics such as progressiveness, VCL, and VSL should be included in determining semen quality together with primary parameters for successful AI and high breeding performance in the swine industry.

Pig Spermatozoa Defect in Acrosome Formation Caused Poor Motion Parameters and Fertilization Failure through Artificial Insemination and In vitro Fertilization

PubMed Central

Lee, Won Young; Lee, Ran; Kim, Hee Chan; Lee, Kyung Hoon; Cui, Xiang Shun; Kim, Nam Hyung; Kim, Sang Hyun; Lee, Il Joo; Uhm, Sang Jun; Yoon, Min Jung; Song, Hyuk

2014-01-01

The selection of morphologically normal spermatozoa is critical to obtain high breeding performances in boar breeding farms and artificial insemination (AI) centers. Parameters for the selection of semen mainly include total sperm motility, concentration, and morphology. However, these primary parameters are often not reliable for discriminating between normal and abnormal, non-fertilizable spermatozoa. The present study was designed to compare the motion characteristics, fertilization ability using in vitro fertilization (IVF), and acrosome formation of the semen from boars having low (boar number 2012) and normal (boar number 2004 and 2023) breeding performances. The ultimate goal was to identify additional simple and easy criteria for the selection of normal sperm. There was no significant difference between boar 2004 and boar 2023 sperm total motility in computer assisted sperm analysis. However, boar number 2012 semen presented a significantly reduced population of rapid moving spermatozoa and an increased population of slow moving spermatozoa compared to boar numbers 2004 and 2023. Analysis of detailed motion characteristics revealed that sperm from boar number 2012 had significantly reduced motility in progressiveness, average path velocity, straight-line velocity (VSL), curvilinear velocity (VCL), straightness, and linearity. The assessment of the fertilizing ability by IVF also showed that sperm from boar number 2012 showed a fertility rate of 3.4%, whereas sperm from boar number 2023 had a fertility rate of 75.45%. Interestingly, most of the sperm nuclei were found on the peripheral area of the oocytes, suggesting that the sperm from boar number 2012 lacked penetration ability into the oocyte zonapellucida. The acrosome formation analysis using Pisum sativum agglutinin staining demonstrated that the sperm from boar number 2012 had a defect in acrosome formation. Consequently, primary parameters for selecting semen before AI such as motility are not sufficient to select normal and fertilizable spermatozoa. In conclusion, the present study suggests that the acrosome staining and detailed motion characteristics such as progressiveness, VCL, and VSL should be included in determining semen quality together with primary parameters for successful AI and high breeding performance in the swine industry. PMID:25178293

Delineating the roles of males and females in sperm competition

PubMed Central

Evans, Jonathan P.; Rosengrave, Patrice; Gasparini, Clelia; Gemmell, Neil J.

2013-01-01

Disentangling the relative roles of males, females and their interactive effects on competitive fertilization success remains a challenge in sperm competition. In this study, we apply a novel experimental framework to an ideally suited externally fertilizing model system in order to delineate these roles. We focus on the chinook salmon, Oncorhynchus tshawytscha, a species in which ovarian fluid (OF) has been implicated as a potential arbiter of cryptic female choice for genetically compatible mates. We evaluated this predicted sexually selected function of OF using a series of factorial competitive fertilization trials. Our design involved a series of 10 factorial crosses, each involving two ‘focal’ rival males whose sperm competed against those from a single ‘standardized’ (non-focal) rival for a genetically uniform set of eggs in the presence of OF from two focal females. This design enabled us to attribute variation in competitive fertilization success among focal males, females (OF) and their interacting effects, while controlling for variation attributable to differences in the sperm competitive ability of rival males, and male-by-female genotypic interactions. Using this experimental framework, we found that variation in sperm competitiveness could be attributed exclusively to differences in the sperm competitive ability of focal males, a conclusion supported by subsequent analyses revealing that variation in sperm swimming velocity predicts paternity success. Together, these findings provide evidence that variation in paternity success can be attributed to intrinsic differences in the sperm competitive ability of rival males, and reveal that sperm swimming velocity is a key target of sexual selection. PMID:24266039

The effect of human sperm chromatin maturity on ICSI outcomes.

PubMed

Gill, Kamil; Rosiak, Aleksandra; Gaczarzewicz, Dariusz; Jakubik, Joanna; Kurzawa, Rafal; Kazienko, Anna; Rymaszewska, Anna; Laszczynska, Maria; Grochans, Elzbieta; Piasecka, Malgorzata

2018-03-29

Because sperm chromatin may play a key role in reproductive success, we verify the associations between sperm chromatin abnormalities, embryo development and the ability to achieve pregnancy. The evaluation of sperm chromatin maturity using aniline blue (AB), chromomycin A3 (CMA3) and toluidine blue (TB) staining were carried out in group of males from infertile couples that underwent ICSI. Low levels of sperm chromatin abnormalities (< 16%) were found in most subjects (> 50%). A higher percentage of TB-positive sperm cells were discovered in the men from couples who achieved ≤ 50% fertilized oocytes compared to men who achieved > 50%. No significant differences were discovered by the applied tests between the men from couples who achieved ≤ 50% and those who achieved > 50% high-quality embryos on the 3rd or 5th day after fertilization, nor between the men from couples who achieved pregnancy and those who failed. The sperm chromatin maturity did not correlate with the ICSI results. However, the ROC analysis revealed a significant predictive value of TB-positive spermatozoa only for fertilization. Therefore, the TB assay can be considered as a useful test for the prediction of fertilization. Our findings suggest that the level of sperm chromatin abnormalities of the examined men was not clinically significant. No found associations between sperm chromatin maturity and embryo development and the ability to achieve pregnancy. We could not exclude the effects of the repairing processes in the fertilized oocyte. The use of complementary tests that verify the status of the sperm chromatin seems justified.

Functional characterization of double-knockout mouse sperm lacking SPAM1 and ACR or SPAM1 and PRSS21 in fertilization.

PubMed

Zhou, Chong; Kang, Woojin; Baba, Tadashi

2012-01-01

Mammalian fertilization requires sperm to penetrate the cumulus to reach the oocyte. Although sperm hyaluronidase has long been believed to participate in the penetration process, our previous works revealed that neither of two sperm hyaluronidases, SPAM1 and HYAL5, are essential for fertilization. In this study, we have produced double-knockout mice lacking SPAM1 and either one of two sperm serine proteases, ACR and PRSS21, and characterized the mutant sperm. The SPAM1/ACR- and SPAM1/PRSS21-deficient males were fertile, whereas epididymal sperm of the mutant mice exhibited a reduced capacity to fertilize the oocytes in vitro. Despite normal motility, the ability of sperm to traverse the cumulus matrix was more severely impaired by the loss of SPAM1 and ACR or SPAM1 and PRSS21 than by the loss of only SPAM1. Moreover, SPAM1/ACR- and SPAM1/PRSS21-deficient sperm accumulated on the surface (outer edge) of the cumulus more abundantly than SPAM1-deficient sperm. These results suggest that ACR or PRSS21 or both may function cooperatively with SPAM1 in sperm/cumulus penetration.

The Control of Male Fertility by Spermatozoan Ion Channels

PubMed Central

Lishko, Polina V.; Kirichok, Yuriy; Ren, Dejian; Navarro, Betsy; Chung, Jean-Ju

2014-01-01

Ion channels control the sperm ability to fertilize the egg by regulating sperm maturation in the female reproductive tract and by triggering key sperm physiological responses required for successful fertilization such as hyperactivated motility, chemotaxis, and the acrosome reaction. CatSper, a pH-regulated, calcium-selective ion channel, and KSper (Slo3) are core regulators of sperm tail calcium entry and sperm hyperactivated motility. Many other channels had been proposed as regulating sperm activity without direct measurements. With the development of the sperm patch-clamp technique, CatSper and KSper have been confirmed as the primary spermatozoan ion channels. In addition, the voltage-gated proton channel Hv1 has been identified in human sperm tail, and the P2X2 ion channel has been identified in the midpiece of mouse sperm. Mutations and deletions in sperm-specific ion channels affect male fertility in both mice and humans without affecting other physiological functions. The uniqueness of sperm ion channels makes them ideal pharmaceutical targets for contraception. In this review we discuss how ion channels regulate sperm physiology. PMID:22017176

Influence of arginine-glycine-aspartic acid (RGD), integrins (alphaV and alpha5) and osteopontin on bovine sperm-egg binding, and fertilization in vitro.

PubMed

Gonçalves, R F; Wolinetz, C D; Killian, G J

2007-02-01

Osteopontin (OPN), a phosphoprotein containing an arginine-glycine-aspartic acid (RGD) sequence, has been identified in cow oviduct epithelium and fluid. To investigate the potential role OPN in fertilization, we evaluated the ability of RGD peptide (arginine-glycine-aspartic), RGE peptide (arginine-glycine-glutamic acid), integrins alphaV and alpha5 antibodies and OPN antibody to influence bovine in vitro sperm-egg binding and fertilization. Treatment of sperm or oocytes with the RGD peptide prior fertilization significantly decreased in vitro sperm-egg binding and fertilization compared to the non-treated controls or those treated with RGE peptide. Binding and fertilization were also significantly decreased when in vitro matured bovine oocytes or sperm were pre-incubated with integrins alphaV and alpha5 antibodies at concentration ranging from 5 to 20 microg/mL. Addition of a rabbit polyclonal IgG antibody against purified bovine milk OPN with sperm or/and oocytes decreased (P<0.05) fertilization compared to the in vitro-fertilized control. These data provided evidence that integrin ligands existed on bovine oocytes and spermatozoa that contained RGD recognition sequences, and that antibody to OPN, a protein that contains that RGD sequence, was capable of reducing sperm-egg binding and fertilization in vitro.

Predictive capacity of sperm quality parameters and sperm subpopulations on field fertility after artificial insemination in sheep.

PubMed

Santolaria, P; Vicente-Fiel, S; Palacín, I; Fantova, E; Blasco, M E; Silvestre, M A; Yániz, J L

2015-12-01

This study was designed to evaluate the relevance of several sperm quality parameters and sperm population structure on the reproductive performance after cervical artificial insemination (AI) in sheep. One hundred and thirty-nine ejaculates from 56 adult rams were collected using an artificial vagina, processed for sperm quality assessment and used to perform 1319 AI. Analyses of sperm motility by computer-assisted sperm analysis (CASA), sperm nuclear morphometry by computer-assisted sperm morphometry analysis (CASMA), membrane integrity by acridine orange-propidium iodide combination and sperm DNA fragmentation using the sperm chromatin dispersion test (SCD) were performed. Clustering procedures using the sperm kinematic and morphometric data resulted in the classification of spermatozoa into three kinematic and three morphometric sperm subpopulations. Logistic regression procedures were used, including fertility at AI as the dependent variable (measured by lambing, 0 or 1) and farm, year, month of AI, female parity, female lambing-treatment interval, ram, AI technician and sperm quality parameters (including sperm subpopulations) as independent factors. Sperm quality variables remaining in the logistic regression model were viability and VCL. Fertility increased for each one-unit increase in viability (by a factor of 1.01) and in VCL (by a factor of 1.02). Multiple linear regression analyses were also performed to analyze the factors possibly influencing ejaculate fertility (N=139). The analysis yielded a significant (P<0.05) relationship between sperm viability and ejaculate fertility. The discriminant ability of the different semen variables to predict field fertility was analyzed using receiver operating characteristic (ROC) curve analysis. Sperm viability and VCL showed significant, albeit limited, predictive capacity on field fertility (0.57 and 0.54 Area Under Curve, respectively). The distribution of spermatozoa in the different subpopulations was not related to fertility. Copyright © 2015 Elsevier B.V. All rights reserved.

Accessory sperm as an indication of fertilizing ability of rabbit spermatozoa frozen in egg yolk-acetamide with detergent.

PubMed

Arriola, J; Foote, R H

2001-01-01

Many factors besides initial semen quality affect fertilization rates as sperm interact with the environment of the female reproductive tract. One of these factors is sperm transport, which can be evaluated by accessory sperm counts. Dutch rabbits were used to test the effects on sperm transport, fertilization, and production of young when sodium and triethanolamine lauryl sulfate (STLS) detergent was added to a medium for sperm cryopreservation. When STLS was added in 10 concentrations ranging from 0% to 2.0% (vol/vol) to an egg yolk-acetamide semen extender, optimal post-thaw motility of rabbit sperm occurred when 0.2% to 0.7% STLS was included. However, when 0%, 0.2%, and 0.7% STLS was included to cryopreserve sperm used for insemination, the fertilization rates were 95%, 68%, and 75%, and the corresponding mean numbers of accessory sperm per embryo were 13.1, 1.7, and 0.4 (P < .05). In another experiment, increasing the acetamide concentration from 0.75 M to 1.25 M decreased fertilization rates from 66% to 35%, and was associated with 4.5 and 0.6 accessory sperm per embryo (P < .05). In the final experiment, 48 does inseminated with sperm cryopreserved with 0%, 0.35%, and 0.70% STLS were allowed to produce young. Corresponding pregnancy rates were 56%, 56%, and 31% (P < .05), and litter sizes were 5.6, 4.1, and 4.2 (P > .05). In these studies, low concentrations of STLS improved motility of frozen-thawed sperm, but fertilization and pregnancy rates were reduced. Sperm transport was correspondingly reduced, and the accessory sperm count provided a reliable measure of the effect of STLS on fertility in contrast to the assessment of the percentage of motile sperm.

Seminal fluid enhances competitiveness of territorial males' sperm in a fish with alternative male reproductive tactics.

PubMed

Poli, Federica; Locatello, Lisa; Rasotto, Maria B

2018-05-29

The most common adaptation to sperm competition in males is represented by an increase in the sperm number and/or quality released at mating, to raise their probability of egg fertilization. However, rapidly mounting evidence highlights that seminal fluid may directly influence the competitive fertilization success of a male by affecting either own and/or rival sperm performances. In the black goby, Gobius niger , an external fertilizer with guard-sneaker mating tactics and high sperm competition level, sneaker males' ejaculates contain less seminal fluid and more sperm, that are also of better quality, than those of territorial males. However, territorial males, gain a higher paternity success inside natural nests. Here, we ask whether the seminal fluid can contribute to territorial males' reproductive success by enhancing their sperm performances and/or by decreasing those of sneaker males. Using sperm and seminal fluid manipulation and in vitro fertilization tests, we found that own seminal fluid influences the velocity and fertilization ability of sperm only in territorial males, making them as faster as those of sneakers and with similar fertilization rate. Moreover, both sneaker and territorial males' sperm remain unaffected by the seminal fluid of rival males. Thus, black goby males respond to the different level of sperm competition faced by differently allocating in sperm and non-sperm components of the ejaculate, with sneakers primarily investing in sperm of intrinsic high quality and territorial males relying on the effect of seminal fluid to increase the lower intrinsic quality of their sperm. © 2018. Published by The Company of Biologists Ltd.

Fertilization of sea urchin eggs and sperm motility are negatively impacted under low hypergravitational forces significant to space flight

NASA Technical Reports Server (NTRS)

Tash, J. S.; Kim, S.; Schuber, M.; Seibt, D.; Kinsey, W. H.

2001-01-01

Sperm and other flagellates swim faster in microgravity (microG) than in 1 G, raising the question of whether fertilization is altered under conditions of space travel. Such alterations have implications for reproduction of plant and animal food and for long-term space habitation by man. We previously demonstrated that microG accelerates protein phosphorylation during initiation of sperm motility but delays the sperm response to the egg chemotactic factor, speract. Thus sperm are sensitive to changes in gravitational force. New experiments using the NiZeMi centrifugal microscope examined whether low hypergravity (hyperG) causes effects opposite to microG on sperm motility, signal transduction, and fertilization. Sperm % motility and straight-line velocity were significantly inhibited by as little as 1.3 G. The phosphorylation states of FP130, an axonemal phosphoprotein, and FP160, a cAMP-dependent salt-extractable flagellar protein, both coupled to motility activation, showed a more rapid decline in hyperG. Most critically, hyperG caused an approximately 50% reduction in both the rate of sperm-egg binding and fertilization. The similar extent of inhibition of both fertilization parameters in hyperG suggests that the primary effect is on sperm rather than eggs. These results not only support our earlier microG data demonstrating that sperm are sensitive to small changes in gravitational forces but more importantly now show that this sensitivity affects the ability of sperm to fertilize eggs. Thus, more detailed studies on the impact of space flight on development should include studies of sperm function and fertilization.

Melatonin improves the fertilization ability of post-ovulatory aged mouse oocytes by stabilizing ovastacin and Juno to promote sperm binding and fusion.

PubMed

Dai, Xiaoxin; Lu, Yajuan; Zhang, Mianqun; Miao, Yilong; Zhou, Changyin; Cui, Zhaokang; Xiong, Bo

2017-03-01

What are the underlying mechanisms of the decline in the fertilization ability of post-ovulatory aged oocytes? Melatonin improves the fertilization ability of post-ovulatory aged oocytes by reducing aging-induced reactive oxygen species (ROS) levels and inhibiting apoptosis and by maintaining the levels and localization of the fertilization proteins, ovastacin and Juno. Following ovulation, the quality of mammalian metaphase II oocytes irreversibly deteriorates over time with a concomitant loss of fertilization ability. Melatonin has been found to prevent post-ovulatory oocyte aging and extend the window for optimal fertilization in mice. Mouse oocytes were randomly assigned to three groups and aged in vitro for 0, 6, 12 and 24 h, respectively. Increasing concentrations of melatonin (10-9 M, 10-7 M, 10-5 M and 10-3 M) were added to the 24 h aging group. Sperm binding assays, in-vitro fertilization, immunofluorescent staining and western blotting were performed to investigate key regulators and events during fertilization of post-ovulatory aged mouse oocytes. We found that the actin cap which promotes a cortical granule (CG) free domain is disrupted with a re-distribution of CGs in the subcortex of aged oocytes. Ovastacin, a CG metalloendoprotease, is mis-located and prematurely exocytosed in aged oocytes with subsequent cleavage of the zona pellucida protein ZP2. This disrupts the sperm recognition domain and dramatically reduces the number of sperm binding to the zona pellucida. The abundance of Juno, the sperm receptor on the oocyte membrane, also is reduced in aged oocytes. Exposure of aged oocytes to melatonin significantly elevates in-vitro fertilization rates potentially by rescuing the above age-associated defects of fertilization, and reducing ROS and inhibiting apoptosis. N/A. We explored the mechanisms of the decline in fertilization ability decline in aged mouse oocytes, in vitro but not in vivo. Our findings may contribute to the development a more efficient method, involving melatonin, for improving IVF success rates. This study was supported by the National Natural Science Foundation (31571545) and the Natural Science Foundation of Jiangsu Province (BK20150677). The authors have no conflict of interest to disclose. © The Author 2017. Published by Oxford University Press on behalf of the European Society of Human Reproduction and Embryology. All rights reserved. For permissions, please e-mail: journals.permissions@oup.com

Maturational changes in the survivability and fertility of fowl sperm during their passage through the male reproductive tract.

PubMed

Ahammad, Muslah U; Nishino, C; Tatemoto, H; Okura, N; Kawamoto, Y; Okamoto, S; Nakada, T

2011-10-01

The objective of this study was to examine whether domestic fowl (Gallus domesticus) sperm undergo maturation in their capacity for survival and fertilization in the male reproductive tract. Sperm collected from the testis, epididymis and the proximal, middle and distal vas deferens were simultaneously stored in vitro in minimum essential medium (MEM) at 39°C for 0, 3 and 6h, and at 4°C for 24 and 48h. Sperm membrane integrity was measured using the dual fluorescent stain SYBR-14/propidium iodide (PI). Aliquots of sperm from the various sites were subjected to artificial insemination (AI) into the uteri of hens to assess the duration of sperm survival in the oviduct and to determine the fertility status of the sperm. Testicular sperm exhibited a very low capacity to survive under in vitro liquid storage conditions, irrespective of the storage temperature used, and in the oviduct, and they had a low ability to fertilize the ovum. On the contrary, sperm from the distal vas deferens had a higher survival rate during in vitro storage periods, a longer life span in the oviduct, and high fertility. Survival and fertilizing capacity of the sperm recovered from the testes increased gradually (P<0.05) from the testes to the distal vas deferens. In conclusion, we suggest that fowl sperm may undergo functional maturation through a process of gradual changes in their survival and fertilization capacities during their passage through the successive parts of the male reproductive tract. Copyright © 2011 Elsevier B.V. All rights reserved.

Profiling of sperm proteins and association of sperm PDC-109 with bull fertility.

PubMed

Somashekar, Lakshminarayana; Selvaraju, Sellappan; Parthipan, Sivashanmugam; Ravindra, Janivara Parameswaraiah

2015-01-01

The composition of sperm proteins influences the fertilizing ability of sperm and hence the present study was conducted (i) to profile sperm proteins expression patterns in bulls of differing fertility index and (ii) to identify and relate the abundant sperm proteins with bull fertility. The semen samples were collected from Holstein-Friesian bulls (n = 12) varying in conception rate (CR) (high/low). The frozen semen straws (three ejaculates, from each bull) were used to study (a) sperm kinetic parameters, (b) plasmalemma integrity, (c) mitochondrial membrane potential, and (d) chromatin distribution. Three bulls were randomly selected from each group (n = 3) and the neat sperm pellets were subjected to percoll purification, followed by protein isolation using 0.1% Triton X100. The sperm kinetic parameters, plasmalemma integrity, mitochondrial membrane potential, and the chromatin distribution did not differ significantly between groups. The number of acidic (pI; 3.1-5.6, 37%) and basic (pI; 7.9-10.0, 27%) proteins and their pattern of expression varied significantly (p < 0.05) between high and low fertile bulls. The abundant sperm protein spots in 2D-gel electrophoresis (2DE) were identified as seminal plasma protein PDC-109 (i.e., protein with N-terminus aspartic acid, D and carboxy terminus cystine, having 109 amino acids) and its isoform and spermadhesin-1 (SPADH1). The western blot analysis confirmed the presence of PDC-109 isoform proteins at 15.4 kDa (pI 5.3 and 5.5). The seminal plasma protein PDC-109 was abundant in the low fertile when compared to the high fertile group (p < 0.05). This study suggests that the imbalance in acidic and basic sperm proteins may influence sperm fertility and sperm PDC-109 levels above a certain threshold affects bull fertility.

Live births from artificial insemination of microfluidic-sorted bovine spermatozoa characterized by trajectories correlated with fertility

PubMed Central

Nagata, Maria Portia B.; Endo, Kenji; Ogata, Kazuko; Yamanaka, Kenichi; Egashira, Junki; Katafuchi, Naoto; Yamanouchi, Tadayuki; Matsuda, Hideo; Goto, Yuki; Sakatani, Miki; Hojo, Takuo; Nishizono, Hirofumi; Yotsushima, Kenji; Takenouchi, Naoki; Hashiyada, Yutaka; Yamashita, Kenichi

2018-01-01

Selection of functional spermatozoa plays a crucial role in assisted reproduction. Passage of spermatozoa through the female reproductive tract requires progressive motility to locate the oocyte. This preferential ability to reach the fertilization site confers fertility advantage to spermatozoa. Current routine sperm selection techniques are inadequate and fail to provide conclusive evidence on the sperm characteristics that may affect fertilization. We therefore developed a selection strategy for functional and progressively motile bovine spermatozoa with high DNA integrity based on the ability to cross laminar flow streamlines in a diffuser-type microfluidic sperm sorter (DMSS). The fluid dynamics, with respect to microchannel geometry and design, are relevant in the propulsion of spermatozoa and, consequently, ultrahigh-throughput sorting. Sorted spermatozoa were assessed for kinematic parameters, acrosome reaction, mitochondrial membrane potential, and DNA integrity. Kinematic and trajectory patterns were used to identify fertility-related subpopulations: the rapid, straighter, progressive, nonsinuous pattern (PN) and the transitional, sinuous pattern (TS). In contrast to the conventional notion that the fertilizing spermatozoon is always vigorously motile and more linear, our results demonstrate that sinuous patterns are associated with fertility and correspond to truly functional spermatozoa as supported by more live births produced from predominant TS than PN subpopulation in the inseminate. Our findings ascertain the true practical application significance of microfluidic sorting of functional sperm characterized by sinuous trajectories that can serve as a behavioral sperm phenotype marker for fertility potential. More broadly, we foresee the clinical application of this sorting technology to assisted reproduction in humans. PMID:29555773

Molecular changes and signaling events occurring in sperm during epididymal maturation

PubMed Central

Gervasi, Maria Gracia; Visconti, Pablo E.

2017-01-01

After leaving the testis, sperm have not yet acquired the ability to move progressively and are unable to fertilize oocytes. To become fertilization-competent they must go through an epididymal maturation process in the male, and capacitation in the female tract. Epididymal maturation can be defined as those changes occurring to sperm in the epididymis that render the sperm the ability to capacitate in the female tract. As part of this process, sperm cells undergo a series of biochemical and physiological changes that require incorporation of new molecules derived from the epididymal epithelium, as well as post-translational modifications of endogenous proteins synthesized during spermiogenesis in the testis. This review will focus on epididymal maturation events, with emphasis in recent advances in the understanding of the molecular basis of this process. PMID:28297559

Assessment of gamete quality for the eastern oyster (Crassostrea virginica) by use of fluorescent dyes

USGS Publications Warehouse

Paniagua-Chavez, C. G.; Jenkins, J.; Segovia, M.; Tiersch, T.R.

2006-01-01

Evaluation of sperm motility is the single most widely used parameter to determine semen quality in mammals and aquatic species. While a good indicator for fresh sperm viability, post-thaw motility is not always effective at predicting fertilizing ability. Techniques using fluorescent dyes can assess functionality of mammalian sperm, but have not been widely applied in aquatic organisms. The eastern oyster Crassostrea virginica is an important mollusk in the United States, and cryopreservation protocols have been developed to preserve sperm and larvae to assist research and hatchery production. In this study, protocols were developed to assess sperm cell membrane integrity and mitochondrial function by flow cytometry and to assess viability of eggs by fluorescence microscopy. The fluorescent dyes SYBR 14 and propidium iodide (PI) (to assess membrane integrity) and rhodamine 123 (R123) (to assess mitochondrial membrane potential) were used to evaluate the quality of thawed oyster sperm previously cryopreserved with different cryoprotectant and thawing treatments. Membrane integrity results were correlated with motility of thawed sperm and mitochondrial membrane potential with fertilizing ability. Fluorescein diacetate (FDA) was used to assess cytotoxicity of cryoprotectant solutions and post-thaw damage to oyster eggs. The results indicated that membrane integrity (P = 0.004) and thawing treatments (P = 0.04), and mitochondrial membrane potential (P = 0.0015) were correlated with motility. Fertilizing ability was correlated with cryoprotectant treatments (P = 0.0258) and with mitochondrial membrane potential (P = 0.001). The dye FDA was useful in indicating structural integrity of fresh and thawed eggs. Exposure of eggs, without freezing, to dimethyl sulfoxide yielded higher percentages of stained eggs and fertilization rate than did exposure to propylene glycol (P = 0.002). Thawed eggs were not stained with FDA (<1%) and larvae were not produced. ?? 2006 Elsevier Inc. All rights reserved.

Cysteine-rich secretory proteins (CRISP) and their role in mammalian fertilization.

PubMed

Cohen, Débora J; Maldera, Julieta A; Weigel Muñoz, Mariana; Ernesto, Juan I; Vasen, Gustavo; Cuasnicu, Patricia S

2011-01-01

Epididymal protein CRISPI is a member of the CRISP (Cysteine-RIch Secretory proteins) family and is involved in sperm-egg fusion through its interaction with complementary sites on the egg surface. Results from our laboratory have shown that this binding ability resides in a 12-amino-acid region corresponding to a highly conserved motif of the CRISP family, named Signature 2 (S2). In addition to this, our results revealed that CRISP1 could also be involved in the previous step of sperm binding to the zona pellucida, identifying a novel role for this protein in fertilization. As another approach to elucidate the participation of CRISP1 in fertilization, a mouse line containing a targeted disruption of CRISP1 was generated. Although CRISP1-deficient mice exhibited normal fertility, CRISP1-defficient sperm presented a decreased level of protein tyrosine phosphorylation during capacitation, and an impaired ability to fertilize both zona-intact and zona-free eggs in vitro, confirming the proposed roles for the protein in fertilization. Evidence obtained in our laboratory indicated that testicular CRISP2 would also be involved in sperm-egg fusion. Competition assays between CRISP1 and CRISP2, as well as the comparison of their corresponding S2 regions, suggest that both proteins bind to common complementary sites in the egg. Together, these results suggest a functional cooperation between CRISP1 and CRISP2 to ensure the success of fertilization.

Spectral interferometry for morphological imaging in in vitro fertilization (IVF) (Conference Presentation)

NASA Astrophysics Data System (ADS)

Zhu, Yizheng; Li, Chengshuai

2016-03-01

Morphological assessment of spermatozoa is of critical importance for in vitro fertilization (IVF), especially intracytoplasmic sperm injection (ICSI)-based IVF. In ICSI, a single sperm cell is selected and injected into an egg to achieve fertilization. The quality of the sperm cell is found to be highly correlated to IVF success. Sperm morphology, such as shape, head birefringence and motility, among others, are typically evaluated under a microscope. Current observation relies on conventional techniques such as differential interference contrast microscopy and polarized light microscopy. Their qualitative nature, however, limits the ability to provide accurate quantitative analysis. Here, we demonstrate quantitative morphological measurement of sperm cells using two types of spectral interferometric techniques, namely spectral modulation interferometry and spectral multiplexing interferometry. Both are based on spectral-domain low coherence interferometry, which is known for its exquisite phase determination ability. While spectral modulation interferometry encodes sample phase in a single spectrum, spectral multiplexing interferometry does so for sample birefringence. Therefore they are capable of highly sensitive phase and birefringence imaging. These features suit well in the imaging of live sperm cells, which are small, dynamic objects with only low to moderate levels of phase and birefringence contrast. We will introduce the operation of both techniques and demonstrate their application to measuring the phase and birefringence morphology of sperm cells.

Epididymal protein CRISP1 plays different roles during the fertilization process.

PubMed

Cohen, Débora J; Maldera, Julieta A; Vasen, Gustavo; Ernesto, Juan I; Muñoz, Mariana Weigel; Battistone, María A; Cuasnicú, Patricia S

2011-01-01

Rat epididymal CRISP1, the first described member of the evolutionarily conserved Cysteine-RIch Secretory Protein (CRISP) family, is expressed in the proximal regions of the epididymis and associates with the sperm during epididymal transit. Evidence indicates the existence of 2 populations of CRISP1 in spermatozoa: a major one, loosely bound, which is released during capacitation and, therefore, proposed as a decapacitating factor; and a minor one, strongly associated with spermatozoa that remains on the cells after capacitation and is proposed to participate in gamete interaction. Originally localized to the dorsal region of capacitated sperm, CRISP1 migrates to the equatorial segment with capacitation and acrosome reaction. Consistent with these localizations, in vitro fertilization experiments support the involvement of CRISP1 in the first step of sperm-zona pellucida (ZP) interaction and subsequent gamete fusion through its interaction with egg-complementary sites. The potential roles of CRISP1 in capacitation and fertilization have been further supported by the finding that capacitated spermatozoa from CRISP1 "knockout" animals exhibit low levels of protein tyrosine phosphorylation and have an impaired ability to fertilize zona-intact and zona-free eggs in vitro. Moreover, recent evidence from mutant spermatozoa reveals that CRISP1 mediates the stage of sperm binding to the ZP. Altogether, these observations support the view that CRISP1 is a multifunctional protein playing different roles during fertilization through its different associations with and localizations on spermatozoa. We believe these results contribute to a better understanding of the molecular mechanisms involved in both the fertilization process and the acquisition of sperm-fertilizing ability that occurs during epididymal maturation.

Effectiveness of glucose-methanol extender for cryopreservation of Huso huso spermatozoa.

PubMed

Aramli, Mohammad Sadegh; Golshahi, Karim; Nazari, Rajab Mohammad; Aramli, Salim; Banan, Ashkan

2015-11-01

The present approach was designed to evaluate the methanol-glucose extender effects on sperm cryopreservation in beluga sturgeon, Huso huso. Sperm quality was examined by measuring post-thaw sperm motility and fertilizing rate at hatching stage. We first tested the effect of glucose concentration (0, 0.10, 0.15, 0.20 and 0.30M) in a methanol extender on post-thaw sperm motility. The optimal cryopreservation conditions were found to be 0.2M glucose in the extender. Then, motility and fertilization rates of sperm cryopreserved with 0.2M glucose and 10% methanol (GM) were compared to Tris-sucrose-KCl in 10% methanol extender (TSKM). Additionally, sperm motility and fertilizing ability in relation to 15 and 30min equilibration in GM extender before and after cryopreservation were measured. Higher post-thaw sperm motility duration and percentage as well as fertilization rate were obtained with the GM extender when compared to TSKM extender. Equilibration of sperm in extender did not affect the motility quality of either fresh-diluted or frozen/thawed sperm, while fertilization rate showed a significant decline alone after 30min of post-thaw storage. Our results indicated that the use of a simple extender consisting of 0.2M glucose in 10% methanol can be an alternative cryopreservation method to those previously described for sturgeons. Copyright © 2015 Elsevier B.V. All rights reserved.

Immune changes during reproduction in sperm storage tubules of the domestic turkey Meleagris gallopavo

USDA-ARS?s Scientific Manuscript database

The storage of sperm in the female reproductive tract is a biological feature of numerous species including birds. The domestic turkey, Meleagris gallopavo, is unique among avian species in that sperm residing in the hen's sperm storage tubules (SST) retain fertilizing ability for up to 10 weeks af...

Methyl-parathion decreases sperm function and fertilization capacity after targeting spermatocytes and maturing spermatozoa

DOE Office of Scientific and Technical Information (OSTI.GOV)

Pina-Guzman, Belem; Sanchez-Gutierrez, M.; Marchetti, Francesco

Paternal germline exposure to organophosphorous pesticides (OP) has been associated with reproductive failures and adverse effects in the offspring. Methyl parathion (Me-Pa), a worldwide-used OP, has reproductive adverse effects and is genotoxic to sperm. Oxidative damage has been involved in the genotoxic and reproductive effects of OP. The purpose of this study was to determine the effects of Me-Pa on spermatozoa function and ability to fertilize. Male mice were exposed to Me-Pa (20 mg/kg bw, i.p.) and spermatozoa from epididymis-vas deferens were collected at 7 or 28 days post-treatment (dpt) to assess the effects on maturing spermatozoa and spermatocytes, respectively.more » DNA damage was evaluated by nick translation (NT-positive cells) and SCSA (percentDFI); lipoperoxidation (LPO) by malondialdehyde production; sperm function by spontaneous- and induced-acrosome reactions (AR); mitochondrial membrane potential (MMP) by using the JC-1 flurochrome; and, fertilization ability by an in vitro assay and in vivo mating. Results showed alterations in DNA integrity (percentDFI and NT-positive cells) at 7 and 28 dpt, in addition to decreased sperm quality and a decrease in induced-AR; reduced MMP and LPO was observed only at 7 dpt. We found negative correlations between LPO and all sperm alterations. Altered sperm functional parameters were associated with reduced fertilization rates at both times, evaluated either in vitro or in vivo. These results show that Me-Pa exposure of maturing spermatozoa and spermatocytes affects many sperm functional parameters that result in a decreased fertilizing capacity. Oxidative stress seems to be a likely mechanism ofthe detrimental effects of Me-Pa in male germ cells.« less

Evaluation of cholesterol- treated dromedary camel sperm function by heterologous IVF and AI.

PubMed

Crichton, Elizabeth G; Malo, Clara; Pukazhenthi, Budhan S; Nagy, Peter; Skidmore, Julian A

2016-11-01

Cholesterol (cholesterol-loaded cyclodextrins: CLC) treatment of dromedary camel sperm prior to freezing enhances cryosurvival. The present study first validated the efficacy of a heterologous zona-free goat oocyte assay (n=115 oocytes) to evaluate camel sperm function in vitro (Experiment 1: n=6 bulls), then examined the effects of CLC treatment (1.5mg/mL CLC; CLC+) versus no treatment (0 CLC) of fresh (Experiment 2: n=4 bulls) and frozen-thawed (Experiment 3: n=5 bulls) camel sperm to penetrate, de-condense and form pro-nuclei in in vitro-matured goat oocytes. Finally, the ability of fresh 0 CLC and CLC+ sperm to fertilize in vivo was studied by artificially inseminating super-ovulated females (n=7-9 per treatment) and examining embryo production (Experiment 4: n=4-5 bulls/treatment). Camel spermatozoa penetrated (60%) and formed pro-nuclei (33%) in goat oocytes demonstrating the utility of this heterologous system for assessing sperm function in vitro. For fresh spermatozoa, 0 CLC-treated sperm performed better than their CLC+ counterparts for all parameters measured (P<0.05). In contrast, cryopreservation resulted in a sharp decline in sperm-oocyte interaction in 0 CLC aliquots but remained unaltered in CLC+ aliquots demonstrating a protective effect of cholesterol treatment. There was no difference between treatments in the in vitro fertilizing ability of frozen-thawed sperm or in the numbers of embryos retrieved following AI with fresh 0 CLC or CLC+ sperm. We conclude that although CLC treatment of dromedary camel sperm improves sperm motility it fails to confer an advantage to them in terms of improved in vitro sperm-oocyte interaction or in vivo fertilization under the conditions tested. Copyright © 2016 Elsevier B.V. All rights reserved.

Mouse spermatozoa with higher fertilization rates have thinner nuclei

PubMed Central

Ikawa, Masahito

2017-01-01

Background Although spermatozoa with normal morphology are assumed to have uniform fertilization ability, recent data show that even normal spermatozoa have considerable variation in their head shape which is associated with differences in fertilization ability. Appropriate quantitative indicators for good sperm morphology, however, remain unidentified. Methods Therefore, in an effort to identify such an indicator, we compared the nuclear contour of normal mouse spermatozoa by quantitative multivariate analysis using elliptic Fourier descriptors combined with principal component analysis. The spermatozoa were obtained from different strains and collection sites which have been shown to be associated with different fertilization abilities. Results We found that the head was 5.7% thinner in spermatozoa from the B6D2F1 (BDF1) strain, known to have a higher fertilization rate, than in those from the C57BL/6N (B6N) strain, which has a lower fertilization rate. Moreover, zona-penetrated spermatozoa in the perivitelline space consistently had 5.4% thinner heads than those isolated from the epididymis before ejaculation. The aspect ratio, which represents the sperm head thinness, uniquely distinguished these sperm populations, confirming its validity as a morphological indicator. Discussion Because aspect ratio has also been shown to characterize human spermatozoa, this unique morphometric indicator might be applicable to compare normal spermatozoa among multiple patients, which will greatly facilitate and enhance current reproductive technologies. PMID:29038763

Does levonorgestrel emergency contraceptive have a post-fertilization effect? A review of its mechanism of action

PubMed Central

Peck, Rebecca; Rella, Walter; Tudela, Julio; Aznar, Justo; Mozzanega, Bruno

2016-01-01

Background Recent studies have identified that levonorgestrel administered orally in emergency contraception (LNG-EC) is only efficacious when taken before ovulation. However, the drug does not consistently prevent follicular rupture or impair sperm function. Objective The present systematic review is performed to analyze and more precisely define the extent to which pre-fertilization mechanisms of action may explain the drug's efficacy in pregnancy avoidance. We also examine the available evidence to determine if pre-ovulatory drug administration may be associated with post-fertilization effects. Conclusion The mechanism of action of LNG-EC is reviewed. The drug has no ability to alter sperm function at doses used in vivo and has limited ability to suppress ovulation. Our analysis estimates that the drug's ovulatory inhibition potential could prevent less than 15 percent of potential conceptions, thus making a pre-fertilization mechanism of action significantly less likely than previously thought. Luteal effects (such as decreased progesterone, altered glycodelin levels, and shortened luteal phase) present in the literature may suggest a pre-ovulatory induced post-fertilization drug effect. Lay Summary Plan B is the most widely used emergency contraceptive available. It is important for patients and physicians to clearly understand the drug’s mechanism of action (MOA). The drug was originally thought to work by preventing fertilization. Recent research has cast doubt on this. Our review of the research suggests that it could act in a pre-fertilization capacity, and we estimate that it could prevent ovulation in only 15 percent or less of cases. The drug has no ability to alter sperm function and limited ability to suppress ovulation. Further, data suggest that when administered pre-ovulation, it may have a post-fertilization MOA. PMID:27833181

Does levonorgestrel emergency contraceptive have a post-fertilization effect? A review of its mechanism of action.

PubMed

Peck, Rebecca; Rella, Walter; Tudela, Julio; Aznar, Justo; Mozzanega, Bruno

2016-02-01

Recent studies have identified that levonorgestrel administered orally in emergency contraception (LNG-EC) is only efficacious when taken before ovulation. However, the drug does not consistently prevent follicular rupture or impair sperm function. The present systematic review is performed to analyze and more precisely define the extent to which pre-fertilization mechanisms of action may explain the drug's efficacy in pregnancy avoidance. We also examine the available evidence to determine if pre-ovulatory drug administration may be associated with post-fertilization effects. The mechanism of action of LNG-EC is reviewed. The drug has no ability to alter sperm function at doses used in vivo and has limited ability to suppress ovulation. Our analysis estimates that the drug's ovulatory inhibition potential could prevent less than 15 percent of potential conceptions, thus making a pre-fertilization mechanism of action significantly less likely than previously thought. Luteal effects (such as decreased progesterone, altered glycodelin levels, and shortened luteal phase) present in the literature may suggest a pre-ovulatory induced post-fertilization drug effect. Plan B is the most widely used emergency contraceptive available. It is important for patients and physicians to clearly understand the drug's mechanism of action (MOA). The drug was originally thought to work by preventing fertilization. Recent research has cast doubt on this. Our review of the research suggests that it could act in a pre-fertilization capacity, and we estimate that it could prevent ovulation in only 15 percent or less of cases. The drug has no ability to alter sperm function and limited ability to suppress ovulation. Further, data suggest that when administered pre-ovulation, it may have a post-fertilization MOA.

A sex-chromosome inversion causes strong overdominance for sperm traits that affect siring success.

PubMed

Knief, Ulrich; Forstmeier, Wolfgang; Pei, Yifan; Ihle, Malika; Wang, Daiping; Martin, Katrin; Opatová, Pavlína; Albrechtová, Jana; Wittig, Michael; Franke, Andre; Albrecht, Tomáš; Kempenaers, Bart

2017-08-01

Male reproductive success depends on the competitive ability of sperm to fertilize the ova, which should lead to strong selection on sperm characteristics. This raises the question of how heritable variation in sperm traits is maintained. Here we show that in zebra finches (Taeniopygia guttata) nearly half of the variance in sperm morphology is explained by an inversion on the Z chromosome with a 40% allele frequency in the wild. The sperm of males that are heterozygous for the inversion had the longest midpieces and the highest velocity. Furthermore, such males achieved the highest fertility and the highest siring success, both within-pair and extra-pair. Males homozygous for the derived allele show detrimental sperm characteristics and the lowest siring success. Our results suggest heterozygote advantage as the mechanism that maintains the inversion polymorphism and hence variance in sperm design and in fitness.

Assessing in vivo fertilizing capacity of liquid-preserved boar semen according to the 'Hanover gilt model'.

PubMed

Ardón, F; Döhring, A; Le Thi, X; Weitze, K F; Waberski, D

2003-04-01

The goal of this study was to determine the ability of the Hanover gilt model to assess in vivo fertilizing capacity of preserved sperm and to consider whether any modifications to this model were needed. This model evaluates the fertilizing capacity of semen based on the fertilization rate, the rate of normal embryos and the accessory sperm count of 3-5-day embryos. Its distinguishing characteristics are the use of one-time insemination of sperm in reduced numbers, of spontaneously ovulating gilts and of ovulation detection through ultrasound examination of ovaries. Reduced sperm numbers allow for an accurate evaluation of the fertilizing potential of different semen treatments, thereby avoiding the compensatory effect of doses calibrated to maximize fertility. The model's usefulness was assessed in a trial run designed to compare the fertilizing capacity of liquid boar semen diluted into two different extenders. The diluent, the boar and the backflow, had no significant effect on any of the parameters studied. Gilts inseminated less than 24 h before ovulation had a significantly higher (p < 0.01) fertilization rate and accessory sperm cell count (p < 0.05) than those inseminated more than 24 h before ovulation. Very good/good embryos from homogeneous litters (only very good/good embryos were present) had a significantly higher (p < 0.01) accessory sperm count than those from heterogeneous litters (at least one embryo was of a different quality and/or oocytes were present). Both very good/good and degenerated/retarded embryos from heterogeneous litters had low accessory sperm numbers. This suggests that accessory sperm count is significantly related to the quality of the litter, but not to the quality of the embryo within gilts. It can be concluded that the Hanover gilt model is sensitive enough to show fertility differences (in this study, those associated with in vivo ageing of semen), while using relatively few gilts and little time.

Egg Water from the Amphibian Bufo arenarum Modulates the Ability of Homologous Sperm to Undergo the Acrosome Reaction in the Presence of the Vitelline Envelope1

PubMed Central

Krapf, Darío; O'Brien, Emma D.; Cabada, Marcelo O.; Visconti, Pablo E.; Arranz, Silvia E.

2008-01-01

Sperm from the toad Bufo arenarum must penetrate the egg jelly before reaching the vitelline envelope (VE), where the acrosome reaction is triggered. When the jelly coat is removed, sperm still bind to the VE, but acrosomal exocytosis is not promoted. Our previous work demonstrated that diffusible substances of the jelly coat, termed “egg water” (EW), triggered capacitation-like changes in B. arenarum sperm, promoting the acquisition of a transient fertilizing capacity. In the present work, we correlated this fertilizing capacity with the ability of the sperm to undergo the acrosome reaction, further substantiating the role of the jelly coat in fertilization. When sperm were exposed to the VE, only those preincubated in EW for 5 or 8 min underwent an increase in the intracellular Ca2+ concentration ([Ca2+]i), which led to acrosomal exocytosis. Responsiveness to the VE was not acquired on preincubation in EW for 2 or 15 min or in Ringer solution regardless of the preincubation time. In contrast, depletion of intracellular Ca2+ stores (induced by thapsigargin) promoted [Ca2+]i rise and the acrosome reaction even in sperm that were not exposed to EW. Acrosomal exocytosis was blocked by the presence of Ca2+ chelators independent of whether a physiological or pharmacological stimulus was used. However, Ni2+ and mibefradil prevented [Ca2+]i rise and the acrosome reaction of sperm exposed to the VE but not of sperm exposed to thapsigargin. These data suggest that the acrosomal responsiveness of B. arenarum sperm, present during a narrow period, is acquired during EW incubation and involves the modulation of a voltage-dependent Ca2+ channel. PMID:18923159

Egg water from the amphibian Bufo arenarum modulates the ability of homologous sperm to undergo the acrosome reaction in the presence of the vitelline envelope.

PubMed

Krapf, Darío; O'Brien, Emma D; Cabada, Marcelo O; Visconti, Pablo E; Arranz, Silvia E

2009-02-01

Sperm from the toad Bufo arenarum must penetrate the egg jelly before reaching the vitelline envelope (VE), where the acrosome reaction is triggered. When the jelly coat is removed, sperm still bind to the VE, but acrosomal exocytosis is not promoted. Our previous work demonstrated that diffusible substances of the jelly coat, termed "egg water" (EW), triggered capacitation-like changes in B. arenarum sperm, promoting the acquisition of a transient fertilizing capacity. In the present work, we correlated this fertilizing capacity with the ability of the sperm to undergo the acrosome reaction, further substantiating the role of the jelly coat in fertilization. When sperm were exposed to the VE, only those preincubated in EW for 5 or 8 min underwent an increase in the intracellular Ca(2+) concentration ([Ca(2+)](i)), which led to acrosomal exocytosis. Responsiveness to the VE was not acquired on preincubation in EW for 2 or 15 min or in Ringer solution regardless of the preincubation time. In contrast, depletion of intracellular Ca(2+) stores (induced by thapsigargin) promoted [Ca(2+)](i) rise and the acrosome reaction even in sperm that were not exposed to EW. Acrosomal exocytosis was blocked by the presence of Ca(2+) chelators independent of whether a physiological or pharmacological stimulus was used. However, Ni(2+) and mibefradil prevented [Ca(2+)](i) rise and the acrosome reaction of sperm exposed to the VE but not of sperm exposed to thapsigargin. These data suggest that the acrosomal responsiveness of B. arenarum sperm, present during a narrow period, is acquired during EW incubation and involves the modulation of a voltage-dependent Ca(2+) channel.

Maturational changes in motility, acrosomal proteolytic activity, and penetrability of the inner perivitelline layer of fowl sperm, during their passage through the male genital tract.

PubMed

Ahammad, Muslah U; Nishino, C; Tatemoto, H; Okura, N; Kawamoto, Y; Okamoto, S; Nakada, T

2011-10-01

The objective was to examine, in vitro, the motility, acrosomal proteolytic activity (APA), and penetrating ability of fowl sperm recovered from the testis and epididymis, as well as the proximal, middle, and distal vas deferens, to assess the potential fertilizing ability of sperm as a function of maturation. A motile sperm separation technique was used to estimate sperm motility with Accudenz, a gelatin slide technique was used to measure the diameter of the halo around the acrosome of individual sperm as an indication of APA, and a sperm-inner perivitelline layer (IPL) interaction assay was done to estimate the number of hole formations as an indication of sperm penetration into the IPL. Sperm in the testis exhibited the least motility, produced the smallest halos, and created the least number of holes per 0.25 mm(2). Motility, diameter of the halo, and number of holes increased gradually (P < 0.05) from the epididymis to the distal vas deferens and were markedly different (P < 0.05) between testicular and deferent duct sperm. Based on these in vitro experimental findings, we inferred that fowl sperm undergo a gradual process of maturational changes in motility, APA, and penetrability as a means of acquiring potential fertility during their passage throughout the male genital tract. Copyright © 2011 Elsevier Inc. All rights reserved.

The "soluble" adenylyl cyclase in sperm mediates multiple signaling events required for fertilization.

PubMed

Hess, Kenneth C; Jones, Brian H; Marquez, Becky; Chen, Yanqiu; Ord, Teri S; Kamenetsky, Margarita; Miyamoto, Catarina; Zippin, Jonathan H; Kopf, Gregory S; Suarez, Susan S; Levin, Lonny R; Williams, Carmen J; Buck, Jochen; Moss, Stuart B

2005-08-01

Mammalian fertilization is dependent upon a series of bicarbonate-induced, cAMP-dependent processes sperm undergo as they "capacitate," i.e., acquire the ability to fertilize eggs. Male mice lacking the bicarbonate- and calcium-responsive soluble adenylyl cyclase (sAC), the predominant source of cAMP in male germ cells, are infertile, as the sperm are immotile. Membrane-permeable cAMP analogs are reported to rescue the motility defect, but we now show that these "rescued" null sperm were not hyperactive, displayed flagellar angulation, and remained unable to fertilize eggs in vitro. These deficits uncover a requirement for sAC during spermatogenesis and/or epididymal maturation and reveal limitations inherent in studying sAC function using knockout mice. To circumvent this restriction, we identified a specific sAC inhibitor that allowed temporal control over sAC activity. This inhibitor revealed that capacitation is defined by separable events: induction of protein tyrosine phosphorylation and motility are sAC dependent while acrosomal exocytosis is not dependent on sAC.

Quality of Pinzgau bull spermatozoa following different periods of cryostorage.

PubMed

Chrenek, P; Spaleková, E; Olexikova, L; Makarevich, A; Kubovicova, E

2017-04-01

The aim of this work was to examine the influence of cryostorage duration of Pinzgau bull's insemination doses (IDs) on some sperm traits. The IDs were frozen by a slow freezing method and stored in liquid nitrogen for different periods: less than 8 years (group 1), 8-13 years (group 2) and 14-18 years (group 3). Motility (CASA), pathological sperm rate (Giemsa staining), apoptotic (Yo-Pro-1-positive) and necrotic (propidium iodide-positive) cell occurrence and fertilizing ability (penetration/fertilization test) of spermatozoa were evaluated post-thaw. The average post-thaw sperm motility in all examined groups was over 40%. No significant influence of storage length either on the sperm total motility or progressive movement was revealed. In each tested group the average rate of malformed spermatozoa did not exceed 20%. No effect of cryostorage length on the occurrence of apoptotic or necrotic sperm was noted. Similarly, penetrating/fertilizing ability of sperm did not differ among the groups, excepting differences in the rate of pronuclei (PN) formation. In group 1, 72.9% of eggs showed two visible PN following 20 h incubation with sperm, whilst in groups 2 and 3 only 67 and 54.5% of zygotes, respectively, had both PN at this time. These results revealed no influence of storage time on the bull spermatozoa in all parameters excepting the rate of PN formation. As high inter-male variability was observed in the susceptibility of bull sperm to cryostorage, individual differences should be taken into account when semen from individual bulls is to be stored for a long time.

Effects of hydrostatic pressure on mouse sperm.

PubMed

Karimi, N; Kamangar, P Bahrami; Azadbakht, M; Amini, A; Amiri, I

2014-01-01

The objective of this study was to investigate the abnormalities in sperm after exposure to hydrostatic pressure. Hydrostatic pressure acting on the cells is one of the fundamental environmental mechanical forces. Disorders of relationship between the cells and this mechanical force, such as when pressure varies beyond physiological limits, can lead to disease or pathological states. Sperm exposed to different range of hydrostatic pressure within male reproductive system and after entering the female reproductive system. Sexually mature male NMRI mice, 8-12 weeks-old were sperm donors. Sperms were separated from the caudal epididymis and maintained in Ham's F-10 culture medium supplemented with 10 % FBS and divided into control and treatments. Sperm suspensions in the treatments were placed within pressure chamber and were subjected to increased hydrostatic pressure of 25, 50 and 100 mmHg (treatment I, II and III) above atmospheric pressure for 2 and 4 h. Sperm viability, motility, morphology, DNA integrity and fertilizing ability were assessed and compared with control. Results showed that hydrostatic pressure dependent on ranges and time manner reduced sperm quality due to adverse effect on viability, motility , morphology, DNA integrity and fertilizing ability in all of treatments, especially after 4h (p<0.05). Our data revealed hydrostatic pressure reduces sperm quality as a consequence of adverse effects on sperm parameters and may cause male infertility or subfertility (Tab. 5, Ref. 5).

Zona-free oocyte fertilized with intracytoplasmic sperm injection and underwent further division: case report and literature review.

PubMed

Hsieh, Y Y; Chang, C C; Tsai, H D

2001-09-01

The zona pellucida (ZP) plays a protective role during fertilization and early embryonic development. It is related to sperm binding, the acrosome reaction, prevention of polyspermic fertilization, and holding blastomeres together before the morular stage. Zona-free oocytes are accidentally encountered. If these oocytes are healthy, they can be fertilized normally by intracytoplasmic sperm injection (ICSI). We reported on a couple with male infertility undergoing oocyte retrieval after ovarian hyperstimulation. Before the ICSI procedure, cumulus cells surrounding the oocytes were removed, which resulted in one oocyte escaping from its ZP. The zona-free oocyte was fertilized normally with ICSI and developed to the 8-cell stage. We observed that the zona-free zygote had the ability to further divide, despite its loose contact. The zona-free embryo was transferred with other zona-intact embryos, but the implantation failed. We conclude that zona-free oocytes can be rescued, fertilized with ICSI, and cultured for further transfer or cryopreservation.

Seminal plasma proteomes and sperm fertility.

PubMed

Druart, Xavier; de Graaf, Simon

2018-04-10

During ejaculation, the spermatozoa are transported by the seminal plasma, a fluid resulting from secretions originating mainly from the prostate and the seminal vesicles in mammals. The interaction of the seminal plasma with spermatozoa induces binding of seminal proteins onto the sperm surface and membrane remodeling potentially impacting the sperm transport, survival and fertilizing ability in the female genital tract. The seminal plasma also contains peptides and proteins involved in the inflammatory and immune response of the female tract. Therefore the seminal plasma proteome has been investigated in a large range of taxa, including mammals, birds, fishes and insect species. The association of the seminal plasma with semen preservation or fertility identified proteic markers of seminal plasma function in domestic species. This review summarizes the current knowledge in seminal plasma proteomes and proteic markers of sperm preservation in animal species. Copyright © 2018. Published by Elsevier B.V.

Inbreeding depresses sperm competitiveness, but not fertilization or mating success in male Tribolium castaneum

PubMed Central

Michalczyk, Łukasz; Martin, Oliver Y.; Millard, Anna L.; Emerson, Brent C.; Gage, Matthew J. G.

2010-01-01

As populations decline to levels where reproduction among close genetic relatives becomes more probable, subsequent increases in homozygous recessive deleterious expression and/or loss of heterozygote advantage can lead to inbreeding depression. Here, we measure how inbreeding across replicate lines of the flour beetle Tribolium castaneum impacts on male reproductive fitness in the absence or presence of male–male competition. Effects on male evolution from mating pattern were removed by enforcing monogamous mating throughout. After inbreeding across eight generations, we found that male fertility in the absence of competition was unaffected. However, we found significant inbreeding depression of sperm competitiveness: non-inbred males won 57 per cent of fertilizations in competition, while inbred equivalents only sired 42 per cent. We also found that the P2 ‘offence’ role in sperm competition was significantly more depressed under inbreeding than sperm ‘defence’ (P1). Mating behaviour did not explain these differences, and there was no difference in the viability of offspring sired by inbred or non-inbred males. Sperm length variation was significantly greater in the ejaculates of inbred males. Our results show that male ability to achieve normal fertilization success was not depressed under strong inbreeding, but that inbreeding depression in these traits occurred when conditions of sperm competition were generated. PMID:20554548

Inbreeding depresses sperm competitiveness, but not fertilization or mating success in male Tribolium castaneum.

PubMed

Michalczyk, Lukasz; Martin, Oliver Y; Millard, Anna L; Emerson, Brent C; Gage, Matthew J G

2010-11-22

As populations decline to levels where reproduction among close genetic relatives becomes more probable, subsequent increases in homozygous recessive deleterious expression and/or loss of heterozygote advantage can lead to inbreeding depression. Here, we measure how inbreeding across replicate lines of the flour beetle Tribolium castaneum impacts on male reproductive fitness in the absence or presence of male-male competition. Effects on male evolution from mating pattern were removed by enforcing monogamous mating throughout. After inbreeding across eight generations, we found that male fertility in the absence of competition was unaffected. However, we found significant inbreeding depression of sperm competitiveness: non-inbred males won 57 per cent of fertilizations in competition, while inbred equivalents only sired 42 per cent. We also found that the P(2) 'offence' role in sperm competition was significantly more depressed under inbreeding than sperm 'defence' (P(1)). Mating behaviour did not explain these differences, and there was no difference in the viability of offspring sired by inbred or non-inbred males. Sperm length variation was significantly greater in the ejaculates of inbred males. Our results show that male ability to achieve normal fertilization success was not depressed under strong inbreeding, but that inbreeding depression in these traits occurred when conditions of sperm competition were generated.

Role of myometrial activity in sperm transport through the genital tract and in fertilization in sows.

PubMed

Langendijk, P; Bouwman, E G; Kidson, A; Kirkwood, R N; Soede, N M; Kemp, B

2002-05-01

The effects of stimulation and suppression of uterine contractility at about the time of insemination on sperm distribution and fertilization in multiparous sows are described. For assessment of fertilization, sows were inseminated about 28 h before (synchronized) ovulation and killed at day 5 after ovulation (n = 53). For assessment of sperm distribution, sows were inseminated about 20 h before expected ovulation and were killed 12 h later (n = 26). At 10 min before insemination, sows received an intrauterine infusion of one of three solutions: (i) saline (control); (ii) 0.60 mg clenbuterol hydrochloride to suppress contractility; or (iii) 1 mg cloprostenol to stimulate contractility. Both clenbuterol and cloprostenol reduced median fertilization rate (P < 0.05) and median number of accessory sperm cells (P < 0.05). Distribution of sperm cells was also affected by treatments. Clenbuterol increased, and cloprostenol decreased, the number of sperm cells (P < 0.05) in the proximal 20 cm of the uterine horn and in the uterotubal junction. In addition, clenbuterol tended to increase and cloprostenol tended to decrease the number of sperm cells in the isthmus, although these effects were not significant. However, relative to the number of sperm cells in the uterus, clenbuterol treatment reduced the number of sperm cells in the uterotubal junction and oviduct, in contrast to cloprostenol. Cloprostenol increased the reflux of semen during insemination. It is hypothesized that suppression of uterine contractility increases transuterine transport time, reducing the ability of sperm cells to enter the uterotubal junction and the oviduct. Stimulation of uterine contractility above a certain level probably increases reflux and impedes transuterine transport of sufficient numbers of sperm cells.

Effect of gametes aging on their activation and fertilizability in zebrafish (Danio rerio).

PubMed

Cardona-Costa, Jose; Pérez-Camps, Mireia; García-Ximénez, Fernando; Espinós, Francisco J

2009-03-01

The zebrafish represents an important model organism for biological research. In this context, in vitro collection and fertilization of zebrafish gametes are basic and widely used techniques for many topical research works. In this work, the fertilization ability and normal embryo development of gold-type zebrafish sperm and eggs were re-evaluated after being stored for different times at 8 degrees C in a modified medium (Hanks' saline supplemented with 1.5 g BSA and 0.1 g ClNa; 320 mOsm, pH 7.4). Results obtained indicated that the temporal limits usually recommended for zebrafish sperm to fertilize fresh eggs (2 h) could be extended for up to 24 h without significant differences compared with fresh sperm. In contrast, the rapid egg aging observed (even less than 1 h) recommends minimizing as far as possible the egg storage time before fertilization. These results suggest a possible strain difference in the fertilization response.

Selfish genetic elements and sexual selection: their impact on male fertility.

PubMed

Price, Tom A R; Wedell, Nina

2008-03-01

Females of many species mate with more than one male (polyandry), yet the adaptive significance of polyandry is poorly understood. One hypothesis to explain the widespread occurrence of multiple mating is that it may allow females to utilize post-copulatory mechanisms to reduce the risk of fertilizing their eggs with sperm from incompatible males. Selfish genetic elements (SGEs) are ubiquitous in eukaryotes, frequent sources of reproductive incompatibilities, and associated with fitness costs. However, their impact on sexual selection is largely unexplored. In this review we examine the link between SGEs, male fertility and sperm competitive ability. We show there is widespread evidence that SGEs are associated with reduced fertility in both animals and plants, and present some recent data showing that males carrying SGEs have reduced paternity in sperm competition. We also discuss possible reasons why male gametes are particularly vulnerable to the selfish actions of SGEs. The widespread reduction in male fertility caused by SGEs implies polyandry may be a successful female strategy to bias paternity against SGE-carrying males.

Selfish genetic elements and sexual selection: their impact on male fertility.

PubMed

Price, Tom A R; Wedell, Nina

2008-09-01

Females of many species mate with more than one male (polyandry), yet the adaptive significance of polyandry is poorly understood. One hypothesis to explain the widespread occurrence of multiple mating is that it may allow females to utilize post-copulatory mechanisms to reduce the risk of fertilizing their eggs with sperm from incompatible males. Selfish genetic elements (SGEs) are ubiquitous in eukaryotes, frequent sources of reproductive incompatibilities, and associated with fitness costs. However, their impact on sexual selection is largely unexplored. In this review we examine the link between SGEs, male fertility and sperm competitive ability. We show there is widespread evidence that SGEs are associated with reduced fertility in both animals and plants, and present some recent data showing that males carrying SGEs have reduced paternity in sperm competition. We also discuss possible reasons why male gametes are particularly vulnerable to the selfish actions of SGEs. The widespread reduction in male fertility caused by SGEs implies polyandry may be a successful female strategy to bias paternity against SGE-carrying males.

Understanding fertilization through intracytoplasmic sperm injection (ICSI)

PubMed Central

Neri, Queenie V.; Lee, Bora; Rosenwaks, Zev; Machaca, Khaled; Palermo, Gianpiero D.

2014-01-01

Summary Since the establishment of in vitro fertilization, it became evident that almost half of the couples failed to achieve fertilization and this phenomenon was attributed to a male gamete dysfunction. The adoption of assisted fertilization techniques particularly ICSI has been able to alleviate male factor infertility by granting the consistent ability of a viable spermatozoon to activate an oocyte. Single sperm injection, by pinpointing the beginning of fertilization, has been an invaluable tool in clarifying the different aspects of early fertilization and syngamy. However, even with ICSI some couples fail to fertilize due to ooplasmic dysmaturity in relation to the achieved nuclear maturation marked by the extrusion of the first polar body. More uncommon are cases where the spermatozoa partially or completely lack the specific oocyte activating factor. In this work, we review the most relevant aspects of fertilization and its failure through assisted reproductive technologies. Attempts at diagnosing and treating clinical fertilization failure are described. PMID:24290744

Effects of modification of in vitro fertilization techniques on the sex ratio of the resultant bovine embryos.

PubMed

Iwata, H; Shiono, H; Kon, Y; Matsubara, K; Kimura, K; Kuwayama, T; Monji, Y

2008-05-01

The duration of sperm-oocyte co-incubation has been observed to affect the sex ratio of in vitro produced bovine embryos. The purpose of this study was to investigate some factors that may be responsible for the skewed sex ratio. The factors studied were selected combinations of the duration of co-incubation, the presence or absence of cumulus cells, and the level of hyaluronic acid (HA) in the culture medium. Experiment 1 examined the effect of selected combinations of different factors during the fertilization phase of in vitro oocyte culture. The factors were the nature of the sperm or its treatment, the duration of the sperm-oocyte co-incubation, and the level of hyaluronic acid in the culture medium. In experiment 2, the capacitation of frozen-thawed-Percoll-washed sperm (control), pre-incubated, and non-binding sperm was evaluated by the zona pellucida (ZP) binding assay and the hypo-osmotic swelling test (HOST). The purpose of experiment 3 was to determine the oocyte cleavage rate and sex ratio of the embryos (>5 cells) produced as a consequence of the 10 treatments used in experiment 1. In treatments 1-3 (experiments 1 and 3) COC were co-cultured with sperm for 1, 5 or 18 h. Polyspermic fertilization rose as the co-incubation period increased (1 h 6.5%, 5 h 15.9%, 18 h 41.8%; P<0.05), and the highest rate of normal fertilization was observed for 5h culture (73.4%; P<0.05). The sex ratio was significantly (P<0.05) skewed from the expected 50:50 towards males following 1 h (64.4%) and 5 h (67.3%) co-incubation, but was not affected by 18 h incubation (52.3%). In treatment 4, sperm was pre-incubated for 1h and cultured with COC for 5 h. Relative to control sperm, pre-incubation of sperm increased ZP binding (116 versus 180 per ZP; P<0.05) and decreased the proportion of HOST positive sperm (65.8-48.6%; P<0.05; experiment 2). Pre-incubation did not affect the rates of polyspermy, normal fertilization or the sex ratio of the embryos (experiments 1 and 3). The oocytes used in treatments 5-10 of experiments 1 and 3 were denuded prior to fertilization. Co-incubation of denuded oocytes for 1h (treatment 5) or 5h (treatment 6) resulted in levels of polyspermic fertilization similar to that for treatment 2 with significantly lower levels of normal fertilization (41.7% and 52.6%, respectively; P<0.05), and the 1h co-incubation significantly skewed (P<0.05) the proportion of male embryos to 70.0%. Denuded oocytes were fertilized for 5h with sperm unable to bind to cumulus cells (NB sperm) in treatment 7 or those that bound to cumulus cells (B) in treatment 8. These two treatments had similar rates of polyspermic, normal and non-fertilization. However, the B sperm caused the sex ratio of the embryos to be significantly skewed to males (63.9%; P<0.05). Fertilization of denuded oocytes in medium containing hyaluronic acid (0.1 mg/ml, treatment 9; 1.0 mg/ml treatment 10) significantly (P<0.05) reduced the incidence of polyspermic fertilization relative to treatments 2 and 6, and normal fertilization relative to treatment 2, but did not affect the sex ratio of the embryos. It was concluded that exposure of sperm to cumulus cells, either before fertilization of denuded oocytes or during the process of fertilization of complete COC, increased the proportion of male embryos produced by in vitro culture. It was hypothesized that this may be due to the capacitation state of the sperm, the cumulus-sperm interaction, and/or the ability of the sperm to bind to cumulus cells or oocytes.

Fertility disturbances of dimethylacetamide and glycerol in rooster sperm diluents: Discrimination among effects produced pre and post freezing-thawing process.

PubMed

Abouelezz, F M K; Sayed, M A M; Santiago-Moreno, J

2017-09-01

With avian sperm cryopreservation protocols, the most widely used cryoprotectants (CPAs) are the glycerol (GLY; in gradual freezing: in-straw freezing method), and the dimethylacetamide (DMA; in pellets by plunging into liquid nitrogen: in-pellet rapid freezing method). Use of both methods results in a small portion of thawed live sperm with lesser fertilizing ability compared with the semen samples immediately after collection. This study was conducted to assess the pre-freezing damage occurring to the sperm due to the interaction with the cryoprotectants (CPAs) GLY (8%) and DMA (5%), as well as the post-freezing damage resulting from both freezing methods Data for each treatment, in fresh and frozen-thawed samples, were compared for sperm motility, fertilizing capacity and sperm-egg penetration holes/germinal disc (SP holes/GD). Hens (n=50) were artificially inseminated (10 hens/treatment) six times with 3day intervals between inseminations. The treatment of fresh sperm with DMA led to a reduction (P<0.05) in the count of SP holes/GD (21.4) and the fertility rate (66.7%). The addition and elimination of GLY in fresh samples resulted in a lesser (P<0.05) number of SP holes/GD (11.8) and the fertility rate (i.e., 50.0%). The number of SP-holes/GD was least in frozen-thawed samples using both DMA and GLY (14.2 and 9.2, respectively). The fertility rate when using semen frozen with DMA in- pellets was greater (P<0.05) than with use of semen that had been frozen using GLY in straws (46.4% compared with 31.3%). The reduction in fertility compared with the control when semen was cryopreserved using GLY was 64.1%; the GLY addition and elimination was responsible for two thirds of this reduction. The reduction in fertility when using semen cryopreserved with DMA was 46.7%; half of the reduction was attributed to the treatment with DMA. In conclusion, the mechanical damage attributed to the process for reducing GLY concentrations was more harmful to sperm fertilizing capacity than the toxicity of DMA and freeze/thaw process. For both freezing methods, the amount of sperm cryo-damage was similar, when the damage attributed to the CPA addition and elimination process was excluded. Copyright © 2017 Elsevier B.V. All rights reserved.

Effect of transfection and co-incubation of bovine sperm with exogenous DNA on sperm quality and functional parameters for its use in sperm-mediated gene transfer.

PubMed

Arias, María Elena; Sánchez-Villalba, Esther; Delgado, Andrea; Felmer, Ricardo

2017-02-01

Sperm-mediated gene transfer (SMGT) is based on the capacity of sperm to bind exogenous DNA and transfer it into the oocyte during fertilization. In bovines, the progress of this technology has been slow due to the poor reproducibility and efficiency of the production of transgenic embryos. The aim of the present study was to evaluate the effects of different sperm transfection systems on the quality and functional parameters of sperm. Additionally, the ability of sperm to bind and incorporate exogenous DNA was assessed. These analyses were carried out by flow cytometry and confocal fluorescence microscopy, and motility parameters were also evaluated by computer-assisted sperm analysis (CASA). Transfection was carried out using complexes of plasmid DNA with Lipofectamine, SuperFect and TurboFect for 0.5, 1, 2 or 4 h. The results showed that all of the transfection treatments promoted sperm binding and incorporation of exogenous DNA, similar to sperm incorporation of DNA alone, without affecting the viability. Nevertheless, the treatments and incubation times significantly affected the motility parameters, although no effect on the integrity of DNA or the levels of reactive oxygen species (ROS) was observed. Additionally, we observed that transfection using SuperFect and TurboFect negatively affected the acrosome integrity, and TurboFect affected the mitochondrial membrane potential of sperm. In conclusion, we demonstrated binding and incorporation of exogenous DNA by sperm after transfection and confirmed the capacity of sperm to spontaneously incorporate exogenous DNA. These findings will allow the establishment of the most appropriate method [intracytoplasmic sperm injection (ICSI) or in vitro fertilization (IVF)] of generating transgenic embryos via SMGT based on the fertilization capacity of transfected sperm.

Single nucleotide polymorphisms in candidate genes associated with fertilizing ability of sperm and subsequent embryonic development in cattle

USDA-ARS?s Scientific Manuscript database

Fertilization and development of the preimplantation embryo is under genetic control. The goal of the current study was to test 434 single nucleotide polymorphisms (SNPs) for association with genetic variation in fertilization and early embryonic development. The approach was to produce embryos from...

EDC IMPACT: Chemical UV filters can affect human sperm function in a progesterone-like manner

PubMed Central

Rehfeld, A; Egeberg, D L; Almstrup, K; Petersen, J H; Dissing, S

2018-01-01

Human sperm cell function must be precisely regulated to achieve natural fertilization. Progesterone released by the cumulus cells surrounding the egg induces a Ca2+ influx into human sperm cells via the CatSper Ca2+-channel and thereby controls sperm function. Multiple chemical UV filters have been shown to induce a Ca2+ influx through CatSper, thus mimicking the effect of progesterone on Ca2+ signaling. We hypothesized that these UV filters could also mimic the effect of progesterone on sperm function. We examined 29 UV filters allowed in sunscreens in the US and/or EU for their ability to affect acrosome reaction, penetration, hyperactivation and viability in human sperm cells. We found that, similar to progesterone, the UV filters 4-MBC, 3-BC, Meradimate, Octisalate, BCSA, HMS and OD-PABA induced acrosome reaction and 3-BC increased sperm penetration into a viscous medium. The capacity of the UV filters to induce acrosome reaction and increase sperm penetration was positively associated with the ability of the UV filters to induce a Ca2+ influx. None of the UV filters induced significant changes in the proportion of hyperactivated cells. In conclusion, chemical UV filters that mimic the effect of progesterone on Ca2+ signaling in human sperm cells can similarly mimic the effect of progesterone on acrosome reaction and sperm penetration. Human exposure to these chemical UV filters may impair fertility by interfering with sperm function, e.g. through induction of premature acrosome reaction. Further studies are needed to confirm the results in vivo. PMID:28874401

EDC IMPACT: Chemical UV filters can affect human sperm function in a progesterone-like manner.

PubMed

Rehfeld, A; Egeberg, D L; Almstrup, K; Petersen, J H; Dissing, S; Skakkebæk, N E

2018-01-01

Human sperm cell function must be precisely regulated to achieve natural fertilization. Progesterone released by the cumulus cells surrounding the egg induces a Ca 2+ influx into human sperm cells via the CatSper Ca 2+ -channel and thereby controls sperm function. Multiple chemical UV filters have been shown to induce a Ca 2+ influx through CatSper, thus mimicking the effect of progesterone on Ca 2+ signaling. We hypothesized that these UV filters could also mimic the effect of progesterone on sperm function. We examined 29 UV filters allowed in sunscreens in the US and/or EU for their ability to affect acrosome reaction, penetration, hyperactivation and viability in human sperm cells. We found that, similar to progesterone, the UV filters 4-MBC, 3-BC, Meradimate, Octisalate, BCSA, HMS and OD-PABA induced acrosome reaction and 3-BC increased sperm penetration into a viscous medium. The capacity of the UV filters to induce acrosome reaction and increase sperm penetration was positively associated with the ability of the UV filters to induce a Ca 2+ influx. None of the UV filters induced significant changes in the proportion of hyperactivated cells. In conclusion, chemical UV filters that mimic the effect of progesterone on Ca 2+ signaling in human sperm cells can similarly mimic the effect of progesterone on acrosome reaction and sperm penetration. Human exposure to these chemical UV filters may impair fertility by interfering with sperm function, e.g. through induction of premature acrosome reaction. Further studies are needed to confirm the results in vivo . © 2018 The authors.

Specialized sperm function tests in varicocele and the future of andrology laboratory.

PubMed

Majzoub, Ahmad; Esteves, Sandro C; Gosálvez, Jaime; Agarwal, Ashok

2016-01-01

Varicocele is a common medical condition entangled with many controversies. Though it is highly prevalent in men with infertility, still it marks its presence in males who do have normal fertility. Determining which patients are negatively affected by varicocele would enable clinicians to better select those men who benefitted the most from surgery. Since conventional semen analysis has been limited in its ability to evaluate the negative effects of varicocele on fertility, a multitude of specialized laboratory tests have emerged. In this review, we examine the role and significance of specialized sperm function tests with regards to varicocele. Among the various tests, analysis of sperm DNA fragmentation and measurements of oxidative stress markers provide an independent measure of fertility in men with varicocele. These diagnostic modalities have both diagnostic and prognostic information complementary to, but distinct from conventional sperm parameters. Test results can guide management and aid in monitoring intervention outcomes. Proteomics, metabolomics, and genomics are areas; though still developing, holding promise to revolutionize our understanding of reproductive physiology, including varicocele.

Absence of Peroxiredoxin 6 Amplifies the Effect of Oxidant Stress on Mobility and SCSA/CMA3 Defined Chromatin Quality and Impairs Fertilizing Ability of Mouse Spermatozoa1

PubMed Central

Ozkosem, Burak; Feinstein, Sheldon I.; Fisher, Aron B.; O'Flaherty, Cristian

2016-01-01

Oxidative stress, the imbalance between reactive oxygen species production and antioxidant defenses, is associated with male infertility. Peroxiredoxins (PRDXs) are antioxidant enzymes with a wide distribution in spermatozoa. PRDX6 is highly abundant and located in all subcellular compartments of the spermatozoon. Infertile men have lower levels of sperm PRDX6 associated with low sperm motility and high DNA damage. In order to better understand the role of PRDX6 in male reproduction, the aim of this study was to elucidate the impact of the lack of PRDX6 on male mouse fertility. Spermatozoa lacking PRDX6 showed significantly increased levels of cellular oxidative damage evidenced by high levels of lipid peroxidation, 8-hydroxy-deoxyguanosine (DNA oxidation), and protein oxidation (S-glutathionylation and carbonylation), lower sperm chromatin quality (high DNA fragmentation and low DNA compaction, due to low levels of protamination and a high percentage of free thiols), along with decreased sperm motility and impairment of capacitation as compared with wild-type (WT) spermatozoa. These manifestations of damage are exacerbated by tert-butyl hydroperoxide treatment in vivo. While WT males partially recovered the quality of their spermatozoa (in terms of motility and sperm DNA integrity), Prdx6−/− males showed higher levels of sperm damage (lower motility and chromatin integrity) 6 mo after the end of treatment. In conclusion, Prdx6−/− males are more vulnerable to oxidative stress than WT males, resulting in impairment of sperm quality and ability to fertilize the oocyte, compatible with the subfertility phenotype observed in these knockout mice. PMID:26792942

Absence of Peroxiredoxin 6 Amplifies the Effect of Oxidant Stress on Mobility and SCSA/CMA3 Defined Chromatin Quality and Impairs Fertilizing Ability of Mouse Spermatozoa.

PubMed

Ozkosem, Burak; Feinstein, Sheldon I; Fisher, Aron B; O'Flaherty, Cristian

2016-03-01

Oxidative stress, the imbalance between reactive oxygen species production and antioxidant defenses, is associated with male infertility. Peroxiredoxins (PRDXs) are antioxidant enzymes with a wide distribution in spermatozoa. PRDX6 is highly abundant and located in all subcellular compartments of the spermatozoon. Infertile men have lower levels of sperm PRDX6 associated with low sperm motility and high DNA damage. In order to better understand the role of PRDX6 in male reproduction, the aim of this study was to elucidate the impact of the lack of PRDX6 on male mouse fertility. Spermatozoa lacking PRDX6 showed significantly increased levels of cellular oxidative damage evidenced by high levels of lipid peroxidation, 8-hydroxy-deoxyguanosine (DNA oxidation), and protein oxidation (S-glutathionylation and carbonylation), lower sperm chromatin quality (high DNA fragmentation and low DNA compaction, due to low levels of protamination and a high percentage of free thiols), along with decreased sperm motility and impairment of capacitation as compared with wild-type (WT) spermatozoa. These manifestations of damage are exacerbated by tert-butyl hydroperoxide treatment in vivo. While WT males partially recovered the quality of their spermatozoa (in terms of motility and sperm DNA integrity), Prdx6(-/-) males showed higher levels of sperm damage (lower motility and chromatin integrity) 6 mo after the end of treatment. In conclusion, Prdx6(-/-) males are more vulnerable to oxidative stress than WT males, resulting in impairment of sperm quality and ability to fertilize the oocyte, compatible with the subfertility phenotype observed in these knockout mice. © 2016 by the Society for the Study of Reproduction, Inc.

Sperm Competitive Ability in Drosophila melanogaster Associated With Variation in Male Reproductive Proteins

PubMed Central

Fiumera, Anthony C.; Dumont, Bethany L.; Clark, Andrew G.

2005-01-01

Multiple mating by females establishes the opportunity for postcopulatory sexual selection favoring males whose sperm is preferentially employed in fertilizations. Here we use natural variation in a wild population of Drosophila melanogaster to investigate the genetic basis of sperm competitive ability. Approximately 101 chromosome 2 substitution lines were scored for components of sperm competitive ability (P1′, P2′, fecundity, remating rate, and refractoriness), genotyped at 70 polymorphic markers in 10 male reproductive genes, and measured for transcript abundance of those genes. Permutation tests were applied to quantify the statistical significance of associations between genotype and phenotype. Nine significant associations were identified between polymorphisms in the male reproductive genes and sperm competitive ability and 13 were identified between genotype and transcript abundance, but no significant associations were found between transcript abundance and sperm competitive ability. Pleiotropy was evident in two genes: a polymorphism in Acp33A associated with both P1′ and P2′ and a polymorphism in CG17331 associated with both elevated P2′ and reduced refractoriness. The latter case is consistent with antagonistic pleiotropy and may serve as a mechanism maintaining genetic variation. PMID:15466425

Understanding fertilization through intracytoplasmic sperm injection (ICSI).

PubMed

Neri, Queenie V; Lee, Bora; Rosenwaks, Zev; Machaca, Khaled; Palermo, Gianpiero D

2014-01-01

Since the establishment of in vitro fertilization, it became evident that almost half of the couples failed to achieve fertilization and this phenomenon was attributed to a male gamete dysfunction. The adoption of assisted fertilization techniques particularly ICSI has been able to alleviate male factor infertility by granting the consistent ability of a viable spermatozoon to activate an oocyte. Single sperm injection, by pinpointing the beginning of fertilization, has been an invaluable tool in clarifying the different aspects of early fertilization and syngamy. However, even with ICSI some couples fail to fertilize due to ooplasmic dysmaturity in relation to the achieved nuclear maturation marked by the extrusion of the first polar body. More uncommon are cases where the spermatozoa partially or completely lack the specific oocyte activating factor. In this work, we review the most relevant aspects of fertilization and its failure through assisted reproductive technologies. Attempts at diagnosing and treating clinical fertilization failure are described. Copyright © 2013 The Authors. Published by Elsevier Ltd.. All rights reserved.

Adult exercise effects on oxidative stress and reproductive programming in male offspring of obese rats.

PubMed

Santos, Mery; Rodríguez-González, Guadalupe L; Ibáñez, Carlos; Vega, Claudia C; Nathanielsz, Peter W; Zambrano, Elena

2015-02-01

Exercise improves health but few data are available regarding benefits of exercise in offspring exposed to developmental programming. There is currently a worldwide epidemic of obesity. Obesity in pregnant women predisposes offspring to obesity. Maternal obesity has well documented effects on offspring reproduction. Few studies address ability of offspring exercise to reduce adverse outcomes. We observed increased oxidative stress and impaired sperm function in rat offspring of obese mothers. We hypothesized that regular offspring exercise reverses adverse effects of maternal obesity on offspring sperm quality and fertility. Female Wistar rats ate chow (C) or high-energy, obesogenic diet (MO) from weaning through lactation, bred at postnatal day (PND) 120, and ate their pregnancy diet until weaning. All offspring ate C diet from weaning. Five male offspring (different litters) ran on a wheel for 15 min, 5 times/week from PND 330 to 450 and were euthanized at PND 450. Average distance run per session was lower in MO offspring who had higher body weight, adiposity index, and gonadal fat and showed increases in testicular oxidative stress biomarkers. Sperm from MO offspring had reduced antioxidant enzyme activity, lower sperm quality, and fertility. Exercise in MO offspring decreased testicular oxidative stress, increased sperm antioxidant activity and sperm quality, and improved fertility. Exercise intervention has beneficial effects on adiposity index, gonadal fat, oxidative stress markers, sperm quality, and fertility. Thus regular physical exercise in male MO offspring recuperates key male reproductive functions even at advanced age: it's never too late. Copyright © 2015 the American Physiological Society.

Effect of semen extender supplementation with cysteine on postthaw sperm quality, DNA damage, and fertilizing ability in the common carp (Cyprinus carpio).

PubMed

Öğretmen, Fatih; İnanan, Burak Evren; Kutluyer, Filiz; Kayim, Murathan

2015-06-01

Amino acids have an important biological role for prevention of cell damage during cryopreservation. The objective of this study is to determine the effects of cysteine on postthaw sperm motility, duration of sperm motility, DNA damage, and fertility in the common carp (Cyprinus carpio). Sperm collected from 10 individuals was cryopreserved in extenders containing different cysteine concentrations (2.5, 5, 10, and 20 mM). Semen samples diluted at the ratio of 1:9 by the extenders were subjected to cryopreservation. After dilution, the semen was aspirated into 0.25-mL straws; the straws were placed on the tray, frozen in nitrogen vapor, and plunged into liquid nitrogen. DNA damage was evaluated by comet assay after cryopreservation. Our results indicated that an increase in the concentration of cysteine caused a significant increase in the motility rate and duration of sperm in the common carp (C carpio; P < 0.05). Comparing all concentrations of cysteine, the best concentration of cysteine was 20 mM. Higher postthaw motility (76.00 ± 1.00%) and fertilization (97.00 ± 1.73%) rates were obtained with the extender at the concentration of 20 mM. Supplementation of the extender with cysteine was increased the fertilization and hatching rate and decreased DNA damage. Consequently, cysteine affected the motility, fertilization, and DNA damage positively, and extenders could be supplemented with cysteine. Copyright © 2015 Elsevier Inc. All rights reserved.

Hyper-activated motility in sperm capacitation is mediated by phospholipase D-dependent actin polymerization.

PubMed

Itach, Sarit Bar-Sheshet; Finklestein, Maya; Etkovitz, Nir; Breitbart, Haim

2012-02-15

In order to fertilize the oocyte, sperm must undergo a series of biochemical changes in the female reproductive tract, known as capacitation. Once capacitated, spermatozoon can bind to the zona pellucida of the egg and undergo the acrosome reaction (AR), a process that enables its penetration and fertilization of the oocyte. Important processes that characterize sperm capacitation are actin polymerization and the development of hyper-activated motility (HAM). Previously, we showed that Phospholipase D (PLD)-dependent actin polymerization occurs during sperm capacitation, however the role of this process in sperm capacitation is not yet known. In the present study, we showed for the first time the involvement of PLD-dependent actin polymerization in sperm motility during mouse and human capacitation. Sperm incubated under capacitation conditions revealed a time dependent increase in actin polymerization and HAM. Inhibition of Phosphatidic Acid (PA) formation by PLD using butan-1-ol, inhibited actin polymerization and motility, as well as in vitro fertilization (IVF) and the ability of the sperm to undergo the AR. The inhibition of sperm HAM by low concentration of butan-1-ol is completely restored by adding PA, further indicating the involvement of PLD in these processes. Furthermore, exogenous PA enhanced rapid actin polymerization that was followed by a rise in the HAM, as well as an increased in IVF rate. In conclusion, our results demonstrate that PLD-dependent actin polymerization is a critical step needed for the development of HAM during mouse and human sperm capacitation. Copyright © 2011 Elsevier Inc. All rights reserved.

Microencapsulation of bovine spermatozoa for use in artificial insemination: a review.

PubMed

Nebel, R L; Vishwanath, R; McMillan, W H; Saacke, R G

1993-01-01

A technique for microencapsulation of bovine spermatozoa has been developed with minimal spermatozoal injury and thus of potential use in artificial insemination. The polymers poly-l-lysine, polyvinylamine and protamine sulfate have proven best for membranes. Encapsulation has been successful with capsules ranging in size from 0.75 to 1.5 mm, and with sperm concentrations from 45 to 180 x 10(6) cells mL-1. Successful extenders include CUE, CAPROGEN, and egg yolk-citrate-glycerol (maximum 10% v/v egg yolk for normal capsular shape). Capsule fragility (ability to rupture under ageing and physical stress) is negatively related to membrane thickness which ranges from 1.92 to 5.32 microns (depending on the concentration of polymer used) and positively related to concentration of sperm encapsulated. Heterospermic studies have shown that encapsulated sperm are capable of fertilization in vivo, but are at a disadvantage to unencapsulated sperm when cows are inseminated at conventional times. Uterine retention of inseminates is favoured by capsules having a 'sticky' membrane. Using current procedures, preliminary homospermic fertility studies indicate that sperm encapsulated with poly-l-lysine or protamine sulfate may achieve normal fertility.

Analysis of limited fertility in intracytoplasmic sperm injection of sperm obtained by electroejaculation

PubMed Central

Nakamura, Yoshihiro; Kitamura, Masaya; Nishimura, Kenji; Tsujimura, Akira; Takeyama, Masami; Kondoh, Nobuyuki; Miyazaki, Kazunori; Okuyama, Akihiko

2004-01-01

Background and Aims:  We correlated findings in semen from patients with ejaculatory dysfunction with results of in vitro fertilization using their electroejaculated sperm. Methods and Results:  Electroejaculation was carried out in six patients with the above‐mentioned criteria for a total of eight times. Sperm was obtained in six attempts. Intracytoplasmic injection of these sperm was performed in 156 eggs. Sixty‐seven eggs were fertilized; most of these were injected with motile sperm. Two women became pregnant, both after injection with motile sperm. As previously reported, electroejaculated sperm showed low motility and a low fertilization rate, but even motile sperm had a low fertilization rate. Conclusion:  The results of the present study suggest the importance in fertilization of undetermined factors in addition to sperm motility. (Reprod Med Biol 2004; 3: 9–12) PMID:29662380

Effect of magnetized extender on sperm membrane integrity and development of oocytes in vitro fertilized with liquid storage boar semen.

PubMed

Lee, Sang-Hee; Park, Choon-Keun

2015-03-01

The objective of this study was to evaluate the effect of a magnetized extender on sperm membrane damage and development of oocytes in vitro fertilized with liquid storage boar semen. Before semen dilution, extender was flowed through a neodymium magnet (0, 2000, 4000 and 6000G) for 5min and collected semen was preserved for 168h at 18°C. In results, plasma membrane integrity with live sperm was significantly higher in semen treated with extenders magnetized at 4000G than sperm treated with extenders magnetized at 0G during semen preservation for 120-168h (p<0.05). In addition, acrosomal membrane damage was significantly lower in semen treated with extenders magnetized at 4000 and 6000G compared to 0 and 2000G during semen preservation for 168h (p<0.05). And mitochondrial membrane damage with all sperm was significantly lower in semen treated with extenders magnetized at 2000G than other groups during semen preservation for 168h. The ability of semen to achieve successful in vitro fertilization was also not significantly different among the groups during preservation. However, when the semen was preserved for 168h, the blastocyst formation rates were significantly higher at 6000G compared to 0 and 2000G (p<0.05). In conclusion, these results suggest that highly magnetized semen extender could protect the sperm membrane from damage, and improve the ability of rates of in vitro blastocyst development and magnetized semen diluter is beneficial for long liquid preservation of boar semen. Copyright © 2014 Elsevier B.V. All rights reserved.

Trypan blue/giemsa staining to assess sperm membrane integrity in salernitano stallions and its relationship to pregnancy rates.

PubMed

Serafini, R; Longobardi, V; Spadetta, M; Neri, D; Ariota, B; Gasparrini, B; Di Palo, R

2014-02-01

Aim of this study was to test the reliability of Trypan blue/Giemsa staining to evaluate sperm membrane integrity, acrosomal intactness and morphology in stallion to verify whether it could be applied in vitro as useful tool for sperm fertilizing ability. Fertility data on inseminated mares were collected to evaluate the relationship of sperm quality to pregnancy rates. Forty-one ejaculates were collected from 3 stallions of Salernitano Horse Breed and evaluated for gross appearance, volume, visual motility and membrane integrity with Trypan blue/Giemsa staining and thirty-five mares were inseminated during the breeding season from April to July. Differences among stallions were found in volume, sperm concentration (p < 0.05) and visual motility (p < 0.01). A decrease in sperm motility, concentration (p < 0.05) and total sperm number was found in June-July (p < 0.01). Live sperm with intact acrosome (LSIA) and proximal droplets (PD) were lower (p < 0.01) in June-July, while acrosome reacted sperm (ARS) percentage increased (p < 0.05). No fertility differences were found among stallions with an average fertility per cycle of 44.6% and a pregnancy rate of 68.6%. Higher percentages of LSIA were found in the ejaculates used to inseminate mares that became pregnant vs those used in mares not pregnant (p < 0.05). The significance of LSIA as test variable to verify the reliability of Trypan blue/Giemsa staining was confirmed by Receiver operating characteristic ROC analysis and the sensitivity of the test was 85% at a cut-off value of 48% LSIA. Trypan blue-Giemsa showed to be an accurate method that can be applied on field to evaluate sperm membrane integrity and to identify poor-quality ejaculates. © 2013 Blackwell Verlag GmbH.

Sexual selection for genetic compatibility: the role of the major histocompatibility complex on cryptic female choice in Chinook salmon (Oncorhynchus tshawytscha).

PubMed

Gessner, C; Nakagawa, S; Zavodna, M; Gemmell, N J

2017-05-01

Cryptic female choice (CFC), a form of sexual selection during or post mating, describes processes of differential sperm utilization by females to bias fertilization outcomes towards certain males. In Chinook salmon (Oncorhynchus tshawytscha) the ovarian fluid surrounding the ova of a given female differently enhances the sperm velocity of males. Sperm velocity is a key ejaculate trait that determines fertilization success in externally fertilizing fishes, thus the differential effect on sperm velocity might bias male fertilization outcomes and represent a mechanism of CFC. Once sperm reach the oocyte, CFC could potentially be further facilitated by sperm-egg interactions, which are well understood in externally fertilizing marine invertebrates. Here, we explored the potential genetic basis of both possible mechanisms of CFC by examining whether the genotypic combinations of mates (amino-acid divergence, number of shared alleles) at the major histocompatibility complex (MHC) class I and II explain the variation in sperm velocity and/or male fertilization success that is not explained by sperm velocity, which might indicate MHC-based sperm-egg interactions. We recorded sperm velocity in ovarian fluid, employed paired-male fertilization trials and evaluated the fertilization success of each male using microsatellite-based paternity assignment. We showed that relative sperm velocity was positively correlated with fertilization success, confirming that the differential effect on sperm velocity may be a mechanism of CFC in Chinook salmon. The variation in sperm velocity was independent of MHC class I and II. However, the MHC class II divergence of mates explained fertilization success, indicating that this locus might influence sperm-egg interactions.

Specialized sperm function tests in varicocele and the future of andrology laboratory

PubMed Central

Majzoub, Ahmad; Esteves, Sandro C; Gosálvez, Jaime; Agarwal, Ashok

2016-01-01

Varicocele is a common medical condition entangled with many controversies. Though it is highly prevalent in men with infertility, still it marks its presence in males who do have normal fertility. Determining which patients are negatively affected by varicocele would enable clinicians to better select those men who benefitted the most from surgery. Since conventional semen analysis has been limited in its ability to evaluate the negative effects of varicocele on fertility, a multitude of specialized laboratory tests have emerged. In this review, we examine the role and significance of specialized sperm function tests with regards to varicocele. Among the various tests, analysis of sperm DNA fragmentation and measurements of oxidative stress markers provide an independent measure of fertility in men with varicocele. These diagnostic modalities have both diagnostic and prognostic information complementary to, but distinct from conventional sperm parameters. Test results can guide management and aid in monitoring intervention outcomes. Proteomics, metabolomics, and genomics are areas; though still developing, holding promise to revolutionize our understanding of reproductive physiology, including varicocele. PMID:26780873

Modified expression of several sperm proteins after chronic exposure to the antiandrogenic compound vinclozolin.

PubMed

Auger, Jacques; Eustache, Florence; Maceiras, Paula; Broussard, Cédric; Chafey, Philippe; Lesaffre, Corinne; Vaiman, Daniel; Camoin, Luc; Auer, Jana

2010-10-01

Little is known about the molecular impact of in vivo exposure to endocrine disruptors (EDs) on sperm structures and functions. We recently reported that the lifelong exposure of rats to the antiandrogenic compound vinclozolin results in low epididymal weight, changes in sperm kinematic parameters, and immature sperm chromatin condensation, together with the impairment of several fertility end points. These results led us to focus specifically on possible molecular abnormalities in sperm. Sperm samples were recovered from the frozen epididymides of rats exposed during the previous study. The proteins present in the samples from six exposed and six control rats were analyzed in pairs, by two-dimensional fluorescence difference gel electrophoresis, to investigate possible exposure-induced changes to sperm protein profiles. Twelve proteins, from the 380 matched spots observed in at least five gels, were present in larger or smaller amounts after vinclozolin exposure. These proteins were identified by mass spectrometry, and several are known to play a crucial role in the sperm fertilizing ability, among which, two mitochondrial enzymes, malate dehydrogenase 2 and aldehyde dehydrogenase (both of which were present in smaller amounts after treatment) and A-kinase anchor protein 4 (larger amounts of precursor after treatment). Finally, Ingenuity Pathway Analysis revealed highly significant interactions between proteins over- and underexpressed after treatment. This is the first study to show an association between in vivo exposure to an ED and changes to the sperm protein profile. These modifications may be at least partly responsible for the reproductive abnormalities and impaired fertility recently reported in this rat model of vinclozolin exposure.

Participation of cysteine-rich secretory proteins (CRISP) in mammalian sperm-egg interaction.

PubMed

Cohen, Débora J; Busso, Dolores; Da Ros, Vanina; Ellerman, Diego A; Maldera, Julieta A; Goldweic, Nadia; Cuasnicu, Patricia S

2008-01-01

Mammalian fertilization is a complex multi-step process mediated by different molecules present on both gametes. CRISP1 (cysteine-rich secretory protein 1) is an epididymal protein thought to participate in gamete fusion through its binding to egg-complementary sites. Structure-function studies using recombinant fragments of CRISP1 as well as synthetic peptides reveal that its egg-binding ability resides in a 12 amino acid region corresponding to an evolutionary conserved motif of the CRISP family, named Signature 2 (S2). Further experiments analyzing both the ability of other CRISP proteins to bind to the rat egg and the amino acid sequence of their S2 regions show that the amino acid sequence of the S2 is needed for CRISP1 to interact with the egg. CRISP1 appears to be involved in the first step of sperm binding to the zona pellucida, identifying a novel role for this protein in fertilization. The observation that sperm testicular CRISP2 is also able to bind to the egg surface suggests a role for this protein in gamete fusion. Subsequent experiments confirmed the participation of CRISP2 in this step of fertilization and revealed that CRISP1 and CRISP2 interact with common egg surface binding sites. Together, these results suggest a functional cooperation between CRISP1 and CRISP2 to ensure the success of fertilization. These observations contribute to a better understanding of the molecular mechanisms underlying mammalian fertilization.

The secretory products of Trichomonas vaginalis decrease fertilizing capacity of mice sperm in vitro

PubMed Central

Roh, Jaesook; Lim, Young-Su; Seo, Min-Young; Choi, Yuri; Ryu, Jae-Sook

2015-01-01

Trichomonas vaginalis infection is one of the most prevalent sexually transmitted infections in humans and is now recognized as an important cause of infertility in men. There is little information about the effect of extracellular polymeric substances (EPS) from T. vaginalis on sperm, but previous reports do not provide a conclusive description of the functional integrity of the sperm. To investigate the impact of EPS on the fertilizing capacity of sperm, we assessed sperm motility, acrosomal status, hypo-osmotic swelling, and in vitro fertilization rate after incubating the sperm with EPS in vitro using mice. The incubation of sperm with EPS significantly decreased sperm motility, viability, and functional integrity in a concentration and time-dependent manner. These effects on sperm quality also resulted in a decreased fertilization rate in vitro. This is the first report that demonstrates the direct negative impact of the EPS of T. vaginalis on the fertilization rate of sperm in vitro. However, further study should be performed using human sperm to determine if EPS has similar negative impact on human sperm fertilizing capacity in vitro. PMID:25578937

The relationship of bull fertility to sperm nuclear shape

USGS Publications Warehouse

Ostermeier, G.C.; Sargeant, G.A.; Yandell, B.S.; Parrish, J.J.

2001-01-01

group had a linear relationship (r .89, P .05) with fertility. To construct a plot of mean sperm shapes, a novel technique to automatically orient and identify the anterior tip of the sperm head was developed. The mean nuclear shape of high-fertility sperm was more elongated and tapered than those of lower fertility. A discriminant function (P .05) was also constructed that separated the 6 bulls into 2 groups based only on the harmonic amplitudes or sperm nuclear shape. The bulls were correctly classified into the 2 fertility groups. A comparison of sperm chromatin structure analysis (SCSA) and harmonic amplitudes found that overall size variance, anterior roundness, and posterior taperedness of sperm nuclei were related to chromatin stability (P .05). Some of the differences observed in sperm nuclear shape between the high- and lower-fertility bulls may be explained by varying levels of chromatin stability. However, sperm nuclear shape appears to contain additional information from chromatin stability alone. In this particular study, with 6 bulls, all with good chromatin quality, sperm nuclear shape was a better predictor of bull fertility.

Fertilization capacity with rainbow trout DNA-damaged sperm and embryo developmental success.

PubMed

Pérez-Cerezales, S; Martínez-Páramo, S; Beirão, J; Herráez, M P

2010-06-01

Mammalian spermatozoa undergo a strong selection process along the female tract to guarantee fertilization by good quality cells, but risks of fertilization with DNA-damaged spermatozoa have been reported. In contrast, most external fertilizers such as fish seem to have weaker selection procedures. This fact, together with their high prolificacy and external embryo development, indicates that fish could be useful for the study of the effects of sperm DNA damage on embryo development. We cryopreserved sperm from rainbow trout using egg yolk and low-density lipoprotein as additives to promote different rates of DNA damage. DNA fragmentation and oxidization were analyzed using comet assay with and without digestion with restriction enzymes, and fertilization trials were performed. Some embryo batches were treated with 3-aminobenzamide (3AB) to inhibit DNA repair by the poly (ADP-ribose) polymerase, which is an enzyme of the base excision repair pathway. Results showed that all the spermatozoa cryopreserved with egg yolk carried more than 10% fragmented DNA, maintaining fertilization rates of 61.1+/-2.3 but a high rate of abortions, especially during gastrulation, and only 14.5+/-4.4 hatching success. Furthermore, after 3AB treatment, hatching dropped to 3.2+/-2.2, showing that at least 10% DNA fragmentation was repaired. We conclude that trout sperm maintains its ability to fertilize in spite of having DNA damage, but that embryo survival is affected. Damage is partially repaired by the oocyte during the first cleavage. Important advantages of using rainbow trout for the study of processes related to DNA damage and repair during development have been reported.

Sperm DNA damage or progressive motility: which one is the better predictor of fertilization in vitro?

PubMed

Simon, Luke; Lewis, Sheena E M

2011-06-01

Sperm progressive motility has been reported to be one of the key factors influencing in vitro fertilization rates. However, recent studies have shown that sperm DNA fragmentation is a more robust predictor of assisted reproductive outcomes including reduced fertilization rates, embryo quality, and pregnancy rates. This study aimed to compare the usefulness of sperm progressive motility and DNA damage as predictive tools of in vitro fertilization rates. Here, 136 couples provided 1,767 eggs with an overall fertilization rate of 64.2%. The fertilization rate in vitro correlated with both sperm progressive motility (r² = 0.236; P = 0.002) and DNA fragmentation (r² = -0.318; P < 0.001). The relative risk of a poor fertilization rate was 9.5 times higher in sperm of men with high DNA fragmentation (>40%) compared with 2.6 times in sperm with poor motility (<40%). Further, sperm DNA fragmentation gave a higher specificity (93.3%) in predicting the fertilization rate than progressive motility (77.8%). Finally, the odds ratio to determine fertilization rate (>70%) was 4.81 (1.89-12.65) using progressive motility compared with 24.18 (5.21-154.51) using DNA fragmentation. This study shows that fertilization rates are directly dependent upon both sperm progressive motility and DNA fragmentation, but sperm DNA fragmentation is a much stronger test.

An intact acrosome is required for the chemotactic response to progesterone in mouse spermatozoa.

PubMed

Guidobaldi, Hector A; Hirohashi, Noritaka; Cubilla, Marisa; Buffone, Mariano G; Giojalas, Laura C

2017-04-01

Mammalian sperm become fertilization-competent in the oviduct, during a process known as capacitation that involves the acquisition of the ability to exocytose the acrosome but also the chemotactic responses-both of which contribute to successful fertilization. Chemotaxis is used by spermatozoa to orient and to locate the egg; the acrosome reaction facilitates sperm binding to and fusing with the egg membrane. Mammalian spermatozoa are able to sense picomolar concentrations of progesterone, which drives chemotactic behavior. The state of the acrosome during the chemotactic response, however, is unknown. Genetically modified mouse spermatozoa were employed in a chemotaxis assay under fluorescence microscopy to evaluate their acrosome status while swimming, allowing us to elucidate the acrosome integrity of sperm responding to progesterone-induced chemotaxis. We first showed that wild-type mouse spermatozoa chemotactically respond to a gradient of progesterone, and that the genetic modifications employed do not affect the chemotactic behavior of sperm to progesterone. Next, we found that acrosome-intact, but not acrosome-reacted, spermatozoa orient and respond to picomolar concentrations of progesterone and that chemotaxis normally occurs prior to the acrosome reaction. Our results suggest that premature commitment to acrosome exocytosis leads to navigation failure, so proper control and timing of the acrosome reaction is required for fertilization success and male fertility. © 2017 Wiley Periodicals, Inc.

Albumin is synthesized in epididymis and aggregates in a high molecular mass glycoprotein complex involved in sperm-egg fertilization.

PubMed

Arroteia, Kélen Fabíola; Barbieri, Mainara Ferreira; Souza, Gustavo Henrique Martins Ferreira; Tanaka, Hiromitsu; Eberlin, Marcos Nogueira; Hyslop, Stephen; Alvares, Lúcia Elvira; Pereira, Luís Antonio Violin Dias

2014-01-01

The epididymis has an important role in the maturation of sperm for fertilization, but little is known about the epididymal molecules involved in sperm modifications during this process. We have previously described the expression pattern for an antigen in epididymal epithelial cells that reacts with the monoclonal antibody (mAb) TRA 54. Immunohistochemical and immunoblotting analyses suggest that the epitope of the epididymal antigen probably involves a sugar moiety that is released into the epididymal lumen in an androgen-dependent manner and subsequently binds to luminal sperm. Using column chromatography, SDS-PAGE with in situ digestion and mass spectrometry, we have identified the protein recognized by mAb TRA 54 in mouse epididymal epithelial cells. The ∼65 kDa protein is part of a high molecular mass complex (∼260 kDa) that is also present in the sperm acrosomal vesicle and is completely released after the acrosomal reaction. The amino acid sequence of the protein corresponded to that of albumin. Immunoprecipitates with anti-albumin antibody contained the antigen recognized by mAb TRA 54, indicating that the epididymal molecule recognized by mAb TRA 54 is albumin. RT-PCR detected albumin mRNA in the epididymis and fertilization assays in vitro showed that the glycoprotein complex containing albumin was involved in the ability of sperm to recognize and penetrate the egg zona pellucida. Together, these results indicate that epididymal-derived albumin participates in the formation of a high molecular mass glycoprotein complex that has an important role in egg fertilization.

Performance of Rodent Spermatozoa Over Time Is Enhanced by Increased ATP Concentrations: The Role of Sperm Competition.

PubMed

Tourmente, Maximiliano; Villar-Moya, Pilar; Varea-Sánchez, María; Luque-Larena, Juan J; Rial, Eduardo; Roldan, Eduardo R S

2015-09-01

Sperm viability, acrosome integrity, motility, and swimming velocity are determinants of male fertility and exhibit an extreme degree of variation among closely related species. Many of these sperm parameters are associated with sperm ATP content, which has led to predictions of trade-offs between ATP content and sperm motility and velocity. Selective pressures imposed by sperm competition have been proposed as evolutionary causes of this pattern of diversity in sperm traits. Here, we examine variation in sperm viability, acrosome integrity, motility, swimming velocity, and ATP content over time, among 18 species of closely related muroid rodents, to address the following questions: (a) Do sperm from closely related species vary in ATP content after a period of incubation? (b) Are these differences in ATP levels related to differences in other sperm traits? (c) Are differences in ATP content and sperm performance over time explained by the levels of sperm competition in these species? Our results revealed a high degree of interspecific variability in changes in sperm ATP content, acrosome integrity, sperm motility and swimming velocity over time. Additionally, species with high sperm competition levels were able to maintain higher levels of sperm motility and faster sperm swimming velocity when they were incubated under conditions that support sperm survival. Furthermore, we show that the maintenance of such levels of sperm performance is correlated with the ability of sperm to sustain high concentrations of intracellular ATP over time. Thus, sperm competition may have an important role maximizing sperm metabolism and performance and, ultimately, the fertilizing capacity of spermatozoa. © 2015 by the Society for the Study of Reproduction, Inc.

Variability in in vitro fertilization outcomes of prepubertal goat oocytes explained by basic semen analyses.

PubMed

Palomo, M J; Quintanilla, R; Izquierdo, M D; Mogas, T; Paramio, M T

2016-12-01

This work analyses the changes that caprine spermatozoa undergo during in vitro fertilization (IVF) of in vitro matured prepubertal goat oocytes and their relationship with IVF outcome, in order to obtain an effective model that allows prediction of in vitro fertility on the basis of semen assessment. The evolution of several sperm parameters (motility, viability and acrosomal integrity) during IVF and their relationship with three IVF outcome criteria (total penetration, normal penetration and cleavage rates) were studied in a total of 56 IVF replicates. Moderate correlation coefficients between some sperm parameters and IVF outcome were observed. In addition, stepwise multiple regression analyses were conducted that considered three grouping of sperm parameters as potential explanatory variables of the three IVF outcome criteria. The proportion of IVF outcome variation that can be explained by the fitted models ranged from 0.62 to 0.86, depending upon the trait analysed and the variables considered. Seven out of 32 sperm parameters were selected as partial covariates in at least one of the nine multiple regression models. Among these, progressive sperm motility assessed immediately after swim-up, the percentage of dead sperm with intact acrosome and the incidence of acrosome reaction both determined just before the gamete co-culture, and finally the proportion of viable spermatozoa at 17 h post-insemination were the most frequently selected sperm parameters. Nevertheless, the predictive ability of these models must be confirmed in a larger sample size experiment.

Hydrodynamic context for considering turbulence impacts on external fertilization.

PubMed

Gaylord, Brian

2008-06-01

Wave-swept shores in the marine environment are characterized by turbulent water motion. This turbulence influences external fertilization in benthic organisms by diluting gametes and producing hydrodynamic shear that is believed to have the capacity to disrupt egg-sperm interaction. However, although turbulence levels associated with decreases in fertilization due to this latter process (shear) have been identified in the laboratory, estimates of the intensities of turbulence in intertidal habitats have been based primarily on scaling arguments of limited precision and unknown accuracy. In the present study, values of energy dissipation rate (a standard measure of the strength of turbulence) were determined for three locations in the surf zone of a rocky shore. These measurements suggest a potential correspondence between threshold levels of turbulence that impair the ability of sperm to fertilize eggs, and actual intensities of turbulence arising in nature.

Sexual rest and post-meiotic sperm ageing in house mice.

PubMed

Firman, R C; Young, F J; Rowe, D C; Duong, H T; Gasparini, C

2015-07-01

Fertilization by aged sperm can result in adverse fitness consequences for both males and females. Sperm storage during male sexual rest could provide an environment for post-meiotic sperm senescence causing a deterioration in the quality of stored sperm, possibly impacting on both sperm performance (e.g. swimming ability) and DNA quality. Here, we compared the proportion of sperm with fragmented DNA, an indicator of structural damage of DNA within the sperm cell, among males that had been sexually rested for approximately 2 months, to that of males that had mated recently. We found no evidence of intra-epididymal sperm DNA damage or any impairment in sperm performance, and consequently no evidence of post-meiotic sperm senescence. Our results suggest that male house mice are likely to possess mechanisms that function to ensure that their sperm reserves remain stocked with 'young', viable sperm during periods of sexual inactivity. We also discuss the possibility that our experimental design leads to no difference in the age of sperm among males from the two mating treatments. Post-meiotic sperm senescence is especially relevant under sperm competition. Thus, we sourced mice from populations that differed in their levels of post-copulatory sexual selection, enabling us to gain insight into how selection for higher sperm production influences the rate of sperm ageing and levels of DNA fragmentation. We found that males from the population that produced the highest number of sperm also had the smallest proportion of DNA-fragmented sperm and discuss this outcome in relation to selection acting upon males to ensure that they produce ejaculates with high-quality sperm that are successful in achieving fertilizations under competitive conditions. © 2015 European Society For Evolutionary Biology. Journal of Evolutionary Biology © 2015 European Society For Evolutionary Biology.

Relationship between phospholipase C-zeta, semen parameters, and chromatin status.

PubMed

Tavalaee, Marziyeh; Kiani-Esfahani, Abbas; Nasr-Esfahani, Mohammad H

2017-08-01

The need for additional tests to complement basic sperm analysis in clinics is well appreciated. In this regard, a number of tests such as sperm DNA integrity test as a tool in diagnosis and treatment of infertility are suggested. But recent studies have focused on main sperm factors involved in oocyte activation such as phospholipase C-zeta (PLCζ) that initiate intracellular Ca 2+ signaling and embryogenesis. Therefore, this study aimed to investigate the relationship between PLCζ, basic semen parameters, sperm DNA fragmentation (SDF), and protamine deficiency in men with normal (n=32) and abnormal (n=23) semen parameters. Unlike SDF and protamine deficiency, as negative factors related to fertility, the mean value of PLCζ as positive factor related to infertility was significantly lower in men with abnormal semen parameters compared to men with normal semen parameters. Significant correlations were also observed between sperm concentration, motility, and abnormal morphology with the percentage of PLCζ positive spermatozoa. In addition, logistic regression analysis revealed that sperm morphology is more predictive than sperm motility and concentration for PLCζ presence. In addition, a statistically significant negative relationship was observed between the percentage of PLCζ positive spermatozoa and SDF. These findings suggested during ICSI, selection of sperm based on morphology has a profound effect on its ability to induce oocyte activation based on the likelihood of PLCζ expression. Therefore, assessment of PLCζ as an index for fertilization potential of a semen sample in men with severe teratozoospermia may define individuals who are candidates for artificial oocyte activation (AOA) and may avoid failed fertilization post ICSI.

Inhibiting Sperm Pyruvate Dehydrogenase Complex and Its E3 Subunit, Dihydrolipoamide Dehydrogenase Affects Fertilization in Syrian Hamsters

PubMed Central

Sailasree, Purnima; Singh, Durgesh K.; Kameshwari, Duvurri B.; Shivaji, Sisinthy

2014-01-01

Background/Aims The importance of sperm capacitation for mammalian fertilization has been confirmed in the present study via sperm metabolism. Involvement of the metabolic enzymes pyruvate dehydrogenase complex (PDHc) and its E3 subunit, dihydrolipoamide dehydrogenase (DLD) in hamster in vitro fertilization (IVF) via in vitro sperm capacitation is being proposed through regulation of sperm intracellular lactate, pH and calcium. Methodology and Principal Findings Capacitated hamster spermatozoa were allowed to fertilize hamster oocytes in vitro which were then assessed for fertilization, microscopically. PDHc/DLD was inhibited by the use of the specific DLD-inhibitor, MICA (5-methoxyindole-2-carboxylic acid). Oocytes fertilized with MICA-treated (MT) [and thus PDHc/DLD-inhibited] spermatozoa showed defective fertilization where 2nd polar body release and pronuclei formation were not observed. Defective fertilization was attributable to capacitation failure owing to high lactate and low intracellular pH and calcium in MT-spermatozoa during capacitation. Moreover, this defect could be overcome by alkalinizing spermatozoa, before fertilization. Increasing intracellular calcium in spermatozoa pre-IVF and in defectively-fertilized oocytes, post-fertilization rescued the arrest seen, suggesting the role of intracellular calcium from either of the gametes in fertilization. Parallel experiments carried out with control spermatozoa capacitated in medium with low extracellular pH or high lactate substantiated the necessity of optimal sperm intracellular lactate levels, intracellular pH and calcium during sperm capacitation, for proper fertilization. Conclusions This study confirms the importance of pyruvate/lactate metabolism in capacitating spermatozoa for successful fertilization, besides revealing for the first time the importance of sperm PDHc/ DLD in fertilization, via the modulation of sperm intracellular lactate, pH and calcium during capacitation. In addition, the observations made in the IVF studies in hamsters suggest that capacitation failures could be a plausible cause of unsuccessful fertilization encountered during human assisted reproductive technologies, like IVF and ICSI. Our studies indicate a role of sperm capacitation in the post-penetration events during fertilization. PMID:24852961

Sea urchin fertilization in a warm, acidified and high pCO2 ocean across a range of sperm densities.

PubMed

Byrne, Maria; Soars, Natalie; Selvakumaraswamy, Paulina; Dworjanyn, Symon A; Davis, Andrew R

2010-05-01

Marine invertebrate gametes are being spawned into an ocean simultaneously warming, acidifying and increasing in pCO(2). Decreased pH/increased pCO(2) narcotizes sperm indicating that acidification may impair fertilization, exacerbating problems of sperm limitation, with dire implications for marine life. In contrast, increased temperature may have a stimulatory effect, enhancing fertilization. We investigated effects of ocean change on sea urchin fertilization across a range of sperm densities. We address two predictions: (1) low pH/increased pCO(2) reduces fertilization at low sperm density and (2) increased temperature enhances fertilization, buffering negative effects of acidification and increased pCO(2). Neither prediction was supported. Fertilization was only affected by sperm density. Increased acidification and pCO(2) did not reduce fertilization even at low sperm density and increased temperature did not enhance fertilization. It is important to identify where vulnerabilities lie across life histories and our results indicate that sea urchin fertilization is robust to climate change stressors. However, developmental stages may be vulnerable to ocean change. Copyright 2009 Elsevier Ltd. All rights reserved.

[Phosphatidylserine externalization and functional-morphological impairment of sperm in men with long barren marriage].

PubMed

Ploskonos, M V

2016-08-01

To identify the relationship between phosphatidylserine externalization, as an early marker of apoptosis, and functional and morphological sperm impairment in infertile men to subsequently evaluate the effect of apoptosis on sperm fertility. Ejaculates of 18 fertile and 78 subfertile men were examined. Phosphatidylserine externalization was detected by staining the sperm with fluorochrome conjugated Annexin V (AnV-FITC) and propidium iodide using fluorescence microscopy. and conclusions: Ejaculates of fertile and subfertile men differed in the percentage of annexin-V-positive sperm. The correlation of (AnV+/PI+) - sperm of subfertile men with sperm concentration, motility and defects of sperm morphology shows the adverse effects of apoptosis on sperm quality and suggests that phosphatidylserine externalization is a factor for reducing sperm fertility.

Identification Male Fertility Through Abnormalities Sperm Based Morphology (Teratospermia) using Invariant Moment Method

NASA Astrophysics Data System (ADS)

Syahputra, M. F.; Chairani, R.; Seniman; Rahmat, R. F.; Abdullah, D.; Napitupulu, D.; Setiawan, M. I.; Albra, W.; Erliana, C. I.; Andayani, U.

2018-03-01

Sperm morphology is still a standard laboratory analysis in diagnosing infertility in men. Manually identification of sperm form is still not accurate, the difficulty in seeing the form of the invisible sperm from the digital microscope image is often a weakness in the process of identification and takes a long time. Therefore, male fertility identification application system is needed Through sperm abnormalities based on sperm morphology (teratospermia). The method used is invariant moment method. This study uses 15 data testing and 20 data training sperm image. That the process of male fertility identification through sperm abnormalities based on sperm morphology (teratospermia) has an accuracy rate of 80.77%. Use of time to process Identification of male fertility through sperm abnormalities Based on sperm morphology (teratospermia) during 0.4369 seconds.

Consequences of uncontrolled cooling during sterlet (Acipenser ruthenus) sperm cryopreservation on post-thaw motility and fertilizing ability.

PubMed

Horokhovatskyi, Yevhen; Rodina, Marek; Asyabar, Hadiseh Dadras; Boryshpolets, Sergii; Dzyuba, Borys

2017-06-01

The significant influence of the number and position of fish sperm sample straws in uncontrolled cooling devices on post-thaw spermatozoa parameters, such as motility and fertilizing ability, is presented in this study. The two most popular uncontrolled cooling devices were used in this study: a Styrofoam box setup with a polystyrene floating raft on liquid nitrogen and the dry shipper setup with a straw holder. We tested the effect of different quantities of straws (6 or 60) placed on the polystyrene floating raft and the position of the straws in the holder (on the periphery or in the centre). Using these cooling methods, sperm of 10 male sterlets diluted with methanol containing cryoprotective medium was frozen. All temperature changes were recorded by a thermocouple inside the straw, and the thermogram intervals were analysed. Spermatozoa motility was evaluated by video microscopy with integrated computer-assisted sperm analysis software. Fertilization trials were conducted at a 10 5 spermatozoa/egg ratio. Post-thaw spermatozoa parameters, including the percent of motile spermatozoa, curvilinear velocity, velocity according to the smoothed path, linearity of track, beat-cross frequency and fertilization rate, were significantly decreased in the 60-straw floating raft setup in comparison to all of the other cooling methods. The freezing rate between -10 °C and -30 °C was significantly decreased by up to 18.6 ± 0.61 °C/min for the 60-straw floating raft setup in comparison to the other freezing conditions. Considering the above results, efforts to standardize cryopreservation protocols using uncontrolled cooling devices should take into account the amount of straws subjected to freezing. Copyright © 2017. Published by Elsevier Inc.

Does being overweight affect seminal variables in fertile men?

PubMed

Taha, Emad A; Sayed, Sohair K; Gaber, Hisham D; Abdel Hafez, Hatem K; Ghandour, Nagwa; Zahran, Asmaa; Mostafa, Taymour

2016-12-01

The effect of being overweight on seminal variables was assesed in 165 fertile men. Participants were divided into three groups: fertile men with normal body mass index (BMI) (18.5-24.9 kg/m 2 ), fertile overweight men (BMI 25-29.9 kg/m 2 ) and fertile obese men (BMI >30 kg/m 2 ). Medical history was taken, a clinical examination conducted. Semen analysis was undertaken and BMI measured. Seminal reactive oxygen species (ROS) was estimated by chemiluminescent assay, sperm vitality by the hypo-osmotic swelling test and sperm DNA fragmentation by propidium iodide staining with flowcytometry. Fertile obese men had significantly lower sperm concentration, progressive sperm motility and sperm normal morphology, with significantly higher seminal ROS and sperm DNA fragmentation compared with fertile normal-weight men and overweight men (all P < 0.05). BMI was negatively correlated with sperm concentration (r = -0.091; P = 0.014), progressive sperm motility (r = -0.697; P = 0.001), normal sperm morphology (r = -0.510; P = 0.001), sperm vitality (r = -0.586; P = 0.001), but positively correlated with sperm DNA fragmentation percentage (r = 0.799; P = 0.001) and seminal ROS (r = 0.673; P = 0.001). Increased BMI was found to affect semen parameters negatively even in fertile men. Copyright © 2016 Reproductive Healthcare Ltd. Published by Elsevier Ltd. All rights reserved.

Rooster semen cryopreservation: effect of pedigree line and male age on postthaw sperm function.

PubMed

Long, J A; Bongalhardo, D C; Pelaéz, J; Saxena, S; Settar, P; O'Sullivan, N P; Fulton, J E

2010-05-01

The fertility rates of cryopreserved poultry semen are highly variable and not reliable for use in preservation of commercial genetic stocks. Our objective was to evaluate the cryosurvival of semen from 8 pedigreed layer lines at 2 different ages: the onset and end of commercial production. Semen from 160 roosters (20/line) was frozen individually with 11% glycerol at 6 and 12 mo of age. Glycerol was removed from thawed semen by Accudenz gradient centrifugation. The viability of thawed sperm from each male was determined using fluorescent live-dead staining and flow cytometry; sperm velocity parameters were measured using computerized motion analysis. The fertilizing ability of thawed sperm was evaluated in vitro by assessing hydrolysis of the inner perivitelline membrane. The postthaw function of sperm from the elite lines varied widely, despite the fact that fresh semen from all of these lines typically yielded high fertility rates. The percentage of thawed sperm with intact plasma membranes ranged from 27.8 + or - 2.1 to 49.6 + or - 1.9 and varied among lines and between age groups. Thawed sperm from 2 lines consistently demonstrated the highest and lowest motility parameters, whereas the velocity parameters of the remaining 6 lines varied widely. The mean number of hydrolysis points per square millimeter of inner perivitelline membrane ranged from 12.5 + or - 4.1 (line 2) to 103.3 + or - 30.2 (line 6). Age effects were observed for 4 out of 8 lines; however, improved postthaw sperm function at 12 mo of age was not consistent for all 3 assays. These results demonstrate variability among pedigreed lines in withstanding glycerol-based semen cryopreservation and provide a model for delineating genotypic and phenotypic factors affecting sperm cryosurvival.

In Vitro Measures for Assessing Boar Semen Fertility.

PubMed

Jung, M; Rüdiger, K; Schulze, M

2015-07-01

Optimization of artificial insemination (AI) for pig production and evaluation of the fertilizing capacity of boar semen are highly related. Field studies have demonstrated significant variation in semen quality and fertility. The semen quality of boars is primarily affected by breed and season. AI centres routinely examine boar semen to predict male fertility. Overall, the evaluation of classical parameters, such as sperm morphology, sperm motility, sperm concentration and ejaculate volume, allows the identification of ejaculates corresponding to poor fertility but not high-efficiency prediction of field fertility. The development of new sperm tests for measuring certain sperm functions has attempted to solve this problem. Fluorescence staining can categorize live and dead spermatozoa in the ejaculate and identify spermatozoa with active mitochondria. Computer-assisted semen analysis (CASA) provides an objective assessment of multiple kinetic sperm parameters. However, sperm tests usually assess only single factors involved in the fertilization process. Thus, basing prediction of fertilizing capacity on a selective collection of sperm tests leads to greater accuracy than using single tests. In the present brief review, recent diagnostic laboratory methods that directly relate to AI performance as well as the development of a new boar fertility in vitro index are discussed. © 2015 Blackwell Verlag GmbH.

Human sperm degradation of zona pellucida proteins contributes to fertilization.

PubMed

Saldívar-Hernández, Analilia; González-González, María E; Sánchez-Tusié, Ana; Maldonado-Rosas, Israel; López, Pablo; Treviño, Claudia L; Larrea, Fernando; Chirinos, Mayel

2015-09-02

The mammalian oocyte extracellular matrix known as the zona pellucida (ZP) acts as a barrier to accomplish sperm fusion with the female gamete. Although penetration of the ZP is a limiting event to achieve fertilization, this is one of the least comprehended stages of gamete interaction. Even though previous studies suggest that proteases of sperm origin contribute to facilitate the passage of sperm through the ZP, in human this process is not yet fully understood. The aim of this study was to determine the ability of human sperm to degrade recombinant human ZP (rhZPs) proteins and to characterize the proteases involved in this process. Purified rhZP2, rhZP3 and rhZP4 proteins were incubated with capacitated sperm and the proteolytic activity was determined by Western blot analysis. To further characterize the proteases involved, parallel incubations were performed in the presence of the protease inhibitors o-phenanthroline, benzamidine and MG-132 meant to block the activity of metalloproteases, serine proteases and the proteasome, respectively. Additionally, protease inhibitors effect on sperm-ZP binding was evaluated by hemizona assay. The results showed that rhZPs were hydrolyzed in the presence of capacitated sperm. O-phenanthroline inhibited the degradation of rhZP3, MG-132 inhibited the degradation of rhZP4 and benzamidine inhibited the degradation of the three proteins under investigation. Moreover, hemizona assays demonstrated that sperm proteasome inhibition impairs sperm interaction with human native ZP. This study suggests that sperm proteasomes could participate in the degradation of ZP, particularly of the ZP4 protein. Besides, metalloproteases may be involved in specific degradation of ZP3 while serine proteases may contribute to unspecific degradation of the ZP. These findings suggest that localized degradation of ZP proteins by sperm is probably involved in ZP penetration and may be of help in understanding the mechanisms of fertilization in humans.

Factors impacting couples' decision-making between vasectomy reversal versus sperm retrieval/in vitro fertilization/intracytoplasmic sperm injection.

PubMed

Kavoussi, P K; Kavoussi, K M; Odenwald, K C; Kavoussi, S K

2018-04-02

The purpose of this study was to identify factors which impact a couples' decision-making between the options of vasectomy reversal vs. sperm retrieval/in vitro fertilization/intracytoplasmic sperm injection when counseled both by a reproductive urologist and a reproductive endocrinologist. A retrospective chart review was performed of couples who wish to achieve a pregnancy with a male partner with a history of prior vasectomy, in a couples' private fertility center. Of patients presenting for fertility options with a history of vasectomy, 175 couples elected to be counseled by both a reproductive urologist and a reproductive endocrinologist on the options between vasectomy reversal and sperm retrieval/in vitro fertilization/intracytoplasmic sperm injection, with 78.3% of the couples opting for vasectomy reversal and 21.7% opting for sperm retrieval/in vitro fertilization/intracytoplasmic sperm injection. The overall mean age of the male partners was 40.5 years of age, and the mean age of the female partners was 33. The mean obstructed interval was 9.7 years. Twenty-three percent of the female partners in couples selecting vasectomy reversal had diminished ovarian reserve, and 31.6% of couples selecting sperm retrieval/in vitro fertilization/intracytoplasmic sperm injection had female partners with diminished ovarian reserve, two of which elected to have donor oocyte in vitro fertilization/intracytoplasmic sperm injection. Male age, female age, and ovarian reserve status did not have significant roles in this decision-making (p value 0.3578, 0.1185, and 0.3041, respectively); however, a longer obstructed interval since vasectomy was a significant factor associated with couples opting for sperm retrieval/in vitro fertilization/intracytoplasmic sperm injection (0.0238). In this study, the majority of couples who were counseled on vasectomy reversal vs. sperm retrieval/in vitro fertilization/intracytoplasmic sperm injection by a reproductive urologist and reproductive endocrinologist chose vasectomy reversal. Neither male partner age, female partner age, nor ovarian reserve status seemed to impact the decision; however, a longer obstructed interval was a significant factor that was associated with the decision of couples toward sperm retrieval/in vitro fertilization/intracytoplasmic sperm injection rather than vasectomy reversal. © 2018 The Authors. Andrology published by John Wiley & Sons Ltd on behalf of American Society of Andrology and European Academy of Andrology.

Cryopreservation and ensuing in vitro fertilization ability of boar spermatozoa from epididymides stored at 4 degrees C.

PubMed

Kikuchi, K; Nagai, T; Kashiwazaki, N; Ikeda, H; Noguchi, J; Shimada, A; Soloy, E; Kaneko, H

1998-09-01

The influence of prolonged storage of boar epididymides on post-thaw sperm motility, and in vitro fertilization was evaluated. Twenty pairs of epididymides were obtained from Large White boars, and spermatozoa from one of each of the pairs were immediately collected and frozen (control group). The remaining epididymides were cooled to 4 degrees C and stored for 1, 2 or 3 d, after which spermatozoa were collected and frozen (experimental groups Day 1, 2 and 3, respectively). Sperm motility was maintained throughout the dilution procedure and then dropped (P < 0.01) after freezing and thawing. During storage the motility of nonfrozen spermatozoa decreased significantly (P < 0.01), reaching a value equal to that of frozen-thawed spermatozoa on Day 3. In vitro fertilization experiments revealed significantly (P < 0.05) lower penetration rates using Day 1, 2 and 3 stored spermatozoa (12, 13 and 2%, respectively) than that of the control group (40%). Oocyte penetration ability seemed to be reflected by acrosome integrity. However, the motility of spermatozoa with the ability to penetrate oocytes in Day 1 and Day 2 groups did not differ from that of the controls. The motility of spermatozoa lacking penetration ability, on the other hand, gradually decreased as the storage period was prolonged. This suggests that the sperm motility and penetration ability are affected by different mechanisms during the cold storage of epididymides. Finally, control and experimental groups exhibited high incidences of monospermic penetration (64 to 90%) and of male pronuclear formation (67 to 71%). These data suggest that cryopreservation of spermatozoa from boar epididymides stored at 4 degrees C for 1 to 2 d can be used for conserving male germ cells when epididymal spermatozoa can not be collected immediately and cryopreserved.

Do sperm possess a molecular passport? Mechanistic insights into sperm selection in the female reproductive tract.

PubMed

Holt, William V; Fazeli, Alireza

2015-06-01

Most male mammals produce far more spermatozoa on a daily basis than is strictly necessary for reproduction and females have evolved mechanisms that prevent all but a small minority from reaching the vicinity of their oocytes. One potential explanation for the stringent selection is that females have developed these mechanisms as a way of avoiding polyspermy as well as exercising post-copulatory choice over the characteristics of the fertilizing spermatozoon. Relatively little is known about how these processes would operate, but here we use evidence from biochemical, molecular and genetic studies of sperm transport in support of a hypothesis proposing that the female reproductive tract can read and interpret a spermatozoon's 'molecular passport' or genetic signature. Such a signature would permit only a highly selected sperm population to reach and fertilize the oocyte. Moreover, the selection criteria might not only be concerned with successful fertilizing ability, but could also be tailored to suit the genetic qualities of individual females. © The Author 2015. Published by Oxford University Press on behalf of the European Society of Human Reproduction and Embryology. All rights reserved. For Permissions, please email: journals.permissions@oup.com.

Sub-fertile sperm cells exemplify telomere dysfunction.

PubMed

Biron-Shental, Tal; Wiser, Amir; Hershko-Klement, Anat; Markovitch, Ofer; Amiel, Aliza; Berkovitch, Arie

2018-01-01

The purpose of this study was to evaluate telomere homeostasis in sub-fertile compared to fertile human sperm. This observational, comparative study included 16 sub-fertile men who required intracytoplasmic sperm injection and 10 fertile men. At least 100 sperm cells from each participant were assessed. Main outcome measures were telomere length and telomere aggregates. Telomerase RNA component (TERC) copy number and telomere capture were assessed using fluorescence in situ hybridization technique and human telomerase reverse transcriptase (hTERT) using immunohistochemistry. Clinical backgrounds were similar. The percentage of sperm cells with shorter telomeres was higher among the sub-fertile compared to the fertile participants (3.3 ± 3.1 vs. 0.6 ± 1.2%, respectively; P < 0.005). The percentage of cells with telomere aggregates was significantly higher in the sub-fertile group (15.12 ± 3.73 vs. 4.73 ± 3.73%; P < 0.005). TERC gene copy number was similar between groups. The percentage of cells that were positive for hTERT was lower in the sub-fertile group (3.81 ± 1.27 vs. 8.42 ± 1.80%; P < 0.005). Telomere capture rates were higher among the sub-fertile sperm cells (P < 0.005). Sub-fertile sperm cells have short telomeres that are elongated by the alternative pathway of telomere capture. Dysfunctional telomeres may affect sperm fertilizability.

Sexual selection for genetic compatibility: the role of the major histocompatibility complex on cryptic female choice in Chinook salmon (Oncorhynchus tshawytscha)

PubMed Central

Gessner, C; Nakagawa, S; Zavodna, M; Gemmell, N J

2017-01-01

Cryptic female choice (CFC), a form of sexual selection during or post mating, describes processes of differential sperm utilization by females to bias fertilization outcomes towards certain males. In Chinook salmon (Oncorhynchus tshawytscha) the ovarian fluid surrounding the ova of a given female differently enhances the sperm velocity of males. Sperm velocity is a key ejaculate trait that determines fertilization success in externally fertilizing fishes, thus the differential effect on sperm velocity might bias male fertilization outcomes and represent a mechanism of CFC. Once sperm reach the oocyte, CFC could potentially be further facilitated by sperm–egg interactions, which are well understood in externally fertilizing marine invertebrates. Here, we explored the potential genetic basis of both possible mechanisms of CFC by examining whether the genotypic combinations of mates (amino-acid divergence, number of shared alleles) at the major histocompatibility complex (MHC) class I and II explain the variation in sperm velocity and/or male fertilization success that is not explained by sperm velocity, which might indicate MHC-based sperm–egg interactions. We recorded sperm velocity in ovarian fluid, employed paired-male fertilization trials and evaluated the fertilization success of each male using microsatellite-based paternity assignment. We showed that relative sperm velocity was positively correlated with fertilization success, confirming that the differential effect on sperm velocity may be a mechanism of CFC in Chinook salmon. The variation in sperm velocity was independent of MHC class I and II. However, the MHC class II divergence of mates explained fertilization success, indicating that this locus might influence sperm–egg interactions. PMID:28051059

Zebrafish reproduction: revisiting in vitro fertilization to increase sperm cryopreservation success.

PubMed

Hagedorn, Mary; Carter, Virginia L

2011-01-01

Although conventional cryopreservation is a proven method for long-term, safe storage of genetic material, protocols used by the zebrafish community are not standardized and yield inconsistent results, thereby putting the security of many genotypes in individual laboratories and stock centers at risk. An important challenge for a successful zebrafish sperm cryopreservation program is the large variability in the post-thaw in vitro fertilization success (0 to 80%). But how much of this variability was due to the reproductive traits of the in vitro fertilization process, and not due to the cryopreservation process? These experiments only assessed the in vitro process with fresh sperm, but yielded the basic metrics needed for successful in vitro fertilization using cryopreserved sperm, as well. We analyzed the reproductive traits for zebrafish males with a strict body condition range. It did not correlate with sperm volume, or motility (P>0.05), but it did correlate with sperm concentration. Younger males produced more concentrated sperm (P<0.05). To minimize the wastage of sperm during the in vitro fertilization process, 10(6) cells/ml was the minimum sperm concentration needed to achieve an in vitro fertilization success of ≥ 70%. During the in vitro process, pooling sperm did not reduce fertilization success (P>0.05), but pooling eggs reduced it by approximately 30 to 50% (P<0.05). This reduction in fertilization success was due not to the pooling of the females' eggs, but to the type of tools used to handle the eggs. Recommendations to enhance the in vitro process for zebrafish include: 1) using males of a body condition closer to 1.5 for maximal sperm concentration; 2) minimizing sperm wastage by using a working sperm concentration of 10(6) motile cells/ml for in vitro fertilization; and 3) never using metal or sharp-edged tools to handle eggs prior to fertilization.

Zebrafish Reproduction: Revisiting In Vitro Fertilization to Increase Sperm Cryopreservation Success

PubMed Central

Hagedorn, Mary; Carter, Virginia L.

2011-01-01

Although conventional cryopreservation is a proven method for long-term, safe storage of genetic material, protocols used by the zebrafish community are not standardized and yield inconsistent results, thereby putting the security of many genotypes in individual laboratories and stock centers at risk. An important challenge for a successful zebrafish sperm cryopreservation program is the large variability in the post-thaw in vitro fertilization success (0 to 80%). But how much of this variability was due to the reproductive traits of the in vitro fertilization process, and not due to the cryopreservation process? These experiments only assessed the in vitro process with fresh sperm, but yielded the basic metrics needed for successful in vitro fertilization using cryopreserved sperm, as well. We analyzed the reproductive traits for zebrafish males with a strict body condition range. It did not correlate with sperm volume, or motility (P>0.05), but it did correlate with sperm concentration. Younger males produced more concentrated sperm (P<0.05). To minimize the wastage of sperm during the in vitro fertilization process, 106 cells/ml was the minimum sperm concentration needed to achieve an in vitro fertilization success of ≥ 70%. During the in vitro process, pooling sperm did not reduce fertilization success (P>0.05), but pooling eggs reduced it by approximately 30 to 50% (P<0.05). This reduction in fertilization success was due not to the pooling of the females' eggs, but to the type of tools used to handle the eggs. Recommendations to enhance the in vitro process for zebrafish include: 1) using males of a body condition closer to 1.5 for maximal sperm concentration; 2) minimizing sperm wastage by using a working sperm concentration of 106 motile cells/ml for in vitro fertilization; and 3) never using metal or sharp-edged tools to handle eggs prior to fertilization. PMID:21698162

Spermatozoal traits and sperm competition in Atlantic salmon: relative sperm velocity is the primary determinant of fertilization success.

PubMed

Gage, Matthew J G; Macfarlane, Christopher P; Yeates, Sarah; Ward, Richard G; Searle, Jeremy B; Parker, Geoffrey A

2004-01-06

Sperm competition occurs when sperm from more than one male compete for fertilizations. This form of post-copulatory sexual selection is recognized as a significant and widespread force in the evolution of male reproductive biology and as a key determinant of differential male reproductive success. Despite its importance, however, detailed mechanisms of sperm competition at the gamete level remain poorly understood. Here, we use natural variation in spermatozoal traits among wild Atlantic salmon (Salmo salar), a species naturally adapted to sperm competition, to examine how the relative influences of sperm (i) number, (ii) velocity, (iii) longevity, and (iv) total length determine sperm competition success. Atlantic salmon fertilize externally, and we were therefore able to conduct controlled in vitro fertilization competitions while concurrently measuring spermatozoal traits within the aqueous micro-environment to which salmon gametes are naturally adapted. Microsatellite DNA fingerprinting revealed that a male's relative sperm velocity was the primary determinant of sperm competition success. There was no significant relationship between fertilization success and either relative sperm number or total length; sperm longevity showed an inverse relationship with competition success. These relationships were consistent for two experimental repeats of the in vitro fertilization competitions. Our results therefore show, under the natural microenvironment for salmon gametes, that relative sperm velocity is a key spermatozoal component for sperm competition success. Atlantic salmon sperm can be considered to enter a competition analogous to a race in which the fastest sperm have the highest probability of success.

Antisperm antibodies and fertility association.

PubMed

Restrepo, B; Cardona-Maya, W

2013-10-01

To evaluate the relation between antisperm antibodies (ASA) and human fertility by reviewing the scientific literature of the last 45 years. We carried out a review of scientific literature about antisperm antibodies and infertility published in spanish or english in databases as Pubmed, Medline, Scielo, some books and another gray literature include information related to this review and that is published in the last 45 years. Infertile couples suffer infertility by immunological mechanisms mainly by the presence of antisperm antibodies ASA in blood, semen or cervicovaginal secretions; the formation of ASA in men and women may be associated with disturbance in immunomodulatory mechanisms that result in functional impairment of sperm and thus its inability to fertilize the oocyte. Immunological infertility caused by ASA is the result of interference of these antibodies in various stages of fertilization process, inhibiting the ability of interaction between sperm and oocyte. Copyright © 2012 AEU. Published by Elsevier Espana. All rights reserved.

Sperm cryopreservation update: Cryodamage, markers, and factors affecting the sperm freezability in pigs.

PubMed

Yeste, Marc

2016-01-01

Cryopreservation is the most efficient method for long-term preservation of mammalian sperm. However, freeze-thawing procedures may strongly impair the sperm function and survival and thus decrease the reproductive performance. In addition, the sperm resilience to withstand cryopreservation, also known as freezability, presents a high individual variability. The present work summarizes the principles of cryoinjury and the relevance of permeating and nonpermeating cryoprotective agents. Descriptions about sperm cryodamage are mainly focused on boar sperm, but reference to other mammalian species is also made when relevant. Main cryoinjuries not only regard to sperm motility and membrane integrity, but also to the degradation effect exerted by freeze-thawing on other important components for sperm fertilizing ability, such as mRNAs. After delving into the main differences between good and poor freezability boar ejaculates, those protein markers predicting the sperm ability to sustain cryopreservation are also mentioned. Moreover, factors that may influence sperm freezability, such as season, diet, breed, or ejaculate fractions are discussed, together with the effects of different additives, like seminal plasma and antioxidants. After briefly referring to the effects of long-term sperm preservation in frozen state and the reproductive performance of frozen-thawed boar sperm, this work speculates with new research horizons on the preservation of boar sperm, such as vitrification and freeze-drying. Copyright © 2016 Elsevier Inc. All rights reserved.

Sperm count. Do we need a new reference value?

PubMed

Cardona Maya, Walter

2010-03-01

To evaluate the sperm count in fertile men, general population, and infertile men in different regions of the world. Sperm counts were recorded according to their fertility status, proven fertility, men recruited from an andrology/infertility clinic, or healthy men. The average of sperm count in the different studies is lower in infertile men that in fertile men (p>0.001) and in the general population (p>0.001). Based on this analysis the normal sperm count is about 65 million per mL. Using these reference value, only the 25% of the studies in infertile men are above this value, and the 75% studies with fertile men (>65 x 106 sperm/mL).

The osmotic tolerance of boar spermatozoa and its usefulness as sperm quality parameter.

PubMed

Yeste, Marc; Briz, Mailo; Pinart, Elisabeth; Sancho, Sílvia; Bussalleu, Eva; Bonet, Sergi

2010-06-01

Predicting the fertility outcome of ejaculates is very important in the field of porcine reproduction. The aims of this study were to determine the effects of different osmotic treatments on boar spermatozoa and to correlate them with fertility and prolificacy, assessed as non-return rates within 60 days (NRR(60d)) of the first inseminations, and litter size (LS), respectively. Sperm samples (n=100) from one hundred healthy Piétrain boars were used to assess 48 treatments combining different osmolalities (ranged between 100 and 4000 mOsm kg(-1)), different compounds used to prepare anisotonic solutions, and two different modalities: return and non-return to isotonic conditions. Sperm quality was evaluated before and after applying the treatments on the basis of analyses of sperm viability, motility, morphology and percentages of acrosome-intact spermatozoa. Statistical analyses were performed using a one-way ANOVA and post hoc Tukey's test, linear regression analyses (Pearson correlation and multiple regression) and Jackknife cross-validation. Although three conventional parameters: sperm viability, sperm morphology and the percentages of acrosome-intact spermatozoa were significantly correlated with NRR(60d) and with LS, their respective osmotic tolerance parameters (defined for each parameter and treatment regarding with negative control) presented a higher Pearson coefficient with both fertility and prolificacy in three treatments (150 mOsm kg(-1) with non-return to isotonic conditions, 200 mOsm kg(-1) with return and 500 mOsm kg(-1) using sodium citrate and non-return to isotonic conditions). We conclude that osmotic resistance in sperm viability, sperm morphology and acrosome-intactness in the treatments mentioned above could be assessed along with classical parameters to better predict the fertilising ability of a given ejaculate. Copyright (c) 2010 Elsevier B.V. All rights reserved.

Sperm preparation through Sephadex™ filtration improves in vitro fertilization rate of buffalo oocytes.

PubMed

Husna, A U; Azam, A; Qadeer, S; Awan, M A; Nasreen, S; Shahzad, Q; Fouladi-Nashta, A; Khalid, M; Akhter, S

2018-04-01

Routinely, swim-up method is used to separate high-quality sperm; however, long processing time and close cell-to-cell contact during the centrifugation step are inevitable elements of oxidative stress to sperm. The objective was to evaluate Sephadex ™ and glass wool filtration to separate motile, intact and viable sperm for in vitro fertilization in buffalo. The cumulus-oocyte complexes (COCs) were collected from ovaries of slaughtered buffaloes by aspiration and matured for 24 hr in CO 2 incubator at 38.5°C and 5% CO 2 . Matured COCs were rinsed twice in fertilization TALP and placed in the pre-warmed fertilization medium without sperm. Cryopreserved buffalo semen was thawed at 37°C for 30 s and processed through Sephadex ™ , glass wool filtration and swim-up (control). Total and motile sperm recovery rates were assessed, resuspended in fertilization TALP and incubated for 15-20 min in CO 2 incubator. Samples prepared by each method were divided into two aliquots: one aliquot was studied for sperm quality (progressive motility, membrane integrity, viability, liveability), while the other was subjected to co-incubation with sets of 10-15 in vitro matured oocytes. Data on sperm quality were analysed by ANOVA, while in vitro fertilizing rates were compared by chi-squared test using SPSS-20. Least significant difference (LSD) test was used to compare treatment means. Glass wool filtration yielded higher total and motile sperm recovery rate, while Sephadex ™ filtration improved (p < .05) sperm quality (progressive motility, membrane integrity, viability, liveability). Sperm preparation through Sephadex filtration yielded higher in vitro fertilization rate in terms of cleavage rate compared to glass wool filtration and swim-up (control). In conclusion, cryopreserved Nili-Ravi buffalo sperm selected through Sephadex filtration showed improved quality and yielded better fertilization rates (cleavage rate) of in vitro matured/fertilized oocytes. Sephadex filtration could be a promising technique for use in in vitro fertilization in buffalo. © 2017 Blackwell Verlag GmbH.

Variation in sperm displacement and its association with accessory gland protein loci in Drosophila melanogaster.

PubMed

Clark, A G; Aguadé, M; Prout, T; Harshman, L G; Langley, C H

1995-01-01

Genes that influence mating and/or fertilization success may be targets for strong natural selection. If females remate frequently relative to the duration of sperm storage and rate of sperm use, sperm displacement may be an important component of male reproductive success. Although it has long been known that mutant laboratory stocks of Drosophila differ in sperm displacement, the magnitude of the naturally occurring genetic variation in this character has not been systematically quantified. Here we report the results of a screen for variation in sperm displacement among 152 lines of Drosophilia melanogaster that were made homozygous for second and/or third chromosomes recovered from natural populations. Sperm displacement was assayed by scoring the progeny of cn;bw females that had been mated sequentially to cn;bw and tested males in either order. Highly significant differences were seen in both the ability to displace sperm that is resident in the female's reproductive tract and in the ability to resist displacement by subsequent sperm. Most lines exhibited nearly complete displacement, having nearly all progeny sired by the second male, but several lines had as few as half the progeny fathered by the second male. Lines that were identified in the screen for naturally occurring variation in sperm displacement were also characterized for single-strand conformation polymorphisms (SSCP) at seven accessory gland protein (Acp) genes, Glucose dehydrogenase (Gld), and Esterase-6 (Est-6). Acp genes encode proteins that are in some cases known to be transmitted to the female in the seminal fluid and are likely candidates for genes that might mediate the phenomenon of sperm displacement. Significant associations were found between particular Acp alleles at four different loci (Acp26Aa/Ab, Acp29B, Acp36DE and Acp53E) and the ability of males to resist displacement by subsequent sperm. There was no correlation between the ability to displace resident sperm and the ability to resist being displaced by subsequent sperm. This lack of correlation, and the association of Acp alleles with resisting subsequent sperm only, suggests that different mechanisms mediate the two components of sperm displacement.

A nonsemen copulatory fluid influences the outcome of sperm competition in Japanese quail.

PubMed

Finseth, F R; Iacovelli, S R; Harrison, R G; Adkins-Regan, E K

2013-09-01

Sperm competition is a powerful and widespread evolutionary force that drives the divergence of behavioural, physiological and morphological traits. Elucidating the mechanisms governing differential fertilization success is a fundamental question of sperm competition. Both sperm and nonsperm ejaculate components can influence sperm competition outcomes. Here, we investigate the role of a nonsemen copulatory fluid in sperm competition. Male Japanese quail possess a gland that makes meringue-like foam. Males produce and store foam independent of sperm and seminal fluid, yet transfer foam to females during copulation. We tested whether foam influenced the outcome of sperm competition by varying foam state and mating order in competitive matings. We found that the presence of foam from one male decreased the relative fertilization success of a rival, and that foam from a given male increased the probability he obtained any fertilizations. Mating order also affected competitive success. Males mated first fertilized proportionally more eggs in a clutch and had more matings with any fertilizations than subsequent males. We conclude that the function of foam in sperm competition is mediated through the positive interaction of foam with a male's sperm, and we speculate whether the benefit is achieved through improving sperm storage, fertilizing efficiency or retention. Our results suggest males can evolve complex strategies to gain fertilizations at the expense of rivals as foam, a copulatory fluid not required for fertilization, nevertheless, has important effects on reproductive performance under competition. © 2013 The Authors. Journal of Evolutionary Biology © 2013 European Society For Evolutionary Biology.

Reduced glutathione enhances fertility of frozen/thawed C57BL/6 mouse sperm after exposure to methyl-beta-cyclodextrin.

PubMed

Takeo, Toru; Nakagata, Naomi

2011-11-01

Sperm cryopreservation is useful for the effective storage of genomic resources derived from genetically engineered mice. However, freezing the sperm of C57BL/6 mice, the most commonly used genetic background for genetically engineered mice, considerably reduces its fertility. We previously reported that methyl-beta-cyclodextrin dramatically improved the fertility of frozen/thawed C57BL/6 mouse sperm. Recently, it was reported that exposing sperm to reduced glutathione may alleviate oxidative stress in frozen/thawed mouse sperm, thereby enhancing in vitro fertilization (IVF); however, the mechanism underlying this effect is poorly understood. In the present study, we examined the combined effects of methyl-beta-cyclodextrin and reduced glutathione on the fertilization rate of IVF with frozen/thawed C57BL/6 mouse sperm and the characteristic changes in the zona pellucida induced by reduced glutathione. Adding reduced glutathione to the fertilization medium increased the fertilization rate. Methyl-beta-cyclodextrin and reduced glutathione independently increased fertilization rates, and their combination produced the strongest effect. We found that reduced glutathione increased the amount of free thiols in the zona pellucida and promoted zona pellucida enlargement. Finally, 2-cell embryos produced by IVF with the addition of reduced glutathione developed normally and produced live offspring. In summary, we have established a novel IVF method using methyl-beta-cyclodextrin during sperm preincubation and reduced glutathione during the IVF procedure to enhance fertility of frozen/thawed C57BL/6 mouse sperm.

Relationship between conventional semen characteristics, sperm motility patterns and fertility of Andalusian donkeys (Equus asinus).

PubMed

Dorado, J; Acha, D; Ortiz, I; Gálvez, M J; Carrasco, J J; Díaz, B; Gómez-Arrones, V; Calero-Carretero, R; Hidalgo, M

2013-12-01

Sperm quality has an important role in determining fertility. The aims of this study were to compare the conventional sperm parameters, plus the characteristics of the motility patterns of the different sperm subpopulations, of donkey donors with different fertility level, and to determine their relationships to fertility. Thirty ejaculates from 6 Andalusian donkeys were assessed for gel-free volume, pH, sperm concentration, motility and morphology. The fertility of donkeys was classified on the basis of pregnancy rates per cycle, where donkeys with a per cycle pregnancy rate ≥60% were considered to be "fertile" (n=3) and those with a per cycle pregnancy rate <40% were categorized to be "sub-fertile" (n=3). Significant differences (P<0.001) between the "fertile" and the "sub-fertile" group were found for total and progressive motility, and for straight line velocity. Sperm variables associated (P<0.05) with an increase in percent pregnant per cycle included total motility (r=0.37), progressive motility (r=0.53), curvilinear velocity (r=0.44), straightness (r=0.39), beat cross frequency (r=0.44), and gel-free volume (r=0.53). Four sperm subpopulations (sP) were identified in fresh semen: sP1 (slow and non-progressive spermatozoa, 20%), sP2 (moderately slow but progressive spermatozoa, 71.2%), sP3 (highly active but non-progressive spermatozoa, 2.9%), and sP4 (highly active and progressive spermatozoa, 5.9%). The lowest percentage (3.1%; P<0.001) of sP4 spermatozoa was observed in the "sub-fertile" group. Three of the sperm subpopulations were related (P<0.05) to fertility (sP2, r=0.54; sP3, r=0.45; sP4, r=0.56). In conclusion, we were able to relate the fertility of donkeys with in vitro measures of sperm motility using computer-assisted sperm analysis techniques. Copyright © 2013 Elsevier B.V. All rights reserved.

Hit or Miss: Fertilization Outcomes of Natural Inseminations by Japanese Quail

PubMed Central

Adkins-Regan, Elizabeth

2015-01-01

Variation in fertilization success underlies sexual selection, yet mating does not guarantee fertilization. The relationship between natural inseminations and fertilization success is essential for understanding sexual selection, yet that relationship and its underlying mechanisms are poorly understood in sperm-storing vertebrates such as birds. Here the relationship is analyzed in mating trials using Japanese quail (Coturnix japonica), which show striking variation in the fertilizing success of inseminations. Failures of males’ inseminations to fertilize eggs were mainly due to failures prior to sperm-egg contact. Fertilization probabilities on any given day were unrelated to whether the female had laid an egg the previous day, arguing against stimulation of sperm release from sperm storage tubules by the events of the daily egg-laying cycle. Instead, an unfertilized egg laid between two fertilized eggs predicted a longer sperm storage interval. Both sexes gained similar numbers of fertilized eggs by mating with a second partner the next day, but males, unlike females in a previous study, did not gain by having two females to mate with at the same time. Instead, they were both behaviorally and sperm limited, whereas females gain by mating twice in quick succession. Even double inseminations often failed to fertilize any eggs, and multiple matings would be needed for an entire clutch to be fertilized with high certainty. Paradoxically, this low and probabilistic fertilization success co-occurs with other notable characteristics of male quail suggestive of past sexual selection for increased success, including vigorous copulatory behavior, forced copulations, foamy secretion aiding in sperm competition, large testes and unusual sperm morphology. PMID:26222780

The Sperm-surface glycoprotein, SGP, is necessary for fertilization in the frog, Xenopus laevis.

PubMed

Nagai, Keita; Ishida, Takuya; Hashimoto, Takafumi; Harada, Yuichirou; Ueno, Shuichi; Ueda, Yasushi; Kubo, Hideo; Iwao, Yasuhiro

2009-06-01

To identify a molecule involved in sperm-egg plasma membrane binding at fertilization, a monoclonal antibody against a sperm-surface glycoprotein (SGP) was obtained by immunizing mice with a sperm membrane fraction of the frog, Xenopus laevis, followed by screening of the culture supernatants based on their inhibitory activity against fertilization. The fertilization of both jellied and denuded eggs was effectively inhibited by pretreatment of sperm with intact anti-SGP antibody as well as its Fab fragment, indicating that the antibody recognizes a molecule on the sperm's surface that is necessary for fertilization. On Western blots, the anti-SGP antibody recognized large molecules, with molecular masses of 65-150 kDa and minor smaller molecules with masses of 20-28 kDa in the sperm membrane vesicles. SGP was distributed over nearly the entire surface of the sperm, probably as an integral membrane protein in close association with microfilaments. More membrane vesicles containing SGP bound to the surface were found in the animal hemisphere compared with the vegetal hemisphere in unfertilized eggs, but the vesicle-binding was not observed in fertilized eggs. These results indicate that SGP mediates sperm-egg membrane binding and is responsible for the establishment of fertilization in Xenopus.

Impact of the Z potential technique on reducing the sperm DNA fragmentation index, fertilization rate and embryo development.

PubMed

Duarte, Carlos; Núñez, Víctor; Wong, Yat; Vivar, Carlos; Benites, Elder; Rodriguez, Urso; Vergara, Carlos; Ponce, Jorge

2017-12-01

In assisted reproduction procedures, we need to develop and enhance new protocols to optimize sperm selection. The aim of this study is to evaluate the ability of the Z potential technique to select sperm with intact DNA in non-normospermic patients and evaluate the impact of this selection on embryonic development. We analyzed a total of 174 human seminal samples with at least one altered parameter. We measured basal, post density gradients, and post density gradients + Z potential DNA fragmentation index. To evaluate the impact of this technique on embryo development, 54 cases were selected. The embryo development parameters evaluated were fertilization rate, cleavage rate, top quality embryos at the third day and blastocysts rate. We found significant differences in the study groups when we compared the sperm fragmentation index by adding the Z potential technique to density gradient selection vs. density gradients alone. Furthermore, there was no significant difference in the embryo development parameters between the low sperm fragmentation index group vs. the moderate and high sperm fragmentation index groups, when selecting sperms with this new technique. The Z potential technique is a very useful tool for sperm selection; it significantly reduces the DNA fragmentation index and improves the parameters of embryo development. This technique could be considered routine for its simplicity and low cost.

Sperm competition, sperm numbers and sperm quality in muroid rodents.

PubMed

Gómez Montoto, Laura; Magaña, Concepción; Tourmente, Maximiliano; Martín-Coello, Juan; Crespo, Cristina; Luque-Larena, Juan José; Gomendio, Montserrat; Roldan, Eduardo R S

2011-03-25

Sperm competition favors increases in relative testes mass and production efficiency, and changes in sperm phenotype that result in faster swimming speeds. However, little is known about its effects on traits that contribute to determine the quality of a whole ejaculate (i.e., proportion of motile, viable, morphologically normal and acrosome intact sperm) and that are key determinants of fertilization success. Two competing hypotheses lead to alternative predictions: (a) sperm quantity and quality traits co-evolve under sperm competition because they play complementary roles in determining ejaculate's competitive ability, or (b) energetic constraints force trade-offs between traits depending on their relevance in providing a competitive advantage. We examined relationships between sperm competition levels, sperm quantity, and traits that determine ejaculate quality, in a comparative study of 18 rodent species using phylogenetically controlled analyses. Total sperm numbers were positively correlated to proportions of normal sperm, acrosome integrity and motile sperm; the latter three were also significantly related among themselves, suggesting no trade-offs between traits. In addition, testes mass corrected for body mass (i.e., relative testes mass), showed a strong association with sperm numbers, and positive significant associations with all sperm traits that determine ejaculate quality with the exception of live sperm. An "overall sperm quality" parameter obtained by principal component analysis (which explained 85% of the variance) was more strongly associated with relative testes mass than any individual quality trait. Overall sperm quality was as strongly associated with relative testes mass as sperm numbers. Thus, sperm quality traits improve under sperm competition in an integrated manner suggesting that a combination of all traits is what makes ejaculates more competitive. In evolutionary terms this implies that a complex network of genetic and developmental pathways underlying processes of sperm formation, maturation, transport in the female reproductive tract, and preparation for fertilization must all evolve in concert.

Therapeutic and fertility restoration effects of Ionidium suffruticosum on sub-fertile male albino Wistar rats: effects on testis and caudal spermatozoa.

PubMed

Chenniappan, Kuppusamy; Murugan, Kadarkari

2017-12-01

Ionidium suffruticosum (L.) Ging (Violaceae) is an important medicinal plant widely used as a herbal traditional medicine in Ayurveda for the treatment of infertility. Currently, little pharmacological information is available on its male fertility properties following prolonged use. To investigate I. suffruticosum leaf extracts for male fertility parameters. The ethanol lyophilized fraction was administered orally on carbendazim-induced sub-fertility rats (250 mg/kg body weight for 28 days). The effects of fractions on rat's fertility parameters i.e., body and testes weight, sperm motility, sperm vitality, epididymal sperm counts, its morphology, enzyme and antioxidant stress and histopathology were studied and compared with clomiphene citrate. The sub-fertile male rats treated with I. suffruticosum leaf extract increased the body weight of 7 g, testis weight of 97 mg, increased cauda epididymal sperm counts of 34.2 × 10 6 sperm/mL, motility of sperm 46% and vitality 28% also increased and normal sperm morphology also improved up to 32%. The carbendazim-treated group showed loss in body weight of 33 g, testis weight of 851 mg, decreased epididymal sperm counts of 15 × 10 6 sperm/mL, with sluggish motility and a highly significant fall in the live sperms of about 57%. The leaf fraction of I. suffructicosum increased the testicular weight, spermatogenesis, sperm counts, lessened sperm agglutination, and increased testicular oxidative biomarkers, SOD, and CAT. This study therefore supports the usage of I. suffructicosum in traditional medicine for infertility.

The role of sperm banking in fertility preservation.

PubMed

Olatunbosun, O A; Zhu, L

2012-01-01

To investigate factors that influence sperm banking before cancer therapy and assess the use and disposal of banked sperm after cancer treatment. Database exploratory study combined with questionnaire survey of a cohort of 55 men who cryopreserved their sperm at an Andrology Clinic. Rate of use, disposal and abandonment of banked sperm, current fertility, and patient satisfaction with sperm banking. Using logistic regression, we analyzed the factors associated with use and disposal of banked sperm, current fertility status, reproductive outcomes and quality of life in 55 survivors of cancer therapy who cryopreserved sperm at our facility. Most (93%) of the patients undergoing sperm banking before cancer treatment did not use their samples and 33% requested sperm disposal following completion of cancer therapy. Married status and fatherhood before cancer therapy were associated with higher rates of sperm disposal. Sperm disposal was requested because the subjects remained fertile, spontaneously fathered a child, or completed their family. The families of four patients (7%) who died from their cancer also requested disposal of the stored sperm. Six (11%) patients could not be located or failed to contact the clinic and were considered to have abandoned their banked sperm. Only 7% of the patients used their cryopreserved sperm for assisted reproduction. Most of the patients that banked sperm achieved pregnancy with their partners through spontaneous conception compared to through the use of cryopreserved sperm. The rates of disposal and abandonment of banked sperm were high following cancer therapy. Retention of fertility appears to contribute to the low utilization of banked sperm, which emphasizes the need for appropriate consent and directives regarding disposal of unused cryopreserved sperm.

Red light improves spermatozoa motility and does not induce oxidative DNA damage

NASA Astrophysics Data System (ADS)

Preece, Daryl; Chow, Kay W.; Gomez-Godinez, Veronica; Gustafson, Kyle; Esener, Selin; Ravida, Nicole; Durrant, Barbara; Berns, Michael W.

2017-04-01

The ability to successfully fertilize ova relies upon the swimming ability of spermatozoa. Both in humans and in animals, sperm motility has been used as a metric for the viability of semen samples. Recently, several studies have examined the efficacy of low dosage red light exposure for cellular repair and increasing sperm motility. Of prime importance to the practical application of this technique is the absence of DNA damage caused by radiation exposure. In this study, we examine the effect of 633 nm coherent, red laser light on sperm motility using a novel wavelet-based algorithm that allows for direct measurement of curvilinear velocity under red light illumination. This new algorithm gives results comparable to the standard computer-assisted sperm analysis (CASA) system. We then assess the safety of red light treatment of sperm by analyzing, (1) the levels of double-strand breaks in the DNA, and (2) oxidative damage in the sperm DNA. The results demonstrate that for the parameters used there are insignificant differences in oxidative DNA damage as a result of irradiation.

Human sperm DNA integrity: correlation with sperm cytoplasmic droplets.

PubMed

Fischer, Marc Anthony; Willis, Jennifer; Zini, Armand

2003-01-01

To examine the retention of sperm cytoplasmic droplets (CD) and DNA denaturation (DD) in semen from fertile and infertile men. Semen samples were obtained from consecutive nonazoospermic men presenting for infertility evaluation (n = 101) and fertile men presenting for vasectomy (n = 13). The standard semen parameters (sperm concentration, motility, and morphology), sperm DD, and sperm CD were monitored. Sperm DD was evaluated by flow cytometry analysis of acridine orange-treated spermatozoa and expressed as the percentage of spermatozoa demonstrating denatured DNA. The mean (+/-SE) percentages of spermatozoa with CD and DD were significantly higher in infertile than in fertile men (sperm CD 15.7% +/- 0.8% versus 4.8% +/- 0.7% and sperm DD 22.0% +/- 1.5% versus 10.8% +/- 1.8%, respectively). Sperm CD and DD were positively correlated (r = 0.59). Also, sperm CD and DD values correlated inversely with the standard semen parameters. Our data demonstrate that the retention of sperm CD correlates positively with sperm DD and that significantly higher sperm DD and CD are found in infertile than in fertile men. These data suggest that the enhanced susceptibility of sperm DNA to denaturation is associated with the abnormal disposal of residual sperm cytoplasm in the testis and/or epididymis.

Validation of a heterologous fertilization assay and comparison of fertilization rates of equine oocytes using in vitro fertilization, perivitelline, and intracytoplasmic sperm injections.

PubMed

Sessions-Bresnahan, D R; Graham, J K; Carnevale, E M

2014-07-15

IVF in horses is rarely successful. One reason for this could be the failure of sperm to fully capacitate or exhibit hyperactive motility. We hypothesized that the zona pellucida (ZP) of equine oocytes prevents fertilization in vitro, and bypassing the ZP would increase fertilization rates. Limited availability of equine oocytes for research has necessitated the use of heterologous oocyte binding assays using bovine oocytes. We sought to validate an assay using bovine oocytes and equine sperm and then to demonstrate that bypassing the ZP using perivitelline sperm injections (PVIs) with equine sperm capacitated with dilauroyl phosphatidylcholine would result in higher fertilization rates than standard IVF in bovine and equine oocytes. In experiment 1, bovine oocytes were used for (1) IVF with bovine sperm, (2) IVF with equine sperm, and (3) intracytoplasmic sperm injections (ICSIs) with equine sperm. Presumptive zygotes were either stained with 4',6-diamidino-2-phenylindole from 18 to 26 hours at 2-hour intervals or evaluated for cleavage at 56 hours after addition of sperm. Equine sperm fertilized bovine oocytes; however, pronuclei formation was delayed compared with bovine sperm after IVF. The delayed pronuclear formation was not seen after ICSI. In experiment 2, bovine oocytes were assigned to the following five groups: (1) cumulus oocyte complexes (COCs) coincubated with bovine sperm; (2) COC exposed to sucrose then coincubated with bovine sperm; (3) COC coincubated with equine sperm; (4) COC exposed to sucrose, and coincubated with equine sperm; and (5) oocytes exposed to sucrose, and 10 to 15 equine sperm injected into the perivitelline (PV) space. Equine sperm tended (P = 0.08) to fertilize more bovine oocytes when injected into the PV space than after IVF. In experiment 3, oocytes were assigned to the following four groups: (1) IVF, equine, and bovine COC coincubated with equine sperm; (2) PVI of equine and bovine oocytes; (3) PVI with equine oocytes pretreated with sucrose; and (4) ICSI of equine oocytes. Oocytes were examined at 24 hours for cleavage. No equine oocytes cleaved after IVF or PVI. However, ICSI conducted with equine sperm treated with dilauroyl phosphatidylcholine resulted in 85% of the oocytes cleaving. Sperm injected into the PV space of equine oocytes did not appear to enter the ooplasm. This study validated the use of bovine oocytes for equine sperm studies and indicates that failure of equine IVF is more than an inability of equine sperm to penetrate the ZP. Copyright © 2014 Elsevier Inc. All rights reserved.

Effects of ocean warming and acidification on fertilization in the Antarctic echinoid Sterechinus neumayeri across a range of sperm concentrations.

PubMed

Ho, M A; Price, C; King, C K; Virtue, P; Byrne, M

2013-09-01

The gametes of marine invertebrates are being spawned into an ocean that is simultaneously warming and decreasing in pH. Predicting the potential for interactive effects of these stressors on fertilization is difficult, especially for stenothermal polar invertebrates adapted to fertilization in cold, viscous water and, when decreased sperm availability may be an additional stressor. The impact of increased temperature (2-4 °C above ambient) and decreased pH (0.2-0.4 pH units below ambient) on fertilization in the Antarctic echinoid Sterechinus neumayeri across a range of sperm concentrations was investigated in cross-factorial experiments in context with near future ocean change projections. The high temperature treatment (+4 °C) was also used to assess thermal tolerance. Gametes from multiple males and females in replicate experiments were used to reflect the multiple spawner scenario in nature. For fertilization at low sperm density we tested three hypotheses, 1) increased temperature enhances fertilization success, 2) low pH reduces fertilization and, 3) due to the cold stenothermal physiology of S. neumayeri, temperature would be the more significant stressor. Temperature and sperm levels had a significant effect on fertilization, but decreased pH did not affect fertilization. Warming enhanced fertilization at the lowest sperm concentration tested likely through stimulation of sperm motility and reduced water viscosity. Our results indicate that fertilization in S. neumayeri, even at low sperm levels potentially found in nature, is resilient to near-future ocean warming and acidification. Copyright © 2013 Elsevier Ltd. All rights reserved.

Customizing semen preservation protocols for individual dogs and individual species: sperm preservation beyond the state of the art.

PubMed

Farstad, W

2012-12-01

Sperm quality can be variable in morphometric and physiological attributes between males of different species, between males within species subtypes reared under different environmental conditions, between ejaculates of the same male or even between sperm populations within an ejaculate. Clinical semen evaluation is based on evaluation of whole ejaculates, which is not a chemically or physiologically well-defined entity, rather a collection of heterogeneous subpopulations giving different measurements and possessing different fertilizing potential. Identification of subpopulations with different motility patterns is important as well as characterizing the subtle structural changes underlying the motility differences observed. The ability to identify populations of sperm responding rapidly or failing to progress through the capacitation process may have clinical applications. Studies of lipid-phase fluidity of sperm membranes, mathematical modelling of membrane ion transport, role of modifying components and detergent-resistant microdomains are of particular interest. When customizing extenders to ejaculates from cryosensitive males or species, a thorough knowledge of species sperm membrane physiology and an assessment of the individual ejaculate's sperm populations are necessary. Structural differences have been found in sperm membranes between fox species with different cryosurvival potential of their spermatozoa. Supplementation of lipids and detergents in cryoextenders may influence membrane fluidity of the surviving spermatozoa in a species-dependent manner and influence capacitation. Immobilization of sperm prior to cryopreservation with subsequent slow release of sperm in the female genital tract may be a way to prolong the fertile life of sperm. In canids with a long oocyte maturation time, delayed capacitation may be beneficial. © 2012 Blackwell Verlag GmbH.

Membrane status and in vitro capacitation of porcine sperm preserved in long-term extender at 16 degrees C.

PubMed

Conejo-Nava, J; Fierro, R; Gutierrez, C G; Betancourt, M

2003-01-01

Preservation of porcine semen in long-term extenders at 15-18 degrees C for more than 5 days results in decreased farrowing rates and reduced litter size after artificial insemination, despite the high progressive motility rates of sperm. To improve this preservation system it is necessary to understand sperm physiology under storage conditions. The purpose of this study was to determine the effect of storing diluted porcine semen (during 0, 2, 4, 6, and 8 days) on the sperm membranes status and the ability of sperm to respond to in vitro capacitation treatment. Ten semen samples from 5 adult boars were analyzed. Two aliquots were obtained from the sperm-rich fraction: one was used to assess fresh semen and the other was diluted in Reading extender and stored at 16 degrees C. Both semen samples were stained with chlortetracycline to assess the status of sperm membranes and with Hoechst 33258 to determine viability. Semen storage for 4-8 days increased the proportion of prematurely capacitated sperm. After 4 days of storage, in vitro capacitation treatment did not increase the percentage of capacitated sperm, but increased the percentage of acrosome reacted sperm. This phenomenon could explain the reduced fertilizing ability of porcine semen stored at 16 degrees C for over 4 days, in spite of the acceptable sperm viability and progressive motility.

Improved cryopreservability of stallion sperm using a sorbitol-based freezing extender.

PubMed

Pojprasath, T; Lohachit, C; Techakumphu, M; Stout, T; Tharasanit, T

2011-06-01

Cryopreservation of stallion semen is often associated with poor post-thaw sperm quality. Sugars are among the important components of a freezing extender and act as non-permeating cryoprotectants. This study aimed to compare the quality of stallion sperm frozen with glucose, fructose or sorbitol-containing freezing extenders. Semen was collected from six stallions of proven fertility and cryopreserved using a freezing extender containing different types of monosaccharide sugars (glucose, fructose or sorbitol). After thawing, the semen was examined for sperm motility, viability, acrosome integrity, plasma membrane functionality and sperm longevity. The fertility of semen frozen in the presence of sorbitol was also tested by artificial insemination. Sperm quality was significantly decreased following freezing and thawing (P < 0.05). Fructose was inferior for protecting sperm during cryopreservation when compared to sorbitol and glucose (P < 0.05). Although the viability, motility and acrosome integrity of sperm cryopreserved with a glucose-containing extender did not significantly differ from sperm frozen in the sorbitol-based extender when examined at 2 and 4 h post-thaw, all of these parameters plus plasma membrane functionality were improved for sperm frozen in the sorbitol extender than in the glucose extender when examined 10 min post-thaw. Two of four mares (50%) inseminated with semen frozen with a sorbitol-containing freezing extender became pregnant. It is concluded that different sugars have different abilities to protect against cryoinjury during freezing and thawing of stallion sperm. This study demonstrated that an extender containing sorbitol as primary sugar can be used to successfully cryopreserve equine sperm; moreover, the quality of frozen-thawed sperm appeared to be better than when glucose or fructose was the principle sugar in the freezing extender. Copyright © 2011 Elsevier Inc. All rights reserved.

The effects of microgravity on gametogenesis, fertilization, and early embryogenesis

NASA Astrophysics Data System (ADS)

Tan, X.

Gametogenesis fertilization and early embryogenesis are crucial periods for normal development afterwards In past three decades many experiments have been conducted in space and in simulated weightlessness induced by clinostats to elucidate the issue Different animal species including Drosophila wasp shrimp fish amphibian mouse rats etc have been used for the study Oogenesis and spermatogenesis are affected by microgravity in different ways Some researches found that microgravity condition perturbed the process of oogenesis in many species A significant increased frequency of chromosomal non-disjunction was found in Drosophila females resulting the loss of chromosomes during meiosis and inhibition of cell division Studies on wasp showed a decreased hatchability and accumulation of unhatched eggs when the insects were exposed to spaceflight at different stages of oogenesis For experiments conducted on vertebrate animal models the results are somehow different however Microgravity has no significant effect for fish Medaka etc amphibian South African clawed toad Xenopus laevis or mammals mouse Spermatogenesis on the other hand is more significantly affected by microgravity condition Some researches indicated sperm are sensitive to changes in gravitational force and this sensitivity affects the ability of sperm to fertilize eggs Sperm swim with higher velocity in microgravity which is coupled with altered protein phosphorylation level in sperm under microgravity condition Microgravity also induced activation of the

DNA repair decline during mouse spermiogenesis results in the accumulation of heritable DNA damage

DOE Office of Scientific and Technical Information (OSTI.GOV)

Marchetti, Francesco; Marchetti, Francesco; Wryobek, Andrew J

The post-meiotic phase of mouse spermatogenesis (spermiogenesis) is very sensitive to the genomic effects of environmental mutagens because as male germ cells form mature sperm they progressively lose the ability to repair DNA damage. We hypothesized that repeated exposures to mutagens during this repair-deficient phase result in the accumulation of heritable genomic damage in mouse sperm that leads to chromosomal aberrations in zygotes after fertilization. We used a combination of single or fractionated exposures to diepoxybutane (DEB), a component of tobacco smoke, to investigate how differential DNA repair efficiencies during the three weeks of spermiogenesis affected the accumulation of DEB-inducedmore » heritable damage in early spermatids (21-15 days before fertilization, dbf), late spermatids (14-8 dbf) and sperm (7- 1 dbf). Analysis of chromosomalaberrations in zygotic metaphases using PAINT/DAPI showed that late spermatids and sperm are unable to repair DEB-induced DNA damage as demonstrated by significant increases (P<0.001) in the frequencies of zygotes with chromosomal aberrations. Comparisons between single and fractionated exposures suggested that the DNA repair-deficient window during late spermiogenesis may be less than two weeks in the mouse and that during this repair-deficient window there is accumulation of DNA damage in sperm. Finally, the dose-response study in sperm indicated a linear response for both single and repeated exposures. These findings show that the differential DNA repair capacity of post-meioitic male germ cells has a major impact on the risk of paternally transmitted heritable damage and suggest that chronic exposures that may occur in the weeks prior to fertilization because of occupational or lifestyle factors (i.e, smoking) can lead to an accumulation of genetic damage in sperm and result in heritable chromosomal aberrations of paternal origin.« less

DNA Repair Decline During Mouse Spermiogenesis Results in the Accumulation of Heritable DNA Damage

DOE Office of Scientific and Technical Information (OSTI.GOV)

Marchetti, Francesco; Marchetti, Francesco; Wyrobek, Andrew J.

The post-meiotic phase of mouse spermatogenesis (spermiogenesis) is very sensitive to the genomic effects of environmental mutagens because as male germ cells form mature sperm they progressively lose the ability to repair DNA damage. We hypothesized that repeated exposures to mutagens during this repair-deficient phase result in the accumulation of heritable genomic damage in mouse sperm that leads to chromosomal aberrations in zygotes after fertilization. We used a combination of single or fractionated exposures to diepoxybutane (DEB), a component of tobacco smoke, to investigate how differential DNA repair efficiencies during the three weeks of spermiogenesis affected the accumulation of DEB-inducedmore » heritable damage in early spermatids (21-15 days before fertilization, dbf), late spermatids (14-8 dbf) and sperm (7-1 dbf). Analysis of chromosomal aberrations in zygotic metaphases using PAINT/DAPI showed that late spermatids and sperm are unable to repair DEB-induced DNA damage as demonstrated by significant increases (P<0.001) in the frequencies of zygotes with chromosomal aberrations. Comparisons between single and fractionated exposures suggested that the DNA repair-deficient window during late spermiogenesis may be less than two weeks in the mouse and that during this repair-deficient window there is accumulation of DNA damage in sperm. Finally, the dose-response study in sperm indicated a linear response for both single and repeated exposures. These findings show that the differential DNA repair capacity of post-meioitic male germ cells has a major impact on the risk of paternally transmitted heritable damage and suggest that chronic exposures that may occur in the weeks prior to fertilization because of occupational or lifestyle factors (i.e, smoking) can lead to an accumulation of genetic damage in sperm and result in heritable chromosomal aberrations of paternal origin.« less

Does egg competition occur in marine broadcast-spawners?

PubMed

Marshall, D J; Evans, J P

2005-09-01

When the availability of sperm limits female reproductive success, competition for sperm, may be an important broker of sexual selection. This is because sperm limitation can increase the variance in female reproductive success, resulting in strong selection on females to compete for limited fertilization opportunities. Sperm limitation is probably common in broadcast-spawning marine invertebrates, making these excellent candidates for investigating scramble competition between broods of eggs and its consequences for female reproductive success. Here, we report our findings from a series of experiments that investigate egg competition in the sessile, broadcast-spawning polychaete Galeolaria caespitosa. We initially tested whether the order in which eggs encounter sperm affects their fertilization success at two ecologically relevant current regimes. We used a split-clutch-split--ejaculate technique to compare the fertilization success of eggs from individual females that had either first access (competition-free treatment) or second access (egg competition treatment) to a batch of sperm. We found that fertilization success depended on the order in which eggs accessed sperm; eggs that were assigned to the competition-free treatment exhibited significantly higher fertilization rates than those assigned to the egg competition treatment at both current speeds. In subsequent experiments we found that prior exposure of sperm to eggs significantly reduced both the quantity and quality of sperm available to fertilize a second clutch of eggs, resulting in reductions in fertilization success at high and low sperm concentrations. These findings suggest that female traits that increase the likelihood of sperm-egg interactions (e.g. egg size) will respond to selection imposed by egg competition.

Sperm chromatin structure assay results in Nigerian men with unexplained infertility

PubMed Central

Kolade, Charles Oluwabukunmi

2015-01-01

Objective Several publications have established a relationship between sperm DNA damage and male factor infertility, based on data from America, Europe, and Asia. This study aimed to compare the extent of sperm DNA damage in sperm samples from Nigerian men with unexplained infertility and in sperm samples from a fertile group composed of sperm donors who had successfully impregnated a female partner naturally or through assisted conception. Methods A total of 404 men underwent male fertility evaluation at Androcare Laboratories and Cryobank participated in this study. Semen analysis and a sperm chromatin structure assay (SCSA) were performed on all subjects. Results The men in the unexplained infertility group were slightly older than the men in the fertile sperm group (36±10 years vs. 32±6 years, p=0.051). No significant difference was observed between the two groups in semen analysis parameters (p≥0.05). Men in the unexplained infertility group with normal semen parameters had a significantly higher DNA fragmentation index (DFI) than men in the fertile sperm group (27.5%±7.0% vs. 14.1%±5.3%, p<0.05). In the unexplained infertility group, 63% of the men had a DFI greater than 20%, compared to 4% in the fertile sperm group. In the unexplained infertility group, 15.2% of the subjects had a DFI greater than 30%, compared to 1% in the fertile sperm group. Conclusion Our study showed that the SCSA may be a more reliable predictor of fertility potential than traditional semen analysis in cases of unexplained infertility. PMID:26473109

Postmating sexual conflict and female control over fertilization during gamete interaction.

PubMed

Firman, Renée C

2018-06-01

Males and females rarely have identical evolutionary interests over reproduction, and when the fitness of both sexes is dependent upon paternity outcomes, sexual conflict over fertilization is inevitable. In internal fertilizers, the female tract is a formidable selective force on the number and integrity of sperm that reach the egg. Selection on sperm quality is intensified when females mate multiply and rival males are forced to compete for fertilizations. While male adaptations to sperm competition have been well documented (e.g., increased sperm fertilizing capacity), much less attention has been given to the evolutionary consequences of postmating sexual conflict for egg form and function. Specifically, increased sperm competitiveness can be detrimental by giving rise to an elevation in reproductive failure resulting from polyspermy. Spanning literature on both internal and external fertilizers, in this review I discuss how females respond to sperm competition via fertilization barriers that mediate sperm entry. These findings, which align directly with sexual conflict theory, indicate that females have greater control over fertilization than has previously been appreciated. I then consider the implications of gametic sexual conflict in relation to the development of reproductive isolation and speculate on potential mechanisms accounting for "egg defensiveness." Finally, I discuss the functional significance of egg defensiveness for both the sexes, and sperm selection for females. © 2018 New York Academy of Sciences.

Generation of rats from vitrified oocytes with surrounding cumulus cells via in vitro fertilization with cryopreserved sperm.

PubMed

Fujiwara, Katsuyoshi; Kamoshita, Maki; Kato, Tsubasa; Ito, Junya; Kashiwazaki, Naomi

2017-01-01

The objective of this study was to evaluate fertility and full-term development of rat vitrified oocytes after in vitro fertilization (IVF) with cryopreserved sperm. Oocytes with or without surrounding cumulus cells were vitrified with 30% ethylene glycol + 0.5 mol/L sucrose + 20% fetal calf serum by using the Cryotop method. The warmed oocytes were co-cultured with sperm. Although the denuded/vitrified oocytes were not fertilized, some of the oocytes vitrified with cumulus cells were fertilized (32.7%) after IVF with fresh sperm. When IVF was performed with cryopreserved sperm, vitrified or fresh oocytes with cumulus cells were fertilized (62.9% or 41.1%, respectively). In addition, to confirm the full-term development of the vitrified oocytes with surrounding cumulus cells after IVF with cryopreserved sperm, 108 vitrified oocytes with two pronuclei (2PN) were transferred into eight pseudopregnant females, and eight pups were obtained from three recipients. The present work demonstrates that vitrified rat oocytes surrounded by cumulus cells can be fertilized in vitro with cryopreserved sperm, and that 2PN embryos derived from cryopreserved gametes can develop to term. To our knowledge, this is the first report of successful generation of rat offspring derived from vitrified oocytes that were fertilized in vitro with cryopreserved sperm. © 2016 Japanese Society of Animal Science.

In vitro fertilization experiments using sockeye salmon reveal that bigger eggs are more fertilizable under sperm limitation

PubMed Central

Macfarlane, Christopher P.; Hoysak, Drew J.; Liley, N. Robin; Gage, Matthew J.G.

2009-01-01

Although theory and widespread evidence show that the evolution of egg size is driven primarily by offspring and maternal fitness demands, an additional explanation invokes sperm limitation as a selective force that could also influence egg size optima. Levitan proposed that constraints from gamete encounter in external fertilization environments could select for enlargement of ova to increase the physical size of the fertilization target. We test this theory using in vitro fertilization experiments in an externally fertilizing fish. Sockeye salmon (Onchorhyncus nerka) females show considerable between-individual variation in ovum size, and we explored the consequences of this natural variation for the fertilization success of individual eggs under conditions of sperm limitation. By engineering consistent conditions where in vitro fertilization rate was always intermediate, we were able to compare the sizes of fertilized and unfertilized eggs across 20 fertilization replicates. After controlling for any changes in volume through incubation, results showed that successfully fertilized eggs were significantly larger than the eggs that failed to achieve fertilization. Under conditions without sperm limitation, fertility was unaffected by egg size. Our findings therefore support Levitan's theory, demonstrating empirically that some element of egg size variation could be selected by fertilization demands under sperm limitation. However, further research on sperm limitation in natural spawnings is required to assess the selective importance of these results. PMID:19364734

In vitro fertilization experiments using sockeye salmon reveal that bigger eggs are more fertilizable under sperm limitation.

PubMed

Macfarlane, Christopher P; Hoysak, Drew J; Liley, N Robin; Gage, Matthew J G

2009-07-07

Although theory and widespread evidence show that the evolution of egg size is driven primarily by offspring and maternal fitness demands, an additional explanation invokes sperm limitation as a selective force that could also influence egg size optima. Levitan proposed that constraints from gamete encounter in external fertilization environments could select for enlargement of ova to increase the physical size of the fertilization target. We test this theory using in vitro fertilization experiments in an externally fertilizing fish. Sockeye salmon (Onchorhyncus nerka) females show considerable between-individual variation in ovum size, and we explored the consequences of this natural variation for the fertilization success of individual eggs under conditions of sperm limitation. By engineering consistent conditions where in vitro fertilization rate was always intermediate, we were able to compare the sizes of fertilized and unfertilized eggs across 20 fertilization replicates. After controlling for any changes in volume through incubation, results showed that successfully fertilized eggs were significantly larger than the eggs that failed to achieve fertilization. Under conditions without sperm limitation, fertility was unaffected by egg size. Our findings therefore support Levitan's theory, demonstrating empirically that some element of egg size variation could be selected by fertilization demands under sperm limitation. However, further research on sperm limitation in natural spawnings is required to assess the selective importance of these results.

Genetic parameters of rabbit semen traits and male fertilising ability.

PubMed

Brun, J M; Sanchez, A; Ailloud, E; Saleil, G; Theau-Clément, M

2016-03-01

This study aimed to estimate genetic parameters for rabbit semen production, semen characteristics and fertilising ability following artificial insemination. It involved five successive batches of 30-36 bucks each, 22 weeks of semen collection, and 11 weeks of semen recording per batch. Semen analyses were based on 2312 ejaculates. A total of 2019 inseminations were performed on 674 females with semen from 236 ejaculates from 128 bucks. Heritability estimates of semen traits ranged from 0.05 to 0.18. At approximately 0.05-0.06 for pH, volume and mass motility, they were higher for concentration (0.10) and the total number of sperms per ejaculate (0.12), and even higher for motility traits based on computer-assisted semen analysis. The percentage of motile sperms had the highest heritability (0.18) and appeared to be a good candidate criterion to select for both sperm number and motility. The heritability estimates were close to zero for all three criteria of fertilising ability: fertility (F), prolificacy (live births, LB) and their product (LB per insemination). A permanent environmental effect of the male seemed to be higher for LB (0.04) than for F (0.01). The rabbit does accounted for approximately 10% of the variance of the three criteria. With respect to the female, the male contribution was negligible for fertility and in a ratio of 4-10 for the number of live births. In our experimental conditions, prolificacy would thus be more highly influenced by the buck than fertility. Copyright © 2016 Elsevier B.V. All rights reserved.

Creatine enhances the duration of sperm capacitation: a novel factor for improving in vitro fertilization with small numbers of sperm.

PubMed

Umehara, Takashi; Kawai, Tomoko; Goto, Masaaki; Richards, JoAnne S; Shimada, Masayuki

2018-06-01

Why are many sperm required for successful fertilization of oocytes in vitro, even though fertilization occurs in vivo when only a few sperm reach the oocyte? Creatine produced in the ovary promotes efficient fertilization in vivo; however, in vitro, creatine is not contained in the in vitro fertilization (IVF) medium. The IVF medium enables capacitation of sperm. However, the IVF medium does not fully mimic the in vivo environment during fertilization. Consequently, fertilization in vitro is more inefficient than in the oviduct. Follicular and oviductal fluids were collected and then analyzed for creatine and glucose levels. To determine the physiological functions of creatine, the creatine antagonist 3-guanidinopropionic acid (GPA) was injected into hormonally primed mice. Using conventional IVF protocols, sperm were pre-incubated in IVF medium with creatine and then co-cultured with 10 ovulated cumulus-oocyte complexes (1-1000 per oocyte) in 50 μl medium droplets. Glucose and creatine levels were measured using commercial enzymatic assay kits. The effect of creatine in vivo was assessed by mating experiments using mice treated with or without GPA just before ovulation. To assess the functions of sperm incubated in IVF medium containing creatine, we analyzed (1) the motility of sperm using computer-assisted sperm assay, (2) the capacitation level of sperm by western blot analyses, and (3) the condition of sperm acrosomes by peanut agglutinin lectin-FITC staining. Oviductal creatine levels were significantly increased following ovulation. Injecting mice with GPA just before ovulation significantly reduced the number of fertilized oocytes. The addition of creatine to IVF medium enhanced sperm capacitation by increasing ATP levels. Successful fertilization was achieved with as few as five sperm/oocyte in the creatine group, and the number of fertilized oocytes was significantly higher than in the control without creatine (P < 0.01). In the present study, a pharmacological approach, creatine antagonist (GPA) treatment, but not a knockout mouse model, was used to understand the role of creatine in vivo. The role of creatine in fertilization processes can only be shown in a mouse model. A modified IVF technique using creatine-containing medium was developed and shown to markedly improve fertilization with small numbers of sperm. This approach has the potential to be highly beneficial for human assisted reproductive technologies, especially for patients with a limited number of good quality sperm. This work was supported in part by JSPS KAKENHI Grant numbers JP24688028, JP16H05017 (to M.S.), and JP15J05331 (to T.U.), the Japan Agency for Medical Research and Development (AMED) (16gk0110015h0001 to M.S.), and National Institutes of Health (NIH-HD-076980 to J.S.R). The authors have nothing to disclose.

Effects of genetic captive-breeding protocols on sperm quality and fertility in the white-footed mouse.

PubMed

Malo, Aurelio F; Martinez-Pastor, Felipe; Alaks, Glen; Dubach, Jean; Lacy, Robert C

2010-10-01

Mice (Peromyscus leucopus noveboracensis) from a captive-breeding program were used to test the effects of three genetic breeding protocols (minimizing mean kinship [MK], random breeding, and selection for docility [DOC]) and inbreeding levels on sperm traits and fertility. Earlier, in generation 8, one DOC replicate went extinct because of poor reproductive success. By generation 10, spermatozoa from DOC mice had more acrosome and midpiece abnormalities, which were shown to be strong determinants of fertility, as well as lower sperm production and resistance to osmotic stress. In addition, determinants of fertility, including male and female components, were assessed in a comprehensive manner. Results showed that the probability (P) of siring litters is determined by sperm number, sperm viability, and midpiece and acrosome abnormalities; that the P of siring one versus two litters is determined by tail abnormalities; and that the total number of offspring is influenced by female size and proportion of normal sperm, showing the relative importance of different sperm traits on fertility. On average, males with 20% normal sperm sired one pup per litter, and males with 70% normal sperm sired eight pups per litter. Interestingly, the proportion of normal sperm was affected by docility but not by relatively low inbreeding. However, inbreeding depression in sperm motility was detected. In the MK group, inbreeding depression not only affected sperm motility but also fertility: An increase in the coefficient of inbreeding (f) of 0.03 reduced sperm motility by 30% and translated into an offspring reduction of three pups in second litters. A genetic load of 48 fecundity equivalents was calculated.

A questionnaire survey on attitude toward sperm cryopreservation among hematologists in Japan.

PubMed

Kobayashi, Tomohiro; Shin, Takeshi; Nishio, Kojiro; Shimomura, Yukihito; Iwahata, Toshiyuki; Suzuki, Keisuke; Miyata, Akane; Kobori, Yoshitomo; Arai, Gaku; Okada, Hiroshi

2017-03-01

Advances in multimodal treatment have led to dramatic improvement in cancer treatment outcomes. It is now necessary to consider cancer patients' holistic quality of life. Fertility preservation is the top concern for cancer survivors of reproductive age. Sperm cryopreservation before treatment is recommended for postpubescent men, but many patients lose fertility without having been informed about options for fertility preservation. To determine how sperm cryopreservation is perceived and practiced in Japan, we surveyed hematologists who often treat young males. A questionnaire about sperm cryopreservation was sent to 45 major hematology institutions. A total of 22 institutions responded before the deadline. All institutions but one responded that they felt sperm cryopreservation is necessary. Only 15 institutions responded that they inform patients about sperm cryopreservation, and 12 institutions responded that they perform sperm cryopreservation before chemotherapy. A total of 213 young males started their first course of chemotherapy during the survey period, of whom 61 (28.6%) had their sperm cryopreserved. Although almost all hematologists stated that sperm cryopreservation is necessary for fertility preservation, not all institutions informed patients about it. Our findings indicate that, to promote fertility preservation in Japan, it will be necessary to systematize sperm cryopreservation and build inter-hospital networks.

Systematic Mapping and Functional Analysis of a Family of Human Epididymal Secretory Sperm-Located Proteins*

PubMed Central

Li, JianYuan; Liu, FuJun; Wang, HaiYan; Liu, Xin; Liu, Juan; Li, Ning; Wan, FengChun; Wang, WenTing; Zhang, ChengLin; Jin, ShaoHua; Liu, Jie; Zhu, Peng; Liu, YunXiang

2010-01-01

The mammalian spermatozoon has many cellular compartments, such as head and tail, permitting it to interact with the female reproductive tract and fertilize the egg. It acquires this fertilizing potential during transit through the epididymis, which secretes proteins that coat different sperm domains. Optimal levels of these proteins provide the spermatozoon with its ability to move to, bind to, fuse with, and penetrate the egg; otherwise male infertility results. As few human epididymal proteins have been characterized, this work was performed to generate a database of human epididymal sperm-located proteins involved in maturation. Two-dimensional gel electrophoresis of epididymal tissue and luminal fluid proteins, followed by identification using MALDI-TOF/MS or MALDI-TOF/TOF, revealed over a thousand spots in gels comprising 745 abundant nonstructural proteins, 408 in luminal fluids, of which 207 were present on spermatozoa. Antibodies raised to 619 recombinant or synthetic peptides, used in Western blots, histological sections, and washed sperm preparations to confirm antibody quality and protein expression, indicated their regional location in the epididymal epithelium and highly specific locations on washed functional spermatozoa. Sperm function tests suggested the role of some proteins in motility and protection against oxidative attack. A large database of these proteins, characterized by size, pI, chromosomal location, and function, was given a unified terminology reflecting their sperm domain location. These novel, secreted human epididymal proteins are potential targets for a posttesticular contraceptive acting to provide rapid, reversible, functional sterility in men and they are also biomarkers that could be used in noninvasive assessments of male fertility. PMID:20736409

Total levels, localization patterns, and proportions of sperm exhibiting phospholipase C zeta are significantly correlated with fertilization rates after intracytoplasmic sperm injection.

PubMed

Yelumalai, Suseela; Yeste, Marc; Jones, Celine; Amdani, Siti N; Kashir, Junaid; Mounce, Ginny; Da Silva, Sarah J Martins; Barratt, Christopher L; McVeigh, Enda; Coward, Kevin

2015-09-01

To study the relationship of total levels, localization patterns, and proportions of sperm exhibiting phospholipase C zeta, with fertilization rates after in vitro fertilization (IVF) and intracytoplasmic sperm injection (ICSI). Laboratory study; controls vs. patients after IVF (n = 27) or ICSI (n = 17) treatment. Fertility center. A total of 44 semen samples, subjected to either IVF or ICSI treatment. Oocyte collection, ICSI or IVF, determination of sperm concentration and motility, and immunocytochemical analyses of phospholipase C zeta (PLCζ). None. Percentages of sperm exhibiting PLCζ. Significant positive correlation between ICSI fertilization rates and total levels, localization patterns, and the proportion (percentage) of sperm exhibiting PLCζ. Total levels, localization patterns, and the proportion of sperm exhibiting PLCζ are correlated with fertilization rates for ICSI, but not for IVF. Evaluating total levels, localization patterns, and proportions of PLCζ may represent a useful diagnostic tool for clinical purposes in men for whom IVF is not advised or has previously failed. This clinical study further supports the fundamental role of PLCζ in the oocyte activation process. Copyright © 2015 American Society for Reproductive Medicine. Published by Elsevier Inc. All rights reserved.

Sperm competition risk generates phenotypic plasticity in ovum fertilizability

PubMed Central

Firman, Renée C.; Simmons, Leigh W.

2013-01-01

Theory predicts that sperm competition will generate sexual conflict that favours increased ovum defences against polyspermy. A recent study on house mice has shown that ovum resistance to fertilization coevolves in response to increased sperm fertilizing capacity. However, the capacity for the female gamete to adjust its fertilizability as a strategic response to sperm competition risk has never, to our knowledge, been studied. We sourced house mice (Mus domesticus) from natural populations that differ in the level of sperm competition and sperm fertilizing capacity, and manipulated the social experience of females during their sexual development to simulate conditions of either a future ‘risk’ or ‘no risk’ of sperm competition. Consistent with coevolutionary predictions, we found lower fertilization rates in ova produced by females from a high sperm competition population compared with ova from a low sperm competition population, indicating that these populations are divergent in the fertilizability of their ova. More importantly, females exposed to a ‘risk’ of sperm competition produced ova that had greater resistance to fertilization than ova produced by females reared in an environment with ‘no risk’. Consequently, we show that variation in sperm competition risk during development generates phenotypic plasticity in ova fertilizability, which allows females to prepare for prevailing conditions during their reproductive life. PMID:24132308

Sperm competition risk generates phenotypic plasticity in ovum fertilizability.

PubMed

Firman, Renée C; Simmons, Leigh W

2013-12-07

Theory predicts that sperm competition will generate sexual conflict that favours increased ovum defences against polyspermy. A recent study on house mice has shown that ovum resistance to fertilization coevolves in response to increased sperm fertilizing capacity. However, the capacity for the female gamete to adjust its fertilizability as a strategic response to sperm competition risk has never, to our knowledge, been studied. We sourced house mice (Mus domesticus) from natural populations that differ in the level of sperm competition and sperm fertilizing capacity, and manipulated the social experience of females during their sexual development to simulate conditions of either a future 'risk' or 'no risk' of sperm competition. Consistent with coevolutionary predictions, we found lower fertilization rates in ova produced by females from a high sperm competition population compared with ova from a low sperm competition population, indicating that these populations are divergent in the fertilizability of their ova. More importantly, females exposed to a 'risk' of sperm competition produced ova that had greater resistance to fertilization than ova produced by females reared in an environment with 'no risk'. Consequently, we show that variation in sperm competition risk during development generates phenotypic plasticity in ova fertilizability, which allows females to prepare for prevailing conditions during their reproductive life.

Young Men With Cancer Experience Low Referral Rates for Fertility Counseling and Sperm Banking.

PubMed

Grover, Natalie S; Deal, Allison M; Wood, William A; Mersereau, Jennifer E

2016-05-01

With improved cancer survival rates and the current trend of delaying parenthood, fertility is a growing issue among cancer patients. The purpose of this study was to evaluate the incidence of fertility counseling and sperm banking in reproductive-age male cancer patients and to assess factors that influence counseling and banking. Male patients ages 13 to 50 years who received a new cancer diagnosis from January 1, 2013, to May 1, 2015, and planned to initiate curative chemotherapy at our center were identified. Documentation of fertility counseling and sperm cryopreservation was abstracted from the medical record. Univariable and multivariable logistic regression modeling was used to examine variables associated with fertility counseling and sperm banking. Of 201 patients who fit the study criteria, 59 (29%) received fertility counseling and 23 (11%) attempted sperm banking. All patients who banked sperm had documentation of fertility counseling. Younger patients were significantly more likely to be counseled, with mean ages of 27.4 and 40.4 years for counseled and noncounseled patients, respectively (P < .001). Among counseled patients, those with a lower median income (P = .038) or who had Medicaid or no insurance (P = .042) were less likely to bank sperm. In a multivariable logistic regression model, older age (5-year odds ratio, 0.61; P < .001) and presence of comorbidities (odds ratio, 0.15; P = .03) remained significantly associated with a lower counseling rate. There is a low rate of fertility counseling and referral for sperm banking in young men with cancer receiving chemotherapy. Further work is needed to develop interventions to improve fertility counseling rates and opportunities for sperm banking. Copyright © 2016 by American Society of Clinical Oncology.

Intact Cell MALDI-TOF MS on Sperm: A Molecular Test For Male Fertility Diagnosis.

PubMed

Soler, Laura; Labas, Valérie; Thélie, Aurore; Grasseau, Isabelle; Teixeira-Gomes, Ana-Paula; Blesbois, Elisabeth

2016-06-01

Currently, evaluation of sperm quality is primarily based on in vitro measures of sperm function such as motility, viability and/or acrosome reaction. However, results are often poorly correlated with fertility, and alternative diagnostic tools are therefore needed both in veterinary and human medicine. In a recent pilot study, we demonstrated that MS profiles from intact chicken sperm using MALDI-TOF profiles could detect significant differences between fertile/subfertile spermatozoa showing that such profiles could be useful for in vitro male fertility testing. In the present study, we performed larger standardized experimental procedures designed for the development of fertility- predictive mathematical models based on sperm cell MALDI-TOF MS profiles acquired through a fast, automated method. This intact cell MALDI-TOF MS-based method showed high diagnostic accuracy in identifying fertile/subfertile males in a large male population of known fertility from two distinct genetic lineages (meat and egg laying lines). We additionally identified 40% of the m/z peaks observed in sperm MS profiles through a top-down high-resolution protein identification analysis. This revealed that the MALDI-TOF MS spectra obtained from intact sperm cells contained a large proportion of protein degradation products, many implicated in important functional pathways in sperm such as energy metabolism, structure and movement. Proteins identified by our predictive model included diverse and important functional classes providing new insights into sperm function as it relates to fertility differences in this experimental system. Thus, in addition to the chicken model system developed here, with the use of appropriate models these methods should effectively translate to other animal taxa where similar tests for fertility are warranted. © 2016 by The American Society for Biochemistry and Molecular Biology, Inc.

Replacing egg yolk with soybean lecithin in the cryopreservation of stallion semen.

PubMed

Papa, Frederico Ozanam; Felício, Gabriel Barcelos; Melo-Oña, Cely Marini; Alvarenga, Marco Antonio; De Vita, Bruna; Trinque, Cássio; Puoli-Filho, José Nicolau P; Dell'Aqua, José Antonio

2011-11-01

The objective of this study was to determine whether replacing the egg yolk with soybean lecithin in the Botu-Crio® cryodiluent would maintain the fertility of cryopreserved stallion sperm. Two experiments were performed to evaluate cell freezability. In experiment 1, sperm from 15 stallions were frozen in Botu-Crio® (BC) or Botu-Crio® which contained 45g/L soybean lecithin (BCLS45) in place of the egg yolk. In experiment 2, we compared different concentrations of soybean lecithin: 0, 10.0, 12.5, 15.0, 17.5 and 20.0g/L (BC, BCLS10, BCLS12.5, BCLS17.5 and BCLS20, respectively). In experiment 1, sperm frozen in BC and BCLS45 exhibited similar (P>0.05) percentages of total motile sperm (61% and 61%, respectively); progressively motile sperm (27% and 27%, respectively) and sperm with intact plasma membranes (IMP; 53% and 57%, respectively). Similarly, sperm frozen in BC or BC containing any concentration of soybean lecithin maintained similar (P>0.05) percentages of total motile sperm (61-68%) and progressively motile sperm (27-31%). In the first fertility trial, we used cryopreserved semen from a single stallion was inseminated into mares. The semen from the sperm that were frozen in BC diluent resulted in a higher fertility rate (66%, 16/24) compared to the sperm that were frozen in BCLS45 diluent (17%, 5/29; P<0.01). Similarly, in a second fertility trial, the mares that were inseminated with the sperm that were frozen in BC diluent exhibited a higher fertility rate (66%, 16/24) compared to the mares that were inseminated with the sperm that were frozen in BCLS20 (40%, 10/25; P<0.05). Finally, in a third trial, the sperm that were frozen in BC resulted in a higher fertility rate in mares (75%, 18/24) compared to the sperm that were frozen in BCLS10 (41%, 10/24; P<0.05). Although replacing the egg yolk in the BC cryodiluent with soybean lecithin provided similar laboratory results for stallion sperm, after cryopreservation, the sperm that was frozen with soybean lecithin in the diluent correlated with lower fertility rates. Based on these results, we concluded that the use of BCLS can be used as an alternative diluent for cryopreserving stallion sperm. However, the resulting reduced fertility rate is a matter of concern. Further studies are necessary to clarify the reasons for this decrease in fertility and to determine the optimal lecithin concentration for diluents to freeze stallion sperm. Copyright © 2011 Elsevier B.V. All rights reserved.

Ovarian fluid allows directional cryptic female choice despite external fertilization

PubMed Central

Alonzo, Suzanne H.; Stiver, Kelly A.; Marsh-Rollo, Susan E.

2016-01-01

In species with internal fertilization, females can favour certain males over others, not only before mating but also within the female's reproductive tract after mating. Here, we ask whether such directional post-mating (that is, cryptic) female mate choice can also occur in species with external fertilization. Using an in vitro sperm competition experiment, we demonstrate that female ovarian fluid (ovarian fluid) changes the outcome of sperm competition by decreasing the importance of sperm number thereby increasing the relative importance of sperm velocity. We further show that ovarian fluid does not differentially affect sperm from alternative male phenotypes, but generally enhances sperm velocity, motility, straightness and chemoattraction. Under natural conditions, female ovarian fluid likely increases the paternity of the preferred parental male phenotype, as these males release fewer but faster sperm. These results imply females have greater control over fertilization and potential to exert selection on males in species with external fertilization than previously thought possible. PMID:27529581

Reliable collection of Caspian brown trout (Salmo trutta caspius) sperm using a catheter.

PubMed

Aramli, M S; Golshahi, K; Banan, A; Sotoudeh, E

2016-10-01

The traditional stripping procedure for collecting fish semen is associated with the risk of urine contamination, which may significantly affect semen quality and quantity. The use of a catheter as an alternative method for semen collection may overcome this problem. Therefore, this study compared Caspian brown trout (Salmo trutta caspius) semen parameters (i.e. sperm density, seminal plasma osmolality, motility parameters of spermatozoa analysed using computer-assisted sperm analysis and fertility) between the traditional stripping method and the use of a catheter. All parameter values of the semen collected with a catheter were significantly higher (p < .05; density = 7.67 ± 1.02 × 10(9)  ml(-1) and osmolality = 279.28 ± 32.84 mOsm kg(-1) ) than those collected with stripping method (density = 4.85 ± 0.47 × 10(9)  ml(-1) and osmolality = 216.42 ± 20.75 mOsm kg(-1) ). Semen collected with a catheter was characterized by higher spermatozoa motility compared with sperm collected via stripping. Similarly, the fertilization ability of sperm collected with a catheter was significantly greater (p < .05) than sperm collected with the traditional stripping method. In conclusion, collection of sperm with a catheter was shown to effectively reduce urine contamination and is therefore recommended for the collection of Caspian brown trout sperm. © 2016 Blackwell Verlag GmbH.

The dynamic relationship between polyandry and selfish genetic elements

PubMed Central

Wedell, Nina

2013-01-01

Selfish genetic elements (SGEs) are ubiquitous in eukaryotes and bacteria, and make up a large part of the genome. They frequently target sperm to increase their transmission success, but these manipulations are often associated with reduced male fertility. Low fertility of SGE-carrying males is suggested to promote polyandry as a female strategy to bias paternity against male carriers. Support for this hypothesis is found in several taxa, where SGE-carrying males have reduced sperm competitive ability. In contrast, when SGEs give rise to reproductive incompatibilities between SGE-carrying males and females, polyandry is not necessarily favoured, irrespective of the detrimental impact on male fertility. This is due to the frequency-dependent nature of these incompatibilities, because they will decrease in the population as the frequency of SGEs increases. However, reduced fertility of SGE-carrying males can prevent the successful population invasion of SGEs. In addition, SGEs can directly influence male and female mating behaviour, mating rates and reproductive traits (e.g. female reproductive tract length and male sperm). This reveals a potent and dynamic interaction between SGEs and polyandry highlighting the potential to generate sexual selection and conflict, but also indicates that polyandry can promote harmony within the genome by undermining the spread of SGEs. PMID:23339240

Human sperm devoid of germinal angiotensin-converting enzyme is responsible for total fertilization failure and lower fertilization rates by conventional in vitro fertilization.

PubMed

Li, Le-Jun; Zhang, Feng-Bin; Liu, Shu-Yuan; Tian, Yong-Hong; Le, Fang; Wang, Li-Ya; Lou, Hang-Ying; Xu, Xiang-Rong; Huang, He-Feng; Jin, Fan

2014-06-01

In conventional in vitro fertilization (IVF), complete failure of fertilization occurs in 5% to 15% of treatments. Although the causes may be unclear, sperm defects appear to be the major contributor. However, a convincing test is not yet available that can predict the risk of fertilization failure. In this study, we found that germinal angiotensin-converting enzyme (gACE) (also called testicular ACE) was undetectable in sperm from patients who had total fertilization failure (TFF) and lower fertilization rates (LFRs) by IVF based on Western blot and indirect immunofluorescence analyses. Additionally, almost all of the patients without gACE on sperm (23 of 25) manifested a TT genotype of the rs4316 single-nucleotide polymorphism of ACE. Overall, our results indicate that the absence of gACE expression is responsible for TFF and LFRs by IVF. The rs4316 polymorphism of ACE might be associated with infertility in those patients. We conclude that sperm lacking gACE may be recognized before commencing IVF and that the patients may be directed instead to consider intracytoplasmic sperm injection. © 2014 by the Society for the Study of Reproduction, Inc.

Sperm Proteasomes Degrade Sperm Receptor on the Egg Zona Pellucida during Mammalian Fertilization

PubMed Central

Zimmerman, Shawn W.; Manandhar, Gaurishankar; Yi, Young-Joo; Gupta, Satish K.; Sutovsky, Miriam; Odhiambo, John F.; Powell, Michael D.; Miller, David J.; Sutovsky, Peter

2011-01-01

Despite decades of research, the mechanism by which the fertilizing spermatozoon penetrates the mammalian vitelline membrane, the zona pellucida (ZP) remains one of the unexplained fundamental events of human/mammalian development. Evidence has been accumulating in support of the 26S proteasome as a candidate for echinoderm, ascidian and mammalian egg coat lysin. Monitoring ZP protein degradation by sperm during fertilization is nearly impossible because those few spermatozoa that penetrate the ZP leave behind a virtually untraceable residue of degraded proteins. We have overcome this hurdle by designing an experimentally consistent in vitro system in which live boar spermatozoa are co-incubated with ZP-proteins (ZPP) solubilized from porcine oocytes. Using this assay, mimicking sperm-egg interactions, we demonstrate that the sperm-borne proteasomes can degrade the sperm receptor protein ZPC. Upon coincubation with motile spermatozoa, the solubilized ZPP, which appear to be ubiquitinated, adhered to sperm acrosomal caps and induced acrosomal exocytosis/formation of the acrosomal shroud. The degradation of the sperm receptor protein ZPC was assessed by Western blotting band-densitometry and proteomics. A nearly identical pattern of sperm receptor degradation, evident already within the first 5 min of coincubation, was observed when the spermatozoa were replaced with the isolated, enzymatically active, sperm-derived proteasomes. ZPC degradation was blocked by proteasomal inhibitors and accelerated by ubiquitin-aldehyde(UBAL), a modified ubiquitin protein that stimulates proteasomal proteolysis. Such a degradation pattern of ZPC is consistent with in vitro fertilization studies, in which proteasomal inhibitors completely blocked fertilization, and UBAL increased fertilization and polyspermy rates. Preincubation of intact zona-enclosed ova with isolated active sperm proteasomes caused digestion, abrasions and loosening of the exposed zonae, and significantly reduced the fertilization/polyspermy rates after IVF, accompanied by en-mass detachment of zona bound sperm. Thus, the sperm borne 26S proteasome is a candidate zona lysin in mammals. This new paradigm has implications for contraception and assisted reproductive technologies in humans, as well as animals. PMID:21383844

Artificial oocyte activation in intracytoplasmic sperm injection cycles using testicular sperm in human in vitro fertilization.

PubMed

Kang, Hee Jung; Lee, Sun-Hee; Park, Yong-Seog; Lim, Chun Kyu; Ko, Duck Sung; Yang, Kwang Moon; Park, Dong-Wook

2015-06-01

Artificial oocyte activation (AOA) is an effective method to avoid total fertilization failure in human in vitro fertilization-embryo transfer (IVF-ET) cycles. AOA performed using a calcium ionophore can induce calcium oscillation in oocytes and initiate the fertilization process. We evaluated the usefulness of AOA with a calcium ionophore in cases of total fertilization failure in previous cycles and in cases of severe male factor infertility patients with non-motile spermatozoa after pentoxifylline (PF) treatment. The present study describes 29 intracytoplasmic sperm injection (ICSI)-AOA cycles involving male factor infertility at Cheil General Hospital from January 2006 to June 2013. Patients were divided into two groups (control, n=480; AOA, n=29) depending on whether or not AOA using a calcium ionophore (A23187) was performed after testicular sperm extraction-ICSI (TESE-ICSI). The AOA group was further split into subgroups according to sperm motility after PF treatment: i.e., motile sperm-injected (n=12) and non-motile sperm-injected (n=17) groups (total n=29 cycles). The good embryo rate (52.3% vs. 66.9%), pregnancy rate (20.7% vs. 52.1%), and delivery rate (10.3% vs. 40.8%) were lower in the PF/AOA group than in the control group. When evaluating the effects of restoration of sperm motility after PF treatment on clinical outcomes there was no difference in fertilization rate (66.6% vs. 64.7% in non-motile and motile sperm, respectively), pregnancy rate (17.6% vs. 33.3%), or delivery rate (5.9% vs. 16.7%) between the two groups. We suggest that oocyte activation is a useful method to ensure fertilization in TESE-ICSI cycles regardless of restoration of sperm motility after PF treatment. AOA may be useful in selected patients who have a low fertilization rate or total fertilization failure.

Artificial oocyte activation in intracytoplasmic sperm injection cycles using testicular sperm in human in vitro fertilization

PubMed Central

Kang, Hee Jung; Lee, Sun-Hee; Park, Yong-Seog; Lim, Chun Kyu; Ko, Duck Sung; Yang, Kwang Moon

2015-01-01

Objective Artificial oocyte activation (AOA) is an effective method to avoid total fertilization failure in human in vitro fertilization-embryo transfer (IVF-ET) cycles. AOA performed using a calcium ionophore can induce calcium oscillation in oocytes and initiate the fertilization process. We evaluated the usefulness of AOA with a calcium ionophore in cases of total fertilization failure in previous cycles and in cases of severe male factor infertility patients with non-motile spermatozoa after pentoxifylline (PF) treatment. Methods The present study describes 29 intracytoplasmic sperm injection (ICSI)-AOA cycles involving male factor infertility at Cheil General Hospital from January 2006 to June 2013. Patients were divided into two groups (control, n=480; AOA, n=29) depending on whether or not AOA using a calcium ionophore (A23187) was performed after testicular sperm extraction-ICSI (TESE-ICSI). The AOA group was further split into subgroups according to sperm motility after PF treatment: i.e., motile sperm-injected (n=12) and non-motile sperm-injected (n=17) groups (total n=29 cycles). Results The good embryo rate (52.3% vs. 66.9%), pregnancy rate (20.7% vs. 52.1%), and delivery rate (10.3% vs. 40.8%) were lower in the PF/AOA group than in the control group. When evaluating the effects of restoration of sperm motility after PF treatment on clinical outcomes there was no difference in fertilization rate (66.6% vs. 64.7% in non-motile and motile sperm, respectively), pregnancy rate (17.6% vs. 33.3%), or delivery rate (5.9% vs. 16.7%) between the two groups. Conclusion We suggest that oocyte activation is a useful method to ensure fertilization in TESE-ICSI cycles regardless of restoration of sperm motility after PF treatment. AOA may be useful in selected patients who have a low fertilization rate or total fertilization failure. PMID:26161332

Birth of mice after in vitro fertilization using C57BL/6 sperm transported within epididymides at refrigerated temperatures.

PubMed

Mochida, K; Ohkawa, M; Inoue, K; Valdez, D M; Kasai, M; Ogura, A

2005-07-01

The transportation of cryopreserved spermatozoa is an economical, efficient, and safe method for the distribution of mouse strains from one facility to another. However, spermatozoa from some strains, including C57BL/6 (B6), are very sensitive to freezing and thawing and frequently fail to fertilize eggs by conventional in vitro fertilization methods at the recipient mouse facility. Since many genetically engineered mice have the B6 genetic background, this sensitivity poses a major obstacle to studies of mouse genetics. We investigated the feasibility of transporting spermatozoa within epididymides under non-freezing conditions. First, we examined the interval that B6 and B6D2F1 (BDF1) spermatozoa retained their ability to fertilize when stored within epididymides at low temperatures (5 degrees C or 7 degrees C). Fertilization rates were >50%, irrespective of the spermatozoa used, when epididymides were stored for 3d at 7 degrees C. B6 spermatozoa, but not BDF1 sperm, had better retention of fertilizing ability at 7 degrees C versus 5 degrees C. We then transported freshly collected B6 and BDF1 epididymides from a sender colony to a recipient colony using a common package delivery service, during which the temperature was maintained at 5 degrees C or 7 degrees C for 2d. Sufficiently high fertilization rates (68.0-77.5%) were obtained for all experimental groups, except for B6 spermatozoa transported at 5 degrees C. These spermatozoa were successfully cryopreserved at the recipient facility and, yielded post-thaw fertilization rates of 27.6-66.4%. When embryos derived from the B6 spermatozoa that were transported at 7 degrees C were transferred into recipient females, 52.7% (38/72) developed to term. In conclusion, transportation of epididymides at refrigerated temperatures is a practical method for the exchange of mouse genetic resources between facilities, especially when these facilities do not specialize in sperm cryopreservation. For the B6 mouse strain, the transportation of epididymides at 7 degrees C rather than 5 degrees C, is recommended.

SPERM COUNT DISTRIBUTIONS IN FERTILE MEN

EPA Science Inventory

Sperm concentration and count are often used as indicators of environmental impacts on male reproductive health. Existing clinical databases may be biased towards subfertile men with low sperm counts and less is known about expected sperm count distributions in cohorts of fertil...

Post-Death Cloning of Endangered Jeju Black Cattle (Korean Native Cattle): Fertility and Serum Chemistry in a Cloned Bull and Cow and Their Offspring

PubMed Central

KIM, Eun Young; SONG, Dong Hwan; PARK, Min Jee; PARK, Hyo Young; LEE, Seung Eun; CHOI, Hyun Yong; MOON, Jeremiah Jiman; KIM, Young Hoon; MUN, Seong Ho; OH, Chang Eon; KO, Moon Suck; LEE, Dong Sun; RIU, Key Zung; PARK, Se Pill

2013-01-01

Abstract To preserve Jeju black cattle (JBC; endangered native Korean cattle), a pair of cattle, namely a post-death cloned JBC bull and cow, were produced by somatic cell nuclear transfer (SCNT) in a previous study. In the present study, we examined the in vitro fertilization and reproductive potentials of these post-death cloned animals. Sperm motility, in vitro fertilization and developmental capacity were examined in a post-death cloned bull (Heuk Oll Dolee) and an extinct nuclear donor bull (BK94-13). We assessed reproductive ability in another post-death cloned cow (Heuk Woo Sunee) using cloned sperm for artificial insemination (AI). There were no differences in sperm motility or developmental potential of in vitro fertilized embryos between the post-death cloned bull and its extinct nuclear donor bull; however, the embryo development ratio was slightly higher in the cloned sperm group than in the nuclear donor sperm group. After one attempt at AI, the post-death cloned JBC cow became pregnant, and gestation proceeded normally until day 287. From this post-death cloned sire and dam, a JBC male calf (Heuk Woo Dolee) was delivered naturally (weight, 25 kg). The genetic paternity/maternity of the cloned JBC bull and cow with regard to their offspring was confirmed using International Society for Animal Genetics standard microsatellite markers. Presently, Heuk Woo Dolee is 5 months of age and growing normally. In addition, there were no significant differences in blood chemistry among the post-death cloned JBC bull, the cow, their offspring and cattle bred by AI. This is the first report showing that a pair of cattle, namely, a post-death cloned JBC bull and cow, had normal fertility. Therefore, SCNT can be used effectively to increase the population of endangered JBC. PMID:23955237

Post-death cloning of endangered Jeju black cattle (Korean native cattle): fertility and serum chemistry in a cloned bull and cow and their offspring.

PubMed

Kim, Eun Young; Song, Dong Hwan; Park, Min Jee; Park, Hyo Young; Lee, Seung Eun; Choi, Hyun Yong; Moon, Jeremiah Jiman; Kim, Young Hoon; Mun, Seong Ho; Oh, Chang Eon; Ko, Moon Suck; Lee, Dong Sun; Riu, Key Zung; Park, Se Pill

2013-12-17

To preserve Jeju black cattle (JBC; endangered native Korean cattle), a pair of cattle, namely a post-death cloned JBC bull and cow, were produced by somatic cell nuclear transfer (SCNT) in a previous study. In the present study, we examined the in vitro fertilization and reproductive potentials of these post-death cloned animals. Sperm motility, in vitro fertilization and developmental capacity were examined in a post-death cloned bull (Heuk Oll Dolee) and an extinct nuclear donor bull (BK94-13). We assessed reproductive ability in another post-death cloned cow (Heuk Woo Sunee) using cloned sperm for artificial insemination (AI). There were no differences in sperm motility or developmental potential of in vitro fertilized embryos between the post-death cloned bull and its extinct nuclear donor bull; however, the embryo development ratio was slightly higher in the cloned sperm group than in the nuclear donor sperm group. After one attempt at AI, the post-death cloned JBC cow became pregnant, and gestation proceeded normally until day 287. From this post-death cloned sire and dam, a JBC male calf (Heuk Woo Dolee) was delivered naturally (weight, 25 kg). The genetic paternity/maternity of the cloned JBC bull and cow with regard to their offspring was confirmed using International Society for Animal Genetics standard microsatellite markers. Presently, Heuk Woo Dolee is 5 months of age and growing normally. In addition, there were no significant differences in blood chemistry among the post-death cloned JBC bull, the cow, their offspring and cattle bred by AI. This is the first report showing that a pair of cattle, namely, a post-death cloned JBC bull and cow, had normal fertility. Therefore, SCNT can be used effectively to increase the population of endangered JBC.

Practical evolution and application of direct intracytoplasmic sperm injection for male factor and idiopathic fertilization failure infertilities.

PubMed

Tucker, M J; Wright, G; Morton, P C; Mayer, M P; Ingargiola, P E; Jones, A E

1995-04-01

To analyze the introduction of a new assisted fertilization technique for the treatment of severe male factor and idiopathic fertilization failure infertilities. Retrospective analysis of 16-month clinical application of IVF-ET where insemination was performed solely by direct intracytoplasmic sperm injection. Clinical IVF-ET program. Ninety-two couples undergoing 105 cycles of sperm injection. One hundred embryo transfers yielded 28 viable pregnancies (28%) from which eight normal deliveries have occurred to date. Complete cleavage arrest or fertilization failure occurred in four cycles, and one couple had all embryos cryopreserved. One thousand one hundred forty-three eggs were injected of which 173 (15%) degenerated. Four hundred seventy-nine of the surviving 970 eggs became normally fertilized (49%), and 381 of these zygotes (79.5%) developed suitably for cryopreservation or for transfer. Thirty-four of 310 embryos transferred implanted, yielding an implantation rate of 11%. Both testicular and epididymal sperm were used successfully to achieve fertilization and pregnancies, as was sperm retrieved by electroejaculation. Older women and couples suffering from prior idiopathic fertilization failure had a markedly poorer outcome. These results confirm that the intracytoplasmic sperm injection technique is a successful form of assisted fertilization that can be applied to a wide range of couples at significant risk from fertilization failure.

Male Investments in High Quality Sperm Improve Fertilization Success, but May Have Negative Impact on Offspring Fitness in Whitefish

PubMed Central

Kekäläinen, Jukka; Soler, Carles; Veentaus, Sami; Huuskonen, Hannu

2015-01-01

Many ejaculate traits show remarkable variation in relation to male social status. Males in disfavoured (subordinate) mating positions often invest heavily on sperm motility but may have less available resources on traits (e.g., secondary sexual ornaments) that improve the probability of gaining matings. Although higher investments in sperm motility can increase the relative fertilization success of subordinate males, it is unclear whether status-dependent differences in sperm traits could have any consequences for offspring fitness. We tested this possibility in whitefish (Coregonus lavaretus L.) by experimentally fertilizing the eggs of 24 females with the sperm of either highly-ornamented (large breeding tubercles, dominant) or less-ornamented (small tubercles, subordinate) males (split-clutch breeding design). In comparison to highly-ornamented individuals, less-ornamented males had higher sperm motility, which fertilized the eggs more efficiently, but produced embryos with impaired hatching success. Also offspring size and body condition were lower among less-ornamented males. Furthermore, sperm motility was positively associated with the fertilization success and offspring size, but only in highly-ornamented males. Together our results indicate that male investments on highly motile (fertile) sperm is not necessarily advantageous during later offspring ontogeny and that male status-dependent differences in sperm phenotype may have important effects on offspring fitness in different life-history stages. PMID:26389594

Post-thaw motility of frozen boar sperm does not predict success with in vitro fertilization

USDA-ARS?s Scientific Manuscript database

Using cryopreserved boar sperm rather than liquid semen for in vitro fertilization (IVF) allows improved IVF consistency. However, cryopreservation of boar sperm results in reduced post-thaw motility, fertilization and embryo development. Boars are often screened on an individual basis prior to use ...

A cross Canada survey of sperm banking practices in pediatric oncology centers.

PubMed

Chong, Amy Lee; Gupta, Abha; Punnett, Angela; Nathan, Paul C

2010-12-15

Childhood cancer survivors have identified fertility preservation as a major concern. Sperm banking is an established fertility preservation option in pubertal males. We sought to describe current practices in Canadian pediatric oncology programs, and to identify perceived barriers to sperm banking for male adolescents. A questionnaire was developed to (1) describe current sperm banking practices and facilities; (2) report on the utilization of sperm banking; and (3) identify barriers to sperm banking and possible solutions to improve current practices. A healthcare professional with an interest in fertility preservation within each institution was approached to participate in the study. Fifteen of 16 institutions participated, 2 have fertility preservation teams. Only one has written guidelines or adolescent focused educational material. Over 2 years, 50/262 (19%) adolescents in 12 institutions successfully banked a specimen. In 11 of these, additional information was available: of 85/172 (49%) adolescents offered the option to bank, 38/85 (45%) subsequently attempted. Reported barriers to sperm banking included the pressure to start therapy and restricted banking hours. Formal education of healthcare providers in fertility preservation practices, provision of financial support for families, and an adolescent focused approach were identified as important initiatives to improve sperm banking. There is a disparity in current sperm banking practices in Canada and at present, <25% of eligible male adolescents attempt to bank sperm. The development of a fertility preservation team, adolescent-specific guidelines, adolescent friendly sperm banking units, financial support, and improving knowledge translation among professionals and patients may improve the rates of banking. Copyright © 2010 Wiley-Liss, Inc.

The coevolution of ova defensiveness with sperm competitiveness in house mice.

PubMed

Firman, Renée C; Gomendio, Montserrat; Roldan, Eduardo R S; Simmons, Leigh W

2014-04-01

Theoretical models have suggested that sperm competition can lead to increased ova resistance to fertilization. While there is some comparative evidence that this might be true, there is no experimental evidence to show that ova defensiveness evolves in response to sperm competition. We performed a series of in vitro fertilization assays to gauge the fertilizability of ova produced by female house mice from experimental populations that evolved either with or without sperm competition. Our analysis revealed that after 24 generations of experimental evolution, females that evolved under a polygamous regime produced more defensive ova than females that evolved under a monogamous regime. We therefore provide the first direct line of evidence that sperm competition can generate sexual conflict at the gametic level and lead to asymmetries in fertilization rates among populations. Our results show that females respond to sperm competition via fertilization barriers that have the potential to mediate sperm entry.

The influence of fluorides on mouse sperm capacitation.

PubMed

Dvoráková-Hortová, K; Sandera, M; Jursová, M; Vasinová, J; Peknicová, J

2008-10-01

Increasing infertility, due to pathological changes on sperm, has become a serious issue. Eco-toxicological effect of rising concentration of fluorides can be enhanced in the presence of aluminium ions by forming fluorometallic complexes, analogues of phosphate groups that interfere with the activity of G-proteins and P-type ATPases, which are part of several signalling pathways during sperm maturation. In order for sperm to gain fertilizing ability, they must undergo in the female reproductive tract, capacitation that includes tyrosine phosphorylation and consequent actin polymerization. The present paper reports the findings of 3-month oral toxicity in mice of fluorides at the concentrations 0, 1, 10, and 100ppm and their synergic action with aluminium at dose of 10ppm. There were no mortalities, clinical signs of discomfort or body weight loss during the experiment. The analysis revealed, for the concentrations of 10 and 100ppm, abnormalities of spermatogenesis and ability of epididymal spermatozoa to capacitate in vitro, as the result of decreased sperm head tyrosine phosphorylation and actin polymerization. The enhancing overload caused by fluorides represents a potential factor, having an impact on function of sperm, hence contributing to a growing infertility in the human population.

Evolution of Pre- and Post-Copulatory Traits in Male Drosophila melanogaster as a Correlated Response to Selection for Resistance to Cold Stress

PubMed Central

Singh, Karan; Samant, Manas Arun; Tom, Megha Treesa; Prasad, Nagaraj Guru

2016-01-01

Background In Drosophila melanogaster the fitness of males depends on a broad array of reproductive traits classified as pre- and post-copulatory traits. Exposure to cold stress, can reduce sperm number, male mating ability and courtship behavior. Therefore, it is expected that the adaptation to cold stress will involve changes in pre- and post-copulatory traits. Such evolution of reproductive traits in response to cold stress is not well studied. Methods We selected replicate populations of D. melanogaster for resistance to cold shock. Over 37–46 generations of selection, we investigated pre- and post-copulatory traits such as mating latency, copulation duration, mating frequency, male fertility, fitness (progeny production) and sperm competitive ability in male flies subjected to cold shock and those not subjected to cold shock. Results We found that post cold shock, the males from the selected populations had a significantly lower mating latency along with, higher mating frequency, fertility, sperm competitive ability and number of progeny relative to the control populations. Conclusion While most studies of experimental evolution of cold stress resistance have documented the evolution of survivorship in response to selection, our study clearly shows that adaptation to cold stress involves rapid changes in the pre- and post-copulatory traits. Additionally, improved performances under stressful conditions need not necessarily trade-off with performance under benign conditions. PMID:27093599

DNA repair efficiency in germ cells and early mouse embryos and consequences for radiation-induced transgenerational genomic damage

DOE Office of Scientific and Technical Information (OSTI.GOV)

Marchetti, Francesco; Wyrobek, Andrew J.

Exposure to ionizing radiation and other environmental agents can affect the genomic integrity of germ cells and induce adverse health effects in the progeny. Efficient DNA repair during gametogenesis and the early embryonic cycles after fertilization is critical for preventing transmission of DNA damage to the progeny and relies on maternal factors stored in the egg before fertilization. The ability of the maternal repair machinery to repair DNA damage in both parental genomes in the fertilizing egg is especially crucial for the fertilizing male genome that has not experienced a DNA repair-competent cellular environment for several weeks prior to fertilization.more » During the DNA repair-deficient period of spermatogenesis, DNA lesions may accumulate in sperm and be carried into the egg where, if not properly repaired, could result in the formation of heritable chromosomal aberrations or mutations and associated birth defects. Studies with female mice deficient in specific DNA repair genes have shown that: (i) cell cycle checkpoints are activated in the fertilized egg by DNA damage carried by the sperm; and (ii) the maternal genotype plays a major role in determining the efficiency of repairing genomic lesions in the fertilizing sperm and directly affect the risk for abnormal reproductive outcomes. There is also growing evidence that implicates DNA damage carried by the fertilizing gamete as a mediator of postfertilization processes that contribute to genomic instability in subsequent generations. Transgenerational genomic instability most likely involves epigenetic mechanisms or error-prone DNA repair processes in the early embryo. Maternal and embryonic DNA repair processes during the early phases of mammalian embryonic development can have far reaching consequences for the genomic integrity and health of subsequent generations.« less

Effects of Cancer Treatment on Fertility (For Parents)

MedlinePlus

... reproductive organs to remove the cancer. Sperm and Egg Preservation Options If your child's treatment carries a ... vitro fertilization (sperm are used to fertilize an egg outside of the uterus, then the fertilized embryo ...

Sperm quality variables as indicators of bull fertility may be breed dependent.

PubMed

Morrell, Jane M; Nongbua, Thanapol; Valeanu, Sabina; Lima Verde, Isabel; Lundstedt-Enkel, Katrin; Edman, Anders; Johannisson, Anders

2017-10-01

A means of discriminating among bulls of high fertility based on sperm quality is needed by breeding centers. The objective of the study was to examine parameters of sperm quality in bulls of known fertility to identify useful indicators of fertility. Frozen semen was available from bulls of known fertility (Viking Genetics, Skara, Sweden): Swedish Red (n=31), Holstein (n=25) and Others (one each of Charolais, Limousin, Blonde, SKB). After thawing, the sperm samples were analyzed for motility (computer assisted sperm analysis), plasma membrane integrity, chromatin integrity, acrosome status, mitochondrial activity and reactive oxygen species. A fertility index score based on the adjusted 56-day non-return rate for >1000 inseminations was available for each bull. Multivariate data analysis (Partial Least Squares Regression and Orthogonal Partial Least Squares Regression) was performed to identify variables related to fertility; Pearson univariate correlations were made on the parameters of interest. Breed of bull affected the relationship of sperm quality variables and fertility index score, as follows: Swedish Red: %DNA Fragmentation Index, r=-0.56, P<0.01; intact plasma membrane, r=0.40, P<0.05; membrane damaged, not acrosome reacted, r=-0.6, P<0.01; Linearity, r=0.37, P<0.05; there was a trend towards significance for Wobble, r=0.34, P=0.08. Holstein: Linearity was significant r=0.46, P<0.05; there was a trend towards significance for Wobble, r=0.45, P=0.08. In conclusion, breed has a greater effect on sperm quality than previously realized; different parameters of sperm quality are needed to indicate potential fertility in different breeds. Copyright © 2017 Elsevier B.V. All rights reserved.

Fertilization: a sperm’s journey to and interaction with the oocyte

PubMed Central

Ikawa, Masahito; Inoue, Naokazu; Benham, Adam M.; Okabe, Masaru

2010-01-01

Mammalian fertilization comprises sperm migration through the female reproductive tract, biochemical and morphological changes to sperm, and sperm-egg interaction in the oviduct. Recent gene knockout approaches in mice have revealed that many factors previously considered important for fertilization are largely dispensable, or if they are essential, they have an unexpected function. These results indicate that what has been observed in in vitro fertilization (IVF) differs significantly from what occurs during “physiological” fertilization. This Review focuses on the advantages of studying fertilization using gene-manipulated animals and highlights an emerging molecular mechanism of mammalian fertilization. PMID:20364096

ERK1/2 mediates sperm acrosome reaction through elevation of intracellular calcium concentration.

PubMed

Jaldety, Yael; Breitbart, Haim

2015-10-01

Mammalian sperm acquire fertilization capacity after residing in the female reproductive tract for a few hours in a process called capacitation. Only capacitated sperm can bind the zona pellucida (ZP) of the egg and undergo the acrosome reaction, a process that allows penetration and fertilization. Extracellular signal regulated kinase (ERK1/2) mediates signalling in many cell types, however its role in sperm function is largely unknown. Here we show that ERK1/2 is highly phosphorylated/activated after a short incubation of mouse sperm under capacitation conditions and that this phosphorylation is reduced after longer incubation. Further phosphorylation was observed upon addition of crude extract of egg ZP or epidermal growth factor (EGF). The mitogen-activated ERK-kinase (MEK) inhibitor U0126 abolished ERK1/2 phosphorylation, in vitro fertilization rate and the acrosome reaction induced by ZP or EGF but not by the Ca2+-ionophore A23187. Moreover, inhibition of ERK1/2 along the capacitation process diminished almost completely the sperm's ability to go through the acrosome reaction, while inhibition at the end of capacitation attenuated the acrosome reaction rate by only 45%. The fact that the acrosome reaction, induced by the Ca2+ -ionophore A23187, was not inhibited by U0126 suggests that ERK1/2 mediates the acrosome reaction by activating Ca2+ transport into the cell. Direct determination of intracellular [Ca2+] revealed that Ca2+ influx induced by EGF or ZP was completely blocked by U0126. Thus, it has been established that the increase in ERK1/2 phosphorylation/activation in response to ZP or by activation of the EGF receptor (EGFR) by EGF, is a key event for intracellular Ca2+ elevation and the subsequent occurrence of the acrosome reaction.

Long-chain fatty acid triglyceride (TG) metabolism disorder impairs male fertility: a study using adipose triglyceride lipase deficient mice.

PubMed

Masaki, Hidetake; Kim, Namhyo; Nakamura, Hitomi; Kumasawa, Keiichi; Kamata, Eriko; Hirano, Ken-Ichi; Kimura, Tadashi

2017-07-01

Does the deletion of adipose triglyceride lipase (Atgl) gene impair male fertility? The deletion of Atgl gene impaired male fertility but the effect was partially reversed by a low long-chain triglyceride (TG) diet. ATGL specifically hydrolyses long-chain fatty acid TG to diacylglycerol and a high level of expression of ATGL in testes has been reported. However, the role of ATGL in male fertility is unknown. To investigate the effect of deletion of Atgl gene on male fertility, cauda epididymides and testes were collected from wild-type, heterozygous and homozygous Atgl-deficient mice at 10 weeks of age and epididymal sperm analysis and histological analysis of the testes were performed. To investigate whether a medium-chain triglycerides (MCTs) replacement diet mitigated the impaired male fertility by deletion of Atgl gene, homozygous Atgl-deficient mice were fed a MCT replacement diet, or a standard diet including long-chain triglycerides (LCTs) in a control group, for 6 weeks from 5 weeks of age (n = 22). The systematic and local effects of the MCT replacement diet on spermatogenesis and sperm maturation in the epididymis were analyzed at 10 weeks of age. Hematoxylin and eosin staining in paraffin-embedded sections of testes and Oil Red O staining in frozen sections of testes were performed. The epididymal sperm concentrations were analyzed. Statistical analyses were performed using the Student's t-test or Mann-Whitney U test with Shapiro-Wilk Normality test. Although heterozygous mice were fertile and showed a similar number of epididymal total and motile sperm concentrations to wild-type mice, the deletion of Atgl gene in homozygous mice led to accumulation of TG deposits in testes and impaired spermatogenesis. The deletion of Atgl gene also impaired the sperm maturation process required for sperm to acquire the ability to move forward in the epididymis. The MCT replacement diet for 6 weeks increased the plasma level of non-esterified fatty acid (NEFA) (1.5-fold, P = 0.005), but not the plasma total cholesterol (T-Cho) and TG levels. In testes, the MCT replacement diet decreased the number of Oil Red O stain positive vacuoles (-40%, P < 0.001) and increased testis tissue weight (1.1-fold, P = 0.012), total sperm concentration (1.5-fold, P = 0.011) and motile sperm concentration (2.1-fold, P < 0.001) compared to the control group. However, there was no significant change in the sperm survival rate between the two groups. None. One previous study reported that Atgl-deficient male mice were fertile. In most studies heterozygous Atgl(+/-) mice were used to generate homozygous Atgl-deficient Atgl(-/-) mice. Although the same gene targeting mice were used in this study and the formation of vaginal plugs were observed after mating with Atgl(-/-) male mice, there were no pregnant wild-type mice observed after mating with Atgl(-/-) male mice. Local TG metabolism in the male reproductive system could affect spermatogenesis and sperm motility in men. The MCT replacement diet could be an effective therapy for idiopathic non-obstructive oligozoospermia or asthenozoospermia in men with low levels of serum NEFA. This study was supported in part by the Japan Society for the Promotion of Science JSPS KAKENHI Grant (Nos. JP24249080, JP25462557, JP16K11086). The authors declare no conflict of interest. © The Author 2016.Published by Oxford University Press on behalf of the European Society of Human Reproduction and Embryology. All rights reserved. For Permissions, please email:journals.permissions@oup.com

Multiple deleterious effects of experimentally aged sperm in a monogamous bird

USGS Publications Warehouse

White, J.; Wagner, R.H.; Helfenstein, F.; Hatch, Shyla A.; Mulard, Hervé; Naves, L.C.; Danchin, E.

2008-01-01

Sperm aging is known to be detrimental to reproductive performance. However, this apparently general phenomenon has seldom been studied in an evolutionary context. The negative impact of sperm aging on parental fitness should constitute a strong selective pressure for adaptations to avoid its effects. We studied the impact of sperm aging on black-legged kittiwakes (Rissa tridactyla), a monogamous seabird. Kittiwakes comprise a model system because (i) of evidence that females eject their mates' sperm to prevent fertilization by sperm that would be old and degraded by the time of fertilization and result in reduced reproductive performance and (ii) the lack of extra-pair fertilization in this species makes cryptic female choice an unlikely explanation of postcopulatory sperm ejection by females. We experimentally manipulated the age of the sperm fertilizing kittiwake eggs by fitting males with anti-insemination rings for variable periods of time preceding egg-laying. We found evidence that sperm aging negatively affected four sequential stages of reproduction: fertilization potential, rate of embryonic development, embryonic mortality, and chick condition at hatching. These results may be produced by a continuum of a single process of sperm aging that differentially affects various aspects of development, depending on the degree of damage incurred to the spermatozoa. The marked impact of sperm age on female fitness may thus drive postcopulatory sperm ejection by females. These results provide experimental evidence of deleterious effects of sperm aging on a nondomestic vertebrate, underlining its taxonomic generality and its potential to select for a wide array of adaptations. ?? 2008 by The National Academy of Sciences of the USA.

Sperm proteasome and fertilization.

PubMed

Sutovsky, Peter

2011-07-01

The omnipresent ubiquitin-proteasome system (UPS) is an ATP-dependent enzymatic machinery that targets substrate proteins for degradation by the 26S proteasome by tagging them with an isopeptide chain composed of covalently linked molecules of ubiquitin, a small chaperone protein. The current knowledge of UPS involvement in the process of sperm penetration through vitelline coat (VC) during human and animal fertilization is reviewed in this study, with attention also being given to sperm capacitation and acrosome reaction/exocytosis. In ascidians, spermatozoa release ubiquitin-activating and conjugating enzymes, proteasomes, and unconjugated ubiquitin to first ubiquitinate and then degrade the sperm receptor on the VC; in echinoderms and mammals, the VC (zona pellucida/ZP in mammals) is ubiquitinated during oogenesis and the sperm receptor degraded during fertilization. Various proteasomal subunits and associated enzymes have been detected in spermatozoa and localized to sperm acrosome and other sperm structures. By using specific fluorometric substrates, proteasome-specific proteolytic and deubiquitinating activities can be measured in live, intact spermatozoa and in sperm protein extracts. The requirement of proteasomal proteolysis during fertilization has been documented by the application of various proteasome-specific inhibitors and antibodies. A similar effect was achieved by depletion of sperm-surface ATP. Degradation of VC/ZP-associated sperm receptor proteins by sperm-borne proteasomes has been demonstrated in ascidians and sea urchins. On the applied side, polyspermy has been ameliorated by modulating sperm-associated deubiquitinating enzymes. Diagnostic and therapeutic applications could emerge in human reproductive medicine. Altogether, the studies on sperm proteasome indicate that animal fertilization is controlled in part by a unique, gamete associated, extracellular UPS.

Efficient utilization of very dilute aquatic sperm: sperm competition may be more likely than sperm limitation when eggs are retained.

PubMed

Pemberton, Andrew J; Hughes, Roger N; Manríquez, Patricio H; Bishop, John D D

2003-11-07

Fertilization success may be severely limited in marine invertebrates that spawn both male and female gametes. In a diverse group of aquatic organisms only sperm are released, with sperm-egg fusion occurring at the mother. Here, we report fertilization kinetics data for two such 'brooding' or 'spermcast' species--representing each major clade of the animal kingdom. High levels of fertilization were achieved at sperm concentrations of two or three orders of magnitude lower than is common with broadcast spawning species. At a concentration of 100 sperm ml(-1), fertilization rates of a bryozoan and colonial ascidian were near maximum, whereas most broadcast spawners would have displayed near complete reproductive failure. A further experiment looked at the rate of uptake of sperm under natural conditions. Results suggested that sperm released at ca. 0.9 m from an acting female could be collected at a rate of 3-12 times greater than the minimum required simply to avoid sperm limitation. Thus, evolutionary pressures on gametic and other reproductive characteristics of many species that release sperm but retain eggs may be quite different from those of broadcast spawners and may confer on the former an enhanced scope for sperm competition and female choice.

Environmental osmolality influences sperm motility activation in an anuran amphibian.

PubMed

Byrne, P G; Dunne, C; Munn, A J; Silla, A J

2015-03-01

Evolutionary theory predicts that selection will favour sperm traits that maximize fertilization success in local fertilization environments. In externally fertilizing species, osmolality of the fertilization medium is known to play a critical role in activating sperm motility, but there remains limited evidence for adaptive responses to local osmotic environments. In this study, we used a split-sample experimental design and computer-assisted sperm analysis to (i) determine the optimal medium osmolality for sperm activation (% sperm motility and sperm velocity) in male common eastern froglets (Crinia signifera), (ii) test for among-population variation in percentage sperm motility and sperm velocity at various activation-medium osmolalities and (iii) test for among-population covariation between sperm performance and environmental osmolality. Frogs were obtained from nine populations that differed in environmental osmolality, and sperm samples of males from different populations were subjected to a range of activation-medium osmolalities. Percentage sperm motility was optimal between 10 and 50 mOsm kg(-1) , and sperm velocity was optimal between 10 and 100 mOsm kg(-1) , indicating that C. signifera has evolved sperm that can function across a broad range of osmolalities. As predicted, there was significant among-population variation in sperm performance. Furthermore, there was a significant interaction between activation-medium osmolality and environmental osmolality, indicating that frogs from populations with higher environmental osmolality produced sperm that performed better at higher osmolalities in vitro. This finding may reflect phenotypic plasticity in sperm functioning, or genetic divergence resulting from spatial variation in the strength of directional selection. Both of these explanations are consistent with evolutionary theory, providing some of the first empirical evidence that local osmotic environments can favour adaptive sperm motility responses in species that use an external mode of fertilization. © 2015 European Society For Evolutionary Biology. Journal of Evolutionary Biology © 2015 European Society For Evolutionary Biology.

Tactic-specific differences in seminal fluid influence sperm performance

PubMed Central

Locatello, Lisa; Poli, Federica; Rasotto, Maria B.

2013-01-01

Seminal fluid often makes up a large part of an ejaculate, yet most empirical and theoretical studies on sperm competition have focused on how sperm characteristics (number and quality) affect fertilization success. However, seminal fluid influences own sperm performance and may potentially influence the outcome of sperm competition, by also affecting that of rivals. As a consequence males may be expected to allocate their investment in both sperm and seminal fluid in relation to the potential level of competition. Grass goby (Zosterisessor ophiocephalus) is an external fertilizer with guard-sneaker mating tactics, where sperm competition risk varies according to the tactic adopted. Here, we experimentally manipulated grass goby ejaculates by separately combining sperm and seminal fluid from territorial and sneaker males. While sperm of sneaker and territorial males did not differ in their performance when they interacted with their own seminal fluid only, sperm of sneakers increased their velocity and fertilization rate in the presence of territorial males' seminal fluid. By contrast, sneaker males' seminal fluid had a detrimental effect on the performance of territorial males' sperm. Sperm velocity was unaffected by the seminal fluid of males employing the same tactic, suggesting that seminal fluid's effect on rival-tactic sperm is not based on a self/non-self recognition mechanism. Our findings show that cross interactions of sperm and seminal fluid may influence the fertilization success of competing ejaculates with males investing in both sperm and seminal fluid in response to sperm competition risk. PMID:23363633

Tactic-specific differences in seminal fluid influence sperm performance.

PubMed

Locatello, Lisa; Poli, Federica; Rasotto, Maria B

2013-03-22

Seminal fluid often makes up a large part of an ejaculate, yet most empirical and theoretical studies on sperm competition have focused on how sperm characteristics (number and quality) affect fertilization success. However, seminal fluid influences own sperm performance and may potentially influence the outcome of sperm competition, by also affecting that of rivals. As a consequence males may be expected to allocate their investment in both sperm and seminal fluid in relation to the potential level of competition. Grass goby (Zosterisessor ophiocephalus) is an external fertilizer with guard-sneaker mating tactics, where sperm competition risk varies according to the tactic adopted. Here, we experimentally manipulated grass goby ejaculates by separately combining sperm and seminal fluid from territorial and sneaker males. While sperm of sneaker and territorial males did not differ in their performance when they interacted with their own seminal fluid only, sperm of sneakers increased their velocity and fertilization rate in the presence of territorial males' seminal fluid. By contrast, sneaker males' seminal fluid had a detrimental effect on the performance of territorial males' sperm. Sperm velocity was unaffected by the seminal fluid of males employing the same tactic, suggesting that seminal fluid's effect on rival-tactic sperm is not based on a self/non-self recognition mechanism. Our findings show that cross interactions of sperm and seminal fluid may influence the fertilization success of competing ejaculates with males investing in both sperm and seminal fluid in response to sperm competition risk.

Improvement strategies in ovine artificial insemination.

PubMed

Anel, L; Alvarez, M; Martinez-Pastor, F; Garcia-Macias, V; Anel, E; de Paz, P

2006-10-01

Artificial insemination in ram is scarcely widespread comparing with other domestic species. This has been due not only to fertility results being irregular and low but also because of the difficulty in the application of enhancements such as the use of frozen-thawed sperm. Although there is a lot of information on the use of different options to improve these AI results (such as transcervical application, the use of thawed sperm, etc.) commercial programmes can be classified on two general categories: those using refrigerated semen (15 degrees C) by superficial intracervical deposition (vaginal), and, more restricted, those using thawed sperm by intrauterine deposition (laparoscopy). In the present work, we have summarized our viewpoint on three general research lines for the improvement of AI results in sheep: semen preservation, AI procedures and semen assessment. Briefly, in ram it is necessary to develop a medium term methodology of sperm refrigeration (3-5 days), which would allow the distribution of sperm doses to a widespread area. Nevertheless, it is also necessary to develop an intrauterine transcervical AI technique, which allows thawed semen to be applied by vaginal insemination. Besides, the low predictive value of classic assessment techniques limits the ability to adjust the number of spermatozoa per dose according to its actual fertility.

Evaluation of cryoprotective effect of Turkish pine honey on common carp (Cyprinus carpio) spermatozoa.

PubMed

Ogretmen, F; Inanan, B E

2014-01-01

The cryopreservation procedures that allow preserving sperm cells have been applied for sperm of many species. A sugar like glucose, fructose and sucrose were frequently used in cryomedia but up to the present pine honey was not used for cryopreservation of sperm cells. The objective of present study is to investigate the effect of pine honey in various concentrations of 100, 200, 300, 400 and 500 mg/ml solutions on cryopreservation and fertilization ability of spermatozoa of common carp (Cyprinus carpio). Totally 12.5 % (v/v) Me2SO as a cryoprotectant and 10 % (v/v) egg yolk added all extenders. Pine honey also compared with sugars as glucose, fructose (monosaccharide) and sucrose (disaccharide). Collected semen samples were diluted at the ratio of 1:9 with the extenders. After dilutions, the sperm motility was assessed for each group and then the diluted semen samples were cryopreserved. The extenders containing 300 mg ml-1 pine honey group showed both highest post thaw motility 75.3 ± 5.1 %, motility duration (s) 47.3 ± 2.5 % and hatching ratio 42.6 ± 4.2 % than other cryopreserved groups (P<0.05). Using the pine honey in cryomedia is effective for cryopreservation especially about hatching success of egg fertilized by frozen-thawed sperm of common carp.

Sperm motility in fishes. I. Effects of temperature and pH: a review.

PubMed

Alavi, Sayyed Mohammad Hadi; Cosson, Jacky

2005-02-01

Sperm motility is a key factor in allowing us to determine semen quality and fertilizing capacity. Motility in semen is mainly controlled by K+ in salmonids, and probably also in sturgeons, and by osmotic pressure in other freshwater and seawater fish species, but other factors, such as concentration of surrounding metabolites and ions (Ca2+, Mg2+, etc.), pH and temperature also influence motility characteristics. In the present study, we have mainly reviewed and summarized the effects of temperature and pH on the motility of spermatozoa in three fish species: salmonids, cyprinids and sturgeons. Data in the literature show that motility, fertilizing ability and velocity of spermatozoa, as well as the duration of the motility period, depend on the temperature of the assay medium and also of that of the brood fish holding tank. In contrast, the pH of the swimming medium, and thus the intracellular pH of spermatozoa, has less influence on sperm motility parameters in cyprinids, salmonids and sturgeons.

Effects of pre-incubation of eggs in fresh water and varying sperm concentration on fertilization rate in sterlet sturgeon, Acipenser ruthenus.

PubMed

Siddique, Mohammad Abdul Momin; Butts, Ian Anthony Ernest; Psenicka, Martin; Linhart, Otomar

2015-08-01

Standardization of fertilization protocols for sterlet Acipenser ruthenus is crucial for improving reproductive techniques and for conservation purposes. Our objectives were to determine the number of sperm (tested 430,000:1, 43,000:1, 4300:1, 430:1 sperm to egg) required to fertilize eggs and explore how pre-incubation of eggs in freshwater for 0min, 0.5min, 1min, and 10min interacts with different sperm ratios. Fertilization success ranged from 29.7% at 430:1 to 84.2% at 430,000:1. Pre-incubation time had no effect on fertilization success at 430,000:1 and 43,000:1 sperm to egg ratios, while it was significant at the 4300:1 and 430:1 ratios. The use of adequate experimental suboptimal sperm to egg ratio revealed a positive effect of pre-incubation time, such that at the 430:1 ratio, 0.5min pre-incubation increased the fertilization rate than 10min. At 0min pre-incubation the proportion of fertilized eggs increased at the 430,000:1 ratio, while at 1min fertilization increased at the 4300:1 ratio. At the 10min pre-incubation time, fertilization increased at the 43,000:1 ratio. Moreover, at the 0.5min pre-incubation time, the 43,000:1 ratio increased the fertilization rate than the 430:1 ratio. Generally, for 430:1 ratio, the fertilization rate is lower than in control. Transmission electron microscopy showed that pre-incubation of eggs in water for <10min does not trigger a cortical reaction or the formation of a perivitelline space. Results suggest that with a low sperm to egg ratio 0.5 to 1min pre-incubation of eggs in freshwater prior to fertilization can enhance fertilization rate of sterlet. Copyright © 2015 Elsevier B.V. All rights reserved.

Male Fertility Issues

Cancer.gov

Fertility issues are common in boys and men getting cancer treatment. Fertility preservation options include sperm banking, testicular shielding, testicular sperm extraction (TESE), and testicular tissue freezing. Support and clinical trials are listed.

Novel agents for sperm purification, sorting, and imaging.

PubMed

Feugang, Jean M

2017-09-01

The stringent selection of viable spermatozoa ensures the transmission of high-quality genetic material to the egg during fertilization. Sperm heterogeneity within or between ejaculates and between males obliges varied post-collection handling of semen to assure satisfactory fertility rates. The current techniques used to assess sperm generally detect non-viable and non-fertilizing gametes in the ejaculate, but do not permit the investigation of semen for improved fertility outcomes. Advances in technology, however, have spurred the search for new approaches to enrich semen with high-quality spermatozoa and to track intra-uterine sperm migration. This review highlights the current and future methodologies used for sperm labeling, selection, tracking, and imaging, with specific emphasis on the recent influence of nanotechnology. © 2017 Wiley Periodicals, Inc.

Mice lacking the USP2 deubiquitinating enzyme have severe male subfertility associated with defects in fertilization and sperm motility.

PubMed

Bedard, Nathalie; Yang, Yaoming; Gregory, Mary; Cyr, Daniel G; Suzuki, João; Yu, Xiaomin; Chian, Ri-Cheng; Hermo, Louis; O'Flaherty, Cristian; Smith, Charles E; Clarke, Hugh J; Wing, Simon S

2011-09-01

The ubiquitin-proteasome system plays an important role in spermatogenesis. However, the functions of deubiquitinating enzymes in this process remain poorly characterized. We previously showed that the deubiquitinating enzyme USP2 is induced in late elongating spermatids. To identify its function, we generated mice lacking USP2. Usp2 -/- mice appeared normal, and the weights of major organs, including the testis, did not differ from wild type (Usp2 +/+). However, although the numbers of testicular spermatids and epididymal spermatozoa were normal in Usp2 -/- males, these animals had a severe defect in fertility, yielding only 12% as many offspring as Usp2 +/+ littermates. Spermatogenesis in Usp2 -/- mice was morphologically normal except for the presence of abnormal aggregations of elongating spermatids and formation of multinucleated cells in some tubules. The epididymal epithelium was morphologically normal in Usp2 -/- mice, but some abnormal cells other than sperm were present in the lumen. Usp2 -/- epididymal spermatozoa manifested normal motility when incubated in culture media, but rapidly became immotile when incubated in PBS in contrast to Usp2 +/+ spermatozoa, which largely maintained motility under this condition. Usp2 -/- and +/+ spermatozoa underwent acrosome reactions in vitro with similar frequency. In vitro fertilization assays demonstrated a severe defect in the ability of Usp2 -/- spermatozoa to fertilize eggs. This could be bypassed by intracytoplasmic sperm injection or removal of the zona pellucida, which resulted in fertilization rates similar to that of Usp2 +/+ mice. We demonstrate for the first time, using mouse transgenic approaches, a role for the ubiquitin system in fertilization.

Live Births from Domestic Dog (Canis familiaris) Embryos Produced by In Vitro Fertilization

PubMed Central

Nagashima, Jennifer B.; Sylvester, Skylar R.; Nelson, Jacquelyn L.; Cheong, Soon Hon; Mukai, Chinatsu; Lambo, Colleen; Flanders, James A.; Meyers-Wallen, Vicki N.; Songsasen, Nucharin; Travis, Alexander J.

2015-01-01

Development of assisted reproductive technologies (ART) in the dog has resisted progress for decades, due to their unique reproductive physiology. This lack of progress is remarkable given the critical role ART could play in conserving endangered canid species or eradicating heritable disease through gene-editing technologies—an approach that would also advance the dog as a biomedical model. Over 350 heritable disorders/traits in dogs are homologous with human conditions, almost twice the number of any other species. Here we report the first live births from in vitro fertilized embryos in the dog. Adding to the practical significance, these embryos had also been cryopreserved. Changes in handling of both gametes enabled this progress. The medium previously used to capacitate sperm excluded magnesium because it delayed spontaneous acrosome exocytosis. We found that magnesium significantly enhanced sperm hyperactivation and ability to undergo physiologically-induced acrosome exocytosis, two functions essential to fertilize an egg. Unlike other mammals, dogs ovulate a primary oocyte, which reaches metaphase II on Days 4–5 after the luteinizing hormone (LH) surge. We found that only on Day 6 are oocytes consistently able to be fertilized. In vitro fertilization of Day 6 oocytes with sperm capacitated in medium supplemented with magnesium resulted in high rates of embryo development (78.8%, n = 146). Intra-oviductal transfer of nineteen cryopreserved, in vitro fertilization (IVF)-derived embryos resulted in seven live, healthy puppies. Development of IVF enables modern genetic approaches to be applied more efficiently in dogs, and for gamete rescue to conserve endangered canid species. PMID:26650234

Candidate genes associated with testicular development, sperm quality, and hormone levels of inhibin, luteinizing hormone, and insulin-like growth factor 1 in Brahman bulls.

PubMed

Fortes, Marina R S; Reverter, Antonio; Hawken, Rachel J; Bolormaa, Sunduimijid; Lehnert, Sigrid A

2012-09-01

Bull fertility is an important target for genetic improvement, and early prediction using genetic markers is therefore a goal for livestock breeding. We performed genome-wide association studies to identify genes associated with fertility traits measured in young bulls. Data from 1118 Brahman bulls were collected for six traits: blood hormone levels of inhibin (IN) at 4 mo, luteinizing hormone (LH) following a gonadotropin-releasing hormone challenge at 4 mo, and insulin-like growth factor 1 (IGF1) at 6 mo, scrotal circumference (SC) at 12 mo, ability to produce sperm (Sperm) at 18 mo, and percentage of normal sperm (PNS) at 24 mo. All the bulls were genotyped with the BovineSNP50 chip. Sires and dams of the bull population (n = 304) were genotyped with the high-density chip (∼800 000 polymorphisms) to allow for imputation, thereby contributing detail on genome regions of interest. Polymorphism associations were discovered for all traits, except for Sperm. Chromosome 2 harbored polymorphisms associated with IN. For LH, associated polymorphisms were located in five different chromosomes. A region of chromosome 14 contained polymorphisms associated with IGF1 and SC. Regions of the X chromosome showed associations with SC and PNS. Associated polymorphisms yielded candidate genes in chromosomes 2, 14, and X. These findings will contribute to the development of genetic markers to help select cattle with improved fertility and will lead to better annotation of gene function in the context of reproductive biology.

Group III secreted phospholipase A2 regulates epididymal sperm maturation and fertility in mice

PubMed Central

Sato, Hiroyasu; Taketomi, Yoshitaka; Isogai, Yuki; Miki, Yoshimi; Yamamoto, Kei; Masuda, Seiko; Hosono, Tomohiko; Arata, Satoru; Ishikawa, Yukio; Ishii, Toshiharu; Kobayashi, Tetsuyuki; Nakanishi, Hiroki; Ikeda, Kazutaka; Taguchi, Ryo; Hara, Shuntaro; Kudo, Ichiro; Murakami, Makoto

2010-01-01

Although lipid metabolism is thought to be important for the proper maturation and function of spermatozoa, the molecular mechanisms that underlie this dynamic process in the gonads remains incompletely understood. Here, we show that group III phospholipase A2 (sPLA2-III), a member of the secreted phospholipase A2 (sPLA2) family, is expressed in the mouse proximal epididymal epithelium and that targeted disruption of the gene encoding this protein (Pla2g3) leads to defects in sperm maturation and fertility. Although testicular spermatogenesis in Pla2g3–/– mice was grossly normal, spermatozoa isolated from the cauda epididymidis displayed hypomotility, and their ability to fertilize intact eggs was markedly impaired. Transmission EM further revealed that epididymal spermatozoa in Pla2g3–/– mice had both flagella with abnormal axonemes and aberrant acrosomal structures. During epididymal transit, phosphatidylcholine in the membrane of Pla2g3+/+ sperm underwent a dramatic shift in its acyl groups from oleic, linoleic, and arachidonic acids to docosapentaenoic and docosahexaenoic acids, whereas this membrane lipid remodeling event was compromised in sperm from Pla2g3–/– mice. Moreover, the gonads of Pla2g3–/– mice contained less 12/15-lipoxygenase metabolites than did those of Pla2g3+/+ mice. Together, our results reveal a role for the atypical sPLA2 family member sPLA2-III in epididymal lipid homeostasis and indicate that its perturbation may lead to sperm dysfunction. PMID:20424323

Recovery of motile sperm using the migration-sedimentation technique in an in-vitro fertilization-embryo transfer programme.

PubMed

Lucena, E; Lucena, C; Gómez, M; Ortiz, J A; Ruiz, J; Arango, A; Diaz, C; Beuerman, C

1989-02-01

Sperm washing techniques, based on the swim-up principle used before inseminating the human oocyte in in-vitro fertilization and embryo transfer programmes (IVF-ET), usually require prior centrifugation which causes damage to the sperm cell. A technique is described for separating sperm at laboratory temperature based on sperm migration--sedimentation principles, using two concentric tubes and recovering 70-90% forward-moving cells. A group of 17 patients is presented who were managed with this method. The results were 85% fertilization rate, 4% polyspermia and six clinical pregnancies.

Why small males have big sperm: dimorphic squid sperm linked to alternative mating behaviours

PubMed Central

2011-01-01

Background Sperm cells are the target of strong sexual selection that may drive changes in sperm structure and function to maximize fertilisation success. Sperm evolution is regarded to be one of the major consequences of sperm competition in polyandrous species, however it can also be driven by adaptation to the environmental conditions at the site of fertilization. Strong stabilizing selection limits intra-specific variation, and therefore polymorphism, among fertile sperm (eusperm). Here we analyzed reproductive morphology differences among males employing characteristic alternative mating behaviours, and so potentially different conditions of sperm competition and fertilization environment, in the squid Loligo bleekeri. Results Large consort males transfer smaller (average total length = 73 μm) sperm to a female's internal sperm storage location, inside the oviduct; whereas small sneaker males transfer larger (99 μm) sperm to an external location around the seminal receptacle near the mouth. No significant difference in swimming speed was observed between consort and sneaker sperm. Furthermore, sperm precedence in the seminal receptacle was not biased toward longer sperm, suggesting no evidence for large sperm being favoured in competition for space in the sperm storage organ among sneaker males. Conclusions Here we report the first case, in the squid Loligo bleekeri, where distinctly dimorphic eusperm are produced by different sized males that employ alternative mating behaviours. Our results found no evidence that the distinct sperm dimorphism was driven by between- and within-tactic sperm competition. We propose that presence of alternative fertilization environments with distinct characteristics (i.e. internal or external), whether or not in combination with the effects of sperm competition, can drive the disruptive evolution of sperm size. PMID:21831296

Why small males have big sperm: dimorphic squid sperm linked to alternative mating behaviours.

PubMed

Iwata, Yoko; Shaw, Paul; Fujiwara, Eiji; Shiba, Kogiku; Kakiuchi, Yasutaka; Hirohashi, Noritaka

2011-08-10

Sperm cells are the target of strong sexual selection that may drive changes in sperm structure and function to maximize fertilisation success. Sperm evolution is regarded to be one of the major consequences of sperm competition in polyandrous species, however it can also be driven by adaptation to the environmental conditions at the site of fertilization. Strong stabilizing selection limits intra-specific variation, and therefore polymorphism, among fertile sperm (eusperm). Here we analyzed reproductive morphology differences among males employing characteristic alternative mating behaviours, and so potentially different conditions of sperm competition and fertilization environment, in the squid Loligo bleekeri. Large consort males transfer smaller (average total length = 73 μm) sperm to a female's internal sperm storage location, inside the oviduct; whereas small sneaker males transfer larger (99 μm) sperm to an external location around the seminal receptacle near the mouth. No significant difference in swimming speed was observed between consort and sneaker sperm. Furthermore, sperm precedence in the seminal receptacle was not biased toward longer sperm, suggesting no evidence for large sperm being favoured in competition for space in the sperm storage organ among sneaker males. Here we report the first case, in the squid Loligo bleekeri, where distinctly dimorphic eusperm are produced by different sized males that employ alternative mating behaviours. Our results found no evidence that the distinct sperm dimorphism was driven by between- and within-tactic sperm competition. We propose that presence of alternative fertilization environments with distinct characteristics (i.e. internal or external), whether or not in combination with the effects of sperm competition, can drive the disruptive evolution of sperm size.

The Role of SPRASA in Female Fertility

PubMed Central

Wagner, Angela; Tong, Mancy; Shelling, Andrew N.; Chamley, Lawrence W.

2014-01-01

Fertility is a complex process and infertility can have many causes. Sperm protein reactive with antisperm antibody (SPRASA)/sperm lysozyme-like protein 1 is a protein discovered as the target of autoantibodies in infertile men and previously thought to be expressed only in sperm. Using a bovine in vitro fertilization model, we have shown that SPRASA antiserum reduced sperm binding to zona-free oocytes and the development of embryos to morulae but did not affect the postfertilization cleavage rate to 2 cells or sperm motility. We demonstrated that SPRASA was expressed in ovarian follicles, corpora lutea, and oocytes by a combination of reverse transcription-polymerase chain reaction and immunohistochemistry. Female mice immunized with SPRASA had profound infertility following timed matings and those mice that did become pregnant had reduced fetal viability. The levels of antibodies reactive with SPRASA in 204 fertile and 202 infertile couples were elevated in 3 infertile but no fertile women. Together, these results indicate that SPRASA has a role in female fertility. PMID:25038051

Viability and fertilizing capacity of cryopreserved sperm from three North American acipenseriform species: A retrospective study

USGS Publications Warehouse

Horvath, A.; Wayman, W.R.; Dean, J.C.; Urbanyi, B.; Tiersch, T.R.; Mims, S.D.; Johnson, D.; Jenkins, J.A.

2008-01-01

Populations of sturgeon across the globe are threatened due to unregulated harvest and habitat loss, and the status varies among species across North America. Ready access to viable and functional sperm would contribute to recovery programmes for these species. In this study, we examined the motility, viability (cell membrane integrity) of cryopreserved sperm from three North American acipenseriform species and fertilizing capacity. Milt samples were collected from captive shortnose sturgeon (Acipenser brevirostrum), wild paddlefish (Polyodon spathula) and pallid sturgeon (Scaphirhynchus albus) and cryopreserved using combinations of Modified Tsvetkova's (MT) extender, Original Tsvetkova's extender, and modified Hanks' balanced salt solution, along with the cryoprotectants methanol (MeOH) or dimethyl sulfoxide (DMSO). A dual-staining technique using the fluorescent stains SYBR-14 and propidium iodide was employed with flow cytometry to determine the percentages of spermatozoa that were viable by virtue of having intact membranes. The percentage of viable spermatozoa ranged from 5% to 12% in shortnose sturgeon, 30-59% in paddlefish, and 44-58% in pallid sturgeon. In the first experiment with shortnose sturgeon sperm, methanol allowed for higher values for dependent variables than did DMSO, and sperm viability generally correlated with post-thaw motility. However, fertilization rate, neurulation, or hatching rates were independent from these factors. In the second experiment with shortnose sturgeon, 5% MeOH combined with MT yielded higher values for all parameters tested than the other combinations: viability was correlated with motility, fertilization rate, and hatching rate. Overall, viability and post-thaw motility was not affected by the use of hyperosmotic extenders (OT) or cryoprotectants (DMSO), but their use decreased fertilization percentages. For paddlefish sperm (experiment 3), MT combined with 10% MeOH was clearly a good choice for cryopreservation; viability and motility results were correlated, but independent of fertilization. For pallid sturgeon sperm (experiment 4), MT with 5-10% MeOH showed significantly higher sperm quality and fertilization parameters. Membrane integrity can be used as a predictor of fertilization by cryopreserved sperm, however additional sperm quality parameters, supplementary to motility and membrane integrity, would be useful in the refining and optimizing cryopreservation protocols with acipenseriform sperm. ?? 2008 Blackwell Verlag, Berlin.

Gene banking of the neotropical fish Leporinus obtusidens (Valenciennes, 1836): a protocol to freeze its sperm in the field.

PubMed

Taitson, P F; Chami, E; Godinho, H P

2008-05-01

A practical sperm cryopreservation protocol using a dry-shipper and a diluent of simple composition is described for the neotropical fish Leporinus obtusidens (Valenciennes, 1836). The cooling rate of the dry-shipper and its period of useful time, established under laboratory conditions, were respectively 25.7-30.8 degrees C/min (between 0 and -60 degrees C) and 9 days after charging. Sperm donors were selected on the basis of their hyperemic genital papilla and the ability to ooze milt under gentle manual pressure, during the reproductive months of November to January. Milt volume (1.3+/-0.3 mL; n=9 fish), fresh sperm motility rate (93.3+/-2.5%; n=6 fish), and sperm concentration (10.9+/-3.0 x 10(9)spermatozoa/mL of milt) were obtained. The sperm cryopreservation experiments were conducted with the following cryoprotectants (all at 10%, before mixing with milt): dimethyl sulphoxide (DMSO; n=10 fish), methanol (n=6 fish), propanediol (n=6 fish) and ethylene glycol (n=5 fish). Glucose (5%) and hen's egg yolk (10%) made up the diluents containing DMSO, ethylene glycol or propanediol. Milk powder (10%) replaced hen's egg yolk in the diluent containing methanol. Distilled water (up to 100%) completed the diluent solutions. Milt freezing (in 0.5-mL straws) was performed in the dry-shipper after 1:5 (milt:diluent) dilution. Thawed sperm cryopreserved in DMSO-containing diluent and activated by 119 mM NaHCO(3) gave the highest motility rate (62+/-14%). The fertilizing capacity of L. obtusidens sperm was tested using the combination of DMSO-containing diluent as the cryoprotectant and 119 mM NaHCO(3) as the activating solution. Oocytes were obtained from artificial spawning and fertilized with different proportions of spermatozoa. The greatest rate of fertilization (74%) occurred when the ratio of about 112,000 motile spermatozoa:oocyte was used. Thus, a protocol to freeze L. obtusidens sperm can be elaborated as follows. Milt (<1.5 mL fish(-1)) was readily available only in November to January; a simple solution, composed of 10% DMSO (concentration before adding milt), 5% glucose, and 10% hen yolk egg, in distilled water, was used as sperm diluent; cooling rate of 25-30 degrees C/min, yielded in a portable dry-shipper, was adequate to freeze diluted milt (1:5; milt:diluent), in 5-mL straws; about 112,000 thawed motile spermatozoa:oocyte activated by 119 mM NaHCO(3) assured a fertilization rate of 74%.

Ocean acidification hampers sperm-egg collisions, gamete fusion, and generation of Ca2+ oscillations of a broadcast spawning bivalve, Tegillarca granosa.

PubMed

Shi, Wei; Han, Yu; Guo, Cheng; Zhao, Xinguo; Liu, Saixi; Su, Wenhao; Wang, Yichen; Zha, Shanjie; Chai, Xueliang; Liu, Guangxu

2017-09-01

Although the effect of ocean acidification on fertilization success of marine organisms is increasingly well documented, the underlying mechanisms are not completely understood. The fertilization success of broadcast spawning invertebrates depends on successful sperm-egg collisions, gamete fusion, and standard generation of Ca 2+ oscillations. Therefore, the realistic effects of future ocean pCO 2 levels on these specific aspects of fertilization of Tegillarca granosa were investigated in the present study through sperm velocity trials, fertilization kinetics model analysis, and intracellular Ca 2+ assays, respectively. Results obtained indicated that ocean acidification significantly reduced the fertilization success of T. granosa, which could be accountable by (i) decreased sperm velocity hence reducing the probability for sperm-egg collisions; (ii) lowered probability of gamete fusion for each gamete collision event; and (iii) disrupted intracellular Ca 2+ oscillations. Copyright © 2017 Elsevier Ltd. All rights reserved.

β1 Integrin is an Adhesion Protein for Sperm Binding to Eggs

PubMed Central

Baessler, Keith A.; Lee, Younjoo; Sampson, Nicole S.

2009-01-01

We investigated the role of β1 integrin in mammalian fertilization and the mode of inhibition of fertilinβ-derived polymers. We determined that polymers displaying the Glu-Cys-Asp peptide from the fertilinβ disintegrin domain mediate inhibition of mammalian fertilization through a β1 integrin receptor on the egg surface. Inhibition of fertilization is a consequence of competition with sperm binding to the cell surface, not activation of an egg-signaling pathway. The presence of the β1 integrin on the egg surface increases the rate of sperm attachment, but does not alter the total number of sperm that can attach or fuse to the egg. We conclude that the presence of β1 integrin enhances the initial adhesion of sperm to the egg plasma membrane and that subsequent attachment and fusion are mediated by additional egg and sperm proteins present in the β1 integrin complex. Therefore, the mechanisms by which sperm fertilize wild-type and β1 knockout eggs are different. PMID:19338281

Comparison of embryo development between intracytoplasmic and Piezo-assisted sperm injection after treating mouse sperms by Ca2+ ionophore.

PubMed

Shahverdi, Abdolhossein; Movahedin, Mansoureh; Rezazadeh Valojerdi, Mojtaba; Kazemi Ashtiani, Saeid

2007-10-01

The purpose of this study was to evaluate the efficiency of intracytoplasmic sperm injection (ICSI) and Piezo-assisted sperm injection after pretreatment with calcium ionophore (CaI) on the mouse embryo development. In this study, the conventional ICSI and Piezo-ICSI procedures were used. The efficacy of the methods was examined after mouse matured oocytes were fertilized with or without CaI-treated sperms. Piezo-ICSI demonstrated significantly more favorable results, with a fertilization rate of 64% (conventional ICSI: 42%, P<0.001) and a cleavage rate of 73% (conventional ICSI: 58%, P<0.05). When the Piezo-ICSI procedure was performed with CaI-pretreated sperms, the cleavage rate significantly increased (92% vs. 73%, P<0.05). However, the fertilization rate did not change significantly (64% vs. 56%). The Piezo-ICSI accompanies with CaI-treated sperms is more efficient than the conventional ICSI method for fertilizing and thus obtaining more mouse embryos.

Group X phospholipase A2 is released during sperm acrosome reaction and controls fertility outcome in mice.

PubMed

Escoffier, Jessica; Jemel, Ikram; Tanemoto, Akemi; Taketomi, Yoshitaka; Payre, Christine; Coatrieux, Christelle; Sato, Hiroyasu; Yamamoto, Kei; Masuda, Seiko; Pernet-Gallay, Karin; Pierre, Virginie; Hara, Shuntaro; Murakami, Makoto; De Waard, Michel; Lambeau, Gérard; Arnoult, Christophe

2010-05-01

Ejaculated mammalian sperm must undergo a maturation process called capacitation before they are able to fertilize an egg. Several studies have suggested a role for members of the secreted phospholipase A2 (sPLA2) family in capacitation, acrosome reaction (AR), and fertilization, but the molecular nature of these enzymes and their specific roles have remained elusive. Here, we have demonstrated that mouse group X sPLA2 (mGX) is the major enzyme present in the acrosome of spermatozoa and that it is released in an active form during capacitation through spontaneous AR. mGX-deficient male mice produced smaller litters than wild-type male siblings when crossed with mGX-deficient females. Further analysis revealed that spermatozoa from mGX-deficient mice exhibited lower rates of spontaneous AR and that this was associated with decreased in vitro fertilization (IVF) efficiency due to a drop in the fertilization potential of the sperm and an increased rate of aborted embryos. Treatment of sperm with sPLA2 inhibitors and antibodies specific for mGX blocked spontaneous AR of wild-type sperm and reduced IVF success. Addition of lysophosphatidylcholine, a catalytic product of mGX, overcame these deficiencies. Finally, recombinant mGX triggered AR and improved IVF outcome. Taken together, our results highlight a paracrine role for mGX during capacitation in which the enzyme primes sperm for efficient fertilization and boosts premature AR of a likely phospholipid-damaged sperm subpopulation to eliminate suboptimal sperm from the pool available for fertilization.

Group X phospholipase A2 is released during sperm acrosome reaction and controls fertility outcome in mice

PubMed Central

Escoffier, Jessica; Jemel, Ikram; Tanemoto, Akemi; Taketomi, Yoshitaka; Payre, Christine; Coatrieux, Christelle; Sato, Hiroyasu; Yamamoto, Kei; Masuda, Seiko; Pernet-Gallay, Karin; Pierre, Virginie; Hara, Shuntaro; Murakami, Makoto; De Waard, Michel; Lambeau, Gérard; Arnoult, Christophe

2010-01-01

Ejaculated mammalian sperm must undergo a maturation process called capacitation before they are able to fertilize an egg. Several studies have suggested a role for members of the secreted phospholipase A2 (sPLA2) family in capacitation, acrosome reaction (AR), and fertilization, but the molecular nature of these enzymes and their specific roles have remained elusive. Here, we have demonstrated that mouse group X sPLA2 (mGX) is the major enzyme present in the acrosome of spermatozoa and that it is released in an active form during capacitation through spontaneous AR. mGX-deficient male mice produced smaller litters than wild-type male siblings when crossed with mGX-deficient females. Further analysis revealed that spermatozoa from mGX-deficient mice exhibited lower rates of spontaneous AR and that this was associated with decreased in vitro fertilization (IVF) efficiency due to a drop in the fertilization potential of the sperm and an increased rate of aborted embryos. Treatment of sperm with sPLA2 inhibitors and antibodies specific for mGX blocked spontaneous AR of wild-type sperm and reduced IVF success. Addition of lysophosphatidylcholine, a catalytic product of mGX, overcame these deficiencies. Finally, recombinant mGX triggered AR and improved IVF outcome. Taken together, our results highlight a paracrine role for mGX during capacitation in which the enzyme primes sperm for efficient fertilization and boosts premature AR of a likely phospholipid-damaged sperm subpopulation to eliminate suboptimal sperm from the pool available for fertilization. PMID:20424324

Sperm chromatin maturity and integrity correlated to zygote development in ICSI program.

PubMed

Asmarinah; Syauqy, Ahmad; Umar, Liya Agustin; Lestari, Silvia Werdhy; Mansyur, Eliza; Hestiantoro, Andon; Paradowszka-Dogan, Agnieszka

2016-10-01

This study aimed to evaluate sperm chromatin maturity and integrity of that injected into good-quality oocytes in an in vitro fertilization-intra cytoplasmic sperm injection (IVF-ICSI) program. A cut-off value of sperm chromatin maturity and integrity was developed as a function of their correlation to the zygote development, i.e., embryo formation and cleavage rate. The study assessed sperm chromatin maturity using aniline blue (AB) staining, whereas toluidine blue (TB) staining was used to assess sperm chromatin integrity. Ejaculates from 59 patients undergoing ICSI and 46 fertile normozoospermic donors for determination of normal values of sperm chromatin status were used in this study. Embryo formation and cleavage rates were observed for the period of 3 days after ICSI. There was a significant difference in the percentage of sperm with mature chromatin between ejaculate from ICSI patients and fertile donor (p=0.020); while there was no significant difference in sperm chromatin integrity of both samples (p=0.120). There was no significant correlation between sperm chromatin maturity and either embryo formation or cleavage rate; as well as sperm chromatin integrity to both parameters of zygote development (p>0.05). Furthermore, we found that the cut-off value of sperm chromatin maturity and integrity of the fertile normozoospermic ejaculates were 87.2% and 80.2%, respectively. Using the cut-offs, we found that low sperm chromatin maturity at the level of <87% correlated significantly with the cleavage rate of the zygote (p=0.022; r=0.371); whereas poor sperm chromatin integrity at the level of <80% correlated with embryo formation (p=0.048; r=0,485). In conclusion, this study showed that poor maturity and integrity of sperm chromatin (AB<87% and TB<80%, respectively), could affect zygote development following ICSI. AB: aniline blue; CMA3: chromomycin A3; ICSI: intra cytoplasmic sperm injection; IVF: in vitro fertilization; PBS: phosphate buffer saline; SPSS: Statistical Package for Social Science; TB: toluidine blue; WHO: World Health Organization.

Aminopurvalanol A, a Potent, Selective, and Cell Permeable Inhibitor of Cyclins/Cdk Complexes, Causes the Reduction of in Vitro Fertilizing Ability of Boar Spermatozoa, by Negatively Affecting the Capacitation-Dependent Actin Polymerization

PubMed Central

Bernabò, Nicola; Valbonetti, Luca; Greco, Luana; Capacchietti, Giulia; Ramal Sanchez, Marina; Palestini, Paola; Botto, Laura; Mattioli, Mauro; Barboni, Barbara

2017-01-01

The adoption of high-througput technologies demonstrated that in mature spermatozoa are present proteins that are thought to be not present or active in sperm cells, such as those involved in control of cell cycle. Here, by using an in silico approach based on the application of networks theory, we found that Cyclins/Cdk complexes could play a central role in signal transduction active during capacitation. Then, we tested this hypothesis in the vitro model. With this approach, spermatozoa were incubated under capacitating conditions in control conditions (CTRL) or in the presence of Aminopurvalanol A a potent, selective and cell permeable inhibitor of Cyclins/Cdk complexes at different concentrations (2, 10, and 20 μM). We found that this treatment caused dose-dependent inhibition of sperm fertilizing ability. We attribute this event to the loss of acrosome integrity due to the inhibition of physiological capacitation-dependent actin polymerization, rather than to a detrimental effect on membrane lipid remodeling or on other signaling pathways such as tubulin reorganization or MAPKs activation. In our opinion, these data could revamp the knowledge on biochemistry of sperm capacitation and could suggest new perspectives in studying male infertility. PMID:29312003

Semen collection and fertility in naturally fertile sandhill cranes

USGS Publications Warehouse

Chen, G.; Gee, G.F.; Nicolich, Jane M.; Taylor, J.A.; Urbanek, R.P.; Stahlecker, D.W.

1997-01-01

Aviculturists often ask if semen collection will interfere with fertility in naturally fertile pairs of cranes. We used 12 naturally fertile Florida sandhill crane (Grus canadensis pratensis) pairs for this study, 6 control and 6 experimental. All pairs had produced fertile eggs in previous years and were in out-of-doors pens scattered throughout different pen complexes, within auditory range but physically isolated. Semen was collected on Tuesday mornings and Friday afternoons from 26 February 1993 to 4 June 1993. We used standard artificial insemination methods to collect and to evaluate the semen and spermatozoa. Semen collection did not affect semen quality or quantity. Semen volume, sperm density, sperm motility, sperm morphology, sperm live, sperm number per collection, and male response to semen collection exhibited significant daily variation (P < 0.05). Although semen collection began 13 days before the first egg in the experimental group, we observed no differences in the date of first egg laid or in fertility between experimental and control groups. Also, we observed no differences in the interval between clutches or in the percentage of broken eggs between experimental and control groups. Sires consistently producing better semen samples produced fewer fertile eggs than sires producing poorer semen samples (r = 0.60).

Sperm plasma membrane remodeling during spermiogenetic maturation in men: relationship among plasma membrane beta 1,4-galactosyltransferase, cytoplasmic creatine phosphokinase, and creatine phosphokinase isoform ratios.

PubMed

Huszar, G; Sbracia, M; Vigue, L; Miller, D J; Shur, B D

1997-04-01

Sperm creatine phosphokinase (CK) concentrations and the synthesis of the CK-M isoform reflect normal spermiogenesis and predict maturity and fertilizing potential of ejaculated human spermatozoa. Immature spermatozoa, characterized by cytoplasmic retention and low CK-M to CK-B isoform ratios, are deficient in zona binding and fail to cause pregnancies. Because these sperm lack zona-binding ability, we examined in this study whether beta 1,4-galactosyltransferase (GalTase), a key element of sperm-zona interactions in mice, is diminished in immature human sperm. Unexpectedly, GalTase was overexpressed in immature sperm relative to mature sperm: the levels of cytoplasmic CK and plasma membrane GalTase were positively correlated (r = 0.78, p < 0.001, n = 88). Sperm populations with various levels of cellular maturity, prepared by Percoll gradients, had different CK and GalTase concentrations, but within each subpopulation the relationship between CK and GalTase was maintained (p < 0.01-0.001). GalTase activities in intact and vortex-disrupted sperm fractions were similar, showing that GalTase is present on the surface membrane of human sperm--similar to the situation in all other species assayed. The changes previously reported by our laboratory in zona-binding ability and lipid peroxidation rates (which occur simultaneously with cytoplasmic extrusion), decline in CK activity, and increased expression of the CK-M isoform are suggestive of a remodeling of the sperm surface concomitant with cytoplasmic maturation. The changes reported here in GalTase expression on the surface of maturing spermatozoa prove this hypothesis.

Sperm mitochondria in reproduction: good or bad and where do they go?

PubMed

Luo, Shi-Ming; Schatten, Heide; Sun, Qing-Yuan

2013-11-20

The mitochondrion is the major energy provider to power sperm motility. In mammals, aside from the nuclear genome, mitochondrial DNA (mtDNA) also contributes to oxidative phosphorylation to impact production of ATP by coding 13 polypeptides. However, the role of sperm mitochondria in fertilization and its final fate after fertilization are still controversial. The viewpoints that sperm bearing more mtDNA will have a better fertilizing capability and that sperm mtDNA is actively eliminated during early embryogenesis are widely accepted. However, this may be not true for several mammalian species, including mice and humans. Here, we review the sperm mitochondria and their mtDNA in sperm functions, and the mechanisms of maternal mitochondrial inheritance in mammals. Copyright © 2013. Published by Elsevier Ltd.

Cystic fibrosis transmembrane conductance regulator is correlated closely with sperm progressive motility and normal morphology in healthy and fertile men with normal sperm parameters.

PubMed

Jiang, L-Y; Shan, J-J; Tong, X-M; Zhu, H-Y; Yang, L-Y; Zheng, Q; Luo, Y; Shi, Q-X; Zhang, S-Y

2014-10-01

Cystic fibrosis transmembrane conductance regulator (CFTR) has been demonstrated to be expressed in mature spermatozoa and correlated with sperm quality. Sperm CFTR expression in fertile men is higher than that in infertile men suffering from teratospermia, asthenoteratospermia, asthenospermia and oligospermia, but it is unknown whether CFTR is correlated with sperm parameters when sperm parameters are normal. In this study, 282 healthy and fertile men with normal semen parameters were classified into three age groups, group (I): age group of 20-29 years (98 cases, 27.1 ± 6.2), group (II): age group of 30-39 years (142 cases, 33.7 ± 2.6) and group (III): age group of more than or equal to 40 years (42 cases, 44.1 ± 4.6). Sperm concentration, total count and progressive motility were analysed by computer-assisted sperm analysis. Sperm morphology was analysed by modified Papanicolaou staining. Sperm CFTR expression was conducted by indirect immunofluorescence staining. There was a significant positive correlation (P < 0.001) between CFTR expression and sperm progressive motility (r = 0.221) and normal morphology (r = 0.202), but there were no correlations between sperm CFTR expression and semen volume, sperm concentration, sperm total count as well as male age (P > 0.05). Our findings show that CFTR expression is associated with sperm progressive motility and normal morphology in healthy and fertile men with normal sperm parameters, but not associated with the number of spermatozoa and male age. © 2013 Blackwell Verlag GmbH.

Protein and carbohydrate intake influence sperm number and fertility in male cockroaches, but not sperm viability.

PubMed

Bunning, Harriet; Rapkin, James; Belcher, Laurence; Archer, C Ruth; Jensen, Kim; Hunt, John

2015-03-07

It is commonly assumed that because males produce many, tiny sperm, they are cheap to produce. Recent work, however, suggests that sperm production is not cost-free. If sperm are costly to produce, sperm number and/or viability should be influenced by diet, and this has been documented in numerous species. Yet few studies have examined the exact nutrients responsible for mediating these effects. Here, we quantify the effects of protein (P) and carbohydrate (C) intake on sperm number and viability in the cockroach Nauphoeta cinerea, as well as the consequences for male fertility. We found the intake of P and C influenced sperm number, being maximized at a high intake of diets with a P : C ratio of 1 : 2, but not sperm viability. The nutritional landscapes for male fertility and sperm number were closely aligned, suggesting that sperm number is the major determinant of male fertility in N. cinerea. Under dietary choice, males regulate nutrient intake at a P : C ratio of 1 : 4.95, which is midway between the ratios needed to maximize sperm production and pre-copulatory attractiveness in this species. This raises the possibility that males regulate nutrient intake to balance the trade-off between pre- and post-copulatory traits in this species. © 2015 The Author(s) Published by the Royal Society. All rights reserved.

Feline spermatozoa from fresh and cryopreserved testicular tissues have comparable ability to fertilize matured oocytes and sustain the embryo development after intracytoplasmic sperm injection.

PubMed

Buarpung, S; Tharasanit, T; Comizzoli, P; Techakumphu, M

2013-01-01

Cryopreservation of testicular tissue associated with intracytoplasmic sperm injection (ICSI) is a critical tool that still needs to be explored for preserving the fertility of endangered species. Using the domestic cat as a model for wild felids, the study aimed at determining the effect of different cryoprotectants and freezing techniques (two-step freezing vs. controlled slow freezing) on the sperm quality (membrane and DNA integrity). Then, spermatozoa were extracted from frozen-thawed testicular tissues and used for ICSI to assess early gamete activation or developmental competence in vitro. The percentage of spermatozoa with intact plasma membrane was not different (P > 0.05) among nonfrozen control, glycerol-, and ethylene glycol-frozen tissues (63.2 ± 2%, 58.2 ± 2.6%, 53.3 ± 2.3%, respectively). However, these percentages were significantly lower (P < 0.05) in groups of dimethyl sulfoxide (46.3 ± 3.3%) and 1,2 propanediol (44.3 ± 2.9%) when compared with control. Conventional freezing combined with 5% (vol/vol) glycerol best preserved sperm membrane integrity (55.0 ± 2.7%) when compared with other freezing techniques. The incidence of DNA fragmentation was found to be low (0.2%-1.1%) in all freezing protocols. After ICSI with frozen testicular spermatozoa, male and female gametes were asynchronously activated and the percentages of normal fertilization at 6, 12, and 18 hours were 11.2%, 20.6%, and 22.1%, respectively. Metaphase II-arrested oocytes containing or not a decondensed sperm head were predominantly found after ICSI with frozen testicular spermatozoa. Although two-pronucleus formation could be observed as soon as 6 hours post ICSI (10%), the rate increased dramatically after 12 and 18 hours post ICSI (17.2% and 19.5%, respectively). ICSI using frozen-thawed testicular spermatozoa yielded cleavage (32.7%), morula (6.5%), and blastocyst (4.4%) percentages similar to nonfrozen control (P > 0.05). It is concluded that conventional freezing technique with glycerol as a principle cryoprotectant is simplified and applicable for cat testicular tissue cryopreservation. We also demonstrate for the first time that feline spermatozoa derived from frozen-thawed testicular tissues retain their fertilizing ability and can be used to produce ICSI-derived embryos. Copyright © 2013 Elsevier Inc. All rights reserved.

Evolution of sperm quality but not quantity in the internally fertilized fish Xiphophorus nigrensis.

PubMed

Smith, C C; Ryan, M J

2010-08-01

Species with alternative reproductive strategies are characterized by discrete differences among males in suites of traits related to competition for fertilizations. Models predict sneaker males should allocate more resources to their ejaculates because they experience sperm competition more frequently and often occupy a disfavoured 'role' owing to subordinance in intramale competition and female preferences for larger males. We examined whether sperm number and quality differed between male strategies in the internally fertilized fish Xiphophorus nigrensis and explored the relationship between sperm morphology and performance. We found sneaker males had similar testes sizes compared to courting males but ejaculates with both more viable and longer lived sperm. Sneaker sperm also had longer midpieces, which was positively correlated with both velocity and longevity. Our study suggests that the evolution of sperm quantity and quality can be decoupled and that the sperm morphology is likely to play an important role in mediating sperm competition through its effects on sperm performance.

Chromatin-unstable boar spermatozoa have little chance of reaching oocytes in vivo.

PubMed

Ardón, Florencia; Helms, Dietmar; Sahin, Evrim; Bollwein, Heinrich; Töpfer-Petersen, Edda; Waberski, Dagmar

2008-04-01

In the present study, the prevalence of chromatin instability in the fertilizing-competent sperm population in the porcine oviduct in vivo was examined through qualitative analysis of the chromatin structure status of accessory boar sperm found in in vivo-derived embryos. The binding of chromatin-unstable sperm to oviductal epithelium in vitro was also studied. To examine the sperm chromatin state, a modified fluorescence microscopic sperm chromatin structure assay was used. Among a population of 173 fertile boars, individuals were selected for according to their chromatin status: 25 animals showed more than 5% of chromatin-unstable sperm in their ejaculates, and 7 showed consistently elevated percentages of chromatin-unstable sperm in three successively collected semen samples. A positive correlation was found between incidence of chromatin instability and attached cytoplasmic droplets (r=0.44, P<0.01). Analyses of accessory spermatozoa from in vivo-derived embryos demonstrated that the proportion of chromatin-unstable sperm was significantly (P<0.05) reduced in the population of fertilizing-competent sperm in the oviduct compared with the inseminated sperm. Populations of sperm bound to the oviduct in vitro had significantly (P<0.05) lower percentages of chromatin instability than in the original diluted semen sample. In conclusion, numbers of sperm with unstable chromatin are reduced in the oviductal sperm reservoir, possibly because of associated changes in the plasma membrane that prevent sperm from binding to the oviductal epithelium. We conclude that in vivo the likelihood that sperm with unstable chromatin will reach the egg and fertilize it is low.

PRESENTED AT TRIANGLE CONSORTIUM FOR REPRODUCTIVE BIOLOGY MEETING IN CHAPEL HILL, NC ON 2/11/2006: SPERM COUNT DISTRIBUTIONS IN FERTILE MEN

EPA Science Inventory

Sperm concentration and count are often used as indicators of environmental impacts on male reproductive health. Existing clinical databases may be biased towards sub-fertile men with low sperm counts and less is known about expected sperm count distributions in cohorts of ferti...

[Comparison of seminal vitamin B12, folate, reactive oxygen species and various sperm parameters between fertile and infertile males].

PubMed

Chen, Q; Ng, V; Mei, J; Chia, S E

2001-03-01

Vitamin B12(VB12), folate and reactive oxygen species(ROS) in human semen from both fertile and infertile males, and their relationships with other parameters were observed. Semen samples from 44 infertile and 176 fentile control subjects were collected and measured based on the guidelines issued by WHO. The results showed that no significant differences on semen VB12 and folate were observed between fertile and infertile groups(P > 0.05). However, the levels of ROS in infertile group were significantly higher than those in fertile group(P < 0.01). The morphological defects and low motility of sperm in infertile group was significantly higher than those in fertile group(P < 0.01). A positive relation was observed between the levels of ROS production and the morphological defect of sperm(P < 0.01). There was a significant negative correlation between the levels of VB12, folate and ROS(P < 0.01) in semen. It is interesting to note that the values of ROS also show a significantly positive correlation with sperm motility (P < 0.01). A significant differences of ROS levels between fertile and infertile group with negative white blood cells in sperm was also observed. It is concluded that the increase of ROS on the morphological defect of sperm is one of the most important factors related to poor sperm quality and human infertility.

Polyspermy in birds: sperm numbers and embryo survival

PubMed Central

Hemmings, N.; Birkhead, T. R.

2015-01-01

Polyspermy is a major puzzle in reproductive biology. In some taxa, multiple sperm enter the ovum as part of the normal fertilization process, whereas in others, penetration of the ovum by more than one sperm is lethal. In birds, several sperm typically enter the germinal disc, yet only one fuses with the female pronucleus. It is unclear whether supernumerary sperm play an essential role in the avian fertilization process and, if they do, how females regulate the progression of sperm through the oviduct to ensure an appropriate number reach the ovum. Here, we show that when very few sperm penetrate the avian ovum, embryos are unlikely to survive beyond the earliest stages of development. We also show that when the number of inseminated sperm is limited, a greater proportion than expected reach and penetrate the ovum, indicating that females compensate for low sperm numbers in the oviduct. Our results suggest a functional role for supernumerary sperm in the processes of fertilization and early embryogenesis, providing an exciting expansion of our understanding of sperm function in birds. PMID:26511048

Fertilization Is Not a New Beginning: The Relationship between Sperm Longevity and Offspring Performance

PubMed Central

Crean, Angela J.; Dwyer, John M.; Marshall, Dustin J.

2012-01-01

Sperm are the most diverse cell type known: varying not only among- and within- species, but also among- and within-ejaculates of a single male. Recently, the causes and consequences of variability in sperm phenotypes have received much attention, but the importance of within-ejaculate variability remains largely unknown. Correlative evidence suggests that reduced within-ejaculate variation in sperm phenotype increases a male’s fertilization success in competitive conditions; but the transgenerational consequences of within-ejaculate variation in sperm phenotype remain relatively unexplored. Here we examine the relationship between sperm longevity and offspring performance in a marine invertebrate with external fertilization, Styela plicata. Offspring sired by longer-lived sperm had higher performance compared to offspring sired by freshly-extracted sperm of the same ejaculate, both in the laboratory and the field. This indicates that within-ejaculate differences in sperm longevity can influence offspring fitness – a source of variability in offspring phenotypes that has not previously been considered. Links between sperm phenotype and offspring performance may constrain responses to selection on either sperm or offspring traits, with broad ecological and evolutionary implications. PMID:23155458

Effect of Pseudomonas aeruginosa on sperm capacitation and protein phosphorylation of boar spermatozoa.

PubMed

Sepúlveda, Lilian; Bussalleu, Eva; Yeste, Marc; Bonet, Sergi

2016-05-01

Several studies have reported the detrimental effects that bacteriospermia causes on boar sperm quality, but little is known about its effects on IVC. Considering that, the present study sought to evaluate the effects of different concentrations of Pseudomonas aeruginosa on different indicators of capacitation status (sperm viability, membrane lipid disorder, sperm motility kinematics, and protein phosphorylation of boar spermatozoa) after IVC. Flow cytometry and computer assisted sperm analysis (CASA) revealed that the presence of P aeruginosa in boar sperm samples, mostly at concentrations greater than 10(6) CFU/mL, is associated with a significant (P < 0.05) decrease in the percentages of both sperm membrane integrity and sperm with low membrane lipid disorder, and also with a reduction in sperm motility kinetic parameters when compared with results obtained from the control sample, which presented the typical motility pattern of capacitated-like boar spermatozoa. Moreover, Western blot results also showed significant (P < 0.05) changes in the levels of tyrosine, serine, and threonine protein phosphorylation because of bacterial contamination, the decrease in phosphotyrosine levels of p32, a well-known marker of IVC achievement in boar sperm, being the most relevant. Indeed, after 3 hours of IVC, phosphotyrosine levels of p32 in the control sample were 3.13 ± 0.81, whereas in the tubes with 10(6) and 10(8) CFU/mL were 1.05 ± 0.20 and 0.36 ± 0.07, respectively. Therefore, the present study provides novel data regarding the effects of bacterial contamination on boar sperm, suggesting that the presence of P aeruginosa affects the fertilizing ability of boar sperm by altering its ability to accomplish IVC. Copyright © 2016 Elsevier Inc. All rights reserved.

Cytoplasmic extrusion and the switch from creatine kinase B to M isoform are completed by the commencement of epididymal transport in human and stallion spermatozoa.

PubMed

Huszar, G; Patrizio, P; Vigue, L; Willets, M; Wilker, C; Adhoot, D; Johnson, L

1998-01-01

Although in several species there is a relationship between epididymal sperm transport and fertility, in human in vitro fertilization (IVF), spermatozoa recovered from the caput epididymidis or even the rete testis are fertile. We studied two objective markers of sperm maturity in the sperm of men and stallions: creatine kinase (CK) concentrations, which are a measure of cytoplasmic retention in immature spermatozoa, and the ratio of CK-M and CK-B isoforms (% CK-M/[CK-M + CK-B]), which is proportional to the incidence of mature sperm. The CK markers and the fertilizing function are closely related: Immature sperm with cytoplasmic retention do not bind to the zona, because during cytoplasmic extrusion, the sperm plasma membrane is also remodeled. We examined whether changes in sperm CK values are still ongoing during epididymal transport, or if cellular maturation is completed prior to the arrival of sperm in the caput epididymidis. The incidences of mature sperm in human caput and corpus epididymidis (studied in six men with obstructive azoospermia of various pathogeneses) were (mean+/-SEM) 55.7+/-2.2 and 49.3+/-7.6%, respectively; and the sperm CK-M ratios in the caput epididymidis of three men were 72, 75, and 70%, values that are similar to those of ejaculated sperm. In four segments of the proximal and distal epididymis of three stallions (the origin of sperm was also verified by the position of the cytoplasmic droplet) and in ejaculate of five stallions, the incidences of mature sperm were 88.2+/-6.2, 89.0+/-6.7, 90.3+/-7.8, 87.6+/-5.9, and 86.7+/-0.8%, and the respective CK-M ratios were 75.0+/-8.7, 84.2+/-2.9, 87.9+/-1.2, 92.5+/-1.5, and 69.3+/-3.5%. There were no differences in the incidences of mature and immature spermatozoa or in CK-M ratios among sperm arising from the various epididymal regions or from the ejaculate in men or stallions. Thus, the cellular maturation events in sperm, as detected by the CK markers, are completed by the time the sperm commences epididymal transport. These findings are in agreement with the IVF fertility of sperm aspirated from the male reproductive tract. The data may also suggest that the primary role of sperm epididymal transport in men is to remodel the plasma membrane to enhance sperm functional integrity in the diverse environments of the male and female reproductive tracts prior to fertilization.

A critical role of solute carrier 22a14 in sperm motility and male fertility in mice

PubMed Central

Maruyama, Shin-ya; Ito, Momoe; Ikami, Yuusuke; Okitsu, Yu; Ito, Chizuru; Toshimori, Kiyotaka; Fujii, Wataru; Yogo, Keiichiro

2016-01-01

We previously identified solute carrier 22a14 (Slc22a14) as a spermatogenesis-associated transmembrane protein in mice. Although Slc22a14 is a member of the organic anion/cation transporter family, its expression profile and physiological role have not been elucidated. Here, we show that Slc22a14 is crucial for sperm motility and male fertility in mice. Slc22a14 is expressed specifically in male germ cells, and mice lacking the Slc22a14 gene show severe male infertility. Although the overall differentiation of sperm was normal, Slc22a14−/− cauda epididymal spermatozoa showed reduced motility with abnormal flagellar bending. Further, the ability to migrate into the female reproductive tract and fertilise the oocyte were also impaired in Slc22a14−/− spermatozoa. The abnormal flagellar bending was thought to be partly caused by osmotic cell swelling since osmotic challenge or membrane permeabilisation treatment alleviated the tail abnormality. In addition, we found structural abnormalities in Slc22a14−/− sperm cells: the annulus, a ring-like structure at the mid-piece–principal piece junction, was disorganised, and expression and localisation of septin 4, an annulus component protein that is essential for the annulus formation, was also impaired. Taken together, our results demonstrated that Slc22a14 plays a pivotal role in normal flagellar structure, motility and fertility in mouse spermatozoa. PMID:27811987

Retained fertilizing capability in cryopreserved feline spermatozoa.

PubMed

Chatdarong, K

2017-04-01

Sperm cryopreservation offers a long-term preservation of male genetic materials for future assisted reproductive technologies. However, dramatic changes in temperature during freezing and thawing injure sperm cells. While motility is essential for AI and membrane integrity is crucial for in vitro fertilization (IVF), sperm DNA integrity is a common index of fertilizing capability required for AI, IVF and intracytoplasmic sperm injection (ICSI). In endangered felids died unexpectedly, attempts have been made to recover as many DNA intact spermatozoa as possible from epididymis and testis to increase the opportunity to produce offspring in future. Although sperm from caudal epididymis has shown retained fertilizing capability after freezing and thawing (27.3% conception rate after unilateral intrauterine insemination), sperm recovery from the corpus epididymis has been suggested as an alternative to increase the amount of preserved genetic materials. To improve epididymal sperm quality, pre-treatment with single-layer centrifugation resulted in selection of sperm cells with intact DNA while post-thaw treatment with extracellular ATP incubation promoted the blastocyst rate. Cold storage of domestic cat testis for 7 days at 4°C demonstrated <1% of sperm cells with fragmented DNA. Moreover, isolated testicular sperm cells, stored for 7 days at 4°C, produced after ICSI poorer percentages of cleavage, morula and blastocyst than the fresh control. In wild felids, a death-to-necropsy time of 2 hr after a jungle cat (Felis chaus) aged 10 years died during anaesthesia plus another necropsy-to-sperm recovery time of 25 hr has been reported to yield the post-thawed testicular sperm with 22.2% intact DNA. In summary, the chromatin structure of feline ejaculated and epididymal sperm seems to be tolerated to cold storage and cryopreservation; thus, fertilizing capability is well protected. In contrast, the cat testicular sperm DNA is generally damaged through the cryopreservation. © 2016 Blackwell Verlag GmbH.

Evaluation of glycerol removal techniques, cryoprotectants, and insemination methods for cryopreserving rooster sperm with implications of regeneration of breed or line or both.

PubMed

Purdy, P H; Song, Y; Silversides, F G; Blackburn, H D

2009-10-01

A series of experiments was designed to evaluate the quality of cryopreserved rooster sperm and its fertility so that programs needing to bank germplasm and recreate animals can do so utilizing a minimal amount of cryopreserved semen. In experiment 1, rooster semen from the National Animal Germplasm Program genebank was thawed and glycerol was removed using a discontinuous Accudenz column or by stepwise dilution. The postthaw sperm motilities, plasma membrane integrity, and concentration were determined before and after deglycerolization. Line differences in postthaw sperm concentration and progressive motility were observed before deglycerolization (P<0.05). After glycerol removal, the sperm that was centrifuged through Accudenz had greater total motility (37 vs. 33% sperm; P<0.05), but use of the stepwise dilution method recovered more sperm per milliliter (320.4x10(6)) compared with the Accudenz method (239.2x10(6) sperm; P<0.05; range across 6 lines of 165.7 to 581.0x10(6) sperm/mL). In experiment 2, rooster semen was cryopreserved using Lake's diluent containing either dimethyl acetamide (DMA) or glycerol as the cryoprotectants. Postthaw analysis revealed that the samples cryopreserved with glycerol survived freezing better, determined by total motility (47.8 and 15.1% glycerol and DMA samples, respectively; P<0.05) and annexin V analyses (1.6 and 11.3% membrane-damaged sperm for glycerol and DMA samples, respectively; P<0.05). Differences in sperm motilities (total and progressive motility) and velocities (path velocity, straight-line velocity, curvilinear velocity) were observed between the 2 cryoprotectant treatments once the glycerol had been removed from those samples cryopreserved with glycerol, of which the glycerol samples had significantly more motile sperm and higher velocities (P<0.05). The fertility of the samples frozen using the 2 cryoprotectants was tested using a single insemination (intravaginal or intramagnal) of 200x10(6) sperm and the fertility (number of live embryos) was evaluated over 18 d. Overall, the intravaginal inseminations had lower fertility than the intramagnal inseminations (P<0.05). In the intravaginal inseminations, the sperm cryopreserved using DMA resulted in lower fertility, but there were no differences in fertility in the intramagnal inseminations due to cryoprotectant (P>0.05). These results indicate that reasonable postthaw sperm quality and fertility can be derived using cryopreserved rooster semen. By utilizing this information, estimations can be made for storing sufficient material for line or breed, or both, recreation programs.

Dynamic resource allocation between pre- and postcopulatory episodes of sexual selection determines competitive fertilization success

PubMed Central

Mehlis, Marion; Rick, Ingolf P.; Bakker, Theo C. M.

2015-01-01

In polyandrous mating systems, male reproductive success depends on both mate-acquisition traits (precopulatory) and sperm competitive abilities (postcopulatory). Empirical data on the interaction between these traits are inconsistent; revealing positive, negative or no relationships. It is generally expected that the investment in pre- and postcopulatory traits is mediated by environmental conditions. To test how dietary resource availability affects sexual ornamentation, sperm quality and their interrelationship in three-spined sticklebacks (Gasterosteus aculeatus), full-sibling groups were raised under three conditions differing in food quantity and/or quality (i.e. carotenoid content): (i) high-quantity/high-quality, (ii) high-quantity/low-quality or (iii) low-quantity/low-quality. After 1 year of feeding, food-restricted males developed a more intense breeding coloration and faster sperm compared with their well-fed brothers, indicating that they allocated relatively more in pre- and postcopulatory traits. Moreover, they outcompeted their well-fed, carotenoid-supplemented brothers in sperm competition trials with equal numbers of competing sperm, suggesting that food-restricted males maximize their present reproductive success. This may result in reduced future reproductive opportunities as food-restricted males suffered from a higher mortality, had an overall reduced body size, and sperm number available for fertilization. In accordance with theory, a trade-off between the investment in pre- and postcopulatory traits was observed in food-restricted males, whereas well-fed males were able to allocate to both traits resulting in a significantly positive relationship. PMID:26490787

Sperm retention site and its influence on cleavage rate and early development following intracytoplasmic sperm injection.

PubMed

Yanaihara, Atsushi; Iwasaki, Shinji; Negishi, Momoko; Okai, Takashi

2006-02-01

Intracytoplasmic sperm injection (ICSI) has risen to the forefront of reproductive technology. In the present study, the location of the sperm injection was noted, and a prospective study was conducted to evaluate the effect of the sperm retention site on cleavage rates and embryo quality after ICSI. This study involved 336 ICSI patients (age 27-44; average 37.4) where 1545 oocytes were observed. An oocyte was divided into nine sites and the sperm retention site was observed microscopically after injection. The polar body was placed at either the twelve or six o'clock position. The injection pipette was introduced at the three o'clock position and oolemma rupture was ascertained by mild suction. The main outcome measures were the relationship of sperm remaining in position in the oocyte to fertilization rate and embryo quality. When the injection pipette was introduced at the three o'clock position, about 80% of the sperm remained in the center or left of center. The fertilization rate was significantly lower (p < 0.05) when the sperm remained near the site of introduction. Embryo quality was not significantly affected by the sperm retention site. About 12-14% of the spermatozoa remained near the introducing position, and in these cases the fertilization rate was low. However, once fertilization occurred, the sperm retention site had minimal impact on embryo quality. Injecting sperm near the spindle site may improve embryo quality.

Fertility-associated antigen on Nelore bull sperm and reproductive outcomes following first-service fixed-time AI of Nelore cows and heifers.

PubMed

Dalton, J C; Deragon, L; Vasconcelos, J L M; Lopes, C N; Peres, R F G; Ahmadzadeh, A

2012-01-15

The objective was to determine whether the presence of fertility-associated antigen (FAA) on sperm collected from Nelore (Bos indicus) bulls can be used to assess potential fertility of sperm for use at first-service fixed-time AI (TAI). Six Nelore bulls were selected based on FAA status (FAA-negative: N = 3; FAA-positive: N = 3) and the ability to produce neat semen with ≥ 70% morphologically normal sperm and 60% estimated progressive motility before cryopreservation. In Experiment 1, suckled multiparous Nelore cows (N = 835) were evaluated for body condition score (BCS) and received an intravaginal progesterone device (CIDR) and 2.0 mg of estradiol benzoate (Day 0). On Day 9 the CIDR was removed, 12.5 mg of PGF(2α) and 0.5 mg of estradiol cypionate were administered, and calves were removed for 48 h. All cows received TAI on Day 11 (48 h after CIDR removal). Pregnancy per TAI (P/TAI) was not different between FAA-positive and FAA-negative bulls (41.5% vs. 39.3%, respectively). There was an effect of AI technician on P/TAI (36.0% vs. 43.9%; P < 0.05) and BCS tended to affect P/TAI (P = 0.09), as cows with BCS ≥ 2.75 were 1.4 times more likely to become pregnant compared with cows with BCS < 2.75. In Experiment 2, nulliparous Nelore heifers (N = 617) were evaluated for BCS and received a CIDR and estradiol benzoate (2.0 mg) on Day 0. On Day 7, all heifers received PGF(2α) (12.5 mg). On Day 9, CIDR inserts were removed and all heifers received estradiol cypionate (0.6 mg) and 200 IU eCG. All heifers received TAI on Day 11 (48 h after CIDR removal). Pregnancy/TAI was different (P = 0.04) between FAA-positive and FAA-negative bulls (33.7% vs. 40.7%, respectively). Presence of FAA on sperm was unsuccessful in assessing the potential fertility of sperm for use in TAI. Copyright © 2012 Elsevier Inc. All rights reserved.

Room temperature storage of mouse epididymal spermatozoa: exploration of factors affecting sperm survival.

PubMed

Sato, Masahiro; Ishikawa, Aki

2004-05-01

To explore optimal conditions for in vitro sperm survival, we examined the effects of several media used for murine egg culture and in vitro fertilization (IVF; including M16, M2, PB1, TYH, and CZB) on motility of murine spermatozoa stored at 22 degrees C under paraffin oil. Of media tested, M2 medium, that had been adjusted to pH 7.2 by adding N-2-hydroxyethylpiperazine-N'-2-ethanesulfonic acid (HEPES), was found to be the best. Addition of various concentrations of HEPES to TYH did not improve sperm survival, suggesting that HEPES (and probably neutral pH) do not enhance survival of murine sperm. Since M16 has higher amounts of bicarbonate than M2 (25 mM versus 4.15 mM), four variations of M16 media containing 4.15, 8.30, 16.60, or 33.20 mM bicarbonate were prepared and tested. The modified M16 media with 4.15-16.60 mM bicarbonate yielded good sperm survival (comparable to M2 medium), while relatively high concentrations of bicarbonate (ranging from 16.60 to 33.20 mM) were deleterious to isolated sperm, suggesting the need for a minimum level of residual bicarbonate. However, the mechanism by which the lifespan of spermatozoa is extended remains unknown. The in vitro fertilizing abilities of spermatozoa left in M2 medium for 1, 3, and 5 days at 22 degrees C were 52.5, 21.8, and 7.0%, respectively, when the cleavage rate to the two-cell stage was examined. Transfer of two-cell embryos produced in vitro with spermatozoa stored for 1, 3, and 5 days at 22 degrees C resulted in production of fetuses with efficiencies of 42.5, 23.4, and 12.5%, respectively, which were lower than that of embryos derived from in vitro fertilization with fresh spermatozoa (68.1%). In conclusion, spermatozoa kept in M2 medium for up to 5 days at 22 degrees C can fertilize oocytes.

Atlantic salmon eggs favour sperm in competition that have similar major histocompatibility alleles.

PubMed

Yeates, Sarah E; Einum, Sigurd; Fleming, Ian A; Megens, Hendrik-Jan; Stet, René J M; Hindar, Kjetil; Holt, William V; Van Look, Katrien J W; Gage, Matthew J G

2009-02-07

Polyandry and post-copulatory sexual selection provide opportunities for the evolution of female differential sperm selection. Here, we examined the influence of variation in major histocompatibility (MH) class I allelic composition upon sperm competition dynamics in Atlantic salmon. We ran in vitro fertilization competitions that mimicked the gametic microenvironment, and replicated a paired-male experimental design that allowed us to compare differences in sperm competition success among males when their sperm compete for eggs from females that were genetically either similar or dissimilar at the MH class I locus. Concurrently, we measured variation in spermatozoal traits that are known to influence relative fertilization success under these conditions. Contrary to the findings demonstrating mechanisms that promote MH complex heterozygosity, our results showed that males won significantly greater relative fertilization success when competing for eggs from genetically similar females at the MH class I. This result also showed covariation with the known influences of sperm velocity on relative fertilization success. We discuss these unexpected findings in relation to sperm-egg recognition and hybridization avoidance mechanisms based upon immunogenetic variation.

Fertilization Mechanisms in Flowering Plants

PubMed Central

Dresselhaus, Thomas; Sprunck, Stefanie; Wessel, Gary M.

2016-01-01

Compared to the animal kingdom, fertilization is particularly complex in flowering plants (angiosperms). Sperm cells of angiosperms have lost their motility and require transportation as a passive cargo by the pollen tube cell to the egg apparatus (egg cell and accessory synergid cells). Sperm cell release from the pollen tube occurs after intensive communication between the pollen tube cell and the receptive synergid, culminating in the lysis of both interaction partners. Following release of the two sperm cells they interact and fuse with two dimorphic female gametes (egg and central cell) forming the major seed components embryo and endosperm, respectively. This process is known as double fertilization. Here we review the current understanding of the processes of sperm cell reception, gamete interaction, their pre-fertilization activation and fusion as well as the mechanisms plants use to prevent the fusion of egg cells with multiple sperm cells. The role of Ca2+ is highlighted in these various processes and comparisons are drawn between fertilization mechanisms in flowering plants and other eukaryotes including mammals. PMID:26859271

New Markers for Predicting Fertility of the Male Gametes in the Post Genomic Age.

PubMed

Dipresa, Savina; De Toni, Luca; Foresta, Carlo; Garolla, Andrea

2018-04-18

A number of test have been proposed to assess male fertility potential, ranging from routine testing by light microscopic method for evaluating semen samples, to screening test for DNA integrity aimed to look at sperm chromatin abnormalities. Spermatozoa are an extremely differentiated cell, they have critical functions for embryo development and heredity, in addiction to delivering a haploid paternal genome to the oocyte. Towards this goal certain requirements must always be met. The ability of spermatozoa to perform its reproductive function taking place in the spermatogenesis, a highly specialized process depending on multiple factors with effect on male fertility. In the past 30 years, large-scale analyses of transcriptomic and genome expression in mammals have generated a large amount of informations on numberless biomolecules involved in spermatogenesis and male germ cell reproductive function. Sperm proteome represents the protein content that spermatozoa needs to survive and work correctly and modifications of sperm proteome play a role in determining functional changes leading to a decrease of reproductive competence into affected spermatozoa. The post-genomic approach consists of different methodologies for concurrently testicular transcriptome studies, protein compositional analysis and metabolomics findings of the spermatozoa in humans. Copyright© Bentham Science Publishers; For any queries, please email at epub@benthamscience.org.

Heat stress affects male reproduction in a parasitoid wasp.

PubMed

Nguyen, Thanh Manh; Bressac, Christophe; Chevrier, Claude

2013-03-01

In insects, reproductive success and survival are affected by temperature. Reproduction is more sensitive than other physiological traits. While the effects of heat stress on females are well known, the effects on males are less clear. Hymenopteran parasitoids are valuable for studying the consequences of heat stress on male reproduction. In these species, through arrhenotoquous parthenogenesis, the sex ratio of the offspring is directly dependent on the sperm stock acquired by females during copulation. In the lab, heat temperature treatments (32-44°C) were applied for 3 days in the pupal stage of Anisopteromalus calandrae males, and development was completed at 30°C. Three different effects were observed depending on the temperature: mortality above 42°C, sterility of emerging males at 40°C, and sub-fertility at 38°C. This sub-fertility is characterized by a dramatic decrease in male sperm supplies, of up to 7% compared to control males. In the course of ageing, the sperm stock of sub-fertile males increases but never reaches the level of control males. Survival was significantly higher in control (30°C) males than those treated at 38°C. Male mating ability was similar whatever the treatment (control and 38°C), but females mated with 38°C-treated males stored 100 times less sperm on average than those mated with control males. The offspring sex ratio of females mated with 38°C-treated males was strongly male biased. The physiological mechanisms are as yet unknown. The relationship between temperature, sperm stock and sex ratio should be taken into account in the management of parasitoids for integrated pest management. Copyright © 2012 Elsevier Ltd. All rights reserved.

Analysis of epididymal sperm maturation by MALDI profiling and top-down mass spectrometry.

PubMed

Labas, Valérie; Spina, Lucie; Belleannee, Clémence; Teixeira-Gomes, Ana-Paula; Gargaros, Audrey; Dacheux, Françoise; Dacheux, Jean-Louis

2015-01-15

The fertilization ability of male gametes is achieved after their transit through the epididymis where important post-gonadal differentiation occurs in different cellular compartments. Most of these maturational modifications occur at the protein level. The epididymal sperm maturation process was investigated using the ICM-MS (Intact Cell MALDI-TOF MS) approach on boar spermatozoa isolated from four different epididymal regions (immature to mature stage). Differential and quantitative MALDI-TOF profiling for whole cells or sub-cellular fractions was combined with targeted top-down MS in order to identify endogenous biomolecules. Using this approach, 172m/z peaks ranging between 2 and 20kDa were found to be modified during maturation of sperm. Using top-down MS, 62m/z were identified corresponding to peptidoforms/proteoforms with post-translational modifications (MS data are available via ProteomeXchange with identifier PXD001303). Many of the endogenous peptides were characterized as N-, C-terminal sequences or internal fragments of proteins presenting specific cleavages, suggesting the presence of sequential protease activities in the spermatozoa. This is the first time that such proteolytic activities could be evidenced for various sperm proteins through quantification of their proteolytic products. ICM-MS/top-down MS thus proved to be a valid approach for peptidome/degradome studies and provided new contributions to understanding of the maturation process of the male gamete involved in the development of male fertility. This peptidomic study (i) characterized the peptidome of epididymal spermatozoa from boar (Sus scrofa); (ii) established characteristic molecular phenotypes distinguishing degrees of maturation of spermatozoa during epididymal transit, and (iii) revealed that protease activities were at the origin of numerous peptides from known and unknown proteins involved in sperm maturation and/or fertility processes. Copyright © 2014 Elsevier B.V. All rights reserved.

Effects of acute postnatal exposure to 3,3',4,4'-tetrachlorobiphenyl on sperm function and hormone levels in adult rats.

PubMed

Hsu, Ping-Chi; Guo, Yueliang Leon; Li, Mei-Hui

2004-02-01

Polychlorinated biphenyls (PCBs) are considered potential endocrine disruptors due to their ability to act as estrogens, antiestrogens and goitrogens. The aim of this study is to ascertain whether acute postnatal treatment with 3,3',4,4'-tetrachlorobiphenyl (CB 77) affects sperm function and hormone levels in adult rats. Male Sprague-Dawley rats received CB 77 by ip injection of 2 or 20 mg/kg at day 21 and sacrificed at day 112. At day 112, right and left testis weights were significantly increased, whereas sperm count, motility, total motile sperm count, curvilinear velocity, average path velocity, straight-line velocity, and beat-cross frequency for motile sperm were significantly decreased in rats treated with 20 mg/kg CB 77. Sperm-oocyte penetration rate was significantly reduced in rats treated with either 2 or 20 mg/kg CB 77. There was high sperm acrosome reaction rate (ARR) in the 20 mg/kg CB 77-treated rats. There was a significant increase in thyroid-stimulating hormone level in the 20 mg/kg CB 77 group. However, no changes were seen in serum testosterone, thyroid hormones, or prolactin concentrations at day 112. In summary, this study showed that postnatal exposure to CB 77 might affect spermatogenesis, motility, ARR, and ability of fertilizing oocytes in mature rats. These results suggest that the sperm functions may be more susceptible or adapt less readily than the thyroid functions to endocrine disruption caused by dioxin-like PCB congeners.

Broiler Breeder Sperm Mobility Phenotype and its Effects on Female Fertility

USDA-ARS?s Scientific Manuscript database

Semen quality in poultry can be characterized by different phenotypic traits including volume, concentration, mobility, viability, and sperm morphology. To date, sperm mobility phenotype has been shown to be the most reliable indicator of male fertilizing potential under artificial insemination (AI...

Rapid evolution of asymmetric reproductive incompatibilities in stalk-eyed flies.

PubMed

Rose, Emily G; Brand, Cara L; Wilkinson, Gerald S

2014-02-01

The steps by which isolated populations acquire reproductive incompatibilities remain poorly understood. One potentially important process is postcopulatory sexual selection because it can generate divergence between populations in traits that influence fertilization success after copulation. Here we present a comprehensive analysis of this form of reproductive isolation by conducting reciprocal crosses between variably diverged populations of stalk-eyed flies (Teleopsis dalmanni). First, we measure seven types of reproductive incompatibility between copulation and fertilization. We then compare fertilization success to hatching success to quantify hybrid inviability. Finally, we determine if sperm competition acts to reinforce or counteract any incompatibilities. We find evidence for multiple incompatibilities in most crosses, including failure to store sperm after mating, failure of sperm to reach the site of fertilization, failure of sperm to fertilize eggs, and failure of embryos to develop. Local sperm have precedence over foreign sperm, but this effect is due mainly to differences in sperm transfer and reduced hatching success. Crosses between recently diverged populations are asymmetrical with regard to the degree and type of incompatibility. Because sexual conflict in these flies is low, postcopulatory sexual selection, rather than antagonistic coevolution, likely causes incompatibilities due to mismatches between male and female reproductive traits. © 2013 The Author(s). Evolution © 2013 The Society for the Study of Evolution.

Monoclonal antibodies, immunofluorometric assay, and detection of human semenogelin in male reproductive tract: no association with in vitro fertilizing capacity of sperm.

PubMed

Koistinen, Hannu; Soini, Tuuli; Leinonen, Jari; Hyden-Granskog, Christel; Salo, Jaakko; Halttunen, Mervi; Stenman, Ulf-Håkan; Seppälä, Markku; Koistinen, Riitta

2002-03-01

Semenogelin plays an important role in sperm clotting and is degraded into smaller fragments by prostate-specific antigen (PSA) during clot liquefaction. Semenogelin and its fragments inhibit sperm motility in vitro. We studied the expression of semenogelin I mRNA and its localization in various tissues of the male genital tract. We also studied semenogelin concentrations with respect to sperm parameters and the outcome of in vitro fertilization. Semenogelin protein was detected by immunohistochemical staining and semenogelin I mRNA was detected by Northern blot analysis in the seminal vesicles and ampullary part of the vas deferens, whereas specimens from the prostate, epididymis, testis, and the female genital tract were negative. Using monoclonal antibodies against semenogelin, an immunofluorometric assay was developed to measure semenogelin levels in seminal plasma and to evaluate possible correlations with sperm parameters and fertilization in vitro. No correlation was found between the semenogelin concentration and the volume of the ejaculate, sperm concentration, sperm motility, or in vitro fertilization rate. Semenogelin levels were positively correlated with the total protein concentration in seminal plasma, and there was an inverse correlation between the concentration of semenogelin and that of PSA. The levels of semenogelin appear to bear no relationship to the in vitro fertilization capacity of the spermatozoa.

Controlling fertilization and cAMP signaling in sperm by optogenetics.

PubMed

Jansen, Vera; Alvarez, Luis; Balbach, Melanie; Strünker, Timo; Hegemann, Peter; Kaupp, U Benjamin; Wachten, Dagmar

2015-01-20

Optogenetics is a powerful technique to control cellular activity by light. The light-gated Channelrhodopsin has been widely used to study and manipulate neuronal activity in vivo, whereas optogenetic control of second messengers in vivo has not been examined in depth. In this study, we present a transgenic mouse model expressing a photoactivated adenylyl cyclase (bPAC) in sperm. In transgenic sperm, bPAC mimics the action of the endogenous soluble adenylyl cyclase (SACY) that is required for motility and fertilization: light-stimulation rapidly elevates cAMP, accelerates the flagellar beat, and, thereby, changes swimming behavior of sperm. Furthermore, bPAC replaces endogenous adenylyl cyclase activity. In mutant sperm lacking the bicarbonate-stimulated SACY activity, bPAC restored motility after light-stimulation and, thereby, enabled sperm to fertilize oocytes in vitro. We show that optogenetic control of cAMP in vivo allows to non-invasively study cAMP signaling, to control behaviors of single cells, and to restore a fundamental biological process such as fertilization.

Phospholipase C-zeta deficiency as a cause for repetitive oocyte fertilization failure during ovarian stimulation for in vitro fertilization with ICSI: a case report.

PubMed

Chithiwala, Zahabiya H; Lee, Hoi Chang; Hill, David L; Jellerette-Nolan, Teru; Fissore, Rafael; Grow, Daniel; Dumesic, Daniel A

2015-09-01

The purpose of this study is to describe impaired oocyte fertilization from phospholipase C-zeta (PLC-ζ) deficiency in normal-appearing sperm that was successfully treated using calcium (Ca(2+)) ionophore with intracytoplasmic sperm injection (ICSI) of oocytes matured in vitro. An infertile couple undergoing in vitro fertilization (IVF) experienced failed oocyte fertilization following ICSI with normal-appearing sperm. A semen sample collected from the patient was used to assess the expression of sperm PLC- ζ protein by Western blot analysis and immunofluorescence and PLC-ζ bioactivity by an in vitro model of Ca(2+) release. A second IVF cycle was performed using Ca(2+) ionophore with ICSI to enhance Ca(2+)-induced oocyte activation of oocytes matured in vitro. Sperm PLC-ζ protein deficiency was demonstrated by Western blot analysis and immunofluorescence and confirmed by reduced PLC-ζ bioactivity using an in vitro model of Ca(2+) release. Nevertheless, with this sperm and supplementation of Ca(2+) ionophore following ICSI, fertilization of four of six oocytes matured in vitro was obtained. In addition, four embryos underwent cleavage and two of them reached the blastocyst stage. Transfer of these blastocysts into the uterus led to a single pregnancy and live birth. Deficiency of PLC-ζ in normal-appearing human sperm is associated with impaired Ca(2+)-dependent oocyte activation during ICSI. Under this condition, use of Ca(2+) ionophore following ICSI of oocytes matured in vitro improves embryo developmental competence, possibly through the activation of Ca(2+)-dependent mechanisms governing fertilization and preimplantation embryogenesis.

Inhibitors of serine proteases decrease sperm penetration during porcine fertilization in vitro by inhibiting sperm binding to the zona pellucida and acrosome reaction.

PubMed

Beek, J; Nauwynck, H; Appeltant, R; Maes, D; Van Soom, A

2015-11-01

Serine proteases are involved in mammalian fertilization. Inhibitors of serine proteases can be applied to investigate at which point these enzymes exert their action. We selected two serine protease inhibitors, 4-(2-aminoethyl)benzenesulfonyl fluoride hydrochloride (AEBSF, 100 μM) and soybean trypsin inhibitor (STI, 5 μM) from Glycine max, via previous dose-response IVF experiments and sperm toxicity tests. In the present study, we evaluated how these inhibitors affect porcine fertilization in vitro as calculated on total fertilization rate, polyspermy rate, and the sperm number per fertilized oocyte of cumulus-intact, cumulus-free, and zona-free oocytes. In the control group (no inhibitor), these parameters were 86%, 49%, and 2.2 for cumulus-intact oocytes and 77%, 43%, and 2.2 for cumulus-free oocytes (6-hour gamete incubation period, 1.25 × 10(5) spermatozoa/mL). 4-(2-Aminoethyl)benzenesulfonyl fluoride hydrochloride and STI significantly reduced total fertilization and polyspermy rate in cumulus-intact and cumulus-free oocytes (P < 0.05). Total fertilization rates were respectively 65% and 53% (AEBSF) and 36% and 17% (STI). Inhibition rates were higher in cumulus-free oocytes than in cumulus-intact oocytes, indicating that inhibitors exerted their action after sperm passage through the cumulus. 4-(2-Aminoethyl)benzenesulfonyl fluoride hydrochloride but not STI reduced sperm binding to the ZP. The acrosome reaction was significantly inhibited by both inhibitors. Only 40.4% (AEBSF) and 11.4% (STI) of spermatozoa completed a calcium-induced acrosome reaction compared to 86.7% of spermatozoa in the control group. There was no effect on sperm binding or fertilization parameters in zona-free oocytes. In conclusion, sperm-zona binding and acrosome reaction were inhibited by serine protease inhibitors during porcine IVF. Copyright © 2015 Elsevier Inc. All rights reserved.

Roles of the zona pellucida and functional exposure of the sperm-egg fusion factor 'IZUMO' during in vitro fertilization in pigs.

PubMed

Tanihara, Fuminori; Nakai, Michiko; Men, Nguyen Thi; Kato, Noriko; Kaneko, Hiroyuki; Noguchi, Junko; Otoi, Takeshige; Kikuchi, Kazuhiro

2014-04-01

The zona pellucida (ZP) is considered to play important roles in the prevention of polyspermy in mammalian oocytes. However, in pigs we have shown that the presence of the ZP accelerates sperm penetration into the ooplasm during in vitro fertilization (IVF). In the present study, we investigated the effects of the ZP on sperm binding, acrosomal status, and functional exposure of IZUMO, a critical factor involved in sperm-egg fusion, during IVF in pigs. We evaluated the numbers and acrosomal statuses of sperm binding to the ZP and oolemma, and being present in the ZP and perivitelline space (PVS) using ZP-intact and ZP-free oocytes. More sperm bound to the ZP than to the oolemma. The average number of sperm present in the PVS was 0.44-0.51 per oocyte, and all sperm had lost their acrosomes. The proportion of sperm that were immunopositive for anti-IZUMO antibody was significantly higher after they were passing or had passed through the ZP. Furthermore, addition of anti-IZUMO antibody to the fertilization medium significantly inhibited the penetration of sperm into ZP-free oocytes. These results suggest that, in pigs, the ZP induces the acrosome reaction, which is associated with the functional exposure of IZUMO, resulting in completion of fertilization. © 2014 Japanese Society of Animal Science.

Transmembrane adenylyl cyclase regulates amphibian sperm motility through Protein Kinase A activation

PubMed Central

O’Brien, Emma D.; Krapf, Darío; Cabada, Marcelo O.; Visconti, Pablo E.; Arranz, Silvia E.

2014-01-01

Sperm motility is essential for achieving fertilization. In animals with external fertilization as amphibians, spermatozoa are stored in a quiescent state in the testis. Spermiation to hypotonic fertilization media triggers activation of sperm motility. Bufo arenarum sperm are immotile in artificial seminal plasma (ASP) but acquire in situ flagellar beating upon dilution. In addition to the effect of low osmolarity on sperm motility activation, we report that diffusible factors of the egg jelly coat (EW) regulate motility patterns, switching from in situ to progressive movement. The signal transduction pathway involved in amphibian sperm motility activation is mostly unknown. In the present study, we show a correlation between motility activation triggered by low osmotic pressure and activation of protein kinase A (PKA). Moreover, this is the first study to present strong evidences that point toward a role of a transmembrane adenyl-cyclase (tmAC) in the regulation of amphibian sperm motility through PKA activation. PMID:21126515

Nuclear microscopy of sperm cell elemental structure

DOE Office of Scientific and Technical Information (OSTI.GOV)

Bench, G.S.; Balhorn, R.; Friz, A.M.

1994-09-28

Theories suggest there is a link between protamine concentrations in individual sperm and male fertility. Previously, biochemical analyses have used pooled samples containing millions of sperm to determine protamine concentrations. These methods have not been able to determine what percentage of morphologically normal sperm are biochemically defective and potentially infertile. Nuclear microscopy has been utilized to measure elemental profiles at the single sperm level. By measuring the amount of phosphorus and sulfur, the total DNA and protamine content in individual sperm from fertile bull and mouse semen have been determined. These values agree with results obtained from other biochemical analyses.more » Nuclear microscopy shows promise for measuring elemental profiles in the chromatin of individual sperm. The technique may be able to resolve theories regarding the importance of protamines to male fertility and identify biochemical defects responsible for certain types of male infertility.« less

Tripeptidyl Peptidase II Regulates Sperm Function by Modulating Intracellular Ca2+ Stores via the Ryanodine Receptor

PubMed Central

Zhou, Yuchuan; Ru, Yanfei; Wang, Chunmei; Wang, Shoulin; Zhou, Zuomin; Zhang, Yonglian

2013-01-01

Recent studies have identified Ca2+ stores in sperm cells; however, it is not clear whether these Ca2+ stores are functional and how they are mobilized. Here, in vitro and in vivo, we determined that tripeptidyl peptidase II antagonists strongly activated the cAMP/PKA signaling pathway that drives sperm capacitation-associated protein tyrosine phosphorylation. We demonstrated that in the absence of Ca2+, TPIII antagonists elevated the intracellular Ca2+ levels in sperm, resulting in a marked improvement in sperm movement, capacitation, acrosome reaction, and the in vitro fertilizing ability. This antagonist-induced release of intracellular Ca2+ could be blocked by the inhibitors of ryanodine receptors (RyRs) which are the main intracellular Ca2+ channels responsible for releasing stored Ca2+. Consistent with these results, indirect immunofluorescence assay using anti-RyR antibodies further validated the presence of RyR3 in the acrosomal region of mature sperm. Thus, TPPII can regulate sperm maturation by modulating intracellular Ca2+ stores via the type 3 RyR. PMID:23818952

What's better than the pill, vasectomy, celibacy and rhythm?

PubMed

Rorvik, D M

1975-01-01

A report of a new technique of male contraception involves the use of heat which lowers the sperm count. Early reports of lowered sperm counts in men wearing jockstraps or increased sperm counts in men whose testicles have been cooled several degrees have led to the experimentation in the male rat of the effects of heat and ultrasound on the sperm count and the ability to fertilize the female. 250 male rats were divided into 5 groups: 1) control, 2) a 60 degree C water circulating testicle cup with 15 minutes exposure, 3) exposure to radiant energy for 15 minutes and raising scrotal temperatures to 60 degrees C, 4) exposure to microwaves of varying powers, and 5) exposure to ultrasound of 1 w/cm to 2 w/cm for 1 minute. Group 2 results indicated that libido was uninhibited, testosterone levels undisturbed a nd organ sizes unaffected by the hot-water treatment. It took 30-35 days for any pregnancies to occur after a single treatment. In group 3, results were substantially the same except that it took 60-75 days for any pregnancies to occur. In group 4, a 20% exposure to radiation for 5 minutes impaired fertility for 65-80 days, while those exposed to 20% for 15 minutes were still infertile at the end of the 10-month study. In these cases libido was also unimpaired. Animals in group 5, exposed to 1 w/cm for 1 minute had impaired fertility for 150-210 days although testicular temperature rose to only 38 degrees C. When exposure to ultr asound was doubled, fertility was impaired throughout the study. In all cases where fertility was restored, resulting offspring appeared normal and were themselves capable of reproducing normal-appearing offspring. Ultrasound was considered the most promising heat source. In all cases the germinal epithelium function is arrested. Future research should be directed to making the ultrasound technique more finely tuned to a contraceptive function.

Essential role of maternal UCHL1 and UCHL3 in fertilization and preimplantation embryo development

PubMed Central

Mtango, Namdori R.; Sutovsky, Miriam; Susor, Andrej; Zhong, Zhisheng; Latham, Keith E.; Sutovsky, Peter

2015-01-01

Posttranslational protein modification by ubiquitination, a signal for lysosomal or proteasomal proteolysis, can be regulated and reversed by deubiquitinating enzymes (DUBs). This study examined the roles of UCHL1 and UCHL3, two members of ubiquitin C-terminal hydrolase (UCH) family of DUBs, in murine fertilization and preimplantation development. Before fertilization, these proteins were associated with the oocyte cortex (UCHL1) and meiotic spindle (UCHL3). Intracytoplasmic injection of the general UCH-family inhibitor ubiquitin-aldehyde (UBAL) or antibodies against UCHL3 into mature metaphase II oocytes blocked fertilization by reducing sperm penetration of the zona pellucida and incorporation into the ooplasm, suggesting a role for cortical UCHL1 in sperm incorporation. Both UBAL and antibodies against UCHL1 injected at the onset of oocyte maturation (germinal vesicle stage) reduced the fertilizing ability of oocytes. The subfertile Uchl1gad−/− mutant mice showed an intriguing pattern of switched UCH localization, with UCHL3 replacing UCHL1 in the oocyte cortex. While fertilization defects were not observed, the embryos from homozygous Uchl1gad−/− mutant females failed to undergo morula compaction and did not form blastocysts in vivo, indicating a maternal effect related to UCHL1 deficiency. We conclude that the activity of oocyte UCHs contributes to fertilization and embryogenesis by regulating the physiology of the oocyte and blastomere cortex. PMID:21678411

Modification of trout sperm membranes associated with activation and cryopreservation. Implications for fertilizing potential

USDA-ARS?s Scientific Manuscript database

Abstract We investigated the effects of two trout sperm activation solutions on sperm physiology and membrane organization prior to and following cryopreservation using flow cytometry and investigated their impact on in vitro fertility. Cryopreservation caused greater phospholipid disorder (high pl...

Pronuclear formation by ICSI using chemically activated ovine oocytes and zona pellucida bound sperm.

PubMed

Hernández-Pichardo, J E; Ducolomb, Y; Romo, S; Kjelland, M E; Fierro, R; Casillas, F; Betancourt, M

2016-01-01

In order to improve ICSI, appropiate sperm selection and oocyte activation is necessary. The objective of the present study was to determine the efficiency of fertilization using ICSI with chemically activated ovine oocytes and sperm selected by swim up (SU) or swim up + zona pellucida (SU + ZP) binding. Experiment 1, 4-20 replicates with total 821 in vitro matured oocytes were chemically activated with ethanol, calcium ionophore or ionomycin, to determine oocyte activation (precense of one PN). Treatments showed similar results (54, 47, 42 %, respectively) but statistically differents ( P  < 0.05) than mechanical activated oocytes in sham, ICSI and sham injection (13, 25, 32 %, respectively) (10-17 replicates; n  = 429). Experiment 2: Twelve ejaculates and 28 straws of semen were used (11-19 replicates). Sperm were selected by SU in BSA-TCM 199-H medium. A total of 2,294 fresh sperm and 2,760 from frozen-thawed semen were analyzed after SU or SU + ZP binding. Fresh sperm selected by SU showed acrosome reaction (AR) of 59 %, the sperm selected by SU + ZP binding increased AR to 91 %. In comparison, the AR of frozen-thawed sperm using SU or SU + ZP binding was 77 and 86 %, respectively ( P  < 0.05). Experiment 3: fertilization in 200 mechanical activativated oocytes (17 replicates) was 4 %, but fertilization increased in ethanol activated oocytes after ICSI (12-28 %) (5-6 replicates). When fresh sperm only selected by SU were injected to 123 oocytes, a fertilization rate (28 %) was achieved; in sperm selected by SU + ZP was 25 % (73 oocytes). In comparison, in frozen-thawed sperm selected by SU, fertilization was 13 % (70 oocytes), whereas sperm from SU + ZP binding displayed 12 % (51 oocytes) ( P  > 0.05). Chemical activation induces higher ovine oocyte activation than mechanical activation. Ethanol slightly displays higher oocyte activation than calcium ionophore and ionomicine. Sperm selection with SU + ZP increased AR/A and AR/D rates in comparison with SU in fresh and frozen-thawed sperm. According to this, in terms of fertilization rates, chemical activation after ICSI increased oocyte PN formation compared to mechanical activation. Also, fresh sperm treated with SU and SU + ZP were significantly different than frozen-thawed sperm, but between sperm treatments no significant differences were obtained.

Changes to Extender, Cryoprotective Medium, and In Vitro Fertilization Improve Zebrafish Sperm Cryopreservation.

PubMed

Matthews, Jennifer L; Murphy, Joy M; Carmichael, Carrie; Yang, Huiping; Tiersch, Terrence; Westerfield, Monte; Varga, Zoltan M

2018-01-25

Sperm cryopreservation is a highly efficient method for preserving genetic resources. It extends the reproductive period of males and significantly reduces costs normally associated with maintenance of live animal colonies. However, previous zebrafish (Danio rerio) cryopreservation methods have produced variable outcomes and low post-thaw fertilization rates. To improve post-thaw fertilization rates after cryopreservation, we developed a new extender and cryoprotective medium (CPM), introduced quality assessment (QA), determined the optimal cooling rate, and improved the post-thaw in vitro fertilization process. We found that the hypertonic extender E400 preserved motility of sperm held on ice for at least 6 h. We implemented QA by measuring sperm cell densities with a NanoDrop spectrophotometer and sperm motility with computer-assisted sperm analysis (CASA). We developed a CPM, RMMB, which contains raffinose, skim milk, methanol, and bicine buffer. Post-thaw motility indicated that the optimal cooling rate in two types of cryogenic vials was between 10 and 15°C/min. Test thaws from this method produced average motility of 20% ± 13% and an average post-thaw fertilization rate of 68% ± 16%.

Unresolved issues in mammalian fertilization.

PubMed

Olds-Clarke, Patricia

2003-01-01

This review considers the role of the sperm in fertilization, addressing areas of misunderstanding and unfounded assumptions and taking particular advantage of the large body of data resulting from work with rodent species in vitro. Considerable attention is given to the appropriate use and interpretation of assays for capacitation, acrosomal exocytosis, hyperactivation, and sperm protein phosphorylation, as well as tests for sperm-zona and sperm-oocyte membrane interactions. The lack of general agreement on the means of sperm adhesion to and penetration of the zona pellucida is addressed, and the need for new approaches to this problem is pointed out. Some molecular advances in our understanding of specific steps in the process of fertilization are discussed in the context of intact cell-matrix and cell-cell interaction. This review should provide practical information for researchers just beginning the study of fertilization and interesting but not widely known observations to stimulate new ideas in experienced scientists.

Reactive oxygen species mediate pollen tube rupture to release sperm for fertilization in Arabidopsis

NASA Astrophysics Data System (ADS)

Duan, Qiaohong; Kita, Daniel; Johnson, Eric A.; Aggarwal, Mini; Gates, Laura; Wu, Hen-Ming; Cheung, Alice Y.

2014-01-01

In flowering plants, sperm are transported inside pollen tubes to the female gametophyte for fertilization. The female gametophyte induces rupture of the penetrating pollen tube, resulting in sperm release and rendering them available for fertilization. Here we utilize the Arabidopsis FERONIA (FER) receptor kinase mutants, whose female gametophytes fail to induce pollen tube rupture, to decipher the molecular mechanism of this critical male-female interactive step. We show that FER controls the production of high levels of reactive oxygen species at the entrance to the female gametophyte to induce pollen tube rupture and sperm release. Pollen tube growth assays in vitro and in the pistil demonstrate that hydroxyl free radicals are likely the most reactive oxygen molecules, and they induce pollen tube rupture in a Ca2+-dependent process involving Ca2+ channel activation. Our results provide evidence for a RHO GTPase-based signalling mechanism to mediate sperm release for fertilization in plants.

Reactive oxygen species mediate pollen tube rupture to release sperm for fertilization in Arabidopsis.

PubMed

Duan, Qiaohong; Kita, Daniel; Johnson, Eric A; Aggarwal, Mini; Gates, Laura; Wu, Hen-Ming; Cheung, Alice Y

2014-01-01

In flowering plants, sperm are transported inside pollen tubes to the female gametophyte for fertilization. The female gametophyte induces rupture of the penetrating pollen tube, resulting in sperm release and rendering them available for fertilization. Here we utilize the Arabidopsis FERONIA (FER) receptor kinase mutants, whose female gametophytes fail to induce pollen tube rupture, to decipher the molecular mechanism of this critical male-female interactive step. We show that FER controls the production of high levels of reactive oxygen species at the entrance to the female gametophyte to induce pollen tube rupture and sperm release. Pollen tube growth assays in vitro and in the pistil demonstrate that hydroxyl free radicals are likely the most reactive oxygen molecules, and they induce pollen tube rupture in a Ca(2+)-dependent process involving Ca(2+) channel activation. Our results provide evidence for a RHO GTPase-based signalling mechanism to mediate sperm release for fertilization in plants.

Slimmer or fertile? Pharmacological mechanisms involved in reduced sperm quality and fertility in rats exposed to the anorexigen sibutramine.

PubMed

Borges, Cibele S; Missassi, Gabriela; Pacini, Enio S A; Kiguti, Luiz Ricardo A; Sanabria, Marciana; Silva, Raquel F; Banzato, Thais P; Perobelli, Juliana E; Pupo, André S; Kempinas, Wilma G

2013-01-01

Sperm acquire motility and fertility capacity during epididymal transit, under the control of androgens and sympathetic innervations. It is already known that the acceleration of epididymal sperm transit time can lead to lower sperm quality. In a previous work we showed that rats exposed to the anorexigen sibutramine, a non-selective serotonin-norepinephrine reuptake inhibitor, presented faster sperm transit time, lower epididymal sperm reserves and potentiation of the tension of epididymal duct to norepinephrine exposed acutely in vitro to sibutramine. In the present work we aimed to further investigate pharmacological mechanisms involved in these alterations and the impact on rat sperm quality. For this, adult male Wistar rats were treated with sibutramine (10 mg/kg/day) or vehicle for 30 days. Sibutramine decreased final body, seminal vesicle, ventral prostate and epididymal weights, as well as sperm transit time in the epididymal cauda. On the contrary of the in vitro pharmacological assays, in which sibutramine was added directly to the bath containing strips of distal epididymal cauda, the ductal tension was not altered after in vivo sub-chronic exposure to sibutramine. However, there is pharmacological evidence that the endogenous epididymal norepinephrine reserves were reduced in these animals. It was also shown that the decrease in prostate weight can be related to increased tension developed of the gland, due to sibutramine sympathomimetic effects. In addition, our results showed reduced sperm quality after in utero artificial insemination, a more sensitive procedure to assess fertility in rodents. The epididymal norepinephrine depletion exerted by sibutramine, associated with decreases in sperm transit time, quantity and quality, leading to reduced fertility in this experimental model, reinforces the concerns about the possible impact on fertility of man taking sibutramine as well as other non-selective serotonin-norepinephrine reuptake inhibitors, especially considering the lower reproductive efficiency of humans compared to males of other species.

Slimmer or Fertile? Pharmacological Mechanisms Involved in Reduced Sperm Quality and Fertility in Rats Exposed to the Anorexigen Sibutramine

PubMed Central

Borges, Cibele S.; Missassi, Gabriela; Pacini, Enio S. A.; Kiguti, Luiz Ricardo A.; Sanabria, Marciana; Silva, Raquel F.; Banzato, Thais P.; Perobelli, Juliana E.; Pupo, André S.; Kempinas, Wilma G.

2013-01-01

Sperm acquire motility and fertility capacity during epididymal transit, under the control of androgens and sympathetic innervations. It is already known that the acceleration of epididymal sperm transit time can lead to lower sperm quality. In a previous work we showed that rats exposed to the anorexigen sibutramine, a non-selective serotonin-norepinephrine reuptake inhibitor, presented faster sperm transit time, lower epididymal sperm reserves and potentiation of the tension of epididymal duct to norepinephrine exposed acutely in vitro to sibutramine. In the present work we aimed to further investigate pharmacological mechanisms involved in these alterations and the impact on rat sperm quality. For this, adult male Wistar rats were treated with sibutramine (10 mg/kg/day) or vehicle for 30 days. Sibutramine decreased final body, seminal vesicle, ventral prostate and epididymal weights, as well as sperm transit time in the epididymal cauda. On the contrary of the in vitro pharmacological assays, in which sibutramine was added directly to the bath containing strips of distal epididymal cauda, the ductal tension was not altered after in vivo sub-chronic exposure to sibutramine. However, there is pharmacological evidence that the endogenous epididymal norepinephrine reserves were reduced in these animals. It was also shown that the decrease in prostate weight can be related to increased tension developed of the gland, due to sibutramine sympathomimetic effects. In addition, our results showed reduced sperm quality after in utero artificial insemination, a more sensitive procedure to assess fertility in rodents. The epididymal norepinephrine depletion exerted by sibutramine, associated with decreases in sperm transit time, quantity and quality, leading to reduced fertility in this experimental model, reinforces the concerns about the possible impact on fertility of man taking sibutramine as well as other non-selective serotonin-norepinephrine reuptake inhibitors, especially considering the lower reproductive efficiency of humans compared to males of other species. PMID:23776614

Rediscovering sperm ion channels with the patch-clamp technique

PubMed Central

Kirichok, Yuriy; Lishko, Polina V.

2011-01-01

Upon ejaculation, mammalian spermatozoa have to undergo a sequence of physiological transformations within the female reproductive tract that will allow them to reach and fertilize the egg. These include initiation of motility, hyperactivation of motility and perhaps chemotaxis toward the egg, and culminate in the acrosome reaction that permits sperm to penetrate the protective vestments of the egg. These physiological responses are triggered through the activation of sperm ion channels that cause elevations of sperm intracellular pH and Ca2+ in response to certain cues within the female reproductive tract. Despite their key role in sperm physiology and their absolute requirement for the process of fertilization, sperm ion channels remain poorly understood due to the extreme difficulty in application of the patch-clamp technique to spermatozoa. This review covers the topic of sperm ion channels in the following order: first, we discuss how the intracellular Ca2+ and pH signaling mediated by sperm ion channels controls sperm behavior during the process of fertilization. Then, we briefly cover the history of the methodology to study sperm ion channels, which culminated in the recent development of a reproducible whole-cell patch-clamp technique for mouse and human cells. We further discuss the main approaches used to patch-clamp mature mouse and human spermatozoa. Finally, we focus on the newly discovered sperm ion channels CatSper, KSper (Slo3) and HSper (Hv1), identified by the sperm patch-clamp technique. We conclude that the patch-clamp technique has markedly improved and shifted our understanding of the sperm ion channels, in addition to revealing significant species-specific differences in these channels. This method is critical for identification of the molecular mechanisms that control sperm behavior within the female reproductive tract and make fertilization possible. PMID:21642646

DNA damage in bovine sperm does not block fertilization and early embryonic development but induces apoptosis after the first cleavages.

PubMed

Fatehi, A N; Bevers, M M; Schoevers, E; Roelen, B A J; Colenbrander, B; Gadella, B M

2006-01-01

The main goal of this study was to investigate whether and at what level damage of paternal DNA influences fertilization of oocytes and early embryonic development. We hypothesized that posttesticular sperm DNA damage will only marginally affect sperm physiology due to the lack of gene expression, but that it will affect embryo development at the stage that embryo genome (including the paternal damaged DNA) expression is initiated. To test this, we artificially induced sperm DNA damage by irradiation with x- or gamma rays (doses of 0-300 Gy). Remarkably, sperm cells survived the irradiation quite well and, when compared with nonirradiated cells, sperm motility and integrity of plasma membrane, acrosome, and mitochondria were not altered by this irradiation treatment. In contrast, a highly significant logarithmic relation between irradiation dose and induced DNA damage to sperm cells was found by both terminal deoxynucleotidyl transferase (TdT)-mediated dUTP nick end labeling (TUNEL) and the acridin orange assay. Despite the DNA damage, irradiated sperm cells did not show any sign of apoptosis (nuclear fragmentation, depolarization of inner mitochondrial membranes, or phospholipid scrambling) and were normally capable of fertilizing oocytes, as there was no reduction in cleavage rates when compared with nonirradiated sperm samples up to irradiation doses of less than 10 Gy. Further embryonic development was completely blocked as the blastocyst rates at days 7 and 9 dropped from 28% (nonirradiated sperm) to less than 3% by greater than 2.5-Gy-irradiated sperm. This block in embryonic development was accompanied with the initiation of apoptosis after the second or third cleavage. Specific signs of apoptosis, such as nuclear fragmentation and aberrations in spindle formation, were observed in all embryos resulting from in vitro fertilization with irradiated sperm (irradiation doses >1.25 Gy). The results show that sperm DNA damage does not impair fertilization of the oocyte or completion of the first 2-3 cleavages, but blocks blastocyst formation by inducing apoptosis. Embryos produced by assisted reproductive techniques (ART) could have incorporated aberrant paternal DNA (frequently detected in sperm of sub/infertile males). Analogously, in the present work, we discuss the possibility of following embryo development of oocytes fertilized by ART through the blastocyst stage before embryo transfer into the uterus in order to reduce risks of reproductive failure.

[Elucidation of the mechanism of fertilization and clinical application of assisted reproductive technology].

PubMed

Hiroi, M

1996-08-01

Fertilization is the process including many events such as maturation of egg and sperm, attachment, binding, acrosomal reaction, penetration, fusion, cortical reaction, zona reaction and nuclear fusion of both gamete, whereby individual gametes from the female and male unite to create offspring. Although the reason for mechanism of fertilization is still not clearly understood, this process may accelerate the rate adaptation in evolution. In this special lecture, I would like to present our experimental and clinical results especially concerning with morphological, physiological, biochemical and molecular approach on the mechanism of fertilization. 1. Development and maturation of follicles and oocytes. It is well known that pituitary FSH, LH control the ovarian function. Follicular development and ovum maturation are also controlled by both pituitary gonadotropins and local factors such as autocrine and paracrine agents. When hMG is injected during 1-6 day of menstrual cycle, several dominant follicles are developed. If hMG is injected after selection of dominant follicles, only one dominant follicle develop in the ovary. When PMS-treated immature rats were injected with immature or mature follicle fluids, rats injected with mature follicular fluid showed strongly suppress in the ovarian weights and numbers of ovulated follicles. Also mature follicle suppress aromatization from and androstenedione to estradiol. These findings mean that mature follicular fluid contains inhibitory factors. Apoptosis of granulosa cells and follicular steroids are related to fertilization. 2. Intracellular calcium of oocyte. Intracellular calcium concentration is known to start to increase in a periodic manner after fertilization in oocytes of mammalians. In 65% of tested mouse oocytes, fertilization occurred during 4 hours observation after sperm insemination in vitro. An initial long lasting intracellular calcium concentration was observed and followed by periodic manner. This calcium oscillation is inhibited by calcium blockers such as verpamil and nifedipine, but increased by high concentration of extracellular calcium concentration in the medium. Role of increase of intracellular calcium are understood to prevent polysperm and activate metabolism of oocytes. 3. Glucose metabolism of oocytes. Mouse embryo utilizes pyruvate as an essential nutrient until the 8-cell stage, and glucose thereafter. We have devised non-radiometrie and enzymatic microassay method to measure glucose, deoxyglucose, deoxyglucose 6-phosphate incorporated into individual mouse oocytes and preimplantation embryo. In parallel, the activities of several enzymes of glycolytic pathway were also determined. In this study, glucose metabolism is necessary to develop in fertilized ova with changing activity of enzymes. 4. Molecular bases of ovarian fluid. The zona pellucida ZP is involved in a number of events in fertilization, all these fertilization events occur in the oviduct. Oviductal glycoprotein 200-240 KD has been identified from oviductal zona pellucida. Monoclonal antibody of oviductal glycoprotein reacted with ZP of oviductal egg but not with the ovarian egg. Anti-ZPO antibody inhibit to bind sperm to ZP. Sequences in mouse and hamster oviduct specific glycoprotein are estimated, this glycoprotein mRNA was observed in only oviduct by northern blotting method. These molecular gene expression was observed by in situ hybridization in the oviduct of estrous cycle of hamster. 5. Microinsemination of sperm. Microinsemination of sperm into oocyte is widely used in clinical medicine. Sperm penetration assay (hamster test) is useful method to estimate fertilization capacity of sperm. But immotile sperm cannot estimate it. So modified micro sperm penetration assay was established to estimate fertilization capacity of sperm by using micro-manipulator. Subzonal sperm injection (SUZI) and intracytoplasmic sperm injection (ICSI) promotes fertilization and cleavage rate in immotile

Fertility prediction of frozen boar sperm using novel and conventional analyses

USDA-ARS?s Scientific Manuscript database

Frozen-thawed boar sperm is seldom used for artificial insemination (AI) because fertility is lower than fresh or cooled semen. Despite the many advantages of AI including reduced pathogen exposure and ease of semen transport, cryo-induced damage to sperm usually results in decreased litter sizes a...

Patterns of intracellular calcium oscillations in horse oocytes fertilized by intracytoplasmic sperm injection: possible explanations for the low success of this assisted reproduction technique in the horse.

PubMed

Bedford, Sylvia J; Kurokawa, Manabu; Hinrichs, Katrin; Fissore, Rafael A

2004-04-01

In all species studied, fertilization induces intracellular Ca2+ ([Ca2+]i) oscillations required for oocyte activation and embryonic development. This species-specific pattern has not been studied in the equine, partly due to the difficulties linked to in vitro fertilization in this species. Therefore, the objective of this study was to use intracytoplasmic sperm injection (ICSI) to investigate fertilization-induced [Ca2+]i signaling and, possibly, ascertain problems linked to the success of this technology in the horse. In vivo- and in vitro-matured mare oocytes were injected with a single motile stallion sperm. Few oocytes displayed [Ca2+]i responses regardless of oocyte source and we hypothesized that this may result from insufficient release of the sperm-borne active molecule (sperm factor) into the oocyte. However, permeabilization of sperm membranes with Triton-X or by sonication did not alleviate the deficient [Ca2+]i responses in mare oocytes. Thus, we hypothesized that a step downstream of release, possibly required for sperm factor function, is not appropriately accomplished in horse oocytes. To test this, ICSI-fertilized horse oocytes were fused to unfertilized mouse oocytes, which are known to respond with [Ca2+]i oscillations to injection of stallion sperm, and [Ca2+]i monitoring was performed. Such pairs consistently displayed [Ca2+]i responses demonstrating that the sperm factor is appropriately released into the ooplasm of horse oocytes, but that these are unable to activate and/or provide the appropriate substrate that is required for the sperm factor delivered by ICSI to initiate oscillations. These findings may have implications to improve the success of ICSI in the equine and other livestock species.

Membrane proteins associated with sperm-oocyte interaction: A proteomic comparison between Kedah Kelantan (Bos indicus) and Mafriwal (Bos taurus × Bos indicus) sperm

NASA Astrophysics Data System (ADS)

Ashrafzadeh, Ali; Nathan, Sheila; Othman, Iekhsan; Yee, Tee Ting; Karsani, Saiful Anuar

2013-11-01

Production performance of European cattle breeds has significantly improved through various breeding programs. However, European breeds are more susceptible to heat stress compared to zebu cattle (Bos indicus) as their conception rate can range between 20 to 30% in hot seasons compared to winter. To identify cattle sperm proteins associated with zebu cattle higher fertility and heat tolerance in tropical environments, we utilised a proteomics-based approach to compare sperm from the highly fertile Malaysian indigenous breed, Kedah Kelantan (Bos indicus), with sperm from the sub-fertile crossbreed, Mafriwal (Bos taurus × Bos indicus). Frozen semen of three high performance bulls from each breed was processed to obtain live and pure sperm. Proteins were separated and gel bands were processed by in-gel tryptic digestion. For each breed, mass spectrometry data was acquired over 11 replicates. The analyzed data identified peptides with different expression levels (99% confidence level) and protein identification was determined by targeted MS/MS. Among the identified proteins associated with sperm-oocyte interaction, two proteins were up-regulated in Kedah Kelantan sperm and 7 proteins were up-regulated in or specific to Mafriwal. Our results suggest that the higher fertility of zebu cattle in tropical areas may not be related to more efficient sperm-oocyte interaction. Further analysis of the other regulated proteins in these two breeds may contribute further knowledge on the physiological reason/s for higher fertility and heat tolerance of Zebu cattle in tropical areas.

Osmotic characteristics and fertility of murine spermatozoa collected in different solutions.

PubMed

Si, Wei; Men, Hongsheng; Benson, James D; Critser, John K

2009-02-01

Osmotic stress is an important factor that can result in cell damage during cryopreservation. Before ejaculation or collection for cryopreservation, murine spermatozoa are stored in epididymal fluid, a physiologically hyperosmotic environment (approximately 415 mmol/kg). The objectives of this study were to determine the osmotic tolerance limits of sperm motion parameters of ICR and C57BL/6 mouse spermatozoa collected in isosmotic (290 mmol/kg) and hyperosmotic (415 mmol/kg) media, and the effect of the osmolality of sperm collection media on sperm fertility after cryopreservation. Our results indicate that murine spermatozoa collected in media with different osmolalities (290 and 415 mmol/kg Dulbecco's phosphate buffered saline (DPBS)) appeared to have different osmotic tolerances for the maintenance of sperm motility and other motion parameters in both mouse strains. The hypo- and hyperosmotic treatments decreased motility and affected other motion parameters of spermatozoa collected in 290 mmol/kg DPBS. The extent of the change of motion parameters after treatments corresponded with the levels of osmotic stress. However, for spermatozoa collected in 415 mmol/kg DPBS, exposure to 290 mmol/kg DPBS tended to increase sperm motility and the quality of their motion parameters. The osmolality of sperm collection medium can affect murine sperm fertility. Spermatozoa collected in 415 mmol/kg medium showed higher fertility compared with spermatozoa collected in 290 mmol/kg as assessed by IVF. Results characterizing murine sperm osmotic tolerance collected in media with different osmolalities from different strains and the effect of collection media osmolality on sperm fertility after cryopreservation will be useful in designing cryopreservation protocols.

PTK2b function during fertilization of the mouse oocyte

DOE Office of Scientific and Technical Information (OSTI.GOV)

Luo, Jinping; McGinnis, Lynda K.; Carlton, Carol

Highlights: • PTK2b is expressed in oocytes and is activated following fertilization. • PTK2b suppression in oocytes prevents fertilization, but not parthenogenetic activation. • PTK2b suppression prevents the oocyte from fusing with or incorporating bound sperm. • PTK2b suppressed oocytes that fail to fertilize do not exhibit calcium oscillations. - Abstract: Fertilization triggers rapid changes in intracellular free calcium that serve to activate multiple signaling events critical to the initiation of successful development. Among the pathways downstream of the fertilization-induced calcium transient is the calcium-calmodulin dependent protein tyrosine kinase PTK2b or PYK2 kinase. PTK2b plays an important role in fertilizationmore » of the zebrafish oocyte and the objective of the present study was to establish whether PTK2b also functions in mammalian fertilization. PTK2b was activated during the first few hours after fertilization of the mouse oocyte during the period when anaphase resumption was underway and prior to the pronuclear stage. Suppression of PTK2b kinase activity in oocytes blocked sperm incorporation and egg activation although sperm-oocyte binding was not affected. Oocytes that failed to incorporate sperm after inhibitor treatment showed no evidence of a calcium transient and no evidence of anaphase resumption suggesting that egg activation did not occur. The results indicate that PTK2b functions during the sperm-egg fusion process or during the physical incorporation of sperm into the egg cytoplasm and is therefore critical for successful development.« less

Species and gamete-specific fertilization success of two sea urchins under near future levels of pCO2

NASA Astrophysics Data System (ADS)

Sung, Chan-Gyung; Kim, Tae Won; Park, Young-Gyu; Kang, Seong-Gil; Inaba, Kazuo; Shiba, Kogiku; Choi, Tae Seob; Moon, Seong-Dae; Litvin, Steve; Lee, Kyu-Tae; Lee, Jung-Suk

2014-09-01

Since the Industrial Revolution, rising atmospheric CO2 concentration has driven an increase in the partial pressure of CO2 in seawater (pCO2), thus lowering ocean pH. We examined the separate effects of exposure of gametes to elevated pCO2 and low pH on fertilization success of the sea urchin Strongylocentrotus nudus. Sperm and eggs were independently exposed to seawater with pCO2 levels ranging from 380 (pH 7.96-8.3) to 6000 ppmv (pH 7.15-7.20). When sperm were exposed, fertilization rate decreased drastically with increased pCO2, even at a concentration of 450 ppmv (pH range: 7.94 to 7.96). Conversely, fertilization of Hemicentrotus pulcherrimus was not significantly changed even when sperm was exposed to pCO2 concentrations as high as 750 ppmv. Exposure of S. nudus eggs to seawater with high pCO2 did not affect fertilization success, suggesting that the effect of increased pCO2 on sperm is responsible for reduced fertilization success. Surprisingly, this result was not related to sperm motility, which was insensitive to pCO2. When seawater was acidified using HCl, leaving pCO2 constant, fertilization success in S. nudus remained high (> 80%) until pH decreased to 7.3. While further studies are required to elucidate the physiological mechanism by which elevated pCO2 impairs sperm and reduces S. nudus fertilization, this study suggests that in the foreseeable future, sea urchin survival may be threatened due to lower fertilization success driven by elevated pCO2 rather than by decreased pH in seawater.

Clinical assessment of the male fertility

PubMed Central

Khatun, Amena; Rahman, Md Saidur

2018-01-01

The evaluation of infertility in males consists of physical examination and semen analyses. Standardized semen analyses depend on the descriptive analysis of sperm motility, morphology, and concentration, with a threshold level that must be surpassed to be considered a fertile spermatozoon. Nonetheless, these conventional parameters are not satisfactory for clinicians since 25% of infertility cases worldwide remain unexplained. Therefore, newer tests methods have been established to investigate sperm physiology and functions by monitoring characteristics such as motility, capacitation, the acrosome reaction, reactive oxygen species, sperm DNA damage, chromatin structure, zona pellucida binding, and sperm-oocyte fusion. After the introduction of intracytoplasmic sperm injection technique, sperm maturity, morphology, and aneuploidy conditions have gotten more attention for investigating unexplained male infertility. In the present article, recent advancements in research regarding the utilization of male fertility prediction tests and their role and accuracy are reviewed. PMID:29564308

Comparison of in vitro fertilization/intracytoplasmic sperm injection outcomes in male factor infertility patients with and without spinal cord injuries.

PubMed

Kathiresan, Anupama S Q; Ibrahim, Emad; Aballa, Teodoro C; Attia, George R; Ory, Steven J; Hoffman, David I; Maxson, Wayne S; Barrionuevo, Marcelo J; Lynne, Charles M; Brackett, Nancy L

2011-09-01

To determine if outcomes after in vitro fertilization with intracytoplasmic sperm injection (IVF/ICSI) using sperm from men with spinal cord injury (SCI group) differ from those of other etiologies of male factor infertility (non-SCI group). In men with SCI, to determine if IVF/ICSI outcomes differ with sperm obtained by penile vibratory stimulation (PVS group) versus electroejaculation (EEJ group). Retrospective analysis. University medical center and major infertility center. Couples with male factor infertility due to SCI versus other etiologies. PVS, EEJ, surgical sperm retrieval, and IVF/ICSI. Rates of fertilization, pregnancy, and live birth. A total of 31 couples in the SCI group underwent 48 cycles of IVF/ICSI, and a total of 297 couples in the non-SCI group underwent 443 cycles of IVF/ICSI. The SCI group had lower fertilization rates but similar pregnancy and live birth rates compared with the non-SCI group. These rates, however, did not differ significantly when the PVS group was compared with the EEJ group. IVF/ICSI of sperm from men with SCI yield lower fertilization rates but similar pregnancy and live birth outcomes as IVF/ICSI of sperm from men with other etiologies of male factor infertility. Sperm collected by PVS versus EEJ in men with SCI appear to result in similar IVF/ICSI success rates. Copyright © 2011 American Society for Reproductive Medicine. Published by Elsevier Inc. All rights reserved.

Sperm function and assisted reproduction technology

PubMed Central

MAAß, GESA; BÖDEKER, ROLF‐HASSO; SCHEIBELHUT, CHRISTINE; STALF, THOMAS; MEHNERT, CLAAS; SCHUPPE, HANS‐CHRISTIAN; JUNG, ANDREAS; SCHILL, WOLF‐BERNHARD

2005-01-01

The evaluation of different functional sperm parameters has become a tool in andrological diagnosis. These assays determine the sperm's capability to fertilize an oocyte. It also appears that sperm functions and semen parameters are interrelated and interdependent. Therefore, the question arose whether a given laboratory test or a battery of tests can predict the outcome in in vitro fertilization (IVF). One‐hundred and sixty‐one patients who underwent an IVF treatment were selected from a database of 4178 patients who had been examined for male infertility 3 months before or after IVF. Sperm concentration, motility, acrosin activity, acrosome reaction, sperm morphology, maternal age, number of transferred embryos, embryo score, fertilization rate and pregnancy rate were determined. In addition, logistic regression models to describe fertilization rate and pregnancy were developed. All the parameters in the models were dichotomized and intra‐ and interindividual variability of the parameters were assessed. Although the sperm parameters showed good correlations with IVF when correlated separately, the only essential parameter in the multivariate model was morphology. The enormous intra‐ and interindividual variability of the values was striking. In conclusion, our data indicate that the andrological status at the end of the respective treatment does not necessarily represent the status at the time of IVF. Despite a relatively low correlation coefficient in the logistic regression model, it appears that among the parameters tested, the most reliable parameter to predict fertilization is normal sperm morphology. (Reprod Med Biol 2005; 4: 7–30) PMID:29699207

In vitro fertilization of in vitro-matured equine oocytes: effect of maturation medium, duration of maturation, and sperm calcium ionophore treatment, and comparison with rates of fertilization in vivo after oviductal transfer.

PubMed

Hinrichs, K; Love, C C; Brinsko, S P; Choi, Y H; Varner, D D

2002-07-01

Three experiments were conducted to evaluate the effect of oocyte and sperm treatments on rates of in vitro fertilization (IVF) in the horse and to determine the capacity of in vitro-matured horse oocytes to be fertilized in vivo. There was no effect of duration of oocyte maturation (24 vs. 42 h) or calcium ionophore concentration during sperm capacitation (3 microM vs. 7.14 microM) on in vitro fertilization rates. Oocytes matured in 100% follicular fluid had significantly higher fertilization (13% to 24%) than did oocytes matured in maturation medium or in 20% follicular fluid (0% to 12%; P < 0.05). There was no significant difference in fertilization rate among 3 sperm treatments utilizing 7.14 microM calcium ionophore (12% to 21%). Of in vitro-matured oocytes recovered 40-44 h after transfer to the oviducts of inseminated mares, 77% showed normal fertilization (2 pronuclei to normal cleavage). Cleavage to 2 or more cells was seen in 22% of oocytes matured in follicular fluid and 63% of oocytes matured in maturation medium; this difference was significant (P < 0.05). We conclude that in vitro-matured horse oocytes are capable of being fertilized at high rates in the appropriate environment and that in vitro maturation of oocytes in follicular fluid increases fertilization rate in vitro but reduces embryo development after fertilization in vivo. Further work is needed to determine the optimum environment for sperm capacitation and IVF in the horse.

Relationships between rabbit semen characteristics and fertilising ability after insemination.

PubMed

Theau-Clément, M; Ailloud, E; Sanchez, A; Saleil, G; Brun, J M

2016-03-01

This study aimed to analyse the relationship between rabbit semen characteristics and semen fertilising ability after insemination, which is generally found to be weak. Our hypothesis was that using high semen dilutions (1 : 19), non-oestrus-stimulated does, and homospermic inseminations would make it easier to predict semen fertilising ability. Semen characteristics were evaluated on 275 ejaculates of 128 INRA1001 bucks, distributed into five successive batches. A total of 1970 inseminations were performed. The continuous semen variables were subdivided into three classes of similar size to account for any non-linear relationship between semen characteristics and fertilising ability. Mass motility was divided into two classes according to the presence or absence of waves under microscope observation. Libido, the presence or absence of gel, volume, percentage of progressive sperms, curvilinear velocity, beat frequency of the flagellum, and straightness and linearity of sperm movement did not affect fertility, prolificacy or productivity. It was confirmed that mass motility, estimated by visual observation under the microscope, significantly influenced fertility as well as the percentage of motile and of rapid sperms, and the amplitude of lateral head displacement, estimated by a computer-assisted semen analysis system. To a lesser extent, the percentage of motile cells and of rapid cells significantly influenced prolificacy. Consequently, mass motility and the percentage of motile cells significantly influenced rabbit doe productivity (+1 live births/AI when the semen showed at least a beginning of wave movement, or when the percentage of motile cells was >84%). Interestingly, a gain of 1.5 rabbits was observed when the percentage of rapid cells changed from 64% to 79%, whereas productivity significantly dropped beyond 83% of rapid cells, reflecting a non-linear relationship.

Sex aneuploidy of unfertilized human oocytes after intracytoplasmic sperm injection

DOE Office of Scientific and Technical Information (OSTI.GOV)

Lee, G.; Ward, D.C.; Jones, E.E.

1994-09-01

Intracytoplasmic sperm injection (ICSI) has recently achieved successful fertilization and pregnancy in human in vitro fertilization, particularly in cases of severe male factor infertility. One criticism of this novel clinical technique is that it bypasses the natural selection process of fertilization. We use fluorescence in situ hybridization (FISH) to analyze oocytes which fail to fertilize after ICSI in the Yale IVF Program. The purpose of this study is to determine whether failed fertilization after ICSI can be attributed to sex chromosome aneuploidy in the oocyte. Fertilization of oocytes is determined by the presence of two pronuclei on light microscopic examinationmore » (400X). Multi-probe FISH with DAPI (4,6,-diamino-2-phenyl-indole) counterstain is then performed to determine oocyte ploidy and the presence of decondensed sperm. Centromeric probes for X, Y and 17 are used simultaneously in each oocyte for in situ hybridization to oocyte chromatin. In all oocytes examined after ICSI to date, unfertilized oocytes have decondensed sperm DNA present confirming appropriate intracytoplasmic placement of the sperm. Preliminary results obtained from 31 oocytes have not identified any sex chromosome aneuploidies. The FISH technique used in post-ICSI oocytes is a model system for delineating genetic causes of failed fertilization in the human.« less

Metabolites involved in cellular communication among human cumulus-oocyte-complex and sperm during in vitro fertilization.

PubMed

Gómez-Torres, María José; García, Eva María; Guerrero, Jaime; Medina, Sonia; Izquierdo-Rico, María José; Gil-Izquierdo, Ángel; Orduna, Jesús; Savirón, María; González-Brusi, Leopoldo; Ten, Jorge; Bernabeu, Rafael; Avilés, Manuel

2015-11-09

Fertilization is a key physiological process for the preservation of the species. Consequently, different mechanisms affecting the sperm and the oocyte have been developed to ensure a successful fertilization. Thus, sperm acrosome reaction is necessary for the egg coat penetration and sperm-oolema fusion. Several molecules are able to induce the sperm acrosome reaction; however, this process should be produced coordinately in time and in the space to allow the success of fertilization between gametes. The goal of this study was to analyze the metabolites secreted by cumulus-oocyte-complex (COC) to find out new components that could contribute to the induction of the human sperm acrosome reaction and other physiological processes at the time of gamete interaction and fertilization. For the metabolomic analysis, eighteen aliquots of medium were used in each group, containing: a) only COC before insemination and after 3 h of incubation; b) COC and capacitated spermatozoa after insemination and incubated for 16-20 hours; c) only capacitated sperm after 16-20 h in culture and d) only fertilization medium as control. Six patients undergoing assisted reproduction whose male partners provided normozoospermic samples were included in the study. Seventy-two COC were inseminated. The metabolites identified were monoacylglycerol (MAG), lysophosphatidylcholine (LPC) and phytosphingosine (PHS). Analysis by PCR and in silico of the gene expression strongly suggests that the cumulus cells contribute to the formation of the PHS and LPC. LPC and PHS are secreted by cumulus cells during in vitro fertilization and they could be involved in the induction of human acrosome reaction (AR). The identification of new molecules with a paracrine effect on oocytes, cumulus cells and spermatozoa will provide a better understanding of gamete interaction.

[The incidence of agglutination and its influence on sperm quality and fertility of boar semen].

PubMed

Bollwein, Heinrich; Petschow, Karola; Weber, Frank; Leiding, Claus; Stolla, Rudolf

2004-01-01

The aim of this study was to examine the incidence of sperm agglutinations and their relationships with sperm quality and fertility. Semen samples of 40 boars of an AI-station were investigated. Nineteen of the 40 investigated boars showed a constantly low (< 10% agglutinated sperm), 3 an intermediate (10-20%) and 6 boars a high level (> 20%) of agglutination in raw semen. The degree of agglutination in sperm samples of 12 boars varied distinctly during the investigation period. During summer more (P < 0.05) agglutinated sperm were observed (11.0 +/- 11.6%) than during winter (6.2 +/- 7.3%). There was no association between bacterial contamination and incidence of agglutinations (P > 0.05). After dilution in extender the percentage of agglutinated sperm decreased from 6.2 +/- 7.3% to 1.1 +/- 1.4% (P < 0.0001). Twenty-four hours after dilution the percentage of progressively motile sperm was 7.4% lower (P < 0.05) in ejaculates with an initially high degree of agglutination (> 20% agglutinated sperm) compared to samples with an initially low degree of agglutinated sperm (< 10%). Plasma membrane integrity, mitochondrial membrane potential, acrosome reaction and chromatin structure were independent (P > 0.05) from the level of agglutination. Fertility data did not differ (P > 0.05) between boars with low and high numbers of agglutinated sperm in raw semen. The results show that there are individual, ejaculatory and seasonal variations in the incidence and degree of agglutination. Agglutinations have a negative effect on motility of sperm and disappear to a large extent after dilution in sperm extender. They have no negative consequences on fertility.

Effect of dilution in sperm maturation media and time of storage on sperm motility and fertilizing capacity of cryopreserved semen of sex-reversed female rainbow trout.

PubMed

Judycka, Sylwia; Ciereszko, Andrzej; Dobosz, Stefan; Zalewski, Tomasz; Dietrich, Grzegorz J

2017-05-01

Masculinized females, also called neomales or sex-reversed females have a male phenotype but retain the female genotype (XX). Therefore, all spermatozoa produced in their functional testes carry an X chromosome, which is desired for the production of all-female rainbow trout populations. Semen of sex-reversed female rainbow trout is of low quality and in vitro maturation is required, which includes dilution of sperm suspensions with specially formulated maturation solutions. The aim of this study was to determine the effect of dilution in different maturation media on sperm quality (sperm motility characteristics and fertilizing capacity) of frozen/thawed sperm of sex-reversed female rainbow trout. The effect of time of post-thaw storage (0, 15, 60 and 120min) on semen quality was also tested. Sperm motility parameters and fertilization rate at the eyed and hatching stages were assessed for post-thaw semen diluted in different media. The cryopreservation procedure resulted in high post-thaw sperm motility of about 57% and did not differ from fresh semen. Unexpectedly, maturation media decreased sperm activation capacity immediately after dilution; however, sperm motility increased over time. Fertilization rates of frozen/thawed semen were high (71-87%) and did not differ significantly between experimental variants at any of tested periods of storage. Our results demonstrated that the effect of the maturation media on frozen/thawed sperm is different from that of fresh sperm. The progressive increase in post-thaw sperm motility in maturation media can potentially be applied to routine hatchery practice. Copyright © 2016 Elsevier Inc. All rights reserved.

Sneaker "jack" males outcompete dominant "hooknose" males under sperm competition in Chinook salmon (Oncorhynchus tshawytscha).

PubMed

Young, Brent; Conti, David V; Dean, Matthew D

2013-12-01

In a variety of taxa, males deploy alternative reproductive tactics to secure fertilizations. In many species, small "sneaker" males attempt to steal fertilizations while avoiding encounters with larger, more aggressive, dominant males. Sneaker males usually face a number of disadvantages, including reduced access to females and the higher likelihood that upon ejaculation, their sperm face competition from other males. Nevertheless, sneaker males represent an evolutionarily stable strategy under a wide range of conditions. Game theory suggests that sneaker males compensate for these disadvantages by investing disproportionately in spermatogenesis, by producing more sperm per unit body mass (the "fair raffle") and/or by producing higher quality sperm (the "loaded raffle"). Here, we test these models by competing sperm from sneaker "jack" males against sperm from dominant "hooknose" males in Chinook salmon. Using two complementary approaches, we reject the fair raffle in favor of the loaded raffle and estimate that jack males were ∼1.35 times as likely as hooknose males to fertilize eggs under controlled competitive conditions. Interestingly, the direction and magnitude of this skew in paternity shifted according to individual female egg donors, suggesting cryptic female choice could moderate the outcomes of sperm competition in this externally fertilizing species.

Effect of sperm entry on blastocyst development after in vitro fertilization and intracytoplasmic sperm injection - mouse model.

PubMed

Piotrowska-Nitsche, Karolina; Chan, Anthony W S

2013-01-01

To investigate whether in vitro fertilization (IVF) and intracytoplasmic sperm injection (ICSI), influence the embryo's development and its quality using the mouse as a model. Assisted fertilization was performed using ICSI and IVF. Fluorescent beads were adhered to the fertilization cone or place of previous sperm injection in the natural mated (NM), IVF and ICSI embryos, respectively. Embryo examination was carried out at the two-cell and blastocyst stage to determine the position of fluorescent bead. Protein expression was detected by fluorescence immunocytochemical staining and confocal microscopic imaging of blastocysts. IVF and ICSI embryos developed at rates comparable to NM group. Embryos show similar expression patterns of two transcription factors, Oct4 and Cdx2. The most preferred place for spermatozoa attachment was the equatorial site of the egg, whether fertilization occurred in vitro or under natural conditions. We also link the sperm entry position (SEP) to embryo morphology and the number of cells at the blastocyst stage, with no influence of the method of fertilization. IVF and ICSI, do not compromise in vitro pre-implantation development. Additional data, related to sperm entry, could offer further criteria to predict embryos that will implant successfully. Based on embryo morphology, developmental rate and protein expression level of key transcription factors, our results support the view that ART techniques, such as IVF and ICSI, do not perturb embryonic development or quality.

Mouse SLLP1, a sperm lysozyme-like protein involved in sperm-egg binding and fertilization.

PubMed

Herrero, María Belén; Mandal, Arabinda; Digilio, Laura C; Coonrod, Scott A; Maier, Bernhard; Herr, John C

2005-08-01

This study demonstrates the retention of mouse sperm lysozyme-like protein (mSLLP1) in the equatorial segment of spermatozoa following the acrosome reaction and a role for mSLLP1 in sperm-egg binding and fertilization. Treatment of cumulus intact oocytes with either recmSLLP1 or its antiserum resulted in a significant (P < or = 0.05) inhibition of fertilization. Co-incubation of zona-free mouse oocytes with capacitated mouse spermatozoa in the presence of varying concentrations of anti-recmSLLP1 serum or recmSLLP1 also inhibited sperm-oolemma binding. A complete inhibition of binding and fusion of spermatozoa to the oocyte occurred at 12.5 muM concentration of recmSLLP1, while conventional chicken and human lysozymes did not block sperm-egg binding. mSLLP1 showed receptor sites in the perivitelline space as well as on the microvillar region of the egg plasma membrane. The retention of mSLLP1 in the equatorial segment of acrosome-reacted sperm, the inhibitory effects of both recmSLLP1 and antibodies to SLLP1 on in vitro fertilization with both cumulus intact and zona-free eggs, and the definition of complementary SLLP1-binding sites on the egg plasma membrane together support the hypothesis that a c lysozyme-like protein is involved in the binding of spermatozoa to the egg plasma membrane during fertilization.

Effect of sperm concentration on characteristics and fertilization capacity of rooster sperm frozen in the presence of the antioxidants catalase and vitamin E.

PubMed

Moghbeli, Morteza; Kohram, Hamid; Zare-Shahaneh, Ahmad; Zhandi, Mahdi; Sharideh, Hossein; Sharafi, Mohsen

2016-10-01

The objective of this study conducted was to determine the influence of different levels of sperm concentration, including catalase (CAT) and vitamin E (VitE) in rooster semen extender on postthawed quality and fertility of rooster semen. Semen was collected twice a week from six roosters (Arian) and diluted according to experimental treatments consisting of sperm suspensions containing different sperm concentrations (200, 400, and 600 × 106 sperm/mL) without antioxidant supplementation as control (Con) groups (Con200, Con400, and Con600, respectively), sperm suspensions containing different sperm concentrations (200, 400, and 600 × 106 sperm/mL) supplemented with 5-μg/mL VitE (VitE200, VitE400, and VitE600, respectively) and different sperm concentrations (200, 400, and 600 × 106 sperm/mL) supplementation with 100 IU/mL CAT (CAT200, CAT400, and CAT600, respectively). After thawing; sperm motility, membrane integrity, and mitochondrial function were assessed. Fertility and hatchability rates were determined by using 100 artificially inseminated hens. The percentage of total motility (TM) and activity of mitochondria decreased (P < 0.05) as the sperm concentration increased in control groups. So, the lowest percentage of the TM and activity of mitochondria were observed in the Con600 as compared with other treatment groups. Extenders containing 100 IU/mL CAT and 5-μg/mL VitE resulted in higher (P < 0.05) TM, progressive motility, membrane integrity, and activity of mitochondria compared with control groups. Adding VitE and CAT in different sperm concentrations, the percentage of TM, membrane integrity, and activity of mitochondria decreased (P < 0.05) as the sperm concentration decreased. The highest (P < 0.05) membrane integrity, TM, and progressive motility were recorded at VitE400 and CAT400. Including VitE and CAT in rooster extender with different level sperm concentrations had no effect (P > 0.05) on fertility and hatchability rates. In conclusion, although adding VitE and CAT in extender with different levels of sperm concentration improved postthawed quality of rooster semen, but adding VitE and CAT in the extender have no effect on fertility rate. Copyright © 2016 Elsevier Inc. All rights reserved.

Diagnostic evaluation of oxidoreductive capability of sperm mitochondria.

PubMed

Piasecka, M; Gaczarzewicz, D; Kurzawa, R; Laszczyńska, M; Kram, A

2004-01-01

In the present paper, morphological and functional features of human sperm midpiece, contributing to the assessment of sperm fertility potential, have been described. The NADH-dependent NBT screening assay was used to identify and visualise: 1/ morphological defects of sperm midpiece, 2/ immature sperm forms with extensive cytoplasmic retention, reflecting developmental failure in spermatogenic remodelling process, 3/ cytoplasmic sperm conglomerates, related to apoptotic bodies and 4/ sperm NADH-dependent oxidoreductase system at the mitochondrial level, related to the reaction intensity. The used assay is an adequate marker of sperm mitochondrial activity and sperm maturity. It can also help discover sperm defects that result in asthenozoospermia and can be used as an additional indicator in the evaluation of the sperm midpiece, as well as in routine morphological examination of spermatozoa, having a considerable predictive value for in vivo and in vitro fertilization.

Royal jelly supplementation in semen extender enhances post-thaw quality and fertility of Nili-Ravi buffalo bull sperm.

PubMed

Shahzad, Qaisar; Mehmood, Muhammad Usman; Khan, Hamayun; ul Husna, Asma; Qadeer, Saima; Azam, Asima; Naseer, Zahid; Ahmad, Ejaz; Safdar, Muhammad; Ahmad, Mushtaq

2016-04-01

Two experiments were conducted to evaluate the effect of royal jelly (RJ) on post-thaw sperm quality, in vitro and in vivo fertility rate of cryopreserved buffalo bull sperm. The semen was collected from three mature regular donor buffalo bulls, ejaculates were pooled and semen evaluated initially. In Experiment 1, the ejaculates were extended in tris-citric acid diluter supplemented with different RJ concentrations (0, 0.05, 0.1, 0.2, 0.3 or 0.4%). The diluted semen was cooled to 4°C, packaged into 0.5 mL straws and frozen using standard procedure. The straws were thawed and assessed for sperm progressive motility, viability, plasma membrane, acrosome, and chromatin integrity. The results indicated that sperm progressive motility was significantly greater (P<0.05) in 0.05, 0.1, 0.2 and 0.3% RJ than 0.4% RJ supplemented and control groups. The sperm viability, plasma membrane and acrosome integrity were significantly improved (P<0.05) in 0.1% RJ supplemented group the compared to other treatment groups. In Experiment 2, cryopreserved sperm with 0.1% RJ supplementation and control (without RJ supplementation) were used to observe the in vitro fertilizing potential and in vivo fertility. In vitro fertilization method was applied to assess the cleavage rate; whereas, AI was performed in buffalo during in vivo fertility trial. The buffaloes were inseminated 12h after standing estrus and pregnancy diagnosis was performed through ultrasonography. The results revealed that the cleavage rate was higher (P<0.05) in 0.1% RJ as compared to control group. However, the pregnancy rate was similar (P>0.05) between 0.1% RJ supplemented and control groups. It is concluded that supplementation of RJ in freezing extender can improve the cryosurvival rate and in vitro fertilizing capacity of buffalo bull sperm. Copyright © 2016 Elsevier B.V. All rights reserved.

LOCALIZATION OF THE SPERM PROTEIN SP22 AND INHIBITION OF FERTILITY IN VIVO AND IN VITRO

EPA Science Inventory

We previously established that the levels sperm membrane protein SP22 are highly correlated with the fertility of sperm from the cauda epididymidis of rats exposed to both epididymal and testicular toxicants, and that a testis-specific SP22 transcript is expressed in post-meiotic...

Semen molecular and cellular features: these parameters can reliably predict subsequent ART outcome in a goat model

PubMed Central

Berlinguer, Fiammetta; Madeddu, Manuela; Pasciu, Valeria; Succu, Sara; Spezzigu, Antonio; Satta, Valentina; Mereu, Paolo; Leoni, Giovanni G; Naitana, Salvatore

2009-01-01

Currently, the assessment of sperm function in a raw or processed semen sample is not able to reliably predict sperm ability to withstand freezing and thawing procedures and in vivo fertility and/or assisted reproductive biotechnologies (ART) outcome. The aim of the present study was to investigate which parameters among a battery of analyses could predict subsequent spermatozoa in vitro fertilization ability and hence blastocyst output in a goat model. Ejaculates were obtained by artificial vagina from 3 adult goats (Capra hircus) aged 2 years (A, B and C). In order to assess the predictive value of viability, computer assisted sperm analyzer (CASA) motility parameters and ATP intracellular concentration before and after thawing and of DNA integrity after thawing on subsequent embryo output after an in vitro fertility test, a logistic regression analysis was used. Individual differences in semen parameters were evident for semen viability after thawing and DNA integrity. Results of IVF test showed that spermatozoa collected from A and B lead to higher cleavage rates (0 < 0.01) and blastocysts output (p < 0.05) compared with C. Logistic regression analysis model explained a deviance of 72% (p < 0.0001), directly related with the mean percentage of rapid spermatozoa in fresh semen (p < 0.01), semen viability after thawing (p < 0.01), and with two of the three comet parameters considered, i.e tail DNA percentage and comet length (p < 0.0001). DNA integrity alone had a high predictive value on IVF outcome with frozen/thawed semen (deviance explained: 57%). The model proposed here represents one of the many possible ways to explain differences found in embryo output following IVF with different semen donors and may represent a useful tool to select the most suitable donors for semen cryopreservation. PMID:19900288

Enhanced fertility prediction of cryopreserved boar spermatozoa using novel sperm function assessment

USDA-ARS?s Scientific Manuscript database

Cryopreserved semen is seldom used for commercial porcine artificial insemination (AI) despite many advantages that cryopreservation provides. Compared to fresh semen, the fertility of frozen-thawed boar sperm is more variable but usually less. Predicting the fertility of individual ejaculates for s...

Chloride Is Essential for Capacitation and for the Capacitation-associated Increase in Tyrosine Phosphorylation*

PubMed Central

Wertheimer, Eva V.; Salicioni, Ana M.; Liu, Weimin; Trevino, Claudia L.; Chavez, Julio; Hernández-González, Enrique O.; Darszon, Alberto; Visconti, Pablo E.

2008-01-01

After epididymal maturation, sperm capacitation, which encompasses a complex series of molecular events, endows the sperm with the ability to fertilize an egg. This process can be mimicked in vitro in defined media, the composition of which is based on the electrolyte concentration of the oviductal fluid. It is well established that capacitation requires Na+, \\documentclass[10pt]{article} \\usepackage{amsmath} \\usepackage{wasysym} \\usepackage{amsfonts} \\usepackage{amssymb} \\usepackage{amsbsy} \\usepackage{mathrsfs} \\usepackage{pmc} \\usepackage[Euler]{upgreek} \\pagestyle{empty} \\oddsidemargin -1.0in \\begin{document} \\begin{equation*}{\\mathrm{HCO}}_{3}^{-}\\end{equation*}\\end{document}, Ca2+, and a cholesterol acceptor; however, little is known about the function of Cl– during this important process. To determine whether Cl–, in addition to maintaining osmolarity, actively participates in signaling pathways that regulate capacitation, Cl– was replaced by either methanesulfonate or gluconate two nonpermeable anions. The absence of Cl– did not affect sperm viability, but capacitation-associated processes such as the increase in tyrosine phosphorylation, the increase in cAMP levels, hyperactivation, the zona pellucidae-induced acrosome reaction, and most importantly, fertilization were abolished or significantly reduced. Interestingly, the addition of cyclic AMP agonists to sperm incubated in Cl–-free medium rescued the increase in tyrosine phosphorylation and hyperactivation suggesting that Cl– acts upstream of the cAMP/protein kinase A signaling pathway. To investigate Cl– transport, sperm incubated in complete capacitation medium were exposed to a battery of anion transport inhibitors. Among them, bumetanide and furosemide, two blockers of Na+/K+/Cl– cotransporters (NKCC), inhibited all capacitation-associated events, suggesting that these transporters may mediate Cl– movements in sperm. Consistent with these results, Western blots using anti-NKCC1 antibodies showed the presence of this cotransporter in mature sperm. PMID:18957426

Bioenergetics of Mammalian Sperm Capacitation

PubMed Central

Ferramosca, Alessandra; Zara, Vincenzo

2014-01-01

After ejaculation, the mammalian male gamete must undergo the capacitation process, which is a prerequisite for egg fertilization. The bioenergetics of sperm capacitation is poorly understood despite its fundamental role in sustaining the biochemical and molecular events occurring during gamete activation. Glycolysis and mitochondrial oxidative phosphorylation (OXPHOS) are the two major metabolic pathways producing ATP which is the primary source of energy for spermatozoa. Since recent data suggest that spermatozoa have the ability to use different metabolic substrates, the main aim of this work is to present a broad overview of the current knowledge on the energy-producing metabolic pathways operating inside sperm mitochondria during capacitation in different mammalian species. Metabolism of glucose and of other energetic substrates, such as pyruvate, lactate, and citrate, is critically analyzed. Such knowledge, besides its obvious importance for basic science, could eventually translate into the development of novel strategies for treatment of male infertility, artificial reproduction, and sperm selection methods. PMID:24791005

Bioenergetics of mammalian sperm capacitation.

PubMed

Ferramosca, Alessandra; Zara, Vincenzo

2014-01-01

After ejaculation, the mammalian male gamete must undergo the capacitation process, which is a prerequisite for egg fertilization. The bioenergetics of sperm capacitation is poorly understood despite its fundamental role in sustaining the biochemical and molecular events occurring during gamete activation. Glycolysis and mitochondrial oxidative phosphorylation (OXPHOS) are the two major metabolic pathways producing ATP which is the primary source of energy for spermatozoa. Since recent data suggest that spermatozoa have the ability to use different metabolic substrates, the main aim of this work is to present a broad overview of the current knowledge on the energy-producing metabolic pathways operating inside sperm mitochondria during capacitation in different mammalian species. Metabolism of glucose and of other energetic substrates, such as pyruvate, lactate, and citrate, is critically analyzed. Such knowledge, besides its obvious importance for basic science, could eventually translate into the development of novel strategies for treatment of male infertility, artificial reproduction, and sperm selection methods.

Female mediation of competitive fertilization success in Drosophila melanogaster.

PubMed

Lüpold, Stefan; Pitnick, Scott; Berben, Kirstin S; Blengini, Cecilia S; Belote, John M; Manier, Mollie K

2013-06-25

How females store and use sperm after remating can generate postcopulatory sexual selection on male ejaculate traits. Variation in ejaculate performance traits generally is thought to be intrinsic to males but is likely to interact with the environment in which sperm compete (e.g., the female reproductive tract). Our understanding of female contributions to competitive fertilization success is limited, however, in part because of the challenges involved in observing events within the reproductive tract of internally fertilizing species while discriminating among sperm from competing males. Here, we used females from crosses among isogenic lines of Drosophila melanogaster, each mated to two genetically standardized males (the first with green- and the second with red-tagged sperm heads) to demonstrate heritable variation in female remating interval, progeny production rate, sperm-storage organ morphology, and a number of sperm performance, storage, and handling traits. We then used multivariate analyses to examine relationships between this female-mediated variation and competitive paternity. In particular, the timing of female ejection of excess second-male and displaced first-male sperm was genetically variable and, by terminating the process of sperm displacement, significantly influenced the relative numbers of sperm from each male competing for fertilization, and consequently biased paternity. Our results demonstrate that females do not simply provide a static arena for sperm competition but rather play an active and pivotal role in postcopulatory processes. Resolving the adaptive significance of genetic variation in female-mediated mechanisms of sperm handling is critical for understanding sexual selection, sexual conflict, and the coevolution of male and female reproductive traits.

Development of the NBT assay as a marker of sperm oxidative stress.

PubMed

Tunc, Ozlem; Thompson, Jeremy; Tremellen, Kelton

2010-02-01

Oxidative stress is a well-established cause of male infertility, with reactive oxygen species (ROS) causing infertility principally by impairing sperm motility and DNA integrity. Currently, most clinics do not test their infertile patients for the presence of oxidative stress because the available tests are expensive or difficult to perform. As antioxidant therapy may improve sperm DNA integrity and pregnancy outcomes, it has become apparent that there is an unmet clinical need for an inexpensive and easy-to-perform assay to identify sperm oxidative stress. The aim of this study was to develop a standardized protocol for performing a photometric nitro blue tetrazolium (NBT) assay for the measurement of seminal ROS production via production of coloured formazan, whilst correlating these results with impaired sperm function (motility and DNA integrity). Semen samples from 21 fertile and 36 male aetiology infertile men were assessed for ROS production (NBT assay), sperm DNA integrity (TUNEL), apoptosis (Annexin V) and sperm motility. Infertile men's semen contained on average fourfold higher levels of ROS than fertile men. The production of ROS by sperm was positively correlated with sperm DNA fragmentation and apoptosis, whilst being negatively correlated with sperm motility. Receiver-operating characteristic plot analysis established a cut-off point of 24 microg formazan/10(7) sperm having a sensitivity of 91.7% and a specificity of 81% for determining the fertility status of an individual. This study has been successful in establishing a standardized protocol for performing a photometric seminal NBT assay that has significant clinical utility in identifying men with impaired fertility because of oxidative stress.

Reconstructing paternal genotypes to infer patterns of sperm storage and sexual selection in the hawksbill turtle.

PubMed

Phillips, Karl P; Jorgensen, Tove H; Jolliffe, Kevin G; Jolliffe, San-Marie; Henwood, Jock; Richardson, David S

2013-04-01

Postcopulatory sperm storage can serve a range of functions, including ensuring fertility, allowing delayed fertilization and facilitating sexual selection. Sperm storage is likely to be particularly important in wide-ranging animals with low population densities, but its prevalence and importance in such taxa, and its role in promoting sexual selection, are poorly known. Here, we use a powerful microsatellite array and paternal genotype reconstruction to assess the prevalence of sperm storage and test sexual selection hypotheses of genetic biases to paternity in one such species, the critically endangered hawksbill turtle, Eretmochelys imbricata. In the majority of females (90.7%, N = 43), all offspring were sired by a single male. In the few cases of multiple paternity (9.3%), two males fertilized each female. Importantly, the identity and proportional fertilization success of males were consistent across all sequential nests laid by individual females over the breeding season (up to five nests over 75 days). No males were identified as having fertilized more than one female, suggesting that a large number of males are available to females. No evidence for biases to paternity based on heterozygosity or relatedness was found. These results indicate that female hawksbill turtles are predominantly monogamous within a season, store sperm for the duration of the nesting season and do not re-mate between nests. Furthermore, females do not appear to be using sperm storage to facilitate sexual selection. Consequently, the primary value of storing sperm in marine turtles may be to uncouple mating and fertilization in time and avoid costly re-mating. © 2013 Blackwell Publishing Ltd.

The presence of human papillomavirus in semen does not affect the integrity of sperm DNA.

PubMed

Cortés-Gutiérrez, E I; Dávila-Rodríguez, M I; Fernández, J L; de la O-Pérez, L O; Garza-Flores, M E; Eguren-Garza, R; Gosálvez, J

2017-12-01

It remains unknown whether human papillomaviruses (HPVs) in semen affect sperm DNA integrity. We investigated whether the presence of these viruses in semen was associated with an elevated sperm DNA fragmentation index. Semen samples of 22 normozoospermic patients undergoing infertility treatment, nine fertile donors and seven fertile men with a risk of HPV infection (genital warts or condylomas) were included in the study. The samples were examined by an INNO-LiPA test PCR-based reverse hybridisation array that identifies 28 types of HPVs as simple or multiple infections. Sperm DNA integrity was determined by sperm chromatin dispersion assay (SCD). Our preliminary findings demonstrate an increase in HPV infection in infertile men with respect to fertile men. However, the sperm DNA fragmentation index was not increased in semen containing these viruses. © 2017 Blackwell Verlag GmbH.

A unique mechanism of successful fertilization in a domestic bird.

PubMed

Sasanami, Tomohiro; Izumi, Shunsuke; Sakurai, Naoki; Hirata, Toshifumi; Mizushima, Shusei; Matsuzaki, Mei; Hiyama, Gen; Yorinaga, Eriko; Yoshimura, Takashi; Ukena, Kazuyoshi; Tsutsui, Kazuyoshi

2015-01-09

Fertilization is an indispensable step for formation of a zygote in sexual reproduction, leading to species survival. When mating occurs, sperm is transported to the female reproductive tracts via the seminal plasma (SP). SP is derived from male accessory sex glands and it plays pivotal roles for fertilization in animals. However, molecular mechanisms of SP or a fluid derived from male accessory sex glands for successful fertilization remain unclear. Here, we report that in male quail the cloacal gland (CG) produces prostaglandin F2α (PGF2α) that contributes to successful fertilization. PGF2α, as well as the secretion of CG (CGS), induced vaginal contractions and caused the opening of the entrance of the sperm storage tubules, the structures responsible for the long-term sperm storage and fertilization. The removal of CGS from the male before mating reduced the fertility, but the supplementation of CGS or PGF2α rescued the subfertility. We further showed that male CG contains glucose that is utilized as energy source for the intrinsic sperm mobility after transportation to female vagina. This mechanism, in concert with the excitatory effects of PGF2α enables successful fertilization in the domestic bird.

The effect of red light irradiation on spermatozoa DNA

NASA Astrophysics Data System (ADS)

Chow, Kay W.; Preece, Daryl; Gomez-Godinez, Veronica; Berns, Michael W.

2016-09-01

A key goal in the conservation of endangered species is to increase successful reproduction. In cases where traditional methods of in vitro fertilization are unsuccessful, new methods of assisted reproduction are needed. One option is selective fertilization via optically trapped sperm. A more passive option is red light irradiation. Red light irradiation has been shown to increase sperm motility, thus increasing fertilizing potential. However, there is some concern that exposure to laser irradiation induces the production of oxidative species in cells, which can be damaging to DNA. In order to test the safety of irradiating sperm, sperm samples were exposed to 633 nm laser light and their DNA were tested for oxidative damage. Using fluorescence microscopy, antibody staining, and ELISA to detect oxidative DNA damage, it was concluded that red light irradiation does not pose a safety risk to sperm DNA. The use of red light on sperm has potential in both animal conservation and human reproduction techniques. This method can also be used in conjunction with optical trapping for viable sperm selection.

HALOACID INDUCED ALTERATIONS IN FERTILITY AND THE SPERM BIOMARKER SP22 IN THE RAT ARE ADDITIVE: VALIDATION OF AN ELISA

EPA Science Inventory

Dibromoacetic acid (DBA) and bromochloroacetic acid (BCA) are prevalent disinfection by-products of drinking water that produce defects in spermatogenesis and fertility in adult rats. Previously we demonstrated that BCA compromises the fertility of cauda epididymal rat sperm an...

Sperm competition, but not major histocompatibility divergence, drives differential fertilization success between alternative reproductive tactics in Chinook salmon.

PubMed

Lehnert, S J; Helou, L; Pitcher, T E; Heath, J W; Heath, D D

2018-01-01

Post-copulatory sexual selection processes, including sperm competition and cryptic female choice (CFC), can operate based on major histocompatibility (MH) genes. We investigated sperm competition between male alternative reproductive tactics [jack (sneaker) and hooknose (guard)] of Chinook salmon (Oncorhynchus tshawytscha). Using a full factorial design, we examined in vitro competitive fertilization success of paired jack and hooknose males at three time points after sperm activation (0, 15 and 60 s) to test for male competition, CFC and time effects on male fertilization success. We also examined egg-mediated CFC at two MH genes by examining both the relationship between competitive fertilization success and MH divergence as well as inheritance patterns of MH alleles in resulting offspring. We found that jacks sired more offspring than hooknose males at 0 s post-activation; however, jack fertilization success declined over time post-activation, suggesting a trade-off between sperm speed and longevity. Enhanced fertilization success of jacks (presumably via higher sperm quality) may serve to increase sneaker tactic competitiveness relative to dominant hooknose males. We also found evidence of egg-mediated CFC (i.e. female × male interaction) influencing competitive fertilization success; however, CFC was not acting on the MH genes as we found no relationship between fertilization success and MH II β 1 or MH I α 1 divergence and we found no deviations from Mendelian inheritance of MH alleles in the offspring. Our study provides insight into evolutionary mechanisms influencing variation in male mating success within alternative reproductive tactics, thus underscoring different strategies that males can adopt to attain success. © 2017 European Society For Evolutionary Biology. Journal of Evolutionary Biology © 2017 European Society For Evolutionary Biology.

Sperm Motility in Flow

NASA Astrophysics Data System (ADS)

Guasto, Jeffrey; Juarez, Gabriel; Stocker, Roman

2012-11-01

A wide variety of plants and animals reproduce sexually by releasing motile sperm that seek out a conspecific egg, for example in the reproductive tract for mammals or in the water column for externally fertilizing organisms. Sperm are aided in their quest by chemical cues, but must also contend with hydrodynamic forces, resulting from laminar flows in reproductive tracts or turbulence in aquatic habitats. To understand how velocity gradients affect motility, we subjected swimming sperm to a range of highly-controlled straining flows using a cross-flow microfluidic device. The motion of the cell body and flagellum were captured through high-speed video microscopy. The effects of flow on swimming are twofold. For moderate velocity gradients, flow simply advects and reorients cells, quenching their ability to cross streamlines. For high velocity gradients, fluid stresses hinder the internal bending of the flagellum, directly inhibiting motility. The transition between the two regimes is governed by the Sperm number, which compares the external viscous stresses with the internal elastic stresses. Ultimately, unraveling the role of flow in sperm motility will lead to a better understanding of population dynamics among aquatic organisms and infertility problems in humans.

Stallion sperm transcriptome comprises functionally coherent coding and regulatory RNAs as revealed by microarray analysis and RNA-seq.

PubMed

Das, Pranab J; McCarthy, Fiona; Vishnoi, Monika; Paria, Nandina; Gresham, Cathy; Li, Gang; Kachroo, Priyanka; Sudderth, A Kendrick; Teague, Sheila; Love, Charles C; Varner, Dickson D; Chowdhary, Bhanu P; Raudsepp, Terje

2013-01-01

Mature mammalian sperm contain a complex population of RNAs some of which might regulate spermatogenesis while others probably play a role in fertilization and early development. Due to this limited knowledge, the biological functions of sperm RNAs remain enigmatic. Here we report the first characterization of the global transcriptome of the sperm of fertile stallions. The findings improved understanding of the biological significance of sperm RNAs which in turn will allow the discovery of sperm-based biomarkers for stallion fertility. The stallion sperm transcriptome was interrogated by analyzing sperm and testes RNA on a 21,000-element equine whole-genome oligoarray and by RNA-seq. Microarray analysis revealed 6,761 transcripts in the sperm, of which 165 were sperm-enriched, and 155 were differentially expressed between the sperm and testes. Next, 70 million raw reads were generated by RNA-seq of which 50% could be aligned with the horse reference genome. A total of 19,257 sequence tags were mapped to all horse chromosomes and the mitochondrial genome. The highest density of mapped transcripts was in gene-rich ECA11, 12 and 13, and the lowest in gene-poor ECA9 and X; 7 gene transcripts originated from ECAY. Structural annotation aligned sperm transcripts with 4,504 known horse and/or human genes, rRNAs and 82 miRNAs, whereas 13,354 sequence tags remained anonymous. The data were aligned with selected equine gene models to identify additional exons and splice variants. Gene Ontology annotations showed that sperm transcripts were associated with molecular processes (chemoattractant-activated signal transduction, ion transport) and cellular components (membranes and vesicles) related to known sperm functions at fertilization, while some messenger and micro RNAs might be critical for early development. The findings suggest that the rich repertoire of coding and non-coding RNAs in stallion sperm is not a random remnant from spermatogenesis in testes but a selectively retained and functionally coherent collection of RNAs.

Stallion Sperm Transcriptome Comprises Functionally Coherent Coding and Regulatory RNAs as Revealed by Microarray Analysis and RNA-seq

PubMed Central

Das, Pranab J.; McCarthy, Fiona; Vishnoi, Monika; Paria, Nandina; Gresham, Cathy; Li, Gang; Kachroo, Priyanka; Sudderth, A. Kendrick; Teague, Sheila; Love, Charles C.; Varner, Dickson D.; Chowdhary, Bhanu P.; Raudsepp, Terje

2013-01-01

Mature mammalian sperm contain a complex population of RNAs some of which might regulate spermatogenesis while others probably play a role in fertilization and early development. Due to this limited knowledge, the biological functions of sperm RNAs remain enigmatic. Here we report the first characterization of the global transcriptome of the sperm of fertile stallions. The findings improved understanding of the biological significance of sperm RNAs which in turn will allow the discovery of sperm-based biomarkers for stallion fertility. The stallion sperm transcriptome was interrogated by analyzing sperm and testes RNA on a 21,000-element equine whole-genome oligoarray and by RNA-seq. Microarray analysis revealed 6,761 transcripts in the sperm, of which 165 were sperm-enriched, and 155 were differentially expressed between the sperm and testes. Next, 70 million raw reads were generated by RNA-seq of which 50% could be aligned with the horse reference genome. A total of 19,257 sequence tags were mapped to all horse chromosomes and the mitochondrial genome. The highest density of mapped transcripts was in gene-rich ECA11, 12 and 13, and the lowest in gene-poor ECA9 and X; 7 gene transcripts originated from ECAY. Structural annotation aligned sperm transcripts with 4,504 known horse and/or human genes, rRNAs and 82 miRNAs, whereas 13,354 sequence tags remained anonymous. The data were aligned with selected equine gene models to identify additional exons and splice variants. Gene Ontology annotations showed that sperm transcripts were associated with molecular processes (chemoattractant-activated signal transduction, ion transport) and cellular components (membranes and vesicles) related to known sperm functions at fertilization, while some messenger and micro RNAs might be critical for early development. The findings suggest that the rich repertoire of coding and non-coding RNAs in stallion sperm is not a random remnant from spermatogenesis in testes but a selectively retained and functionally coherent collection of RNAs. PMID:23409192

Ocean acidification reduces sperm flagellar motility in broadcast spawning reef invertebrates.

PubMed

Morita, Masaya; Suwa, Ryota; Iguchi, Akira; Nakamura, Masako; Shimada, Kazuaki; Sakai, Kazuhiko; Suzuki, Atsushi

2010-05-01

Ocean acidification is now recognized as a threat to marine ecosystems; however, the effect of ocean acidification on fertilization in marine organisms is still largely unknown. In this study, we focused on sperm flagellar motility in broadcast spawning reef invertebrates (a coral and a sea cucumber). Below pH 7.7, the pH predicted to occur within the next 100 years, sperm flagellar motility was seriously impaired in these organisms. Considering that sperm flagellar motility is indispensable for transporting the paternal haploid genome for fertilization, fertilization taking place in seawater may decline in the not too distant future. Urgent surveys are necessary for a better understanding of the physiological consequences of ocean acidification on sperm flagellar motility in a wide range of marine invertebrates.

Molecular andrology as related to sperm DNA fragmentation/sperm chromatin biotechnology.

PubMed

Shafik, A; Shafik, A A; Shafik, I; El Sibai, O

2006-01-01

Genetic male infertility occurs throughout the life cycle from genetic traits carried by the sperm, to fertilization and post-fertilization genome alterations, and subsequent developmental changes in the blastocyst and fetus as well as errors in meiosis and abnormalities in spermatogenesis/spermatogenesis. Genes encoding proteins for normal development include SRY, SOX9, INSL3 and LGR8. Genetic abnormalities affect spermatogenesis whereas polymorphisms affect receptor affinity and hormone bioactivity. Transgenic animal models, the human genome project, and other techniques have identified numerous genes related to male fertility. Several techniques have been developed to measure the amount of sperm DNA damage in an effort to identify more objective parameters for evaluation of infertile men. The integrity of sperm DNA influences a couple's fertility and helps predict the chances of pregnancy and its successful outcome. The available tests of sperm DNA damage require additional large-scale clinical trials before their integration into routine clinical practice. The physiological/molecular integrity of sperm DNA is a novel parameter of semen quality and a potential fertility predictor. Although DNA integrity assessment appears to be a logical biomarker of sperm quality, it is not being assessed as a routine part of semen analysis by clinical andrologists. Extensive investigation has been conducted for the comparative evaluation of these techniques. However, some of these techniques require expensive instrumentation for optimal and unbiased analysis, are labor intensive, or require the use of enzymes whose activity and accessibility to DNA breaks may be irregular. Thus, these techniques are recommended for basic research rather than for routine andrology laboratories.

Reproductive toxicity of the water accommodated fraction (WAF) of crude oil in the polychaetes Arenicola marina (L.) and Nereis virens (Sars).

PubMed

Lewis, Ceri; Pook, Chris; Galloway, Tamara

2008-10-20

Accidental pollution incidents are common in the marine environment and are often caused by oil-related activities. Here the potential of such an incident to disrupt reproduction in two polychaete species is investigated, using an environmentally relevant preparation of weathered Forties crude oil, i.e. the water accommodated fraction (WAF). Oocytes were collected and exposed to three concentrations of WAF for 1h prior to the addition of sperm, so that fertilization took place under exposure conditions. Fertilization success was significantly reduced in both species by an exposure to WAF concentrations equivalent to 0.38 mgL(-1) PAHs, to just 26.8% in Arenicola marina compared to 76% in Nereis virens. The effects of WAF exposure on fertilization were greatly enhanced at lower sperm concentrations in N. virens, with a complete lack of fertilization reactions observed at sperm concentrations of 10(3)sperm per mL. We therefore suggest a mechanism of toxicity related to sperm swimming behaviour, resulting in reduced sperm:egg collision rates. WAF was found to reduce post-fertilization development rates and have teratogenic effects on early embryonic stages in both species, which exhibited abnormal cleavage patterns and high levels of fluctuating asymmetry. These results illustrate how the presence of crude oil in its soluble form in seawater at the time of a spawning event for either A. marina or N. virens could impact on fertilization success with implications for the fertilization ecology of these free spawning marine invertebrates.

Effects of 17beta-estradiol, and its metabolite, 4-hydroxyestradiol on fertilization, embryo development and oxidative DNA damage in sand dollar (Dendraster excentricus) sperm.

PubMed

Rempel, Mary Ann; Hester, Brian; Deharo, Hector; Hong, Haizheng; Wang, Yinsheng; Schlenk, Daniel

2009-03-15

Oxidative compounds have been demonstrated to decrease the fertilization capability and viability of offspring of treated spermatozoa. As estrogen and its hydroxylated metabolites readily undergo redox cycling, this study was undertaken to determine if estrogens and other oxidants could damage DNA and impair sperm function. Sperm was preexposed to either 17beta-estradiol (E2), 4-hydroxyestradiol (4OHE2) or the oxidant t-butyl hydroperoxide (t-BOOH), and allowed to fertilize untreated eggs. The fertilization rates and development of the larvae were assessed, as well as the amount of 8-oxodeoxyguanosine (8-oxodG) as an indication of oxidative DNA damage. All compounds caused significant decreases in fertilization and increases in pathological abnormalities in offspring, with 4OHE2 being the most toxic. Treatment with 4OHE2 caused a significant increase of 8-oxodG, but E2 failed to show any effect. Pathological abnormalities were significantly correlated (r(2)=0.44, p< or =0.05) with 8-oxodG levels in sperm treated with t-BOOH and 4OHE2, but not E2. 8-OxodG levels also were somewhat weakly correlated with impaired fertilization in 4OHE2-treated sperm (r(2)=0.33, p< or =0.05). The results indicate that biotransformation of E2 to 4OHE2 enhances oxidative damage of DNA in sperm, which can reduce fertilization and impair embryonic development, but other mechanisms of action may also contribute to these effects.

Effects of 17β-estradiol, and its metabolite, 4-hydroxyestradiol on fertilization, embryo development and oxidative DNA damage in sand dollar (Dendraster excentricus) sperm

PubMed Central

Rempel, Mary Ann; Hester, Brian; DeHaro, Hector; Hong, Haizheng; Wang, Yinsheng; Schlenk, Daniel

2011-01-01

Oxidative compounds have been demonstrated to decrease the fertilization capability and viability of offspring of treated spermatozoa. As estrogen and its hydroxylated metabolites readily undergo redox cycling, this study was undertaken to determine if estrogens and other oxidants could damage DNA and impair sperm function. Sperm was preexposed to either 17β-estradiol (E2), 4-hydroxyestradiol (4OHE2) or the oxidant t-butyl hydroperoxide (t-BOOH), and allowed to fertilize untreated eggs. The fertilization rates and development of the larvae were assessed, as well as the amount of 8-oxodeoxyguanosine (8-oxodG) as an indication of oxidative DNA damage. All compounds caused significant decreases in fertilization and increases in pathological abnormalities in offspring, with 4OHE2 being the most toxic. Treatment with 4OHE2 caused a significant increase of 8-oxodG, but E2 failed to show any effect. Pathological abnormalities were significantly correlated (r2 = 0.44, p ≤ 0.05) with 8-oxodG levels in sperm treated with t-BOOH and 4OHE2, but not E2. 8-OxodG levels also were somewhat weakly correlated with impaired fertilization in 4OHE2-treated sperm (r2 = 0.33, p ≤ 0.05). The results indicate that biotransformation of E2 to 4OHE2 enhances oxidative damage of DNA in sperm, which can reduce fertilization and impair embryonic development, but other mechanisms of action may also contribute to these effects. PMID:19171371

INHIBITION OF IN VITRO FERTILIZATION IN THE HAMSTER BY ANTIBODIES RAISED AGAINST THE RAT SPERM PROTEIN SP22

EPA Science Inventory

INHIBITION OF IN VITRO FERTILIZATION IN THE HAMSTER BY ANTIBODIES RAISED AGAINST THE RAT SPERM PROTEIN SP22. SC Jeffay*, SD Perreault, KL Bobseine*, JE Welch*, GR Klinefelter, US EPA, Research Triangle Park, NC.
SP22, a rat sperm membrane protein that is highly-correlated w...

The effects of semen collection on fertility in captive, naturally fertile, sandhill cranes

USGS Publications Warehouse

Chen, G.; Gee, G.F.; Nicolich, Jane M.; Taylor, J.A.

2001-01-01

We tested to see if semen collection interferes with fertility in naturally fertile pairs of cranes. We used 12 naturally fertile, Florida sandhill crane (Grus canadensis pratensis) pairs for this study, 6 control and 6 experimental. All pairs had previously produced fertile eggs. Semen was collected on Tuesday mornings and Friday afternoons from 26 February 1993 to 4 June 1993. We used standard artificial insemination methods to collect and to evaluate the semen and spermatozoa. Semen collection had minimal effect on semen quality and semen quantity. Semen volume, sperm density, sperm motility, sperm morphology, sperm viability, sperm number per collection, and male response to semen collection exhibited significant daily variation. Although semen collection began 13 days before the first egg in the experimental group, we did not observe differences in the date of first egg laid or in fertility between experimental and control groups. Also, we observed no statistically significant differences in the interval between clutches or in the percentage of broken eggs between experimental and control groups. However, 4 eggs were broken by adults during the disturbance associated with capturing birds for semen collection. We found that females with mates from which we consistently gathered better semen samples produced fewer fertile eggs than females with sires producing poorer semen samples (r = 0.60). We interpret these results to mean that males that were successfully breeding with their mates had little left at the time of our collection.

Cryotolerance of stallion spermatozoa is related to ROS production and mitochondrial membrane potential rather than to the integrity of sperm nucleus.

PubMed

Yeste, M; Estrada, E; Rocha, L G; Marín, H; Rodríguez-Gil, J E; Miró, J

2015-03-01

Although cryopreservation of stallion spermatozoa allows long-term preservation of spermatozoa from particular stallions and facilitates international trade, it is understood to inflict damages on sperm cells that may finally reduce their fertilizing ability. In addition, individual differences are known to exist in the sperm ability to withstand freeze-thawing protocols. To date, these differences have mainly been reported on the basis of sperm motility and membrane integrity. For this reason, the present work sought to determine differences between good (good freezability ejaculates: GFE) and poor (poor freezability ejaculates: PFE) freezability stallion ejaculates in other sperm parameters, including peroxide and superoxide levels, potential of mitochondrial membrane and nuclear integrity. With this purpose, a total of 24 stallion ejaculates were cryopreserved and classified into two groups (GFE vs. PFE), depending on their sperm membrane integrity and motility after freeze-thawing. From the total of 24 ejaculates, 13 were classified as GFE and the other 11 were classified as PFE. Apart from differences in sperm membrane permeability and lipid disorder after freeze-thawing, GFE presented significantly (p < 0.05) higher percentages of viable spermatozoa with high content of peroxides and of superoxides than PFE. In contrast, and despite cryopreservation of stallion spermatozoa increasing DNA fragmentation and disrupting disulphide bonds in sperm head proteins, no significant differences between GFE and PFE were seen. We can thus conclude that good and poor freezability stallion ejaculates differ in their reactive oxygen species levels after cryopreservation, but not in the damage extent on sperm nucleus. © 2014 American Society of Andrology and European Academy of Andrology.

Revisiting "The fertilization fairytale:" an analysis of gendered language used to describe fertilization in science textbooks from middle school to medical school

NASA Astrophysics Data System (ADS)

Campo-Engelstein, Lisa; Johnson, Nadia L.

2014-03-01

Emily Martin's (Signs J Women Cult Soc 16(31):485-501, 1991) article, "The Egg and the Sperm: How Science Has Constructed a Romance Based on Stereotypical Male-Female Roles," was published in Signs over 20 years ago. In this groundbreaking article, she discusses how gender roles are often projected onto reproductive biology, leading to the portrayal of eggs as passive and sperm as active. We were interested in seeing if many of her findings are still relevant today. We analyzed science textbooks from the middle school to the medical school level to determine if fertilization in human reproduction is described in gender-biased language regarding the sentence structure, amount of information provided for female and male processes/parts, and neutrality in describing female and male processes/parts. Although there has been much improvement, there is still a long way to go. Sexist language in scientific textbooks is troubling because it negatively affects both female and male students and undermines teachers' ability to teach in an accurate and gender-neutral way.

Review: Diagnosis and impact of sperm DNA alterations in assisted reproduction.

PubMed

Simon, Luke; Emery, Benjamin R; Carrell, Douglas T

2017-10-01

Sperm nuclear and chromatin abnormalities are common among infertile men and are known to influence natural reproduction. These abnormalities are also considered detrimental to normal fertilization, embryo development, and successful implantation and pregnancies following assisted reproductive treatment (ART). Abnormalities in the sperm nucleus can be broadly classified into sperm chromosomal abnormalities (aneuploidies) and sperm DNA abnormalities such as abnormal packing, DNA integrity, or DNA fragmentation. For the past 30 years, numerous tests have been developed to quantify these abnormalities in sperm. In this chapter, we review the causes of sperm DNA and chromosomal abnormalities, describe the commonly used tests to evaluate these abnormalities, and finally review the impact of these abnormalities on male fertility and ART outcomes. We also performed a comprehensive meta-analysis and systematic review from the existing literature to summarize the effect of sperm DNA fragmentation on ART outcomes such as fertilization rate, embryo quality, and clinical pregnancies. A review of the literature presented in this chapter suggests that sperm nuclear and chromatin abnormalities are associated with male infertility, and they reduce the probability of a successful pregnancy following ART. Copyright © 2017. Published by Elsevier Ltd.

Sperm storage in the oviduct of the internal fertilizing frog Ascaphus truei.

PubMed

Sever, D M; Moriarty, E C; Rania, L C; Hamlett, W C

2001-04-01

This study provides the first descriptions of sperm storage at the tissue and cellular levels in a female frog or toad. Oviducal anatomy was studied by light and electron microscopy in Ascaphus truei from north coastal California. Ascaphus truei is one of the few species of anurans in which fertilization is internal. Unlike other anurans with internal fertilization, however, mating in A. truei consists of a unique combination of amplectic and copulatory mechanisms that we term "copulexus." Posterior to a short, aglandular infundibular region, the oviduct possesses: 1) a proximal, convoluted ampullary region where intrinsic tubular glands secrete gelatinous envelopes around eggs; 2) a middle ovisac region where fertilization occurs; and 3) a distal oviducal sinus formed by medial junction of the ovisacs. Sperm storage tubules (SSTs) occur in the anterior portions of the ovisacs and consist of simple tubular glands. SSTs and the rest of the oviducal lining stain positively with the periodic acid-Schiff's procedure for neutral carbohydrates and this reaction is especially intense in reproductively active females. Sperm were found in the SSTs of gravid females as well as some nonvitellogenic females. The sperm are in orderly bundles in the SSTs, and although occasionally sperm nuclei were embedded in the epithelium, no evidence for spermiophagy was found. Oviducal sperm storage in A. truei is homoplastic, with closest structural similarities to squamate reptiles. Oviduct/sperm design constraints appear to limit the options for expression of features associated with oviducal sperm storage. Copyright 2001 Wiley-Liss, Inc.

High total antioxidant capacity of the porcine seminal plasma (SP-TAC) relates to sperm survival and fertility

PubMed Central

Barranco, Isabel; Tvarijonaviciute, Asta; Perez-Patiño, Cristina; Parrilla, Inmaculada; Ceron, Jose J.; Martinez, Emilio A.; Rodriguez-Martinez, Heriberto; Roca, Jordi

2015-01-01

The study attempted to clarify the role of total antioxidant capacity of seminal plasma (SP-TAC) on boar sperm survival and fertility after artificial insemination (AI). SP-TAC differed (P < 0.001) among boars (n° = 15) and, to a lesser degree, among ejaculates within male (4 ejaculates/boar). SP-TAC also differed (P < 0.001) among ejaculate fractions (43 ejaculates and 3 fractions per ejaculate), of which the sperm-peak portion of the sperm rich ejaculate fraction (SRF) had the highest SP-TAC. SP-TAC was not correlated with sperm quality (motility and viability) or functionality (intracellular ROS generation and lipid peroxidation) of liquid AI-semen samples stored at 17 °C for 72 h (90 AI-samples), but the decline in sperm quality was larger (P < 0.05) in ejaculates with low, compared with high SP-TAC (hierarchically grouped). The SP-TAC differences among ejaculate portions agree with sperm cryosurvival rates (14 ejaculates from 7 boars), showing sperm from sperm-peak portion better (P < 0.01) post-thaw quality and functionality than those from the entire ejaculate (mainly post-SRF). Boars (n° = 18) with high SP-TAC (hierarchically grouped) had higher (P < 0.05) fertility outcomes (5,546 AI-sows) than those with low SP-TAC. Measurement of SP-TAC ought to be a discriminative tool to prognosis fertility in breeding boars. PMID:26688188

Efficacy of testicular sperm chromatin condensation assay using aniline blue-eosin staining in the IVF-ET cycle.

PubMed

Park, Yong-Seog; Kim, Myo Kyung; Lee, Sun-Hee; Cho, Jae Won; Song, In Ok; Seo, Ju Tae

2011-09-01

This study was performed to evaluate testicular sperm chromatin condensation using aniline blue-eosin (AB-E) staining and its effects on IVF-ET. Chromatin condensation was analyzed using AB-E staining in 27 cases of testicular sperm extraction. There were 19 cases of obstructive azoospermia (OA) and 8 cases of non-obstructive azoospermia (NOA) in IVF-ET. Mature sperm heads were stained red-pink whereas immature sperm heads were stained dark blue. The percentage of sperm chromatin condensation was calculated from the ratio of the number of red-pink sperm to the total number of sperm analyzed. The overall percentages of chromatin condensation in OA and NOA were 31.1±11.2% and 26.3±14.4%, respectively. The fertilization rate was significant higher in OA than NOA (p<0.05); however, the rates of good embryos and clinical pregnancy did not show statistical differences. In OA and NOA, statistical differences were not observed in the rate of chromatin condensation, fertilization, good embryos, and clinical pregnancy between the pregnant group and non-pregnant group. Chromatin condensation is less stable than OA and showed a low fertilization rate in NOA. While there were no significant differences in chromatin condensation results between NOA and OA, we propose that a pattern of decreased chromatin condensation in NOA is one of the factors of low fertilization results requiring further study.

Cryopreservation of common carp (Cyprinus carpio) sperm in 1.2 and 5 ml straws and occurrence of haploids among larvae produced with cryopreserved sperm.

PubMed

Horváth, Akos; Miskolczi, Edit; Mihálffy, Szilvia; Osz, Katalin; Szabó, Krisztián; Urbányi, Béla

2007-06-01

Experiments were carried out on the cryopreservation of common carp (Cyprinus carpio) sperm in order to test the suitability of using 1.2 and 5 ml straws and to investigate the ploidy of malformed larvae found among the hatched progeny. In the first set of experiments, the effect of freezing time was investigated on the hatch rate of embryos. The highest hatch rate for 1.2 ml straws was 69+/-16% at the freezing time of 4 min, and 39+/-27% for 5 ml straws at 5 min. In the second set, the effect different egg volumes fertilized with one straw of sperm on the hatch rate and the rate of malformed larvae was investigated. The highest hatch rate with 1.2 ml straws (86+/-12%) was observed when 10 g of eggs were fertilized with one straw, whereas with 5 ml straws the hatch rate was highest (65+/-18%) when 40 g of eggs were fertilized. The highest rate of malformed larvae (15+/-9%) was found in the control, whereas the highest rate of malformed larvae among the groups fertilized with cryopreserved sperm (13+/-7%) was found in the 1x dose group fertilized with 5 ml straw. The chromosome numbers of malformed larvae were investigated and haploids were found among those hatched from eggs fertilized with cryopreserved sperm whereas only diploids were found in the controls.

Effect of caffeine on motility and vitality of sperm and in vitro fertilization of outbreed mouse in T6 and M16 media.

PubMed

Nabavi, Narges; Todehdehghan, Fatemeh; Shiravi, Abdollhossein

2013-09-01

Caffeine increases the CAMP production that stimulates spermatozoa movement. Caffeine is also used for induction of in vitro acrosome reaction in mammalian spermatozoa, an important step in achieving fertilization. The aim of this study was to assess the effect of caffeine on sperm's motility, vitality and laboratory fertilization rates in mouse in two T6 and M16 media. Epididymal mouse sperms were collected and treated by caffine in T6 and M16 media and their motility and vitality rates were evaluated. The pretreated sperms were added to oocytes in T6 and M16 media with and without caffeine and fertilization rates were recorded after 24 hours incubation. Sperm's motility (81.7±1.67%) and vitality (88.7±1.33%) rates and percentage of fertilized oocytes (67.52±8.16%) in T6 medium plus caffeine compare to control group have increased and shown significant differences at p≤0.01. While the percentages of these parameters in M16 medium supplemented with caffeine were 68.3±6.01%, 78±6.11%, and 42.6±12.96 respectively and in comparison to control group (M16 without caffeine) have not shown significant differences. Addition of caffeine to T6 medium promotes the sperm's motility and vitality and enhances fertilization and early in vitro development of mouse embryos. This article extracted from M.Sc. thesis. (Narges Navabi).

Comparison of reproductive traits of regular and irradiated male desert locust Schistocerca gregaria (Orthoptera: Acrididae): Evidence of last-male sperm precedence

PubMed Central

Dushimirimana, Severin; Hance, Thierry; Damiens, David

2012-01-01

Summary The sterile insect technique (SIT) is increasingly used to control pest insect populations. The success of SIT control programs depends on the ability to release sterile males and on the capacity of sterile males to compete with wild males to inseminate wild females. In this study, we evaluated the mating performance of Schistocerca gregaria (Försk.) males irradiated with 4 Gray. We compared reproductive traits, such as duration of precopulation time, mating duration, quantity of sperm stored by females after copulation, number of females mated successively and postmating competition of irradiated males with non-irradiated males. Irradiated males were able to mate but the resulting number of offspring was dramatically reduced compared to the average number of offspring observed during a regular mating. During a single copulation, irradiated males transferred fewer sperm than regular males but, theoretically, this quantity is enough to fertilize all the eggs produced by a female during its reproductive life. Irradiated males also had the ability to remove sperm from a previous mating with unirraditated males. This new information on the mating strategies helps explain the post-copulation guarding behaviour of S. gregaria. PMID:23213413

Low levels of PRSS37 protein in sperm are associated with many cases of unexplained male infertility.

PubMed

Liu, Jianbing; Shen, Chunling; Fan, Weimin; Chen, Yan; Zhang, Aijun; Feng, Yun; Li, Zheng; Kuang, Ying; Wang, Zhugang

2016-11-01

PRSS37, a putative trypsin-like serine protease, is highly conserved during mammalian evolution as revealed by multiple sequence alignment. Mice deficient for Prss37 gene exhibit male infertility, but their mating behavior, spermatogenesis, sperm morphology, and motility remain unaffected, similar to a situation called unexplained male infertility (UMI) in men (human being). Here, we demonstrated that PRSS37 is restrictively expressed in human testis, where it is mainly located in the elongating and elongated spermatids during spermiogenesis as shown by immunohistochemical analysis of normal human testicular sections. In mature sperm, PRSS37 appears in the acrosome region and diminishes during acrosome reaction. Further examination reveals that PRSS37 contents in sperm from patients with UMI are dramatically lower than those in sperm from men with proven fertility or from sperm donors. Sperm with low PRSS37 contents exhibit abnormal activation of the proacrosin/acrosin system and premature proteolysis of ADAM2, which may impair the functional competence of human sperm in vivo However, the in vitro fertilization outcomes of sperm with low PRSS37 contents are not affected. Together, these data implicate an important role of PRSS37 for male fertility. PRSS37 can be used as a potential molecular biomarker for evaluating sperm fertilization capability in vivo but not in vitro. © The Author 2016. Published by Oxford University Press on behalf of the Institute of Biochemistry and Cell Biology, Shanghai Institutes for Biological Sciences, Chinese Academy of Sciences. All rights reserved. For permissions, please e-mail: journals.permissions@oup.com.

Dimorphic ejaculates and sperm release strategies associated with alternative mating behaviors in the squid.

PubMed

Apostólico, Lígia H; Marian, José E A R

2017-11-01

Sperm competition is a powerful postcopulatory selective force influencing male adaptations associated with increasing fertilization success, and it is usually related to the evolution of different strategies of ejaculate expenditure between individuals. Ejaculates may also be influenced by additional selective pressures associated with sperm competition, such as timing between insemination and fertilization, female reproductive tract morphology, and fertilization environment. Also, males that adopt alternative mating tactics may face distinct sperm competition pressures, which may lead to the evolution of intraspecific diversity in ejaculates. In loliginid squids, males with alternative reproductive tactics (sneakers and consorts) differ not only in mating behavior, but also transfer spermatophores into two distinct sites within the female. Here, we compared structure and functioning of spermatophores between sneakers and consorts in the squid Doryteuthis plei applying microscopy techniques and in vitro experiments. Sneakers and consorts exhibit differences in spermatophore structure that lead to distinct spermatophoric reactions and spermatangium morphologies. Moreover, in sneakers, sperm release lasts longer and their sperm show an aggregative behavior not detected in consorts. Slow sperm release may be a strategy to guarantee longer sperm provision, given the wide interval between sneaker mating and egg release. For consorts, in turn, intense and quick sperm discharge may be advantageous, as timing between mating and egg-laying is relatively short. Within the complex squid mating system, factors such as (i) different fertilization sites and (ii) interval between mating and egg release may also influence sperm competition, and ultimately shape the evolution of divergent ejaculates between dimorphic males. © 2017 Wiley Periodicals, Inc.

Importance of β-defensins in sperm function.

PubMed

Dorin, Julia R; Barratt, Christopher L R

2014-09-01

Recent work in humans and mouse has confirmed the involvement of the host defence β-defensin peptides in male fertility. We discuss here the work that has implicated β-defensins in sperm function including the identification of the epididymis as the predominant site of expression of the peptides and the in vivo consequences of mutation and deletion. The potential dual role of these peptides in the regulation of infection and control of sperm maturation is compelling and may combine their antimicrobial activity with the ability of these molecules to interact with cell membrane receptors and modulate ion transport. © The Author 2014. Published by Oxford University Press on behalf of the European Society of Human Reproduction and Embryology. All rights reserved. For Permissions, please email: journals.permissions@oup.com.

Update on sexed semen technology in cattle.

PubMed

Seidel, G E

2014-05-01

The technology in current use for sexing sperm represents remarkable feats of engineering. These flow cytometer/cell sorters can make over 30 000 consecutive evaluations of individual sperm each second for each nozzle and sort the sperm into three containers: X-sperm, Y-sperm and unsexable plus dead sperm. Even at these speeds it is not economical to package sperm at standard numbers per inseminate. However, with excellent management, pregnancy rates in cattle with 2 million sexed sperm per insemination dose are about 80% of those with conventional semen at normal sperm doses. This lowered fertility, in part due to damage to sperm during sorting, plus the extra cost of sexed semen limits the applications that are economically feasible. Even so, on the order of 2 million doses of bovine semen are sexed annually in the United States. The main application is for dairy heifers to have heifer calves, either for herd expansion or for sale as replacements, often for eventual export. Breeders of purebred cattle often use sexed semen for specific matings; thawing and then sexing frozen semen and immediately using the few resulting sexed sperm for in vitro fertilization is done with increasing frequency. Beef cattle producers are starting to use sexed semen to produce crossbred female replacements. Proprietary improvements in sperm sexing procedures, implemented in 2013, are claimed to improve fertility between 4 and 6 percentage points, or about 10%.

A national study of the provision of oncology sperm banking services among Canadian fertility clinics.

PubMed

Yee, S; Buckett, W; Campbell, S; Yanofsky, R A; Barr, R D

2013-07-01

The purpose of this study was to survey the current state of oncology sperm banking services provided by fertility clinics across Canada. A total of 78 Canadian fertility facilities were invited to complete a questionnaire related to the availability, accessibility, affordability and utilisation of sperm banking services for cancer patients. The total response rate was 59%, with 20 (69%) in vitro fertilisation clinics and 26 (53%) other fertility centres returning the survey. A total of 24 responding facilities accepted oncology sperm banking referrals. The time frame to book the first banking appointment for 19 (79%) facilities was within 2 days. Inconsistent practice was found regarding the consent process for cancer patients who are of minority age. Eight (33%) facilities did not provide any subsidy and charged a standard banking fee regardless of patients' financial situations. Overall, the utilisation of oncology sperm banking services was low despite its availability and established efficacy, suggesting that Canadian cancer patients are notably underserved. The study has highlighted some important issues for further consideration in improving access to sperm banking services for cancer patients, especially for adolescents. Better collaboration between oncology and reproductive medicine to target healthcare providers would help to improve sperm banking rates. © 2013 John Wiley & Sons Ltd.

Finding out about sperm banking: what information is available online for men diagnosed with cancer?

PubMed

Merrick, H; Wright, E; Pacey, A A; Eiser, C

2012-09-01

Sperm banking is routinely offered to men where there is a risk of infertility following cancer treatment but uptake is lower than expected. Since these men may turn to the internet for information, we used the search engine www.google.com to identify the material available about sperm banking and fertility preservation options. Sixty-six resources (NHS/Private Clinic, Charity, Press Releases, General and Forums/Blogs) fulfilled the criteria for inclusion and were examined for quality including readability, layout and content. The most frequently reported information related to: (1) effects of cancer treatment on fertility (77.3%); (2) reasons to bank sperm (69.7%); and (3) fertility recovery after treatment (57.6%). Information about maintaining contact with the sperm bank (18.2%) and disposal of banked samples (10.6%) was less often included. The quality of information available on the Internet about sperm banking was variable. The readability of all resources was assessed as 'fairly difficult', i.e. reading skills required were too complex for the average member of the public to understand. Furthermore, visual presentation of material (e.g. lay out) did not facilitate easy reading. More attention should be given to information about longer-term issues, such as fertility recovery and the use or disposal of banked sperm.

CRYPTIC CHOICE OF CONSPECIFIC SPERM CONTROLLED BY THE IMPACT OF OVARIAN FLUID ON SPERM SWIMMING BEHAVIOR

PubMed Central

Yeates, Sarah E; Diamond, Sian E; Einum, Sigurd; Emerson, Brent C; Holt, William V; Gage, Matthew J G

2013-01-01

Despite evidence that variation in male–female reproductive compatibility exists in many fertilization systems, identifying mechanisms of cryptic female choice at the gamete level has been a challenge. Here, under risks of genetic incompatibility through hybridization, we show how salmon and trout eggs promote fertilization by conspecific sperm. Using in vitro fertilization experiments that replicate the gametic microenvironment, we find complete interfertility between both species. However, if either species’ ova were presented with equivalent numbers of both sperm types, conspecific sperm gained fertilization precedence. Surprisingly, the species’ identity of the eggs did not explain this cryptic female choice, which instead was primarily controlled by conspecific ovarian fluid, a semiviscous, protein-rich solution that bathes the eggs and is released at spawning. Video analyses revealed that ovarian fluid doubled sperm motile life span and straightened swimming trajectory, behaviors allowing chemoattraction up a concentration gradient. To confirm chemoattraction, cell migration tests through membranes containing pores that approximated to the egg micropyle showed that conspecific ovarian fluid attracted many more spermatozoa through the membrane, compared with heterospecific fluid or water. These combined findings together identify how cryptic female choice can evolve at the gamete level and promote reproductive isolation, mediated by a specific chemoattractive influence of ovarian fluid on sperm swimming behavior. PMID:24299405

Sneaker “jack” males outcompete dominant “hooknose” males under sperm competition in Chinook salmon (Oncorhynchus tshawytscha)

PubMed Central

Young, Brent; Conti, David V; Dean, Matthew D

2013-01-01

In a variety of taxa, males deploy alternative reproductive tactics to secure fertilizations. In many species, small “sneaker” males attempt to steal fertilizations while avoiding encounters with larger, more aggressive, dominant males. Sneaker males usually face a number of disadvantages, including reduced access to females and the higher likelihood that upon ejaculation, their sperm face competition from other males. Nevertheless, sneaker males represent an evolutionarily stable strategy under a wide range of conditions. Game theory suggests that sneaker males compensate for these disadvantages by investing disproportionately in spermatogenesis, by producing more sperm per unit body mass (the “fair raffle”) and/or by producing higher quality sperm (the “loaded raffle”). Here, we test these models by competing sperm from sneaker “jack” males against sperm from dominant “hooknose” males in Chinook salmon. Using two complementary approaches, we reject the fair raffle in favor of the loaded raffle and estimate that jack males were ∼1.35 times as likely as hooknose males to fertilize eggs under controlled competitive conditions. Interestingly, the direction and magnitude of this skew in paternity shifted according to individual female egg donors, suggesting cryptic female choice could moderate the outcomes of sperm competition in this externally fertilizing species. PMID:24455130

Migration of fresh and cryopreserved human spermatozoa in polyacrylamide gel.

PubMed

Goldstein, M C; Wix, L S; Foote, R H; Feldschuh, R; Feldschuh, J

1982-05-01

The ability of freshly collected and frozen human spermatozoa to migrate in round capillary tubes containing specially formulated polyacrylamide gel was investigated, using 33 ejaculates from 27 donors. Each semen sample was divided; one portion was left undiluted, and the other portion was diluted to 50 x 10(6) sperm/ml. Glycerol was used as the cryoprotectant. The percentage of motile sperm cells was determined before and after freezing. Fresh semen contained a higher percentage of motile cells, which migrated farther than those of cryopreserved-thawed semen. Various correlations between the percentage of motile sperm and migration distance ranged from 0.57 to 0.62. There was a low positive correlation of migration distance with sperm cell concentration per milliliter, r = 0.25 to 0.34; and thus adjusting semen samples to a standard sperm concentration improved the accuracy of the test only slightly. The regression coefficient of migration distance on the percentage of motile sperm in fresh semen was 0.65, indicating that for each 10% increase in sperm motility, migration distance is predicted to increase 6.5 mm. Five batches of polyacrylamide gel gave uniform results, and the application of this stable gel to fertility investigations is discussed.

Automated Analysis of Human Sperm Number and Concentration (Oligospermia) Using Otsu Threshold Method and Labelling

NASA Astrophysics Data System (ADS)

Susrama, I. G.; Purnama, K. E.; Purnomo, M. H.

2016-01-01

Oligospermia is a male fertility issue defined as a low sperm concentration in the ejaculate. Normally the sperm concentration is 20-120 million/ml, while Oligospermia patients has sperm concentration less than 20 million/ml. Sperm test done in the fertility laboratory to determine oligospermia by checking fresh sperm according to WHO standards in 2010 [9]. The sperm seen in a microscope using a Neubauer improved counting chamber and manually count the number of sperm. In order to be counted automatically, this research made an automation system to analyse and count the sperm concentration called Automated Analysis of Sperm Concentration Counters (A2SC2) using Otsu threshold segmentation process and morphology. Data sperm used is the fresh sperm directly in the analysis in the laboratory from 10 people. The test results using A2SC2 method obtained an accuracy of 91%. Thus in this study, A2SC2 can be used to calculate the amount and concentration of sperm automatically

Impaired Sperm Maturation in Rnase9 Knockout Mice1

PubMed Central

Westmuckett, Andrew D.; Nguyen, Edward B.; Herlea-Pana, Oana M.; Alvau, Antonio; Salicioni, Ana M.; Moore, Kevin L.

2014-01-01

ABSTRACT Ribonuclease, RNase A family, 9 (RNASE9) is a ribonuclease A superfamily member that is expressed only in the epididymis. It is a small, secreted polypeptide, it lacks ribonuclease activity, and its function(s) is unknown. However, epididymis-specific expression suggests a role in sperm maturation. We generated Rnase9−/− mice to study RNASE9 function in vivo. We confirm that RNASE9 expression is restricted to the epididymis. Within the epididymis, RNASE9 is first detected in midcaput, persists through the distal caput and corpus, and wanes in the cauda. Rnase9−/− mice are born at the expected Mendelian ratio, have normal postnatal growth and development, and have no outwardly apparent phenotype. Spermatogenesis is normal, and Rnase9-null sperm are morphologically normal. Rnase9−/− males have normal fertility in unrestricted mating trials, and fertilization rates in in vitro fertilization assays are indistinguishable from wild-type mice. Visual observations coupled with analyses of sperm velocities shortly after swim out from the corpus shows that motility of Rnase9-null sperm is significantly impaired. However, no differences between wild-type and Rnase9-null sperm are detected by computer-assisted sperm analysis 10–90 min after sperm isolation from the corpus or cauda. Assessment of capacitation-dependent signaling pathways in Rnase9-null sperm showed that, while levels of tyrosine phosphorylation of sperm proteins were normal, there was decreased phosphorylation of protein kinase A substrates upon capacitation compared to wild-type mice. In conclusion, RNASE9 is dispensable for fertility, but the absence of RNASE9 during epididymal transit results in impaired sperm maturation. PMID:24719258

Mitochondrial membrane potential and reactive oxygen species in liquid stored and cryopreserved turkey (Meleagris gallopavo) spermatozoa.

PubMed

Slowinska, M; Liszewska, E; Judycka, S; Konopka, M; Ciereszko, A

2018-06-01

The extensive use of artificial insemination in turkeys has led to the development of in vitro semen storage. However, fertility rates from liquid stored and frozen/thawed turkey semen are still unsatisfactory. The aim of the study was to assess spermatozoa viability, mitochondrial membrane potential (MMP), and reactive oxygen species production (ROS) in liquid stored and cryopreserved turkey semen with the use of flow cytometry. Moreover, motility and adenosine triphosphate (ATP) content in sperm were monitored at the same time to link flow cytometry data with sperm movement and energetics. Liquid storage led to a decrease in sperm motility (80.6 vs. 55.6%, for fresh and stored for 48 h), live sperm with an intact MMP (59.9 vs. 30.5% for fresh and stored for 48 h), and a 20-fold decrease in ATP content after 24 h of storage. A 3-fold increase in ROS+ sperm was observed after 48 h of storage (9.3 vs. 26.8% for fresh and stored for 48 h). Semen equilibration before cryopreservation affected only ATP content. However, freezing/thawing led to a dramatic decrease in all of the studied semen quality parameters. A 5-fold decrease in live sperm with intact MMP (59.8 vs. 11.9%) and a 7-fold increase in sperm ROS+ (10.8 vs. 74.4%) were recorded between fresh and frozen/thawed semen. The results strongly suggested that a significant loss of MMP and a disturbance in sperm ATP production during semen storage can be the main reason for the decline in sperm motility. The disturbance of mitochondria activity during storage seems to be associated with the increase in oxidative stress in turkey semen. Turkey sperm mitochondria also appear to be very sensitive to cryodamage. Diminished energy production in turkey spermatozoa, visible as the low percentage of sperm with an intact MMP and low level of ATP after freezing/thawing, which is associated with high ROS generation, could be responsible for the low fertilizing ability of cryopreserved turkey semen.

Effects of ovarian fluid and genetic differences on sperm performance and fertilization success of alternative reproductive tactics in Chinook salmon.

PubMed

Lehnert, S J; Butts, I A E; Flannery, E W; Peters, K M; Heath, D D; Pitcher, T E

2017-06-01

In many species, sperm velocity affects variation in the outcome of male competitive fertilization success. In fishes, ovarian fluid (OF) released with the eggs can increase male sperm velocity and potentially facilitate cryptic female choice for males of specific phenotypes and/or genotypes. Therefore, to investigate the effect of OF on fertilization success, we measured sperm velocity and conducted in vitro competitive fertilizations with paired Chinook salmon (Oncorhynchus tshawytscha) males representing two alternative reproductive tactics, jacks (small sneaker males) and hooknoses (large guarding males), in the presence of river water alone and OF mixed with river water. To determine the effect of genetic differences on fertilization success, we genotyped fish at neutral (microsatellites) and functional [major histocompatibility complex (MHC) II ß1] markers. We found that when sperm were competed in river water, jacks sired significantly more offspring than hooknoses; however, in OF, there was no difference in paternity between the tactics. Sperm velocity was significantly correlated with paternity success in river water, but not in ovarian fluid. Paternity success in OF, but not in river water alone, was correlated with genetic relatedness between male and female, where males that were less related to the female attained greater paternity. We found no relationship between MHC II ß1 divergence between mates and paternity success in water or OF. Our results indicate that OF can influence the outcome of sperm competition in Chinook salmon, where OF provides both male tactics with fertilization opportunities, which may in part explain what maintains both tactics in nature. © 2017 European Society For Evolutionary Biology. Journal of Evolutionary Biology © 2017 European Society For Evolutionary Biology.

Cryopreservation of epididymal stallion sperm.

PubMed

Olaciregui, M; Gil, L; Montón, A; Luño, V; Jerez, R A; Martí, J I

2014-02-01

Any event that makes semen collection or mating impossible, such as death, castration, or injury, may terminate a stallion's breeding career. Fortunately, stallion sperm which are capable of fertilization can be harvested from the epididymis, and frozen for future use. However, the fertility of frozen-thawed epididymal sperm has been found to be lower than that of ejaculated sperm. Therefore, this study aimed to optimize the fertility of frozen epididymal stallion sperm by investigating the effects of different cryoprotectants and freezing protocols on sperm quality. Dimethylformamide was tested alone or combination with pasteurized egg yolk as substitute of fresh egg yolk. In addition, the effect of the pre-freeze stabilization on sperm quality was analyzed. Heterospermic samples obtained from stallion epididymis were collected and cryopreserved in lactose-egg-yolk extender or in the same extender with varying content of cryoprotectant and content of egg yolk, stabilized and no-stabilized. Sperm motility, viability, hypoosmotic swelling test (HOST) and acrosome integrity were evaluated post-thawing. No improvement was observed on the replacement of fresh yolk by pasteurized egg yolk, whereas the results suggest that dimethylformamide is a cryoprotectant suitable for cryopreservation of equine epididymal semen, even better than glycerol. In addition, we found that the stabilization before freezing on epididymal stallion sperm, can improve sperm quality parameters. Copyright © 2014 Elsevier Inc. All rights reserved.

Varicocele is associated with abnormal retention of cytoplasmic droplets by human spermatozoa.

PubMed

Zini, A; Defreitas, G; Freeman, M; Hechter, S; Jarvi, K

2000-09-01

To determine whether varicocele is associated with retention of sperm cytoplasmic droplets in infertile men. Retrospective study. University infertility clinic. Nonazoospermic men with idiopathic (n = 69) and varicocele-associated infertility (n = 73), and 20 fertile controls presenting for vasectomy. None. Standard semen parameters and percentage of spermatozoa with cytoplasmic droplets on Papanicolaou smears. No statistically significant differences were found between the fertile and infertile groups with respect to semen volume. Fertile controls had significantly greater mean percent sperm motility and normal morphology than infertile men. The mean percentage of sperm with residual cytoplasm was statistically significantly different in all three groups. Infertile men with varicocele had the highest percentage of sperm with cytoplasmic droplets, the next highest level being in men with idiopathic infertility and the lowest level in fertile controls (11.7 +/- 1.0, 8.1 +/- 0.9 and 3.2 +/- 0.4%, respectively, P<.0001). Our data show that idiopathic and even moreso, varicocele-related male infertility are conditions associated with impaired disposal of residual sperm cytoplasm by the testis and/or epididymis. These data provide a possible mechanism for the observed semen abnormalities and reduced fertility potential associated with varicocele and idiopathic male infertility.

Cryptic female choice enhances fertilization success and embryo survival in chinook salmon

PubMed Central

2016-01-01

In this study, we investigated two potentially important intersexual postcopulatory gametic interactions in a population of chinook salmon (Oncorhynchus tshawytscha): (i) the effect of female ovarian fluid (OF) on the behaviour of spermatozoa during fertilization and (ii) the effects of multilocus heterozygosity (MLH) (as an index of male quality) and female–male genetic relatedness on sperm behaviour and male fertilization success when there is sperm competition in the presence of that OF. To do this, we conducted a series of in vitro competitive fertilization experiments and found that, when ejaculates from two males are competing for access to a single female's unfertilized eggs, fertilization success was significantly biased towards the male whose sperm swam fastest in the female's OF. Embryo survival—a measure of fitness—was also positively correlated with both sperm swimming speed in OF and male MLH, providing novel evidence that cryptic female choice is adaptive for the female, enhancing the early survival of her offspring and potentially influencing her fitness. PMID:27009221

Cryptic female choice enhances fertilization success and embryo survival in chinook salmon.

PubMed

Rosengrave, Patrice; Montgomerie, Robert; Gemmell, Neil

2016-03-30

In this study, we investigated two potentially important intersexual postcopulatory gametic interactions in a population of chinook salmon (Oncorhynchus tshawytscha): (i) the effect of female ovarian fluid (OF) on the behaviour of spermatozoa during fertilization and (ii) the effects of multilocus heterozygosity (MLH) (as an index of male quality) and female-male genetic relatedness on sperm behaviour and male fertilization success when there is sperm competition in the presence of that OF. To do this, we conducted a series of in vitro competitive fertilization experiments and found that, when ejaculates from two males are competing for access to a single female's unfertilized eggs, fertilization success was significantly biased towards the male whose sperm swam fastest in the female's OF. Embryo survival--a measure of fitness--was also positively correlated with both sperm swimming speed in OF and male MLH, providing novel evidence that cryptic female choice is adaptive for the female, enhancing the early survival of her offspring and potentially influencing her fitness. © 2016 The Author(s).

Use of spin labels to evaluate effects of cold shock and osmolality on sperm

DOE Office of Scientific and Technical Information (OSTI.GOV)

Hammerstedt, R.H.; Keith, A.D.; Snipes, W.

1978-05-01

Spin labels were used to evaluate the effects of butylated hydroxytoluene (BHT), rapid cooling to 0/sup 0/C and osmolality on the integrity of sperm membranes. In vitro incubation of rabbit sperm with 0.5 mM BHT prior to artificial insemination did not alter the fertilizing ability of the sperm. Sperm from 6 species were ranked in terms of susceptibility to membrane damage caused by rapid cooling to 0/sup 0/C. The integrity of bull and ram sperm membranes was destroyed by the rapid cooling; BHT protected membranes of these spermatozoa from cold-induced lysis. Boar sperm membranes were porous after rapid cooling andmore » BHT did not prevent this membrane damage. Membranes of rabbit and rooster sperm were not damaged by rapid cooling to 0/sup 0/C. Stallion sperm could not be analyzed because their membranes were altered by addition of reagents necessary to use the technique. The responses of bull, ram and rabbit sperm membranes to hyper- and hypo-osmotic conditions were determined. Hypotonic treatment (less than 200 mOsm) resulted in a 50 percent expansion of the volume of the aqueous compartment of sperm while hypertonic (700 mOsm) conditions compressed the volume of the aqueous compartment to 25 to 30 percent of the volume measured at 300 mOsm. Bull sperm, but not rabbit or ram sperm, responded as ''perfect osmometers'' between 300 and 700 mOsm.« less

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

PubMed

Wong, Chi-Wai; Lam, Kevin K W; Lee, Cheuk-Lun; Yeung, William S B; Zhao, Wei E; Ho, Pak-Chung; Ou, Jian-Ping; Chiu, Philip C N

2017-04-01

Are multimeric sperm plasma membrane protein complexes, ERp57 and sperm surface thiol content involved in human spermatozoa-zona pellucida (ZP) interaction? 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. 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. 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. 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. 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. N/A. The mechanisms by which up-regulation of surface thiol content stimulates spermatozoa-ZP binding have not been depicted. 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. 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. © The Author 2017. Published by Oxford University Press on behalf of the European Society of Human Reproduction and Embryology. All rights reserved. For permissions, please e-mail: journals.permissions@oup.com

Intracytoplasmic sperm injection for treatment of the infertile male.

PubMed

Kim, E D; Lamb, D J; Lipshultz, L I

1997-07-01

Intracytoplasmic sperm injection (ICSI) with in vitro fertilization represents one of the most significant advances in fertility technology. In this relatively new procedure, a single viable sperm is microinjected into an oocyte that has been extracted transvaginally. After fertilization occurs, the embryo is transferred into the uterus. This procedure now affords men who were previously thought to be irreversibly infertile the chance to initiate their own biologic pregnancy. However, because of the procedure's significant costs and its potential risk to the mother, careful selection of couples following a thorough male factor evaluation is mandatory.

Sperm quality assays: How good are they? The horse perspective.

PubMed

Love, Charles C

2018-04-22

Sperm quality assays have increased in number in the last 10 years. Most of these assays are flow cytometry based in application and are modified from assays that have been developed to measure somatic cell function. The goal of any sperm quality assay should be to advance the clinicians/researchers understanding of sperm cell function and the relationship to fertility. While these assays appear to measure somatic cell-like functions in sperm there tends to be little understanding how the results of these assays relate to fertility. Copyright © 2018. Published by Elsevier B.V.

Morphometry of boar sperm head and flagellum in semen backflow after insemination.

PubMed

García-Vázquez, Francisco Alberto; Hernández-Caravaca, Iván; Yánez-Quintana, Wellington; Matás, Carmen; Soriano-Úbeda, Cristina; Izquierdo-Rico, María José

2015-09-01

Once deposited in the female reproductive system, sperm begin their competition and undergo a selection to reach the site of fertilization. Little is known about the special characteristics of sperm that reach the oviduct and are able to fertilize, with even less information on the role of sperm dimension and shape in transport and fertilization. Here, we examine whether sperm morphometry could be involved in their journey within the uterus. For this purpose, sperm head dimension (length, width, area, and perimeter) and shape (shape factor, ellipticity, elongation, and regularity), and flagellum length were analyzed in the backflow at different times after insemination (0-15, 16-30, and 31-60 minutes). Sperm morphometry in the backflow was also analyzed taking into account the site of semen deposition (cervical vs. intrauterine). Finally, flagellum length was measured at the uterotubal junction. Sperm analyzed in the backflow were small (head and flagellum) with different head shapes compared with sperm observed in the dose before insemination. The site of deposition influenced head morphometry and tail size both being smaller in the backflow after cervical insemination compared with intrauterine insemination. Mean tail length of sperm collected in the backflow was smaller than that in the insemination dose and at the uterotubal junction. Overall, our results suggest that sperm size may be involved in sperm transport either because of environment or through sperm selection and competence on their way to encounter the female gamete. Copyright © 2015 Elsevier Inc. All rights reserved.

Alternative male morphs solve sperm performance/longevity trade-off in opposite directions.

PubMed

Taborsky, Michael; Schütz, Dolores; Goffinet, Olivier; van Doorn, G Sander

2018-05-01

Males pursuing alternative reproductive tactics have been predicted to face a trade-off between maximizing either swimming performance or endurance of their sperm. However, empirical evidence for this trade-off is equivocal, which may be due to simplistic assumptions. In the shell-brooding cichlid fish Lamprologus callipterus , two Mendelian male morphs compete for fertilization by divergent means: Bourgeois nest males ejaculate sperm, on average, about six times farther from the unfertilized ova than do parasitic dwarf males. This asymmetry is opposite to the usual situation, in which bourgeois males typically benefit from superior fertilization opportunities, suggesting that nest males' sperm should persist longer than dwarf male sperm. The assumed trade-off between sperm swimming performance and longevity predicts that, in turn, sperm of dwarf males should outperform that of nest males in swimming efficiency. Measurement of sperm performance and endurance reveals that dwarf male spermatozoa swim straighter initially than those of nest males, but their motility declines earlier and their velocity slows down more abruptly. Nest male sperm survives longer, which relates to a larger sperm head plus midpiece, implying more mitochondria. Thus, the trade-off between sperm performance and endurance is optimized in opposite directions by alternative male morphs. We argue that the relative success of alternative sperm performance strategies can be influenced strongly by environmental factors such as the time window between gamete release and fertilization, and the position of gamete release. This is an important yet little understood aspect of gametic adaptations to sperm competition.

Gonad morphology, gametogenesis, and reproductive modes in fishes of the tribe Starksiini (Teleostei, Blenniiformes).

PubMed

Fishelson, Lev; Baldwin, Carole C; Hastings, Philip A

2013-05-01

A comparative study of the reproductive organs in 17 of the 30 species of the tribe Starksiini (Labrisomidae, Blenniiformes) and related labrisomids reveals the major traits of gamete form and production and likely reproductive modes. The testes are of the lobular type and have a testicular gland and sperm ducts. Isodiametric sperm (aquasperm) with a globular head or anisodiametric sperm (introsperm) with an elongate head, or both, were observed in the studied species. Both types have either one or two flagella in the sperm tail. Ovaries of the Starksiini are bilobed and exhibit synchronous or asynchronous egg production. Although viviparity or "ovoviviparity" reportedly characterizes the group, our study revealed evidence of both internal and external fertilization and three modes of reproduction. External fertilization or ovuliparity is suggested for the Starksia atlantica and S. lepicoelia species complexes by the presence in males of a short genital papilla that is not reinforced through adhesion with the first anal-fin spine and by the absence of sperm within the ovaries. Internal fertilization and zygoparity is indicated for most species by the presence of an intromittent papilla in males that is adhered to the first anal-fin spine, "nests" of sperm within the ovaries, absence of embryos within the ovarian lamellae and usually thick egg envelopes bearing dense covers of adhesive filaments. Internal fertilization and embryoparity is indicated for starksia fulva and Xenomedea rhodopyga by an intromittent papilla that is adhered to the first anal-fin spine of males, anisodiametric sperm in males, delicate egg envelopes without adhesive filaments and developing embryos within follicular envelopes or within the follicle in females. Although many of these features are seen in the internally fertilizing clinid blennies, starksiins differ in retaining the testicular gland typical of labrisomids and in lacking sperm packaging typical of other internally fertilizing teleosts. Copyright © 2013 Wiley Periodicals, Inc.

Protein expression pattern of PAWP in bull spermatozoa is associated with sperm quality and fertility following artificial insemination.

PubMed

Kennedy, Chelsey E; Krieger, Kari Beth; Sutovsky, Miriam; Xu, Wei; Vargovič, Peter; Didion, Bradley A; Ellersieck, Mark R; Hennessy, Madison E; Verstegen, John; Oko, Richard; Sutovsky, Peter

2014-05-01

Post-acrosomal WW-domain binding protein (PAWP) is a signaling molecule located in the post-acrosomal sheath (PAS) of mammalian spermatozoa. We hypothesized that the proper integration of PAWP in the sperm PAS is reflective of bull-sperm quality and fertility. Cryopreserved semen samples from 298 sires of acceptable, but varied, fertility used in artificial insemination services were analyzed using immunofluorescence microscopy and flow cytometry for PAWP protein. In normal spermatozoa, PAWP fluorescence formed a regular band around the proximal PAS. Anomalies of PAWP labeling in defective spermatozoa were reflected in flow cytometry by varied intensities of PAWP-induced fluorescence. Distinct sperm phenotypes were also identified, including morphologically normal and some defective spermatozoa with moderate levels of PAWP; grossly defective spermatozoa with low/no PAWP; and defective spermatozoa with high PAWP. Analysis by ImageStream flow cytometry confirmed the prevalence of abnormal sperm phenotypes in the spermatozoa with abnormal PAWP content. Live/dead staining and video recording showed that some abnormal spermatozoa are viable and capable of progressive motility. Conventional flow-cytometric measurements of PAWP correlated significantly with semen quality and fertility parameters that reflect the sires' artificial insemination fertility, including secondary sperm morphology, conception rate, non-return rate, and residual value. A multiplex, flow-cytometric test detecting PAWP, aggresomes (ubiquitinated protein aggregates), and acrosomal integrity (peanut-agglutinin-lectin labeling) had a predictive value for conception rate, as demonstrated by step-wise regression analysis. We conclude that PAWP correlates with semen/fertility parameters used in the cattle artificial insemination industry, making PAWP a potential biomarker of bull fertility. © 2014 Wiley Periodicals, Inc.

Molecular morphology and function of bull spermatozoa linked to histones and associated with fertility.

PubMed

de Oliveira, Rodrigo V; Dogan, Sule; Belser, Lauren E; Kaya, Abdullah; Topper, Einko; Moura, Arlindo; Thibaudeau, Giselle; Memili, Erdogan

2013-09-01

Sub-par fertility in bulls is influenced by alterations in sperm chromatin, and it might not be solved with increased sperm concentration in artificial insemination. Appropriate histone retention during sperm chromatin condensation plays critical roles in male fertility. The objective of this study was to determine failures of sperm chromatin condensation associated with abnormal persistence or accessibility of histones by aniline blue (ANBL) test, expression levels, and cellular localizations of one variant and two core histones (H3.3, H2B, and H4 respectively) in the spermatozoa of low-fertility (LF) vs high-fertility (HF) bulls. The expression levels and cellular localizations of histones in spermatozoa were studied using immunoblotting, immunocytochemistry, and staining methods. The bioinformatics focused on the sequence identity and evolutionary distance of these proteins among three mammalian species: bovine, mouse, and human. We demonstrated that ANBL staining was different within the LF (1.73 (0.55, 0.19)) and HF (0.67 (0.17, 0.06)) groups (P<0.0001), which was also negatively correlated with in vivo bull fertility (r=-0.90, P<0.0001). Although these histones were consistently detectable and specifically localized in bull sperm cells, they were not different between the two groups. Except H2B variants, H3.3 and H4 showed 100% identity and were evolutionarily conserved in bulls, mice and humans. The H2B variants were more conserved between bulls and humans, than in mice. In conclusion, we showed that H2B, H3.3, and H4 were detectable in bull spermatozoa and that sperm chromatin condensation status, changed by histone retention, is related to bull fertility.

Evidence for participation of GCS1 in fertilization of the starlet sea anemone Nematostella vectensis: Implication of a common mechanism of sperm–egg fusion in plants and animals

DOE Office of Scientific and Technical Information (OSTI.GOV)

Ebchuqin, Eerdundagula; Yokota, Naoto; Yamada, Lixy

Highlights: • GCS1 is a sperm transmembrane protein that is essential for gamete fusion in flowering plants. • The GCS1 gene is present not only in angiosperms but also in unicellular organisms and animals. • NvGCS1 gene is expressed in the testis and GCS1 protein exists in sperm of a sea anemone. • Anti-GCS1 antibodies inhibited the fertilization, showing the participation in fertilization. - Abstract: It has been reported that GCS1 (Generative Cell Specific 1) is a transmembrane protein that is exclusively expressed in sperm cells and is essential for gamete fusion in flowering plants. The GCS1 gene is presentmore » not only in angiosperms but also in unicellular organisms and animals, implying the occurrence of a common or ancestral mechanism of GCS1-mediated gamete fusion. In order to elucidate the common mechanism, we investigated the role of GCS1 in animal fertilization using a sea anemone (Cnidaria), Nematostella vectensis. Although the existence of the GCS1 gene in N. vectensis has been reported, the expression of GCS1 in sperm and the role of GCS1 in fertilization are not known. In this study, we showed that the GCS1 gene is expressed in the testis and that GCS1 protein exists in sperm by in situ hybridization and proteomic analysis, respectively. Then we made four peptide antibodies against the N-terminal extracellular region of NvGCS1. These antibodies specifically reacted to NvGCS1 among sperm proteins on the basis of Western analysis and potently inhibited fertilization in a concentration-dependent manner. These results indicate that sperm GCS1 plays a pivotal role in fertilization, most probably in sperm–egg fusion, in a starlet sea anemone, suggesting a common gamete-fusion mechanism shared by eukaryotic organisms.« less

The immediate impact of semen diluent and rate of dilution on the sperm quality index, ATP utilization, gas exchange, and ionic balance of broiler breeder sperm.

PubMed

Parker, H M; McDaniel, C D

2006-01-01

The sperm quality index (SQI) is a tool used to predict overall rooster semen quality, fertility, and hatchability. However, semen must be diluted before SQI analysis, and research has shown that the SQI is most predictive of fertility at lower semen dilutions. Therefore, the present study was undertaken to determine why the SQI is not as predictive of fertility at higher semen dilutions and whether semen diluent type alters the SQI, adenosine triphosphate (ATP) utilization, gas exchange, and ionic balance of broiler breeder sperm. Semen was diluted with saline, seminal plasma, or minimum essential medium (MEM) from 2- to 200-fold. The following parameters were measured for each diluent type at each dilution: SQI, ATP, Na+, Ca2+, K+, Cl-, CO2, and O2. To examine the rate of sperm motility, the SQI was expressed as SQI/million sperm per mL (SQI/sperm). There was an interaction between diluent type and dilution for the SQI, SQI/sperm, CO2 generated, O2 used, as well as Na+, Ca2+, and K+ internalization. For sperm diluted with saline, the SQI declined more rapidly with increasing dilution. However, SQI/sperm increased rapidly when semen was diluted with MEM or SP. Sperm diluted in SP used ATP with increasing dilution whereas sperm diluted with saline and MEM generated ATP. Neat semen contained no free O2; however, each diluent type contained abundant O2 resulting in more O2 available as semen was diluted. Sperm diluted in SP produced more CO2 and used more O2 than semen diluted in saline or MEM. For SQI/sperm, ATP and CO2 generated, as well as Na+ and Ca2+ internalization, differences between diluent types occurred when semen was diluted 50-fold and greater. In conclusion, it appears that sperm motility, ATP utilization, gas exchange, and ionic balance are altered by diluent type and rate of dilution. These alterations in semen quality are exacerbated at semen dilutions of 50-fold and greater yielding an SQI that is not indicative of sperm motility or fertility.

In vitro differentiation of fertile sperm from cryopreserved spermatogonia of the endangered endemic cyprinid honmoroko (Gnathopogon caerulescens)

NASA Astrophysics Data System (ADS)

Higaki, Shogo; Shimada, Manami; Kawamoto, Kazuaki; Todo, Takaaki; Kawasaki, Toshihiro; Tooyama, Ikuo; Fujioka, Yasuhiro; Sakai, Noriyoshi; Takada, Tatsuyuki

2017-02-01

Many endemic fish species are threatened with extinction. Conservation strategies and the restoration of endemic fish after extinction must therefore be investigated. Although sperm cryopreservation is indispensable for the conservation of endangered fishes, the limited number of mature fish and limited availability (volume and period) of sperm from small endemic fish hinders the optimization and practical use of this material. In this report, we demonstrate the in vitro differentiation of fertile sperm from cryopreserved spermatogonia of juveniles of the endangered small cyprinid honmoroko (Gnathopogon caerulescens), which is endemic to Lake Biwa in Japan. The entire process of spermatogenesis was recapitulated in vitro using cryopreserved spermatogonia of non-spawning adult and juvenile fish. The differentiation of sperm from spermatogonia was captured as a time-lapse video and confirmed by 5-ethynyl-2‧-deoxyuridine (EdU) incorporation into sperm. Fertility was demonstrated by artificial insemination. These results suggest that the combination of cryopreservation of spermatogonia and in vitro sperm differentiation will provide a new and promising strategy for the preservation of paternal genetic materials.

Acute toxicity effects of perfluorooctane sulfonate on sperm vitality, kinematics and fertilization success in zebrafish

NASA Astrophysics Data System (ADS)

Xia, Jigang; Niu, Cuijuan

2017-07-01

Perfluorooctane sulfonate (PFOS) has emerged as one of the most concerning contaminants in recent years. This study aimed to investigate the acute toxicity effect of PFOS on sperm viability, kinematics and fertilization success in zebrafish ( Danio rerio). Sperm were activated in aqueous media containing a range of PFOS concentrations (0, 0.09, 0.9 and 9 mg/L). Viabilities and kinematics of the sperm exposed to different PFOS treatments were assessed via computer-assisted sperm analysis (CASA) at 20, 40, 60, and 80 s after activation. PFOS exposure decreased the percentage of motile sperm, the curvilinear velocity (VCL), and the mean angular displacement (MAD) of spermatozoa, but showed no influence on the straight-line velocity (VSL) or the angular path velocity (VAP). Furthermore, a significant decrease in fertilization success was observed in spermatozoa that were exposed to 0.9 mg/L PFOS or more. These findings indicate that PFOS pollution in natural aquatic environment may be a potential threaten to successful reproduction of fish.

Heat stress during in vitro fertilization decreases fertilization success by disrupting anti-polyspermy systems of the oocytes.

PubMed

Sakatani, Miki; Yamanaka, Kenichi; Balboula, Ahmed Z; Takenouchi, Naoki; Takahashi, Masashi

2015-01-01

Low pregnancy rates during the summer are due, in part, to reduced fertilization. Given that elevated temperature is associated with this season, we investigated the effect of heat stress during fertilization using an in vitro model. Three experiments were performed to determine the mechanism by which exposure to elevated temperature disrupts fertilization. Oocytes were fertilized for 6 hr at 38.5°C or 41.0°C or 40.0°C with non-pre-incubated sperm, or for 6 hr at 38.5°C with sperm that had been pre-incubated at 38.5°C or 41.0°C for 4 hr. In each experiment, zygotes were cultured at 38.5°C in 5% CO(2) and 5% O(2). Rates of cleavage and blasocyst formation were reduced when fertilization occurs at elevated temperatures. The percent of sperm classified as alive, using fluorescein diacetate labeling, was decreased by pre-incubation and fertilization at 40.0°C. Although no difference was observed in sperm penetration rate, polyspermy tended to be increased by heat stress during fertilization. The zona pellucidae of zygotes formed following fertilization at 40.0°C for 6 hr were more sensitive to digestion with pronase. Furthermore, these zygotes exhibited higher hydrogen peroxide levels, measured by 2,7-dihydrodichlorofluorescein diacetate staining, and showed increased transcript abundance for HSPA1A, a gene involved in the heat-shock response, but decreased transcript abundance for UCHL1, a gene involved in preventing polyspermy. Results indicate that heat stress during fertilization is lethal to sperm, and causes oxidative stress, altered transcript abundance, and a defective block to polyspermy in the zygote. Thus, an increase in polyspermy is likely one cause of the reduced competency of zygotes fertilized under elevated temperatures to develop to the blastocyst stage. © 2014 Wiley Periodicals, Inc.

Micropuncture retrieval of epididymal sperm with in vitro fertilization: importance of in vitro micromanipulation techniques.

PubMed

Schlegel, P N; Palermo, G D; Alikani, M; Adler, A; Reing, A M; Cohen, J; Rosenwaks, Z

1995-08-01

To evaluate the importance of in vitro micromanipulation techniques, specifically intracytoplasmic sperm injection (ICSI), for the fertility treatment of men with congenital absence of the vas deferens (CAV) or other unreconstructable male reproductive tract obstruction. Results using ICSI during in vitro fertilization (IVF) were compared to previously published results of IVF alone and IVF with other micromanipulation techniques at the same infertility center. Main outcome parameters evaluated were: fertilization rate per oocyte, clinical pregnancy rate, and ongoing pregnancies and deliveries. IVF with ICSI yielded a fertilization rate per oocyte of 140 of 312 (45%) and a clinical pregnancy rate of 14 of 27 (52%) per cycle of sperm and egg retrieval. Ongoing pregnancies or deliveries have occurred for 13 of 27 (48%) cycles with ICSI. These results were better than our previously published results of IVF alone or in conjunction with the micromanipulation techniques of subzonal insertion (SuZI) or partial zona dissection (PZD) that yielded a 119 of 631 (19%; P < 0.0001) fertilization rate, clinical pregnancy rate of 14 of 51 (27%; P < 0.001) and ongoing pregnancy or delivery for 12 of 51 cycles (24%; P < 0.001). Epididymal sperm retrieval should be performed only when micromanipulation is available in conjunction with IVF to maximize chances of fertilization and subsequent pregnancies. The use of ICSI for epididymal sperm appears to maximize chances of pregnancy for couples with surgically unreconstructable obstructive male infertility.

Post-copulatory opportunities for sperm competition and cryptic female choice provide no offspring fitness benefits in externally fertilizing salmon

PubMed Central

Lumley, Alyson J.; Diamond, Sian E.; Einum, Sigurd; Yeates, Sarah E.; Peruffo, Danielle; Emerson, Brent C.; Gage, Matthew J. G.

2016-01-01

There is increasing evidence that females can somehow improve their offspring fitness by mating with multiple males, but we understand little about the exact stage(s) at which such benefits are gained. Here, we measure whether offspring fitness is influenced by mechanisms operating solely between sperm and egg. Using externally fertilizing and polyandrous Atlantic salmon (Salmo salar), we employed split-clutch and split-ejaculate in vitro fertilization experiments to generate offspring using designs that either denied or applied opportunities for sperm competition and cryptic female choice. Following fertilizations, we measured 140 days of offspring fitness after hatch, through growth and survival in hatchery and near-natural conditions. Despite an average composite mortality of 61%, offspring fitness at every life stage was near-identical between groups fertilized under the absence versus presence of opportunities for sperm competition and cryptic female choice. Of the 21 551 and 21 771 eggs from 24 females fertilized under monandrous versus polyandrous conditions, 68% versus 67.8% survived to the 100-day juvenile stage; sub-samples showed similar hatching success (73.1% versus 74.3%), had similar survival over 40 days in near-natural streams (57.3% versus 56.2%) and grew at similar rates throughout. We therefore found no evidence that gamete-specific interactions allow offspring fitness benefits when polyandrous fertilization conditions provide opportunities for sperm competition and cryptic female choice. PMID:27069665

Behavioral and spermatogenic hybrid male breakdown in Nasonia.

PubMed

Clark, M E; O'Hara, F P; Chawla, A; Werren, J H

2010-03-01

Several reproductive barriers exist within the Nasonia species complex, including allopatry, premating behavioral isolation, postzygotic inviability and Wolbachia-induced cytoplasmic incompatibility. Here we show that hybrid males suffer two additional reproductive disadvantages, an inability to properly court females and decreased sperm production. Hybrid behavioral sterility, characterized by a reduced ability of hybrids to perform necessary courtship behaviors, occurs in hybrids between two species of Nasonia. Hybrid males produced in crosses between N. vitripennis and N. giraulti courted females at a reduced frequency (23-69%), compared with wild-type N. vitripennis and N. giraulti males (>93%). Reduced courtship frequency was not a simple function of inactivity among hybrids. A strong effect of cytoplasmic (mitochondrial) background was also found in N. vitripennis and N. giraulti crosses; F2 hybrids with giraulti cytoplasm showing reduced ability at most stages of courtship. Hybrids produced between a younger species pair, N. giraulti and N. longicornis, were behaviorally fertile. All males possessed motile sperm, but sperm production is greatly reduced in hybrids between the older species pair, N. vitripennis and N. giraulti. This effect on hybrid males, lowered sperm counts rather than nonfunctional sperm, is different from most described cases of hybrid male sterility, and may represent an earlier stage of hybrid sperm breakdown. The results add to previous studies of F2 hybrid inviability and behavioral sterility, and indicate that Wolbachia-induced hybrid incompatibility has arisen early in species divergence, relative to behavioral sterility and spermatogenic infertility.

Behavioural and spermatogenic hybrid male breakdown in Nasonia

PubMed Central

Clark, Michael E.; O’Hara, F. Patrick; Chawla, Ankur; Werren, John H.

2010-01-01

Several reproductive barriers exists within the Nasonia species complex, including allopatry, premating behavioural isolation, postzygotic inviability and Wolbachia-induced cytoplasmic incompatibility. Here we show that hybrid males suffer two additional reproductive disadvantages, an inability to properly court females and decreased sperm production. Hybrid behavioural sterility, characterized by a reduced ability of hybrids to perform necessary courtship behaviours, occurs in hybrids between two species of Nasonia. Hybrid males produced in crosses between N. vitripennis and N. giraulti courted females at a reduced frequency (23-69%), compared to wild-type N. vitripennis and N. giraulti males (>93%). Reduced courtship frequency was not a simple function of inactivity among hybrids. A strong effect of cytoplasmic (mitochondrial) background was also found in N. vitripennis and N. giraulti crosses; F2 hybrids with giraulti cytoplasm showing reduced ability at most stages of courtship. Hybrids produced between a younger species pair, N. giraulti and N. longicornis, were behaviourally fertile. All males possessed motile sperm, but sperm production is greatly reduced in hybrids between the older species pair, N. vitripennis and N. giraulti. This effect on hybrid males, lowered sperm counts rather than non-functional sperm, is different from most described cases of hybrid male sterility and may represent an earlier stage of hybrid sperm breakdown. The results add to previous studies of F2 hybrid inviability and behavioural sterility, and indicated that Wolbachia induced hybrid incompatibility has arisen early in species divergence, relative to behavioural sterility and spermatogenic infertility. PMID:20087395

Conserving, Distributing and Managing Genetically Modified Mouse Lines by Sperm Cryopreservation

PubMed Central

Farley, Jane S.; Taft, Robert A.

2008-01-01

Background Sperm from C57BL/6 mice are difficult to cryopreserve and recover. Yet, the majority of genetically modified (GM) lines are maintained on this genetic background. Methodology/Principal Findings Reported here is the development of an easily implemented method that consistently yields fertilization rates of 70±5% with this strain. This six-fold increase is achieved by collecting sperm from the vas deferens and epididymis into a cryoprotective medium of 18% raffinose (w/v), 3% skim milk (w/v) and 477 µM monothioglycerol. The sperm suspension is loaded into 0.25 mL French straws and cooled at 37±1°C/min before being plunged and then stored in LN2. Subsequent to storage, the sperm are warmed at 2,232±162°C/min and incubated in in vitro fertilization media for an hour prior to the addition of oocyte cumulus masses from superovulated females. Sperm from 735 GM mouse lines on 12 common genetic backgrounds including C57BL/6J, BALB/cJ, 129S1/SvImJ, FVB/NJ and NOD/ShiLtJ were cryopreserved and recovered. C57BL/6J and BALB/cByJ fertilization rates, using frozen sperm, were slightly reduced compared to rates involving fresh sperm; fertilization rates using fresh or frozen sperm were equivalent in all other lines. Developmental capacity of embryos produced using cryopreserved sperm was equivalent, or superior to, cryopreserved IVF-derived embryos. Conclusions/Significance Combined, these results demonstrate the broad applicability of our approach as an economical and efficient option for archiving and distributing mice. PMID:18665210

Sperm quality but not relatedness predicts sperm competition success in threespine sticklebacks (Gasterosteus aculeatus).

PubMed

Mehlis, Marion; Rahn, Anna K; Bakker, Theo C M

2015-04-26

Mating between close relatives often leads to a reduction of an individual's fitness, due to an increased expression of deleterious alleles. Thus, in many animal taxa pre- as well as postcopulatory inbreeding avoidance mechanisms have evolved. An increased risk of inbreeding and hence a loss of genetic variation may occur during founder events as in most cases only few individuals establish a new population. The threespine stickleback (Gasterosteus aculeatus) is a small externally fertilizing fish species subject to strong sperm competition. Sticklebacks inhabit both marine and freshwater environments and anadromous populations have repeatedly established new genetically less diverse freshwater populations. Previous studies showed that anadromous sticklebacks strongly suffer from inbreeding depression and when given the choice females prefer to mate with unrelated males. The present study aimed to address whether there exists a postcopulatory inbreeding avoidance mechanism solely based on sperm-egg interactions in sperm competition experiments. We used F1 individuals that originated either from a large, genetically heterogeneous anadromous population or from a small, genetically less diverse freshwater population. For each population, eggs of two different females were in vitro fertilized by the same two males' sperm in a paired study design. In the main experiment one male was the female's full-sib brother and in the control experiment all individuals were unrelated. The results revealed that fertilization success was independent of relatedness in both populations suggesting a general lack of a postcopulatory inbreeding avoidance mechanism. Instead, male quality (i.e. sperm morphology) predicted paternity success during competitive fertilization trials. In sticklebacks, there is no evidence for postcopulatory inbreeding avoidance. Sperm morphology predicted paternity instead, thus sperm quality traits are under strong sexual selection, presumably driven by the high risk of sperm competition under natural conditions.

Distinct sperm nucleus behaviors between genotypic and temperature-dependent sex determination males are associated with replication and expression-related pathways in a gynogenetic fish.

PubMed

Zhu, Yao-Jun; Li, Xi-Yin; Zhang, Jun; Li, Zhi; Ding, Miao; Zhang, Xiao-Juan; Zhou, Li; Gui, Jian-Fang

2018-06-05

Coexistence and transition of diverse sex determination strategies have been revealed in some ectothermic species, but the variation between males caused by different sex determination strategies and the underlying mechanism remain unclear. Here, we used the gynogenetic gibel carp (Carassius gibelio) with both genotypic sex determination (GSD) and temperature-dependent sex determination (TSD) strategies to illustrate this issue. We found out that males of GSD and TSD in gibel carp had similar morphology, testicular histology, sperm structure and sperm vitality. However, when maternal individuals were mated with males of GSD, sperm nucleus swelling and fusing with the female pronucleus were observed in the fertilized eggs. On the contrary, when maternal individuals were mated with males of TSD, sperm nucleus remained in the condensed status throughout the whole process. Subsequently, semen proteomics analysis unveiled that DNA replication and gene expression-related pathways were inhibited in the sperm from males of TSD compared to males of GSD, and most differentially expressed proteins associated with DNA replication, transcription and translation were down-regulated. Moreover, via BrdU incorporation and immunofluorescence detection, male nucleus replication was revealed to be present in the fertilized eggs by the sperm from males of GSD, but absent in the fertilized eggs by the sperm from males of TSD. These findings indicate that DNA replication and gene expression-related pathways are associated with the distinct sperm nucleus development behaviors in fertilized eggs in response to the sperm from males of GSD and TSD. And this study is the first attempt to screen the differences between males determined via GSD and TSD in gynogenetic species, which might give a hint for understanding evolutionary adaption of diverse sex determination mechanisms in unisexual vertebrates.

Chemical UV Filters Mimic the Effect of Progesterone on Ca2+ Signaling in Human Sperm Cells.

PubMed

Rehfeld, A; Dissing, S; Skakkebæk, N E

2016-11-01

Progesterone released by cumulus cells surrounding the egg induces a Ca 2+ influx into human sperm cells via the cationic channel of sperm (CatSper) Ca 2+ channel and controls multiple Ca 2+ -dependent responses essential for fertilization. We hypothesized that chemical UV filters may mimic the physiological action of progesterone on CatSper, thus affecting Ca 2+ signaling in human sperm cells. We examined 29 UV filters allowed in sunscreens in the United States and/or the European Union for their ability to induce Ca 2+ signals in human sperm by applying measurements of the intracellular free Ca 2+ concentration. We found that 13 UV filters induced a significant Ca 2+ signal at 10 μM. Nine UV filters induced Ca 2+ signals primarily by activating the CatSper channel. The UV filters 3-benzylidene camphor (3-BC) and benzylidene camphor sulfonic acid competitively inhibited progesterone-induced Ca 2+ signals. Dose-response relations for the UV filters showed that the Ca 2+ signal-inducing effects began in the nanomolar-micromolar range. Single-cell Ca 2+ measurements showed a Ca 2+ signal-inducing effect of the most potent UV filter, 3-BC, at 10 nM. Finally, we demonstrated that the 13 UV filters acted additively in low-dose mixtures to induce Ca 2+ signals. In conclusion, 13 of 29 examined UV filters (44%) induced Ca 2+ signals in human sperm. Nine UV filters primarily activated CatSper and thereby mimicked the effect of progesterone. The UV filters 3-BC and benzylidene camphor sulfonic acid competitively inhibited progesterone-induced Ca 2+ signals. In vivo exposure studies are needed to investigate whether UV filter exposure affects human fertility.

Effect of caffeine on motility and vitality of sperm and in vitro fertilization of outbreed mouse in T6 and M16 media

PubMed Central

Nabavi, Narges; Todehdehghan, Fatemeh; Shiravi, Abdollhossein

2013-01-01

Background: Caffeine increases the CAMP production that stimulates spermatozoa movement. Caffeine is also used for induction of in vitro acrosome reaction in mammalian spermatozoa, an important step in achieving fertilization. Objective: The aim of this study was to assess the effect of caffeine on sperm's motility, vitality and laboratory fertilization rates in mouse in two T6 and M16 media. Materials and Methods: Epididymal mouse sperms were collected and treated by caffine in T6 and M16 media and their motility and vitality rates were evaluated. The pretreated sperms were added to oocytes in T6 and M16 media with and without caffeine and fertilization rates were recorded after 24 hours incubation. Results: Sperm's motility (81.7±1.67%) and vitality (88.7±1.33%) rates and percentage of fertilized oocytes (67.52±8.16%) in T6 medium plus caffeine compare to control group have increased and shown significant differences at p≤0.01. While the percentages of these parameters in M16 medium supplemented with caffeine were 68.3±6.01%, 78±6.11%, and 42.6±12.96 respectively and in comparison to control group (M16 without caffeine) have not shown significant differences. Conclusion: Addition of caffeine to T6 medium promotes the sperm's motility and vitality and enhances fertilization and early in vitro development of mouse embryos. This article extracted from M.Sc. thesis. (Narges Navabi) PMID:24639814

Role of tetraspanin CD9 molecule in fertilization of mammals.

PubMed

Jankovičová, J; Simon, M; Antalíková, J; Cupperová, P; Michalková, K

2015-01-01

Fertilization process is a very clever and unique process comprising some essential steps resulting in formation of zygote. Tetraspanin CD9 is considered to be a serious candidate molecule participating in these events. The importance of CD9 has been discussed in relation to acrosome reaction, sperm-binding, sperm-penetration, sperm-egg fusion and eventually, egg activation. The abundant expression of CD9 oocyte plasma membrane and the presence of CD9-containing vesicles in the perivitelline space of intact oocytes have been confirmed. Despite the fact that majority of authors analyzed CD9 expressed on oocytes, several studies considered the function of sperm CD9, too. To understand CD9 involvement, various conditions of in vitro fertilization (IVF) assays using polyclonal as well as monoclonal antibodies or knockout mice were carried out. However, ambiguous data have been obtained about the importance of CD9 in sperm-egg binding or fusion. Although the current findings did not prove any hypothesis, the indispensable role of CD9 in fertilization process was not excluded and the precise role of CD9 remains unexplained.

High-throughput cryopreservation of spermatozoa of blue catfish (Ictalurus furcatus): Establishment of an approach for commercial-scale processing.

PubMed

Hu, E; Yang, Huiping; Tiersch, Terrence R

2011-02-01

Hybrid catfish created by crossing of female channel catfish (Ictalurus punctatus) and male blue catfish (Ictalurus furcatus) are being used increasingly in foodfish aquaculture because of their fast growth and efficient food conversion. However, the availability of blue catfish males is limited, and their peak spawning is at a different time than that of the channel catfish. As such, cryopreservation of sperm of blue catfish could improve production of hybrid catfish, and has been studied in the laboratory and tested for feasibility in a commercial dairy bull cryopreservation facility. However, an approach for commercially relevant production of cryopreserved blue catfish sperm is still needed. The goal of this study was to develop practical approaches for commercial-scale sperm cryopreservation of blue catfish by use of an automated high-throughput system (MAPI, CryoBioSystem Co.). The objectives were to: (1) refine cooling rate and cryoprotectant concentration, and evaluate their interactions; (2) evaluate the effect of sperm concentration on cryopreservation; (3) refine cryoprotectant concentration based on the highest effective sperm concentration; (4) compare the effect of thawing samples at 20 or 40°C; (5) evaluate the fertility of thawed sperm at a research scale by fertilizing with channel catfish eggs; (6) test the post-thaw motility and fertility of sperm from individual males in a commercial setting, and (7) test for correlation of cryopreservation results with biological indices used for male evaluation. The optimal cooling rate was 5°C/min (Micro Digitcool, IMV) for high-throughput cryopreservation using CBS high-biosecurity 0.5-ml straws with 10% methanol, and a concentration of 1×10(9)sperm/ml. There was no difference in post-thaw motility when samples were thawed at 20°C for 40s or 40°C for 20s. After fertilization, the percentage of neurulation (Stage V embryos) was 80±21%, and percentage of embryonic mobility (Stage VI embryo) was 51±22%. There was a significant difference among the neurulation values produced by thawed blue catfish sperm, fresh blue catfish sperm (P=0.010) and channel catfish sperm (P=0.023), but not for Stage VI embryos (P≥0.585). Cryopreserved sperm from ten males did not show significant variation in post-thaw motility or fertility at the neurulation stage. This study demonstrates that the protocol established for high-throughput cryopreservation of blue catfish sperm can provide commercially relevant quantities and quality of sperm with stable fertility for hybrid catfish production and provides a model for establishment of commercial-scale approaches for other aquatic species. Copyright © 2010 Elsevier Inc. All rights reserved.

Cryptic choice of conspecific sperm controlled by the impact of ovarian fluid on sperm swimming behavior.

PubMed

Yeates, Sarah E; Diamond, Sian E; Einum, Sigurd; Emerson, Brent C; Holt, William V; Gage, Matthew J G

2013-12-01

Despite evidence that variation in male-female reproductive compatibility exists in many fertilization systems, identifying mechanisms of cryptic female choice at the gamete level has been a challenge. Here, under risks of genetic incompatibility through hybridization, we show how salmon and trout eggs promote fertilization by conspecific sperm. Using in vitro fertilization experiments that replicate the gametic microenvironment, we find complete interfertility between both species. However, if either species' ova were presented with equivalent numbers of both sperm types, conspecific sperm gained fertilization precedence. Surprisingly, the species' identity of the eggs did not explain this cryptic female choice, which instead was primarily controlled by conspecific ovarian fluid, a semiviscous, protein-rich solution that bathes the eggs and is released at spawning. Video analyses revealed that ovarian fluid doubled sperm motile life span and straightened swimming trajectory, behaviors allowing chemoattraction up a concentration gradient. To confirm chemoattraction, cell migration tests through membranes containing pores that approximated to the egg micropyle showed that conspecific ovarian fluid attracted many more spermatozoa through the membrane, compared with heterospecific fluid or water. These combined findings together identify how cryptic female choice can evolve at the gamete level and promote reproductive isolation, mediated by a specific chemoattractive influence of ovarian fluid on sperm swimming behavior. © 2013 The Authors. Evolution published by Wiley Periodicals, Inc. on behalf of The Society for the Study of Evolution.

Atropine-induced inhibition of sperm and semen transport impairs fertility in male rats.

PubMed

Sato, Takahiro; Ban, Yoshiki; Uchida, Miki; Gondo, Eri; Yamamoto, Masakatsu; Sekiguchi, Yoshiko; Sakaue, Akiko; Kemi, Masayuki; Nakatsuka, Toshio

2005-08-01

Previous studies revealed that atropine reduced male fertility in rats without any effects on mating performance, sperm production and motility, and testicular morphology. The present study was conducted to investigate whether the impairment of male fertility induced by atropine was related to the inhibition of sperm and semen transports from the vas deferens and seminal vesicle to the urethra during the process of emission. Male rats were treated with atropine at 125 mg/kg/day for 10-17 days prior to mating with untreated females. After confirmation of mating, male rats were euthanized and sperm number in the vas deferens and weights of the seminal vesicle and copulatory plug were determined as indicators of inhibition of sperm and semen transports, respectively. Reproductive status of mated females was determined on gestation days 15-17. A low pregnancy rate associated with a decreased number of implants was observed in females that mated with the atropine-treated males. The average number of sperm in the vas deferens was increased in the atropine-treated males. The average seminal vesicle weight in the atropine-treated males was greater than that of controls. The copulatory plug weights were decreased in the atropine-treated males. These results suggest that inhibitions of sperm and semen transports from the vas deferens and seminal vesicle to the urethra during the process of emission result in reduced male fertility in rats.

Semen parameters in fertile US men: the Study for Future Families.

PubMed

Redmon, J B; Thomas, W; Ma, W; Drobnis, E Z; Sparks, A; Wang, C; Brazil, C; Overstreet, J W; Liu, F; Swan, S H

2013-11-01

Establishing reference norms for semen parameters in fertile men is important for accurate assessment, counselling and treatment of men with male factor infertility. Identifying temporal or geographic variability in semen quality also requires accurate measurement of semen parameters in well-characterized, defined populations of men. The Study for Future Families (SFF) recruited men who were partners of pregnant women attending prenatal clinics in Los Angeles CA, Minneapolis MN, Columbia MO, New York City NY and Iowa City IA. Semen samples were collected on site from 763 men (73% White, 15% Hispanic/Latino, 7% Black and 5% Asian or other ethnic group) using strict quality control and well-defined protocols. Semen volume (by weight), sperm concentration (hemacytometer) and sperm motility were measured at each centre. Sperm morphology (both WHO, 1999 strict and WHO, 1987) was determined at a central laboratory. Mean abstinence was 3.2 days. Mean (median; 5th-95th percentile) values were: semen volume, 3.9 (3.7; 1.5-6.8) mL; sperm concentration, 60 (67; 12-192) × 10(6) /mL; total sperm count 209 (240; 32-763) × 10(6) ; % motile, 51 (52; 28-67) %; and total motile sperm count, 104 (128; 14-395) × 10(6) respectively. Values for sperm morphology were 11 (10; 3-20) % and 57 (59; 38-72) % normal forms for WHO (1999) (strict) and WHO (1987) criteria respectively. Black men had significantly lower semen volume, sperm concentration and total motile sperm counts than White and Hispanic/Latino men. Semen parameters were marginally higher in men who achieved pregnancy more quickly but differences were small and not statistically significant. The SFF provides robust estimates of semen parameters in fertile men living in five different geographic locations in the US. Fertile men display wide variation in all of the semen parameters traditionally used to assess fertility potential. © 2013 American Society of Andrology and European Academy of Andrology.

Advancing age increases sperm chromatin damage and impairs fertility in peroxiredoxin 6 null mice

PubMed Central

Ozkosem, Burak; Feinstein, Sheldon I.; Fisher, Aron B.; O’Flaherty, Cristian

2015-01-01

Due to socioeconomic factors, more couples are choosing to delay conception than ever. Increasing average maternal and paternal age in developed countries over the past 40 years has raised the question of how aging affects reproductive success of males and females. Since oxidative stress in the male reproductive tract increases with age, we investigated the impact of advanced paternal age on the integrity of sperm nucleus and reproductive success of males by using a Prdx6−/− mouse model. We compared sperm motility, cytoplasmic droplet retention sperm chromatin quality and reproductive outcomes of young (2-month-old), adult (8-month-old), and old (20-month-old) Prdx6−/− males with their age-matched wild type (WT) controls. Absence of PRDX6 caused age-dependent impairment of sperm motility and sperm maturation and increased sperm DNA fragmentation and oxidation as well as decreased sperm DNA compaction and protamination. Litter size, total number of litters and total number of pups per male were significantly lower in Prdx6−/− males compared to WT controls. These abnormal reproductive outcomes were severely affected by age in Prdx6−/− males. In conclusion, the advanced paternal age affects sperm chromatin integrity and fertility more severely in the absence of PRDX6, suggesting a protective role of PRDX6 in age-associated decline in the sperm quality and fertility in mice. PMID:25796034

Evaluation of epididymis storage temperature and cryopreservation conditions for improved mitochondrial membrane potential, membrane integrity, sperm motility and in vitro fertilization in bovine epididymal sperm.

PubMed

Nichi, M; Rijsselaere, T; Losano, Jda; Angrimani, Dsr; Kawai, Gkv; Goovaerts, Igf; Van Soom, A; Barnabe, V H; De Clercq, Jbp; Bols, Pej

2017-04-01

The maintaining of the epididymis at lower temperatures during storage and transport improves sperm quality. Our study aimed to test whether epididymis storage temperature (post-mortem) and sperm cryopreservation affect sperm kinetics, membrane integrity, mitochondrial potential and fertility capacity. Thirty-six epididymides were collected from 18 bulls after slaughter and divided into two groups: at 4 or 34°C for 2-3 hr. The sperm was collected from the epididymis cauda. The evaluation consisted of computer-assisted sperm analysis (CASA), SYBR14/PI/JC1 to evaluate membrane integrity, mitochondrial membrane potential (MMP) and measurement of lipid peroxidation (TBARS). The sperm was then frozen using an automatic device. After thawing, sperm samples were evaluated by the same variables and further in vitro fertilization rates. Cryopreservation negatively affected sperm motility in samples stored at 4 and 34°C. Nevertheless, the 4°C samples yielded higher rates of blastocyst formation. Pre-freeze sperm motility, progressive motility and velocity were higher in sperm from epididymis stored at 4°C while post-thaw sperm motility, progressive motility and velocity remained the same among samples from epididymis stored at 4 or 34°C. However, with regard to the kinetic patterns, samples collected from epididymis stored at 34°C had lower values when compared to those stored at 4°C prior the cryopreservation process. Our results indicate that epididymis handling conditions after cryopreservation may affect sperm quality after thawing, especially due to compromised MMP in sperm collected from epididymis stored at higher temperatures. © 2016 Blackwell Verlag GmbH.

Obesity-Induced Infertility in Male Mice Is Associated With Disruption of Crisp4 Expression and Sperm Fertilization Capacity.

PubMed

Borges, Beatriz C; Garcia-Galiano, David; da Silveira Cruz-Machado, Sanseray; Han, Xingfa; Gavrilina, Galina B; Saunders, Thomas L; Auchus, Richard J; Hammoud, Saher S; Smith, Gary D; Elias, Carol F

2017-09-01

Approximately 15% of human couples of reproductive age have impaired fertility, and the male component accounts for about half of these cases. The etiology is usually unknown, but high correlation with the increase in obesity rates is documented. In this study, we show that diet-induced and genetically obese mice display copulatory behavior comparable to controls, but the number of females impregnated by obese males is remarkably low. Screening for changes in gene expression in the male reproductive tract showed decreased Crisp4 expression in testis and epididymis of obese mice. Lack of CRISP4 in the luminal membrane of epididymal cells indicated inadequate secretion. Consistent with CRISP4 action in acrosome reaction, sperm from mice fed a high-fat diet (HFD) had decreased fertilization capacity. CRISP4 treatment of sperm from HFD mice prior to in vitro fertilization improved fertilization rate. In leptin-deficient obese and infertile mice, leptin's effect to restore CRISP4 expression and function required gonadal hormones. Our findings indicate that the obesity-induced decline in sperm motility and fertilization capacity results in part from the disruption of epididymal CRISP4 expression and secretion. Copyright © 2017 Endocrine Society.

Faster fertilization rate in conspecific versus heterospecific matings in house mice.

PubMed

Dean, Matthew D; Nachman, Michael W

2009-01-01

Barriers to gene flow can arise at any stage in the reproductive sequence. Most studies of reproductive isolation focus on premating or postzygotic phenotypes, leaving the importance of differences in fertilization rate overlooked. Two closely related species of house mice, Mus domesticus and M. musculus, form a narrow hybrid zone in Europe, suggesting that one or more isolating factors operate in the face of ongoing gene flow. Here, we test for differences in fertilization rate using laboratory matings as well as in vitro sperm competition assays. In noncompetitive matings, we show that fertilization occurs significantly faster in conspecific versus heterospecific matings and that this difference arises after mating and before zygotes form. To further explore the mechanisms underlying this conspecific advantage, we used competitive in vitro assays to isolate gamete interactions. Surprisingly, we discovered that M. musculus sperm consistently outcompeted M. domesticus sperm regardless of which species donated ova. These results suggest that in vivo fertilization rate is mediated by interactions between sperm, the internal female environment, and/or contributions from male seminal fluid. We discuss the implications of faster conspecific fertilization in terms of reproductive isolation among these two naturally hybridizing species.

Who should be offered sperm banking for fertility preservation? A survey of UK oncologists and haematologists.

PubMed

Gilbert, E; Adams, A; Mehanna, H; Harrison, B; Hartshorne, G M

2011-05-01

Fertility after cancer therapy is a significant quality-of-life concern for many patients, their partners and families. Authoritative guidance states that men whose fertility may be affected by impending therapies should be offered sperm banking. Yet some patients are not offered this opportunity and are thereby disadvantaged. We sought to understand oncologists' and haematologists' decision making concerning sperm-banking referrals. We surveyed all oncologists and haematologists on the Royal College of Radiotherapists' Faculty of Oncology and British Society for Haematology circulation lists. From 2357 across all specialties, 499 responses were received: 253 haematologists and 246 oncologists (21% response rate). Twenty-one percent of respondents were unaware of local policies on sperm banking and 42% considered that sperm banking should be offered to more patients. Respondents' decisions reveal either assumptions about patients' needs based on characteristics such as age, sexual orientation and severity of illness or the influence of their own moral conclusions upon their patients. The survey identified paucity of training for clinicians, information for patients and systematic recording of discussions about fertility. A robust care infrastructure supporting male fertility storage is needed urgently to include targeted information for cancer clinicians and patients, identified individuals responsible for coordination and documentation of discussions with patients.

Supporters of sperm

PubMed Central

Løvlie, Hanne

2014-01-01

The Biology of Spermatozoa (BoS) meetings have run on a biannual basis since the early 1990s. They are dedicated to the fascinating research topic of sperm and their complicated route to fertilization. The BoS meetings focus on sperm, but they also explore additional supporting factors important in fertilization, such as those present in seminal and ovarian fluid, as well as the genomic bases of sperm biology. Here, I present a report of the recent BoS meeting, and showcase some of the highlights of this year’s meeting. PMID:25225623

Prostasomes: Their Characterisation: Implications for Human Reproduction: Prostasomes and Human Reproduction.

PubMed

Ronquist, Gunnar

2015-01-01

The prostate is a principal accessory genital gland that is vital for normal fertility. Epithelial cells lining the prostate acini release in a defined fashion (exocytosis) organellar nanosized structures named prostasomes. They are involved in the protection of sperm cells against immune response in the female reproductive tract by modulating the complement system and by inhibiting monocyte and neutrophil phagocytosis and lymphocyte proliferation. The immunomodulatory function most probably involves small non-coding RNAs present in prostasomes. Prostasomes have also been proposed to regulate the timing of sperm cell capacitation and induction of the acrosome reaction, since they are rich in various transferable bioactive molecules (e.g. receptors and enzymes) that promote the fertilising ability of sperm cells. Antigenicity of sperm cells has been well documented and implicated in involuntary immunological infertility of human couples, and antisperm antibodies (ASA) occur in several body fluids. The propensity of sperm cells to carry attached prostasomes suggests that they are a new category of sperm antigens. Circulating human ASA recognise prostasomes, and among 12 identified prostasomal antigens, prolactin- inducible protein (95 %) and clusterin (85 %) were immunodominant at the expense of the other 10 that were sporadically occurring.

Comprehensive proteomic analysis of bovine spermatozoa of varying fertility rates and identification of biomarkers associated with fertility.

PubMed

Peddinti, Divyaswetha; Nanduri, Bindu; Kaya, Abdullah; Feugang, Jean M; Burgess, Shane C; Memili, Erdogan

2008-02-22

Male infertility is a major problem for mammalian reproduction. However, molecular details including the underlying mechanisms of male fertility are still not known. A thorough understanding of these mechanisms is essential for obtaining consistently high reproductive efficiency and to ensure lower cost and time-loss by breeder. Using high and low fertility bull spermatozoa, here we employed differential detergent fractionation multidimensional protein identification technology (DDF-Mud PIT) and identified 125 putative biomarkers of fertility. We next used quantitative Systems Biology modeling and canonical protein interaction pathways and networks to show that high fertility spermatozoa differ from low fertility spermatozoa in four main ways. Compared to sperm from low fertility bulls, sperm from high fertility bulls have higher expression of proteins involved in: energy metabolism, cell communication, spermatogenesis, and cell motility. Our data also suggests a hypothesis that low fertility sperm DNA integrity may be compromised because cell cycle: G2/M DNA damage checkpoint regulation was most significant signaling pathway identified in low fertility spermatozoa. This is the first comprehensive description of the bovine spermatozoa proteome. Comparative proteomic analysis of high fertility and low fertility bulls, in the context of protein interaction networks identified putative molecular markers associated with high fertility phenotype.

Comprehensive proteomic analysis of bovine spermatozoa of varying fertility rates and identification of biomarkers associated with fertility

PubMed Central

Peddinti, Divyaswetha; Nanduri, Bindu; Kaya, Abdullah; Feugang, Jean M; Burgess, Shane C; Memili, Erdogan

2008-01-01

Background Male infertility is a major problem for mammalian reproduction. However, molecular details including the underlying mechanisms of male fertility are still not known. A thorough understanding of these mechanisms is essential for obtaining consistently high reproductive efficiency and to ensure lower cost and time-loss by breeder. Results Using high and low fertility bull spermatozoa, here we employed differential detergent fractionation multidimensional protein identification technology (DDF-Mud PIT) and identified 125 putative biomarkers of fertility. We next used quantitative Systems Biology modeling and canonical protein interaction pathways and networks to show that high fertility spermatozoa differ from low fertility spermatozoa in four main ways. Compared to sperm from low fertility bulls, sperm from high fertility bulls have higher expression of proteins involved in: energy metabolism, cell communication, spermatogenesis, and cell motility. Our data also suggests a hypothesis that low fertility sperm DNA integrity may be compromised because cell cycle: G2/M DNA damage checkpoint regulation was most significant signaling pathway identified in low fertility spermatozoa. Conclusion This is the first comprehensive description of the bovine spermatozoa proteome. Comparative proteomic analysis of high fertility and low fertility bulls, in the context of protein interaction networks identified putative molecular markers associated with high fertility phenotype. PMID:18294385

Effects of intermediate frequency magnetic fields on male fertility indicators in mice.

PubMed

Kumari, K; Capstick, M; Cassara, A M; Herrala, M; Koivisto, H; Naarala, J; Tanila, H; Viluksela, M; Juutilainen, J

2017-08-01

Human exposure to intermediate frequency (IF) fields is increasing due to new applications such as electronic article surveillance systems, wireless power transfer and induction heating cookers. However, limited data is available on effects of IF magnetic fields (MF) on male fertility function. This study was conducted to assess possible effects on fertility indicators from exposure to IF MF. Male C57BL/6J mice were exposed continuously for 5 weeks to 7.5kHz MF at 12 and 120μT. Sperm cells from cauda epididymis were analysed for motility, total sperm counts, and head abnormalities. Motile sperm cells were classified as progressive or non-progressive. Testicular spermatid heads were counted as well. The body weight development and reproductive tissue weights were not affected. No exposure-related differences were observed in sperm counts or sperm head abnormalities. Proportion of non-motile cells was significantly decreased in the 120µT group, and a corresponding increase was seen in the percentage of motile cells (significant in non-progressive motile cells). In conclusion, no adverse effects on fertility indicators were observed. Increased sperm motility is an interesting finding that needs to be confirmed in further studies. Copyright © 2017 The Authors. Published by Elsevier Inc. All rights reserved.

Sperm characteristics and teratology in rats following vas deferens occlusion with RISUG and its reversal.

PubMed

Lohiya, N K; Suthar, R; Khandelwal, A; Goyal, S; Ansari, A S; Manivannan, B

2010-02-01

The functional success of the reversal of vas occlusion by styrene maleic anhydride (RISUG), using the solvent vehicle, Dimethyl Sulphoxide (DMSO), has been investigated. Reversal with DMSO was carried out in Wistar albino rats 90 days after bilateral vas occlusion. The body weight, organ weight, sperm characteristics, fertility test and teratology, including skeletal morphology were evaluated in vas occlusion and reversal animals and in F(1) progenies to assess the functional success of the occlusion and reversal. Body weight, organ weight and the cauda epididymal sperm characteristics of vas occlusion and reversal animals and of F(1) progenies were comparable to control. Ejaculated spermatozoa in the vaginal smear showed detached head/tail, acrosomal damage, bent midpiece, bent tail and morphological aberrations in sperm head after vas occlusion, which returned to normal, 90 days after reversal. Monthly fertility test, post-injection showed 0% fertility, which improved gradually and 100% fertility was achieved 90 days after reversal. The fertility/pregnancy/implantation record and skeletal morphology of the offspring were comparable to control. The results suggest functional success and safety of vas occlusion reversal by DMSO.

Transmission electron microscopy analysis of the origin and incidence of sperm intranuclear cytoplasmic retention in fertile and teratozoospermia men.

PubMed

Zhu, W-J

2018-03-01

The human sperm nucleus contains cytoplasm. However, the origin and incidence of human sperm intranuclear cytoplasmic retention (INCR) remain unknown. The objectives of this study were to observe the morphological origin of INCR within the seminiferous epithelium and investigate the incidence of INCR in fertile and teratozoospermia men using transmission electron microscopy (TEM). By TEM, INCR initially appeared in elongating round spermatid nuclei and varied in size, number, shape, content, location and distribution within sperm nuclei. The teratozoospermia group (n = 16) demonstrated a higher incidence of INCR than did the fertile group (n = 16) (17.6 ± 5.2% vs. 9.7 ± 3.4%; p = 0.000). In the fertile group, no correlations were found between the incidence of INCR and abnormal sperm morphology, nuclear vacuole, acrosome integrity, motility or concentration (p > 0.05). However, the incidence of INCR exhibited a positive relationship with sperm abnormal morphology in the teratozoospermia group (r = 0.616, p = 0.011). These results demonstrate that INCR occurs in the early process of spermatogenesis and is an alteration found in the nucleus. Spermatozoa from teratozoospermia men contained more INCRs than those from fertile males. More attention should be paid to the possibility of spermatozoa containing INCR when using spermatozoa with abnormal head morphology for clinical or diagnostic purposes. © 2018 American Society of Andrology and European Academy of Andrology.

Sperm selection and genetic incompatibility: does relatedness of mates affect male success in sperm competition?

PubMed Central

Stockley, P.

1999-01-01

Sperm selection may be said to occur if females influence the relative success of ejaculates competing to fertilize their ova. Most evidence that female animals or their ova are capable of sperm selection relates to male genetic incompatibility, although relatively few studies focus on competition between conspecific males. Here I look for evidence of sperm selection with respect to relatedness of mates. Reduced fitness or inbreeding effects in offspring resulting from copulations between close relatives are well documented. If females are capable of sperm selection, they might therefore be expected to discriminate against the sperm of sibling males during sperm competition. I describe an experimental protocol designed to test for evidence of sperm selection while controlling for inbreeding effects. Using decorated field crickets (Gryllodes supplicans), I found that sibling males achieved lower fertilization success in competition with a male unrelated to the female than in competition with another sibling more frequently than expected by chance, although the mean paternity values did not differ significantly between treatments. The tendancy for sibling males to achieve relatively lower fertilization success in competition with males unrelated to the female could not be explained by the effects of increased ejaculate allocation, female control of sperm transfer or inbreeding. This study therefore provides some evidence in support of the idea that female insects (or their ova) may be capable of selection against sperm on the basis of genetic similarity of conspecific males.

Comparative proteome analysis of cryopreserved flagella and head plasma membrane proteins from sea bream spermatozoa: effect of antifreeze proteins.

PubMed

Zilli, Loredana; Beirão, José; Schiavone, Roberta; Herraez, Maria Paz; Gnoni, Antonio; Vilella, Sebastiano

2014-01-01

Cryopreservation induces injuries to fish spermatozoa that in turn affect sperm quality in terms of fertilization ability, motility, DNA and protein integrity and larval survival. To reduce the loss of sperm quality due to freezing-thawing, it is necessary to improve these procedures. In the present study we investigated the ability of two antifreeze proteins (AFPI and AFPIII) to reduce the loss of quality of sea bream spermatozoa due to cryopreservation. To do so, we compared viability, motility, straight-line velocity and curvilinear velocity of fresh and (AFPs)-cryopreserved spermatozoa. AFPIII addition to cryopreservation medium improved viability, motility and straight-line velocity with respect to DMSO or DMSO plus AFPI. To clarify the molecular mechanism(s) underlying these findings, the protein profile of two different cryopreserved sperm domains, flagella and head plasma membranes, was analysed. The protein profiles differed between fresh and frozen-thawed semen and results of the image analysis demonstrated that, after cryopreservation, out of 270 proteins 12 were decreased and 7 were increased in isolated flagella, and out of 150 proteins 6 showed a significant decrease and 4 showed a significant increase in head membranes. Mass spectrometry analysis identified 6 proteins (4 from isolated flagella and 2 present both in flagella and head plasma membranes) within the protein spots affected by the freezing-thawing procedure. 3 out of 4 proteins from isolated flagella were involved in the sperm bioenergetic system. Our results indicate that the ability of AFPIII to protect sea bream sperm quality can be, at least in part, ascribed to reducing changes in the sperm protein profile occurring during the freezing-thawing procedure. Our results clearly demonstrated that AFPIII addition to cryopreservation medium improved the protection against freezing respect to DMSO or DMSO plus AFPI. In addition we propose specific proteins of spermatozoa as markers related to the procedures of fish sperm cryopreservation.

Comparative biology of sperm factors and fertilization-induced calcium signals across the animal kingdom.

PubMed

Kashir, Junaid; Deguchi, Ryusaku; Jones, Celine; Coward, Kevin; Stricker, Stephen A

2013-10-01

Fertilization causes mature oocytes or eggs to increase their concentrations of intracellular calcium ions (Ca²⁺) in all animals that have been examined, and such Ca²⁺ elevations, in turn, provide key activating signals that are required for non-parthenogenetic development. Several lines of evidence indicate that the Ca²⁺ transients produced during fertilization in mammals and other taxa are triggered by soluble factors that sperm deliver into oocytes after gamete fusion. Thus, for a broad-based analysis of Ca²⁺ dynamics during fertilization in animals, this article begins by summarizing data on soluble sperm factors in non-mammalian species, and subsequently reviews various topics related to a sperm-specific phospholipase C, called PLCζ, which is believed to be the predominant activator of mammalian oocytes. After characterizing initiation processes that involve sperm factors or alternative triggering mechanisms, the spatiotemporal patterns of Ca²⁺ signals in fertilized oocytes or eggs are compared in a taxon-by-taxon manner, and broadly classified as either a single major transient or a series of repetitive oscillations. Both solitary and oscillatory types of fertilization-induced Ca²⁺ signals are typically propagated as global waves that depend on Ca²⁺ release from the endoplasmic reticulum in response to increased concentrations of inositol 1,4,5-trisphosphate (IP₃). Thus, for taxa where relevant data are available, upstream pathways that elevate intraoocytic IP3 levels during fertilization are described, while other less-common modes of producing Ca²⁺ transients are also examined. In addition, the importance of fertilization-induced Ca²⁺ signals for activating development is underscored by noting some major downstream effects of these signals in various animals. © 2013 Wiley Periodicals, Inc.

THE SAGA OF A MALE FERTILITY PROTEIN (SP22)

EPA Science Inventory

Toxicologic studies designed to identify chemical-induced alterations in the structure and function of the epididymis, particularly the acquisition of fertility by proximal cauda epididymal sperm, have lead to the discovery of a novel sperm protein (SP22) that is well correlated ...

Difference Between Identical and Fraternal Twins

MedlinePlus

... chromosomes and a girl has XX chromosomes. Girl-boy twins occur when one X egg is fertilized with an X sperm, and a Y sperm fertilizes the other X egg. Sometimes health care professionals identify same-sex twins as fraternal or identical based on ultrasound ...

MOLECULAR ARCHITECTURE OF THE HUMAN SPERM IZUMO1 AND EGG JUNO FERTILIZATION COMPLEX

PubMed Central

Aydin, Halil; Sultana, Azmiri; Li, Sheng; Thavalingam, Annoj; Lee, Jeffrey E.

2017-01-01

Fertilization is an essential biological process in sexual reproduction and comprises a series of molecular interactions between the sperm and egg1,2. The fusion of haploid spermatozoon and oocyte is the culminating event in mammalian fertilization, enabling the creation of a new genetically distinct diploid organism3,4. The merger of two gametes is achieved through a two-step mechanism where the sperm Izumo1 on the equatorial segment of the acrosome-reacted sperm recognizes its receptor Juno, on the egg surface4–6. This is followed by the fusion of two plasma membranes. Izumo1 and Juno proteins are indispensable for fertilization as constitutive knockout of either Izumo1 or Juno result in mice that are healthy but infertile5,6. Despite their central importance in reproductive medicine, the molecular architectures and the details of their functional roles in fertilization are not known. Here, we present the crystal structures of the human Izumo1 and Juno in unbound and bound conformations. The human Izumo1 structure exhibits a distinct boomerang shape and provides the first structural insights into the Izumo family of proteins7. Human Izumo1 forms a high-affinity complex with Juno and undergoes a major conformational change within its N-terminal domain upon binding to the egg-surface receptor. Our results provide new insights into the molecular basis of sperm-egg recognition, cross-species fertilization, and barrier to polyspermy, thus promising benefits for the rational development of novel non-hormonal contraceptives and fertility treatments for humans and other species of mammals. PMID:27309818

Application of intracytoplasmic sperm injection (ICSI) for fertilization and development in birds.

PubMed

Shimada, Kiyoshi; Ono, Tamao; Mizushima, Shusei

2014-01-15

Intracytoplasmic sperm injection (ICSI) technology in birds has been hampered due to opacity of oocyte. We developed ICSI-assisted fertilization and gene transfer in quail. This paper reviews recent advances of our ICSI experiments. The oocyte retrieved from the oviduct and a quail sperm was injected into the oocyte under a stereomicroscope. The oocyte was cultured for 24h at 41°C under 5% CO2 in air. The fertilization and development was assessed by microscopic observation. The fertility rate ranged 12-18% and development varied from stage II to V in trials. To improve the fertility rate, phospholipase C (PLC) zeta was injected with a sperm. It was increased to 37-50%. Furthermore, injection of inositol trisphosphate increased to over 85%. Quail oocyte can be fertilized with chicken sperm and so can testicular elongated spermatid. To extend embryonic development, chicken eggshell was used as a surrogate culture at 37°C after the 24h incubation at 41°C under 5% CO2 in air. It survived up to 2days thereafter. Finally, gene transfer was attempted in quail egg. The sperm membrane was disrupted with Triton X-100 (TX-100) and was injected with PLCzeta cRNA and enhanced green fluorescent protein (EGFP) gene in oocyte. The GFP expression was evaluated at 24h incubation at 41°C under 5% CO2 in air in the embryos. While the expression was not detected in the control oocytes, the experimental treatment induced blastoderm development (44%) of the oocytes and 86% of blastoderm showed fluorescent emission. In addition, PCR analysis detected EGFP fragments in 50% of GFP-expressing blastoderm. Our ICSI method may be the first step toward the production of transgenic birds. Copyright © 2013 Elsevier Inc. All rights reserved.

Influences of DMP on the Fertilization Process and Subsequent Embryogenesis of Abalone (Haliotis diversicolor supertexta) by Gametes Exposure

PubMed Central

Cai, Zhong-Hua

2011-01-01

Di-methyl phthalate (DMP), a typical endocrine disrupting chemical (EDC), is ubiquitously distributed in aquatic environments; yet studies regarding its impact on gametes and the resulting effects on embryogenesis in marine gastropods are relatively scarce. In this study, the influences of DMP on the gametes and subsequent developmental process of abalone (Haliotis diversicolor supertexta, a representative marine benthic gastropod) were assessed. Newborn abalone eggs and sperm were exposed separately to different DMP concentrations (1, 10 or 100 ppb) for 60 min. At the end-point of exposure, the DMP-treated eggs and sperm were collected for analysis of their ultra-structures, ATPase activities and total lipid levels, and the fertilized gametes (embryos) were collected to monitor related reproductive parameters (fertilization rate, abnormal development rate and hatching success rate). Treatment with DMP did not significantly alter the structure or total lipid content of eggs at any of the doses tested. Hatching failures and morphological abnormalities were only observed with the highest dose of DMP (100 ppb). However, DMP exposure did suppress sperm ATPase activities and affect the morphological character of their mitochondria. DMP-treated sperm exhibited dose-dependent decreases in fertilization efficiency, morphogenesis and hatchability. Relatively obvious toxicological effects were observed when both sperm and eggs were exposed to DMP. Furthermore, RT-PCR results indicate that treatment of gametes with DMP changed the expression patterns of physiologically-regulated genes (cyp3a, 17β-HSD-11 and 17β-HSD-12) in subsequent embryogenesis. Taken together, this study proofed that pre-fertilization exposure of abalone eggs, sperm or both to DMP adversely affects the fertilization process and subsequent embryogenesis. PMID:22028799

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.

PubMed

Intra, Jari; Veltri, Concetta; De Caro, Daniela; Perotti, Maria Elisa; Pasini, Maria Enrica

2017-09-01

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. © 2017 Wiley Periodicals, Inc.

Does advancing male age influence the expression levels and localisation patterns of phospholipase C zeta (PLCζ) in human sperm?

PubMed Central

Yeste, Marc; Jones, Celine; Amdani, Siti Nornadhirah; Yelumalai, Suseela; Mounce, Ginny; da Silva, Sarah J. Martins; Child, Tim; Coward, Kevin

2016-01-01

Socio-economic factors have led to an increasing trend for couples to delay parenthood. However, advancing age exerts detrimental effects upon gametes which can have serious consequences upon embryo viability. While such effects are well documented for the oocyte, relatively little is known with regard to the sperm. One fundamental role of sperm is to activate the oocyte at fertilisation, a process initiated by phospholipase C zeta (PLCζ), a sperm-specific protein. While PLCζ deficiency can lead to oocyte activation deficiency and infertility, it is currently unknown whether the expression or function of PLCζ is compromised by advancing male age. Here, we evaluate sperm motility and the proportion of sperm expressing PLCζ in 71 males (22–54 years; 44 fertile controls and 27 infertile patients), along with total levels and localisation patterns of PLCζ within the sperm head. Three different statistical approaches were deployed with male age considered both as a categorical and a continuous factor. While progressive motility was negatively correlated with male age, all three statistical models concurred that no PLCζ–related parameter was associated with male age, suggesting that advancing male age is unlikely to cause problems in terms of the sperm’s fundamental ability to activate an oocyte. PMID:27270687

Provider Influences on Sperm Banking Outcomes among Adolescent Males Newly Diagnosed with Cancer

PubMed Central

Klosky, James L.; Anderson, L. Elizabeth; Russell, Kathryn M.; Huang, Lu; Zhang, Hui; Schover, Leslie R.; Simmons, Jessica L.; Kutteh, William H.

2017-01-01

Purpose To examine provider communication and sociodemographic factors which associate with sperm banking outcomes in at-risk adolescents newly diagnosed with cancer. Methods A prospective single group quasi-experimental study design was utilized to test the contributions of provider factors on sperm banking outcomes. Medical providers (N=52, 86.5% oncologists) and 99 of their at-risk adolescent patients from eight leading pediatric oncology centers in North America completed questionnaires querying provider factors and patient sperm banking outcomes. Logistic regression with single covariates was utilized to test each provider factor as a potential correlate of the two binary sperm banking study outcomes (collection attempt/no attempt and successful sperm bank/no bank). Multi-covariate logistic regression was used to calculate odds ratios (OR) and 95% confidence intervals (CIs) for specified banking outcomes. Results Fertility referral (OR=9.01, 95% CI=2.54–31.90, p<.001) and provider comfort/skills in negotiating barriers to sperm banking with families (OR=1.94, 95% CI=1.03–3.63, p<0.04) were associated with collection attempts. Adolescents who were referred for a specialized fertility consultation were also almost 5 times more likely to successfully bank (OR=4.96, 95% CI=1.54–16.00, p<.01) relative to those who were not. Conclusions Provider training in communicating/managing adolescents and their families about sperm banking, and increasing utilization of fertility preservation referrals, should increase the proportion of at-risk males preserving fertility prior to treatment initiation. Title Registration Clinicaltrials.gov NCT01152268 PMID:27998702

Production of F1 interspecies hybrid offspring with cryopreserved sperm from a live-bearing fish, the swordtail Xiphophorus helleri.

PubMed

Yang, Huiping; Hazlewood, Leona; Heater, Sheila J; Guerrero, Paula A; Walter, Ronald B; Tiersch, Terrence R

2007-03-01

Despite study of sperm cryopreservation in more than 200 fish species, production of broods from cryopreserved sperm in live-bearing fish has not been demonstrated. This has not been due to a lack of effort, but instead is a result of the unique morphology, biology, and biochemistry of reproduction in viviparous fishes. For example, sperm of Xiphophorus helleri have a cylindrical nucleus, can swim for days after being activated, have glycolytic capabilities, and can reside in the female reproduction tract for months before fertilization. These traits are not found in fishes with external fertilization. The long-standing research use of the genus Xiphophorus has led to development of over 60 pedigreed lines among the 26 species maintained around the world. These species and lines serve as contemporary models in medical research, although they must be maintained as live populations. Previous attempts at establishing sperm cryopreservation protocols for Xiphophorus have not produced live young. To address this we have been studying the parameters surrounding cryobiology of Xiphophorus sperm and applying this information to an improved understanding of internal fertilization and reproduction. Here we report the first successful fertilization and offspring production by cryopreserved sperm in any live-bearing fish. This claim is supported by our use of artificial insemination between two species that yield distinct hybrid offspring to verify paternity via cryopreserved sperm. We provide a practical approach for preservation of valuable genetic resources from live-bearing fish species, a group that is rapidly being lost due to destruction of native habitats.

Sperm-storage defects and live birth in Drosophila females lacking spermathecal secretory cells.

PubMed

Schnakenberg, Sandra L; Matias, Wilfredo R; Siegal, Mark L

2011-11-01

Male Drosophila flies secrete seminal-fluid proteins that mediate proper sperm storage and fertilization, and that induce changes in female behavior. Females also produce reproductive-tract secretions, yet their contributions to postmating physiology are poorly understood. Large secretory cells line the female's spermathecae, a pair of sperm-storage organs. We identified the regulatory regions controlling transcription of two genes exclusively expressed in these spermathecal secretory cells (SSC): Spermathecal endopeptidase 1 (Send1), which is expressed in both unmated and mated females, and Spermathecal endopeptidase 2 (Send2), which is induced by mating. We used these regulatory sequences to perform precise genetic ablations of the SSC at distinct time points relative to mating. We show that the SSC are required for recruiting sperm to the spermathecae, but not for retaining sperm there. The SSC also act at a distance in the reproductive tract, in that their ablation: (1) reduces sperm motility in the female's other sperm-storage organ, the seminal receptacle; and (2) causes ovoviviparity--the retention and internal development of fertilized eggs. These results establish the reproductive functions of the SSC, shed light on the evolution of live birth, and open new avenues for studying and manipulating female fertility in insects.

Recombinant mouse sperm ZP3-binding protein (ZP3R/sp56) forms a high order oligomer that binds eggs and inhibits mouse fertilization in vitro.

PubMed

Buffone, Mariano G; Zhuang, Tiangang; Ord, Teri S; Hui, Ling; Moss, Stuart B; Gerton, George L

2008-05-02

Many candidates have been proposed as zona pellucida-binding proteins. Without precluding a role for any of those candidates, we focused on mouse sperm protein ZP3R/sp56, which is localized in the acrosomal matrix. The objective of this study was to analyze the role of ZP3R/sp56 in mouse fertilization. We expressed recombinant ZP3R/sp56 as a secreted protein in HEK293 cells and purified it from serum-free, conditioned medium. In the presence of reducing agents, the recombinant ZP3R/sp56 exhibited a molecular weight similar to that observed for the native ZP3R/sp56. Reminiscent of the native protein, recombinant ZP3R/sp56 formed a high molecular weight, disulfide cross-linked oligomer consisting of six or more monomers under non-reducing conditions. Recombinant ZP3R/sp56 bound to the zona pellucida of unfertilized eggs but not to 2-cell embryos, indicating that the changes that take place in the zona pellucida at fertilization affected the interaction of this protein with the zona pellucida. The extent of in vitro fertilization was reduced in a dose-dependent manner when unfertilized eggs were preincubated with recombinant ZP3R/sp56 (74% drop at the maximum concentrations assayed). Eggs incubated with the recombinant protein showed an absence of or very few sperm in the perivitelline space, suggesting that the reduction in the fertilization rate is caused by the inhibition of sperm binding and/or penetration through the zona pellucida. These results indicate that sperm ZP3R/sp56 is important for sperm-zona interactions during fertilization and support the concept that the acrosomal matrix plays an essential role in mediating the binding of sperm to the zona pellucida.

Loss of heat shock protein 70 from apical region of buffalo (Bubalus bubalis) sperm head after freezing and thawing.

PubMed

Varghese, Tincy; Divyashree, Bannur C; Roy, Sudhir C; Roy, Kajal S

2016-03-15

The post-thaw fertility of frozen-thawed mammalian spermatozoa is substantially low as compared with that of fresh sperm. Furthermore, the post-thaw fertility of the cryopreserved buffalo sperm has been reported to be poor as compared with that of cattle sperm. Recently, heat shock protein 70 (HSP70) has been found to play a critical role in mammalian fertilization and early embryonic development in boar and cattle. However, the presence of such fertility-related HSP70 in buffalo sperm and its status after cryopreservation has not been reported so far. Thus, a study was conducted to determine the effect of cryopreservation on the level and distribution pattern of HSP70 molecule in buffalo sperm after cryopreservation. Buffalo semen samples, after dilution in semen extender, were aliquoted in straws and divided into two groups. One group was not cryopreserved, and the other group was cryopreserved for 60 days. Sperm proteins were extracted from both non-cryopreserved (NC) and cryopreserved (C) sperm and subjected to Western blot analysis for detection of HSP70 using a monoclonal anti-HSP70 antibody. The distribution pattern of these proteins in buffalo sperm was also monitored before and after cryopreservation using indirect immunofluorescence technique. A prominent 70-kDa protein band of HSP70 protein was detected in protein extracts of both NC and C buffalo sperm. Densitometry analysis revealed that the intensity of 70-kDa HSP70 protein band of cryopreserved sperm decreased significantly (P < 0.05) compared with that of NC sperm. However, the level of HSP70 in cryopreserved extended seminal plasma (ESP) did not change as compared with that of NC samples indicating a possible degradation of HSP70 in the spermatozoa itself rather than leakage of the protein into the ESP. Furthermore, Western blot also confirmed that several HSP70 immunoreactive protein bands detected in the ESP were contributed by the egg yolk that was added to the extender. Immunocytochemistry revealed that HSP70 proteins were distributed over the apical region of sperm head and/or acrosome, post-acrosomal, and middle piece regions of NC buffalo spermatozoa. However, the fluorescence signal of apical region of sperm head was lost significantly (P < 0.05) after a cycle of freezing and thawing. Thus, the present study confirmed that there was loss of HSP70 from buffalo sperm head after freezing and thawing of buffalo spermatozoa, and this may be one of the causes of the reduced post-thaw fertility of sperm in this species. Copyright © 2016 Elsevier Inc. All rights reserved.

Relationship between Porcine Sperm Motility and Sperm Enzymatic Activity using Paper-based Devices

NASA Astrophysics Data System (ADS)

Matsuura, Koji; Huang, Han-Wei; Chen, Ming-Cheng; Chen, Yu; Cheng, Chao-Min

2017-04-01

Mammalian sperm motility has traditionally been analyzed to determine fertility using computer-assisted semen analysis (CASA) systems. To develop low-cost and robust male fertility diagnostics, we created a paper-based MTT assay and used it to estimate motile sperm concentration. When porcine sperm motility was inhibited using sperm enzyme inhibitors for sperm enzymes related to mitochondrial activity and glycolysis, we simultaneously recorded sperm motility and enzymatic reactivity using a portable motility analysis system (iSperm) and a paper-based MTT assay, respectively. When using our paper-based MTT-assay, we calculated the area mean value signal intensity (AMV) to evaluate enzymatic reactivity. Both sperm motility and AMV decreased following treatment with iodoacetamide (IODO) and 3-bromopyruvic acid (3BP), both of which are inhibitors of glycolytic enzymes including glyceraldehyde-3-phosphate dehydrogenase (GAPDH). We found a correlation between recorded motility using iSperm and AMV from our paper-based assay (P < 0.05), suggesting that a sperm-related enzymatic reaction is involved in sperm motility. Under this protocol, MTT reduction was coupled with catalysis of GAPDH and was promoted by electron transfer from NADH. Based on this inhibitor study, sperm motility can be estimated using our paper-based MTT-assay.

In-vitro effects of Thymus munbyanus essential oil and thymol on human sperm motility and function.

PubMed

Chikhoune, Amirouche; Stouvenel, Laurence; Iguer-Ouada, Mokrane; Hazzit, Mohamed; Schmitt, Alain; Lorès, Patrick; Wolf, Jean Philippe; Aissat, Kamel; Auger, Jacques; Vaiman, Daniel; Touré, Aminata

2015-09-01

Traditional medicine has been used worldwide for centuries to cure or prevent disease and for male or female contraception. Only a few studies have directly investigated the effects of herbal compounds on spermatozoa. In this study, essential oil from Thymus munbyanus was extracted and its effect on human spermatozoa in vitro was analysed. Gas chromatography and Gas chromatography-mass spectrometry analyses identified 64 components, accounting for 98.9% of the composition of the oil. The principal components were thymol (52.0%), γ-terpinene (11.0%), ρ-cymene (8.5%) and carvacrol (5.2%). Freshly ejaculated spermatozoa was exposed from control individuals to various doses of the essential oil for different time periods, and recorded the vitality, the mean motility, the movement characteristics (computer-aided sperm analysis), the morphology and the ability to undergo protein hyperphosphorylation and acrosomal reaction, which constitute two markers of sperm capacitation and fertilizing ability. In vitro, both the essential oil extracted from T. munbyanus and thymol, the principal compound present in this oil, impaired human sperm motility and its capacity to undergo hyperphosphorylation and acrosome reaction. These compounds may, therefore, be of interest in the field of reproductive biology, as potential anti-spermatic agents. Copyright © 2015 Reproductive Healthcare Ltd. Published by Elsevier Ltd. All rights reserved.

Development and evolution of the female gametophyte and fertilization process in Welwitschia mirabilis (Welwitschiaceae).

PubMed

Friedman, William E

2015-02-01

The female gametophyte of Welwitschia has long been viewed as highly divergent from other members of the Gnetales and, indeed, all other seed plants. However, the formation of female gametes and the process of fertilization have never been observed. Standard histological techniques were applied to study gametophyte development and the fertilization process in Welwitschia. In Welwitschia, fertilization events occur when pollen tubes with binucleate sperm cells grow down through the nucellus and encounter prothallial tubes, free nuclear tubular extensions of the micropylar end of the female gametophyte that grow up through the nucellus. Entry of a binucleate sperm cell into a vacuolate prothallial tube appears to stimulate the rapid coagulation of cytoplasm around a single female nucleus, which differentiates into an egg cell. One sperm nucleus enters the female gamete, while the second sperm nucleus remains outside and ultimately degenerates. Only a single fertilization event occurs per mating pair of pollen tube and prothallial tube. Welwitschia lacks the gnetalean pattern of regular double fertilization, as found in Ephedra and Gnetum, involving sperm from a single pollen tube to yield two zygotes. Moreover, an analysis of character evolution indicates that the female gametophyte of Welwitschia is highly apomorphic both among seed plants, and specifically within Gnetales, but also shares several key synapomorphies with its sister taxon Gnetum. Finally, the biological role of prothallial tubes in Welwitschia is examined from the perspectives of gamete competition and kin conflict. © 2015 Botanical Society of America, Inc.

The oviducal protein, heat-shock 70-kDa protein 8, improves the long-term survival of ram spermatozoa during storage at 17°C in a commercial extender.

PubMed

Lloyd, R E; Fazeli, A; Watson, P F; Holt, W V

2012-01-01

Poor fertility rates are often observed when fresh ram semen stored in conventional extenders is used for cervical artificial insemination (AI). Heat-shock 70-kDa protein 8 (HSPA8), found within the oviduct, prolongs boar, ram and bull sperm survival at body temperatures in vitro. Here, we aimed to determine whether supplementing extenders (INRA-96 and RSD-1) with HSPA8 (4 µg mL⁻¹) would improve their performance in maintaining freshly collected ram sperm viability and sperm nuclear DNA integrity during storage over 48 h at 17°C. Sperm function was assessed at 1, 6, 24 and 48h and this experiment was repeated using 25 × 10⁶ and 800 × 10⁶ spermatozoa mL⁻¹. INRA96 supplemented with HSPA8 maintained sperm viability significantly better than INRA96 alone at both sperm concentrations. However, sperm nuclear DNA fragmentation (DF) increased significantly during storage using the higher sperm concentration, irrespective of the extender and the protein treatment used. Increasing levels of sperm nuclear DF over time could explain why poor fertility rates are often observed following cervical AI using stored ram semen. However, further research is required to ascertain whether supplementing the commercially available INRA96 extender with HSPA8 will improve fertility rates following cervical AI using stored ram semen.

Clinical utility of sperm DNA fragmentation testing: practice recommendations based on clinical scenarios

PubMed Central

Majzoub, Ahmad; Esteves, Sandro C.; Ko, Edmund; Ramasamy, Ranjith; Zini, Armand

2016-01-01

Sperm DNA fragmentation (SDF) has been generally acknowledged as a valuable tool for male fertility evaluation. While its detrimental implications on sperm function were extensively investigated, little is known about the actual indications for performing SDF analysis. This review delivers practice based recommendations on commonly encountered scenarios in the clinic. An illustrative description of the different SDF measurement techniques is presented. SDF testing is recommended in patients with clinical varicocele and borderline to normal semen parameters as it can better select varicocelectomy candidates. High SDF is also linked with recurrent spontaneous abortion (RSA) and can influence outcomes of different assisted reproductive techniques. Several studies have shown some benefit in using testicular sperm rather than ejaculated sperm in men with high SDF, oligozoospermia or recurrent in vitro fertilization (IVF) failure. Infertile men with evidence of exposure to pollutants can benefit from sperm DNA testing as it can help reinforce the importance of lifestyle modification (e.g., cessation of cigarette smoking, antioxidant therapy), predict fertility and monitor the patient’s response to intervention. PMID:28078226

Internalization of silver nanoparticles into mouse spermatozoa results in poor fertilization and compromised embryo development

PubMed Central

Yoisungnern, Ton; Choi, Yun-Jung; Woong Han, Jae; Kang, Min-Hee; Das, Joydeep; Gurunathan, Sangiliyandi; Kwon, Deug-Nam; Cho, Ssang-Goo; Park, Chankyu; Kyung Chang, Won; Chang, Byung-Soo; Parnpai, Rangsun; Kim, Jin-Hoi

2015-01-01

Silver nanoparticles (AgNPs) have many features that make them attractive as medical devices, especially in therapeutic agents and drug delivery systems. Here we have introduced AgNPs into mouse spermatozoa and then determined the cytotoxic effects of AgNPs on sperm function and subsequent embryo development. Scanning electron microscopy and transmission electron microscopy analyses showed that AgNPs could be internalized into sperm cells. Furthermore, exposure to AgNPs inhibited sperm viability and the acrosome reaction in a dose-dependent manner, whereas sperm mitochondrial copy numbers, morphological abnormalities, and mortality due to reactive oxygen species were significantly increased. Likewise, sperm abnormalities due to AgNPs internalization significantly decreased the rate of oocyte fertilization and blastocyst formation. Blastocysts obtained from AgNPs-treated spermatozoa showed lower expression of trophectoderm-associated and pluripotent marker genes. Overall, we propose that AgNPs internalization into spermatozoa may alter sperm physiology, leading to poor fertilization and embryonic development. Such AgNPs-induced reprotoxicity may be a valuable tool as models for testing the safety and applicability of medical devices using AgNPs. PMID:26054035

A cost for high levels of sperm competition in rodents: increased sperm DNA fragmentation

PubMed Central

Roldan, Eduardo R. S.

2016-01-01

Sperm competition, a prevalent evolutionary process in which the spermatozoa of two or more males compete for the fertilization of the same ovum, leads to morphological and physiological adaptations, including increases in energetic metabolism that may serve to propel sperm faster but that may have negative effects on DNA integrity. Sperm DNA damage is associated with reduced rates of fertilization, embryo and fetal loss, offspring mortality, and mutations leading to genetic disease. We tested whether high levels of sperm competition affect sperm DNA integrity. We evaluated sperm DNA integrity in 18 species of rodents that differ in their levels of sperm competition using the sperm chromatin structure assay. DNA integrity was assessed upon sperm collection, in response to incubation under capacitating or non-capacitating conditions, and after exposure to physical and chemical stressors. Sperm DNA was very resistant to physical and chemical stressors, whereas incubation in non-capacitating and capacitating conditions resulted in only a small increase in sperm DNA damage. Importantly, levels of sperm competition were positively associated with sperm DNA fragmentation across rodent species. This is the first evidence showing that high levels of sperm competition lead to an important cost in the form of increased sperm DNA damage. PMID:26936246

Anti-bacterial factors secreted from cumulus cells of ovulated COCs enhance sperm capacitation during in vitro fertilization.

PubMed

Shimada, Masayuki; Mihara, Toshihiro; Kawashima, Ikko; Okazaki, Tetsuji

2013-02-01

The aim of this study was to find immune-related genes expressed in cumulus cells of ovulated cumulus oocyte complexes (COCs) and to clear the functional roles during fertilization process. Ovulated COCs were collected from oviduct 16 hr after the hCG injections followed by eCG priming. The cumulus cells were used for RT-PCR or western blotting study. COCs were also used for in vitro fertilization study. Cramp, Trf, Lyz2, S100a8, and S100a9 were expressed in cumulus cells during ovulation process. The protein levels of CRAMP or transferrin were detected in ovulated COCs and then secreted into hyaluronan-rich matrix. The high dose of these factors reduced the proliferative activity of E. coli; however, the lower levels of them significantly increased the rate of fertilization in in vitro via the induction of sperm capacitation. Cumulus-secreted anti-bacterial factors act on sperm to induce sperm capacitation. © 2012 John Wiley & Sons A/S.

Subtle membrane changes in cryopreserved bull semen in relation with sperm viability, chromatin structure, and field fertility.

PubMed

Januskauskas, A; Johannisson, A; Rodriguez-Martinez, H

2003-09-01

This study investigated the use of annexin-V/PI assay to assess sub lethal changes in bull spermatozoa post-thawing, and to further relate these changes to results obtained by fluorometric assessment of sperm viability and sperm chromatin structure assay (SCSA), as well as field fertility (as 56-day non-return rates, 56-day NRR) after AI. Frozen-thawed semen samples were obtained from 18 Swedish Red and White bulls (one to three semen batches/bull) and fertility data was based on 6900 inseminations. The annexin-V/PI assay revealed that post-thaw semen samples contained on average 41.8+/-7.5% annexin-V-positive cells. Most of the annexin-V-positive cells were dying cells, i.e. also PI-positive. The incidence of annexin-V-positive cells was negatively related (r=-0.59, P<0.01) to the percentage of viable cells, as detected by fluorometry. The incidence of annexin-V-positive spermatozoa significantly correlated to the SCSA variable xalphat (r=0.53, P<0.05). The incidence of annexin-V-negative, dead cells was the only annexin-V/PI assay variable that correlated significantly with fertility both at batch (r=-0.40, P<0.05), and bull (r=-0.56, P<0.05) levels. Among sperm viability variables, subjectively assessed sperm motility (r=0.52-0.59, P<0.01), CASA-assessed sperm motility (r=0.43-0.61, P<0.05), and the incidence of live spermatozoa, expressed as total numbers (r=0.39-0.54, P<0.05), or percentage values (r=0.68-0.68, P<0.01), correlated significantly with field fertility both at batch, and bull levels. Among the SCSA variables, only the COMP alphat correlated significantly (r=0.33-0.51, P<0.05) with fertility results. The results indicate a certain proportion of bull spermatozoa express PS on their surface after thawing, e.g. they have altered membrane function, and that the incidence of such cells is inversely correlated to sperm viability, and positively correlated to abnormal sperm chromatin condensation since they eventually undergo necrosis.

Sperm morphology and chromatin integrity in Swedish warmblood stallions and their relationship to pregnancy rates

PubMed Central

Morrell, Jane M; Johannisson, Anders; Dalin, Anne-Marie; Hammar, Linda; Sandebert, Thomas; Rodriguez-Martinez, Heriberto

2008-01-01

Background Artificial insemination is not as widely used in horses as in other domestic species, such as dairy cattle and pigs, partly because of the wide variation in sperm quality between stallion ejaculates and partly due to decreased fertility following the use of cooled transported spermatozoa. Furthermore, predictive tests for sperm fertilising ability are lacking. The objective of the present study was to assess sperm morphology and chromatin integrity in ejaculates obtained from 11 warmblood breeding stallions in Sweden, and to evaluate the relationship of these parameters to pregnancy rates to investigate the possibility of using these tests predictively. Methods Aliquots from fortyone ejaculates, obtained as part of the normal semen collection schedule at the Swedish National Stud, were used for morphological analysis by light microscopy, whereas thirtyseven were used for chromatin analysis (SCSA) by flow cytometry. The outcome of inseminations using these ejaculates was made available later in the same year. Results Ranges for the different parameters were as follows; normal morphology, 27–79.5%; DNA-fragmentation index (DFI), 4.8–19.0%; standard deviation of DNA fragmentation index (SD_DFI) 41.5–98.9, and mean of DNA fragmentation index (mean_DFI), 267.7–319.5. There was considerable variation among stallions, which was statistically significant for all these parameters except for mean_DFI (P < 0.001, P < 0.01, P < 0.001 and P < 0.2 respectively). There was a negative relationship between normal morphology and DFI (P < 0.05), between normal morphology and SD_DFI (P < 0.001), and between normal morphology and mean_DFI (P < 0.05). For specific defects, there was a direct relationship between the incidence of pear-shaped sperm heads and DFI (P < 0.05), and also nuclear pouches and DFI (P < 0.001), indicating that either morphological analysis or chromatin analysis was able to identify abnormalities in spermiogenesis that could compromise DNA-integrity. A positive relationship was found between normal morphology and pregnancy rate following insemination (r = 0.789; P < 0.01) and a negative relationship existed between DFI and pregnancy rate (r = -0.63; P < 0.05). Sperm motility, assessed subjectively, was not related to conception rate. Conclusion Either or both of the parameters, sperm morphology and sperm chromatin integrity, seem to be useful in predicting the fertilising ability of stallion ejaculates, particularly in determining cases of sub-fertility. PMID:18179691

Use of heterospermic inseminations and paternity testing to evaluate the relative contributions of common sperm traits and seminal plasma proteins in boar fertility.

PubMed

Flowers, W L; Deller, F; Stewart, K R

2016-11-01

The objective of this study was to evaluate relationships between common semen quality estimates including sperm motility, sperm morphology, spontaneous capacitation status and seminal plasma proteins and boar fertility using heterospermic inseminations and subsequent paternity testing. All boars (n=12) used in the study had excellent semen quality (≥70% normal sperm) that resulted in average farrowing rates and litter sizes of 88.9±0.7% and 11.7±0.1 pigs, respectively. Their ejaculates were combined to make heterospermic insemination doses in such a way that each boar was tested against all of his contemporaries. The proportion of piglets sired by each individual was used to separate boars into three fertility groups: High (71.6±4.8%; n=3); Medium (51.6±3.8%; n=6); and Low (25.2%±5.3%; n=3). Ejaculates from High fertility boars had more motile sperm with normal acrosomes that moved faster in a straight-line and were more likely to undergo an acrosome reaction (p≤0.05) compared with their counterparts in the Low fertility group. Ejaculates from High fertility boars contained the greatest concentrations of three seminal plasma proteins (25.9kD/5.9pI; 55.1kD/4.8pI; and 70.1kD/5.2pI; p≤0.05), whereas concentrations of a 19.1kD/6.8pI were highest in semen from Low fertility boars (p≤0.05). Multiple regression analyses indicated that concentrations of the 25.9kD/5.9pI seminal plasma protein explained 66% of the variation observed in the proportion of pigs sired within a litter among boars (p≤0.00001). These results demonstrate that heterospermic inseminations and subsequent paternity testing is an effective technique for defining relationships between common semen quality tests and fertility, especially in situations where reproductive performance of all the boars is high. Motility, normal acrosome morphology, average linear velocity of motile sperm, and the proportion of sperm capable of an acrosome reaction were all positively associated with boar fertility. However, concentrations of a 25.9kD/5.9pI seminal plasma protein were the best single semen characteristic for ranking boars in terms of their fertility. Copyright © 2016 Elsevier B.V. All rights reserved.

A method for hormonal induction of sperm release in anurans (eight species) and in vitro fertilization in lepidobatrachus species.

PubMed

Waggener, W L; Carroll, E J

1998-02-01

Injections of synthetic human gonadotropin releasing hormone (GnRH) into the dorsal pelvic area were used in an attempt to stimulate sperm release in isolated males of eight anuran species including Xenopus laevis, Rana pipiens and Lepidobatrachus laevis. Sperm were obtained within 1-5 h post injection either by mechanical stimulation or by cloacal lavage. Sperm suspensions varied from 8 microL to 7 mL and the cell densities ranged from 4 x 10(5) to 4 x 10(7) sperm/mL. The sperm obtained from seven species using GnRH-induced release were viable based on light microscopic observations of motility. In addition, sperm preparations fertilized eggs in vitro and produced normal tadpoles in the case of L. laevis and L. Ilanensis. This hormonal method of anuran sperm collection will provide a convenient non-injurious way to obtain anuran sperm for basic studies of reproduction and development.

Nematode sperm maturation triggered by protease involves sperm-secreted serine protease inhibitor (Serpin)

PubMed Central

Zhao, Yanmei; Sun, Wei; Zhang, Pan; Chi, Hao; Zhang, Mei-Jun; Song, Chun-Qing; Ma, Xuan; Shang, Yunlong; Wang, Bin; Hu, Youqiao; Hao, Zhiqi; Hühmer, Andreas F.; Meng, Fanxia; L'Hernault, Steven W.; He, Si-Min; Dong, Meng-Qiu; Miao, Long

2012-01-01

Spermiogenesis is a series of poorly understood morphological, physiological and biochemical processes that occur during the transition of immotile spermatids into motile, fertilization-competent spermatozoa. Here, we identified a Serpin (serine protease inhibitor) family protein (As_SRP-1) that is secreted from spermatids during nematode Ascaris suum spermiogenesis (also called sperm activation) and we showed that As_SRP-1 has two major functions. First, As_SRP-1 functions in cis to support major sperm protein (MSP)-based cytoskeletal assembly in the spermatid that releases it, thereby facilitating sperm motility acquisition. Second, As_SRP-1 released from an activated sperm inhibits, in trans, the activation of surrounding spermatids by inhibiting vas deferens-derived As_TRY-5, a trypsin-like serine protease necessary for sperm activation. Because vesicular exocytosis is necessary to create fertilization-competent sperm in many animal species, components released during this process might be more important modulators of the physiology and behavior of surrounding sperm than was previously appreciated. PMID:22307610

Advancing age increases sperm chromatin damage and impairs fertility in peroxiredoxin 6 null mice.

PubMed

Ozkosem, Burak; Feinstein, Sheldon I; Fisher, Aron B; O'Flaherty, Cristian

2015-08-01

Due to socioeconomic factors, more couples are choosing to delay conception than ever. Increasing average maternal and paternal age in developed countries over the past 40 years has raised the question of how aging affects reproductive success of males and females. Since oxidative stress in the male reproductive tract increases with age, we investigated the impact of advanced paternal age on the integrity of sperm nucleus and reproductive success of males by using a Prdx6(-/-) mouse model. We compared sperm motility, cytoplasmic droplet retention sperm chromatin quality and reproductive outcomes of young (2-month-old), adult (8-month-old), and old (20-month-old) Prdx6(-/-) males with their age-matched wild type (WT) controls. Absence of PRDX6 caused age-dependent impairment of sperm motility and sperm maturation and increased sperm DNA fragmentation and oxidation as well as decreased sperm DNA compaction and protamination. Litter size, total number of litters and total number of pups per male were significantly lower in Prdx6(-/-) males compared to WT controls. These abnormal reproductive outcomes were severely affected by age in Prdx6(-/-) males. In conclusion, the advanced paternal age affects sperm chromatin integrity and fertility more severely in the absence of PRDX6, suggesting a protective role of PRDX6 in age-associated decline in the sperm quality and fertility in mice. Copyright © 2015 The Authors. Published by Elsevier B.V. All rights reserved.

Murine sperm capacitation, oocyte penetration and decondensation following moderate alcohol intake.

PubMed

Sánchez, Melisa C; Fontana, Vanina A; Galotto, Camila; Cambiasso, Maite Y; Sobarzo, Cristian M A; Calvo, Lucrecia; Calvo, Juan C; Cebral, Elisa

2018-06-01

Male chronic alcohol abuse causes testicular failure and infertility. We analyzed the effects of moderate sub-chronic alcohol intake on sperm morphology, capacitation, fertilization and sperm head decondensation. CF-1 male mice were administered 15% ethanol in drinking water for 15 days; control mice received ethanol-free water. Similar patterns of tyrosine phosphorylation were observed in capacitated spermatozoa of control and treated males. Percentage of hyperactivation (H) and spontaneous (SAR) and progesterone-induced (IAR) acrosome reaction significantly decreased at 120 and 150 min of capacitation in treated males compared to controls (H: 14.1 ± 2.5 vs 23.7 ± 2.6, P  < 0.05; SAR-T120 min: 17.9 ± 2.5 vs 32.9 ± 4.1, P  < 0.01; IAR-150 min: 43.3 ± 3.5 vs 73.1 ± 1.1, P  < 0.001, n  = 6). During in vitro fertilization (2.5, 3.5 and 4.5 h post-insemination), there was an increased percentage of fertilized oocytes (with a decondensed sperm head and one or two pronuclei) in treated males ( P  < 0.001, n  = 7). After 60 min of in vitro decondensation with glutathione plus heparin, the percentage of decondensed sperm heads was significantly higher in treated males than in controls (mean ± s.d.: 57.1 ± 5.6 vs 48.3 ± 4.5, P  < 0.05, n  = 5). The percentage of morphologically normal sperm heads was significantly decreased in treated males with respect to controls ( P  < 0.001, n  = 9). These results show that short-term moderate alcohol consumption in outbred mice affect sperm morphology, hyperactivation, acrosomal exocytosis, and the dynamics of in vitro fertilization and in vitro sperm nuclear decondensation. © 2018 Society for Reproduction and Fertility.

Spermatozoa Expression of piR-31704, piR-39888, and piR-40349 and Their Correlation to Sperm Concentration and Fertilization Rate After ICSI.

PubMed

Cui, Long; Fang, Li; Shi, Biwei; Qiu, Sunquan; Ye, Yinghui

2018-05-01

To investigate the relationship between spermatozoa PIWI-interacting RNAs (piRNAs) levels and semen parameters and to evaluate the role of expression of piRNAs on fertilization and embryo development after intracytoplasmic sperm injection (ICSI) treatment. One hundred and eighty-six patients with idiopathic male infertility who had undergone first ICSI cycles were enrolled in our study. The levels of piRNAs in spermatozoa were measured by real-time polymerase chain reaction. Semen parameters, including sperm concentration, motility, and morphology, were evaluated. The rates of fertilization, early cleavage, and day 3 good-quality embryo were calculated to assess embryo development potential. Spermatozoa levels of piR-31704 and piR-39888 were decreased in male factor infertility group as compared with control group (for piR-31704, P = .027 and for piR-39888, P = .041, respectively). And these 2 piRNAs were expressed at higher levels in patients with normal sperm concentration compared with subnormal sperm concentration group (for piR-31704, P = .042; for piR-39888, P = .047, respectively), while there were no correlation between the 3 piRNAs expression levels in spermatozoa and the rates of sperm progressive motility and normal sperm morphology. There were significant increases in the levels of all 3 piRNAs in spermatozoa from the group with higher 2PN rates (for piR-31704, P = .002; for piR-39888, P < .001; for piR-40349, P < .001; respectively), but there was no correlation between spermatozoa levels of these 3 piRNAs and the rates of embryo early cleavage, day 3 good-quality embryos and pregnancy. Spermatozoa piRNA levels correlate with sperm concentration and fertilization rate after ICSI. Paternal piRNAs may play a role in fertilization process.

Exploring the Cytoskeleton During Intracytoplasmic Sperm Injection in Humans

NASA Astrophysics Data System (ADS)

Rawe, Vanesa Y.; Chemes, Héctor

Understanding the cellular events during fertilization in mammals is a major challenge that can contribute to the improvement of future infertility treatments in humans and reproductive performance in farm animals. Of special interest is the role of the oocyte and sperm cytoskeleton during the initial interaction between gametes. The aim of this chapter is to describe methods for studying cytoskeletal features during in vitro fertilization after intracytoplasmic sperm injection (ICSI) in humans. The following protocols will provide a detailed description of how to perform immunodetection and imaging of human eggs, zygotes, and sperm by fluorescence (confocal and epifluorescence) and electron microscopy.

New strategies of boar sperm cryopreservation: development of novel freezing and thawing methods with a focus on the roles of seminal plasma.

PubMed

Okazaki, Tetsuji; Shimada, Masayuki

2012-09-01

Cryopreservation of boar spermatozoa offers an effective means of long-term storage of important genetic material. Many researchers have investigated how to improve reproductive performance by artificial insemination (AI) using cryopreserved boar spermatozoa. Recently, we and other groups reported that high conception rates (70-80%) can be achieved by AI with frozen-thawed boar spermatozoa using a modified temperature program during freezing, or a novel cryopreservation extender to improve sperm quality (including sperm survivability, motility, membrane status and fertilization ability) after thawing, or a novel sperm infusion method, deep intra uterine insemination. However, these techniques have not yet been used for commercial pig production. The variation in sperm freezability among boars or among ejaculations in an identical boar is one of the main reasons for this problem. In our previous study, it was revealed that some components of seminal plasma have a negative effect on the freezability of boar sperm. One of these factors is bacteria-released endotoxin (lipopolysaccharide: LPS). LPS binds to Toll-like receptor-4 (TLR-4) expressed on the sperm surface, resulting in induction of apoptosis. On the other hand, seminal plasma suppresses cryo-capacitation induced by thawing stress. On the basis of these findings, we designed a novel protocol of AI using frozen-thawed boar sperm. © 2012 Japanese Society of Animal Science.

Redox regulation of mammalian sperm capacitation

PubMed Central

O’Flaherty, Cristian

2015-01-01

Capacitation is a series of morphological and metabolic changes necessary for the spermatozoon to achieve fertilizing ability. One of the earlier happenings during mammalian sperm capacitation is the production of reactive oxygen species (ROS) that will trigger and regulate a series of events including protein phosphorylation, in a time-dependent fashion. The identity of the sperm oxidase responsible for the production of ROS involved in capacitation is still elusive, and several candidates are discussed in this review. Interestingly, ROS-induced ROS formation has been described during human sperm capacitation. Redox signaling during capacitation is associated with changes in thiol groups of proteins located on the plasma membrane and subcellular compartments of the spermatozoon. Both, oxidation of thiols forming disulfide bridges and the increase on thiol content are necessary to regulate different sperm proteins associated with capacitation. Reducing equivalents such as NADH and NADPH are necessary to support capacitation in many species including humans. Lactate dehydrogenase, glucose-6-phospohate dehydrogenase, and isocitrate dehydrogenase are responsible in supplying NAD (P) H for sperm capacitation. Peroxiredoxins (PRDXs) are newly described enzymes with antioxidant properties that can protect mammalian spermatozoa; however, they are also candidates for assuring the regulation of redox signaling required for sperm capacitation. The dysregulation of PRDXs and of enzymes needed for their reactivation such as thioredoxin/thioredoxin reductase system and glutathione-S-transferases impairs sperm motility, capacitation, and promotes DNA damage in spermatozoa leading to male infertility. PMID:25926608

Novel and traditional traits of frozen-thawed porcine sperm related to in vitro fertilization success

USDA-ARS?s Scientific Manuscript database

Cryopreserved semen allows the use of single ejaculates for repeated analyses, potentially improving in vitro fertilization (IVF) consistency by eliminating inter-ejaculate variability observed with fresh semen. However, the freezing and thawing processes result in compromised sperm function and IVF...

Field data analysis of boar semen quality.

PubMed

Broekhuijse, M L W J; Feitsma, H; Gadella, B M

2011-09-01

This contribution provides an overview of approaches to correlate sow fertility data with boar semen quality characteristics. Large data sets of fertility data and ejaculate data are more suitable to analyse effects of semen quality characteristics on field fertility. Variation in fertility in sows is large. The effect of semen factors is relatively small and therefore impossible to find in smaller data sets. Large data sets allow for statistical corrections on both sow- and boar-related parameters. Remaining sow fertility variation can then be assigned to semen quality parameters, which is of huge interest to AI (artificial insemination) companies. Previous studies of Varkens KI Nederland to find the contribution to field fertility of (i) the number of sperm cells in an insemination dose, (ii) the sperm motility and morphological defects and (iii) the age of semen at the moment of insemination are discussed in context of the possibility to apply such knowledge to select boars on the basis of their sperm parameters for AI purposes. © 2011 Blackwell Verlag GmbH.

Sperm chromatin structure assay results after swim-up are related only to embryo quality but not to fertilization and pregnancy rates following IVF.

PubMed

Niu, Zhi-Hong; Shi, Hui-Juan; Zhang, Hui-Qin; Zhang, Ai-Jun; Sun, Yi-Juan; Feng, Yun

2011-11-01

The aim of this study was to investigate whether the sperm chromatin structure assay (SCSA) results after swim-up are related to fertilization rates, embryo quality and pregnancy rates following in vitro fertilization (IVF). A total of 223 couples undergoing IVF in our hospital from October 2008 to September 2009 were included in this study. Data on the IVF process and sperm chromatin structure assay results were collected. Fertilization rate, embryo quality and IVF success rates of different DNA fragmentation index (DFI) subgroups and high DNA stainability (HDS) subgroups were compared. There were no significant differences in fertilization rate, clinical pregnancy or delivery rates between the DFI and HDS subgroups. However, the group with abnormal DFI had a lower good embryo rate. So, we concluded that the SCSA variables, either DFI or HDS after swim-up preparation, were not valuable in predicting fertilization failure or pregnancy rate, but an abnormal DFI meant a lower good embryo rate following IVF.

Chemotactic Motility of Sperm in Shear

NASA Astrophysics Data System (ADS)

Guasto, Jeffrey S.; Riffell, Jeffrey A.; Zimmer, Richard K.; Stocker, Roman

2011-11-01

Chemical gradients are utilized by plants and animals in sexual reproduction to guide swimming sperm cells toward the egg. This process (``chemotaxis''), which can greatly increase the success of fertilization, is subject to interference by fluid flow, both in the bodily conduits of internal fertilizers (e.g. mammals) and in the aquatic environment of external fertilizers (e.g. benthic invertebrates). We studied the biomechanics of chemotaxing sea urchin spermatozoa using microfluidic devices, which allow for the precise and independent control of attractant gradients and fluid shear. We captured swimming trajectories and flagellar beat patterns using high-speed video-microscopy, to detect chemotactic responses and measure the effect of fluid forces on swimming. This work will ultimately help us to understand how swimming sperm cells actively navigate natural chemoattractant gradients for successful fertilization.

Relationship between sperm quality traits and field-fertility of porcine semen

PubMed Central

Lymberopoulos, A. G.; Khalifa, T. A. A.

2010-01-01

An investigation involving seven boars, active in artificial insemination, and 1,350 multiparous sows was conducted at a private farm and aimed at examining the relationship between sperm quality traits and boar fertility in terms of farrowing rate and litter size. This experiment was done for 6 months. The semen samples were evaluated for subjective sperm motility and concentration. Ejaculates with at least 1 × 108 sperm/mL and 70% sperm progressive motility were extended with a commercial medium to 30 × 106 sperm/mL and used for artificial insemination (AI). AI dose was 100 mL semen containing 3 × 109 spermatozoa. Aliquots of diluted semen were assessed for live morphologically normal spermatozoa (LMNS, eosin-nigrosin stain exclusion assay) and sperm chromatin instability (SCI, acridine orange assay). Farrowing rates according to different boar sperm varied (p < 0.001) from 59.3 to 88.92%. The mean values of LMNS (47.2~76.5%) and SCI (0.16~4.67%) differed significantly among boars. LMNS (r = 0.79, p < 0.05) and SCI (r = -0.90, p < 0.02) accounted for 62.2 and 81.7% of the variability in farrowing rates, respectively. After the combination of sperm traits, the relationship between percentage of LMNS with stable chromatin structure and farrowing rate was significant (r = 0.86, p < 0.05). The number of live piglets per parturition was not significantly correlated with sperm quality attributes. In conclusion, boar fertility after AI with freshly diluted semen can be predicted based on the evaluation of sperm morphology and chromatin integrity. PMID:20458156

CASAnova: a multiclass support vector machine model for the classification of human sperm motility patterns.

PubMed

Goodson, Summer G; White, Sarah; Stevans, Alicia M; Bhat, Sanjana; Kao, Chia-Yu; Jaworski, Scott; Marlowe, Tamara R; Kohlmeier, Martin; McMillan, Leonard; Zeisel, Steven H; O'Brien, Deborah A

2017-11-01

The ability to accurately monitor alterations in sperm motility is paramount to understanding multiple genetic and biochemical perturbations impacting normal fertilization. Computer-aided sperm analysis (CASA) of human sperm typically reports motile percentage and kinematic parameters at the population level, and uses kinematic gating methods to identify subpopulations such as progressive or hyperactivated sperm. The goal of this study was to develop an automated method that classifies all patterns of human sperm motility during in vitro capacitation following the removal of seminal plasma. We visually classified CASA tracks of 2817 sperm from 18 individuals and used a support vector machine-based decision tree to compute four hyperplanes that separate five classes based on their kinematic parameters. We then developed a web-based program, CASAnova, which applies these equations sequentially to assign a single classification to each motile sperm. Vigorous sperm are classified as progressive, intermediate, or hyperactivated, and nonvigorous sperm as slow or weakly motile. This program correctly classifies sperm motility into one of five classes with an overall accuracy of 89.9%. Application of CASAnova to capacitating sperm populations showed a shift from predominantly linear patterns of motility at initial time points to more vigorous patterns, including hyperactivated motility, as capacitation proceeds. Both intermediate and hyperactivated motility patterns were largely eliminated when sperm were incubated in noncapacitating medium, demonstrating the sensitivity of this method. The five CASAnova classifications are distinctive and reflect kinetic parameters of washed human sperm, providing an accurate, quantitative, and high-throughput method for monitoring alterations in motility. © The Authors 2017. Published by Oxford University Press on behalf of Society for the Study of Reproduction. All rights reserved. For permissions, please e-mail: journals.permissions@oup.com.

Contemporary and future insights into fertility preservation in male cancer patients

PubMed Central

Ong, Chloe; Durairajanayagam, Damayanthi

2014-01-01

In recent years, survival rates of cancer patients have increased, resulting in a shift of focus from quantity to quality of life. A key aspect of quality of life is fertility potential; patients suffering from iatrogenic infertility often become depressed. Since many cancer therapies—chemotherapy, radiotherapy and/or surgery—and even cancer itself have detrimental effects on the male reproductive system, it is important to preserve fertility before any treatment commences. Currently, the only reliable method of male fertility preservation is sperm banking. For patients who are unable to provide semen samples by the conventional method of masturbation, there are other techniques such as electroejaculation, microsurgical epididymal sperm aspiration and testicular sperm extraction that can be employed. Unfortunately, it is presently impossible to preserve the fertility potential of pre-pubertal patients. Due to the increasing numbers of adolescent cancer patients surviving treatment, extensive research is being conducted into several possible methods such as testicular tissue cryopreservation, xenografting, in vitro gamete maturation and even the creation of artificial gametes. However, in spite of its ease, safety, convenience and many accompanying benefits, sperm banking remains underutilized in cancer patients. There are several barriers involved such as the lack of information and the urgency to begin treatment, but various measures can be put in place to overcome these barriers so that sperm banking can be more widely utilized. PMID:26816750

Contemporary and future insights into fertility preservation in male cancer patients.

PubMed

Agarwal, Ashok; Ong, Chloe; Durairajanayagam, Damayanthi

2014-03-01

In recent years, survival rates of cancer patients have increased, resulting in a shift of focus from quantity to quality of life. A key aspect of quality of life is fertility potential; patients suffering from iatrogenic infertility often become depressed. Since many cancer therapies-chemotherapy, radiotherapy and/or surgery-and even cancer itself have detrimental effects on the male reproductive system, it is important to preserve fertility before any treatment commences. Currently, the only reliable method of male fertility preservation is sperm banking. For patients who are unable to provide semen samples by the conventional method of masturbation, there are other techniques such as electroejaculation, microsurgical epididymal sperm aspiration and testicular sperm extraction that can be employed. Unfortunately, it is presently impossible to preserve the fertility potential of pre-pubertal patients. Due to the increasing numbers of adolescent cancer patients surviving treatment, extensive research is being conducted into several possible methods such as testicular tissue cryopreservation, xenografting, in vitro gamete maturation and even the creation of artificial gametes. However, in spite of its ease, safety, convenience and many accompanying benefits, sperm banking remains underutilized in cancer patients. There are several barriers involved such as the lack of information and the urgency to begin treatment, but various measures can be put in place to overcome these barriers so that sperm banking can be more widely utilized.

Optimization of the sperm:oocyte ratio and sperm economy in the artificial reproduction of Rhamdia quelen using fructose as a sperm motility modulator.

PubMed

Adames, Maurício Spagnolo; de Toledo, Cesar Pereira Rebechi; Neumann, Giovano; Buzzi, Alexandre Henrique; Buratto, Cíntia Nara; Piana, Pitágoras Augusto; Bombardelli, Robie Allan

2015-10-01

This research was conducted to evaluate the effects of fructose as a modulator of sperm motility and its effects on the reduction in number of sperm cells in IVF using cryopreserved Rhamdia quelen semen. Sperm activation occurred in solutions containing fructose (0.0, 0.9, 1.8, 2.7, 3.6 and 4.5%). The sperm motility rate, velocity and duration of sperm motility were assessed by polynomial regression analysis and grouped by the principal component analysis (PCA). Then, the oocytes were mixed with semen at proportions of 1×10(4), 3×10(4), 5×10(4), 7×10(4) and 9×10(4) for the sperm:oocyte ratio and fertilization was induced by the activation of gametes with the fructose-containing solutions. The fertilization, hatching and larval normality rate were evaluated by response surface protocol and were further grouped by PCA. All sperm variables were affected by the activating solutions, and the most desirable theoretical results for the rate of sperm motility were obtained when using a solution containing 2.85% fructose. In the IVF and incubation assays, there was an interactive effect between the motile sperm:oocyte ratio and the fructose concentration on the rates of oocyte fertilization, hatching and on the clustered index for reproductive success. The results suggest the possibility of reducing the sperm cells on IVF by 17.77% when using a solution containing 2.28% fructose. In conclusion, the use of solutions containing fructose at concentrations that maximize sperm movement allow the reduction of the motile sperm:oocyte ratio, thus promoting sperm metabolic efficiencies and contributing to the feasibility of using cryopreserved semen at a large-scale in IVF. Copyright © 2015 Elsevier B.V. All rights reserved.

Calcium Influx and Male Fertility in the Context of the Sperm Proteome: An Update

PubMed Central

Rahman, Md Saidur; Kwon, Woo-Sung; Pang, Myung-Geol

2014-01-01

Freshly ejaculated spermatozoa are incapable or poorly capable of fertilizing an oocyte. The fertilization aptness of spermatozoa depends on the appropriate and time-dependent acquisition of hyperactivation, chemotaxis, capacitation, and the acrosome reaction, where calcium (Ca2+) is extensively involved in almost every step. A literature review showed that several ion channel proteins are likely responsible for regulation of the Ca2+ uptake in spermatozoa. Therefore, manipulation of the functions of channel proteins is closely related to Ca2+ influx, ultimately affecting male fertility. Recently, it has been shown that, together with different physiological stimuli, protein-protein interaction also modifies the Ca2+ influx mechanism in spermatozoa. Modern proteomic analyses have identified several sperm proteins, and, therefore, these findings might provide further insight into understanding the Ca2+ influx, protein functions, and regulation of fertility. The objective of this review was to synthesize the published findings on the Ca2+ influx mechanism in mammalian spermatozoa and its implications for the regulation of male fertility in the context of sperm proteins. Finally, Pathway Studio (9.0) was used to catalog the sperm proteins that regulate the Ca2+ influx signaling by using the information available from the PubMed database following a MedScan Reader (5.0) search. PMID:24877140

A novel test of the phenotype-linked fertility hypothesis reveals independent components of fertility.

PubMed Central

Pizzari, Tommaso; Jensen, Per; Cornwallis, Charles K.

2004-01-01

The phenotype-linked fertility hypothesis predicts that male sexual ornaments signal fertilizing efficiency and that the coevolution of male ornaments and female preference for such ornaments is driven by female pursuit of fertility benefits. In addition, directional testicular asymmetry frequently observed in birds has been suggested to reflect fertilizing efficiency and to covary with ornament expression. However, the idea of a phenotypic relationship between male ornaments and fertilizing efficiency is often tested in populations where environmental effects mask the underlying genetic associations between ornaments and fertilizing efficiency implied by this idea. Here, we adopt a novel design, which increases genetic diversity through the crossing of two divergent populations while controlling for environmental effects, to test: (i) the phenotypic relationship between male ornaments and both, gonadal (testicular mass) and gametic (sperm quality) components of fertilizing efficiency; and (ii) the extent to which these components are phenotypically integrated in the fowl, Gallus gallus. We show that consistent with theory, the testosterone-dependent expression of a male ornament, the comb, predicted testicular mass. However, despite their functional inter-dependence, testicular mass and sperm quality were not phenotypically integrated. Consistent with this result, males of one parental population invested more in testicular and comb mass, whereas males of the other parental population had higher sperm quality. We found no evidence that directional testicular asymmetry covaried with ornament expression. These results shed new light on the evolutionary relationship between male fertilizing efficiency and ornaments. Although testosterone-dependent ornaments may covary with testicular mass and thus reflect sperm production rate, the lack of phenotypic integration between gonadal and gametic traits reveals that the expression of an ornament is unlikely to reflect the overall fertilizing efficiency of a male. PMID:15002771

Effects of Saikokaryukotsuboreito on Spermatogenesis and Fertility in Aging Male Mice.

PubMed

Zang, Zhi-Jun; Ji, Su-Yun; Zhang, Ya-Nan; Gao, Yong; Zhang, Bin

2016-04-05

Aspermia caused by exogenous testosterone limit its usage in late-onset hypogonadism (LOH) patients desiring fertility. Saikokaryukotsuboreito (SKRBT) is reported to improve serum testosterone and relieve LOH-related symptoms. However, it is unclear whether SKRBT affects fertility. We aimed to examine the effects of SKRBT on spermatogenesis and fertility in aging male mice. Thirty aging male mice were randomly assigned to three groups. Mice were orally administered with phosphate-buffer solution or SKRBT (300 mg/kg, daily) or received testosterone by subcutaneous injections (10 mg/kg, every 3 days). Thirty days later, each male mouse was mated with two female mice. All animals were sacrificed at the end of 90 days. Intratesticular testosterone (ITT) levels, quality of sperm, expression of synaptonemal complex protein 3 (SYCP3), and fertility were assayed. In the SKRBT-treated group, ITT, quality of sperm, and expression of SYCP3 were all improved compared with the control group (ITT: 85.50 ± 12.31 ng/g vs. 74.10 ± 11.45 ng/g, P = 0.027; sperm number: [14.94 ± 4.63] × 106 cells/ml vs. [8.79 ± 4.38] × 106 cells/ml, P = 0.002; sperm motility: 43.16 ± 9.93% vs. 33.51 ± 6.98%, P = 0.015; the number of SYCP3-positive cells/tubule: 77.50 ± 11.01 ng/ml vs. 49.30 ± 8.73 ng/ml, P < 0.001; the expression of SYCP3 protein: 1.23 ± 0.09 vs. 0.84 ± 0.10, P < 0.001), but fertility was not significantly changed (P > 0.05, respectively). In the testosterone-treated group, ITT, quality of sperm, and expression of SYCP3 were markedly lower than the control group (ITT: 59.00 ± 8.67, P = 0.005; sperm number: [4.34 ± 2.45] × 106 cells/ml, P = 0.018; sperm motility: 19.53 ± 7.69%, P = 0.001; the number of SYCP3-positive cells/tubule: 30.00 ± 11.28, P < 0.001; the percentage of SYCP3-positive tubules/section 71.98 ± 8.88%, P = 0.001; the expression of SYCP3 protein: 0.71 ± 0.09, P < 0.001), and fertility was also suppressed (P < 0.05, respectively). SKRBT had no adverse effect on fertility potential in aging male mice.

Semen amyloids participate in spermatozoa selection and clearance.

PubMed

Roan, Nadia R; Sandi-Monroy, Nathallie; Kohgadai, Nargis; Usmani, Shariq M; Hamil, Katherine G; Neidleman, Jason; Montano, Mauricio; Ständker, Ludger; Röcker, Annika; Cavrois, Marielle; Rosen, Jared; Marson, Kara; Smith, James F; Pilcher, Christopher D; Gagsteiger, Friedrich; Sakk, Olena; O'Rand, Michael; Lishko, Polina V; Kirchhoff, Frank; Münch, Jan; Greene, Warner C

2017-06-27

Unlike other human biological fluids, semen contains multiple types of amyloid fibrils in the absence of disease. These fibrils enhance HIV infection by promoting viral fusion to cellular targets, but their natural function remained unknown. The similarities shared between HIV fusion to host cell and sperm fusion to oocyte led us to examine whether these fibrils promote fertilization. Surprisingly, the fibrils inhibited fertilization by immobilizing sperm. Interestingly, however, this immobilization facilitated uptake and clearance of sperm by macrophages, which are known to infiltrate the female reproductive tract (FRT) following semen exposure. In the presence of semen fibrils, damaged and apoptotic sperm were more rapidly phagocytosed than healthy ones, suggesting that deposition of semen fibrils in the lower FRT facilitates clearance of poor-quality sperm. Our findings suggest that amyloid fibrils in semen may play a role in reproduction by participating in sperm selection and facilitating the rapid removal of sperm antigens.

Some Reflections on Intracytoplasmic Morphologically Selected Sperm Injection

PubMed Central

Ebner, Thomas; Shebl, Omar; Oppelt, Peter; Mayer, Richard Bernhard

2014-01-01

Although intracytoplasmic sperm injection (ICSI) allows proper fertilization in most cases of male sub fertility, it is one of the most unphysiological techniques in assisted reproductive technologies (ART). Thus, over the last decade, researchers have tried to improve sperm observation with higher-resolution microscopy techniques such as the intracytoplasmic morphologically selected sperm injection (IMSI) technique. In order to identify literatures for this review, the PubMed database was searched from 2000 onwards using the terms IMSI, motile sperm organelle morphology examination (MSOME) and sperm vacuole. Approximately 10 years after the introduction of the MSOME and IMSI procedures, several questions related to the prevalence, origin, location, and clinical consequences of sperm vacuoles have not yet been clarified. It seems that IMSI as a routine application is not state of the art and the only confirmed indications for IMSI are recurrent implantation failure following ICSI and severe male factor. PMID:25083173

Some reflections on intracytoplasmic morphologically selected sperm injection.

PubMed

Ebner, Thomas; Shebl, Omar; Oppelt, Peter; Mayer, Richard Bernhard

2014-07-01

Although intracytoplasmic sperm injection (ICSI) allows proper fertilization in most cases of male sub fertility, it is one of the most unphysiological techniques in assisted reproductive technologies (ART). Thus, over the last decade, researchers have tried to improve sperm observation with higher-resolution microscopy techniques such as the intracytoplasmic morphologically selected sperm injection (IMSI) technique. In order to identify literatures for this review, the PubMed database was searched from 2000 onwards using the terms IMSI, motile sperm organelle morphology examination (MSOME) and sperm vacuole. Approximately 10 years after the introduction of the MSOME and IMSI procedures, several questions related to the prevalence, origin, location, and clinical consequences of sperm vacuoles have not yet been clarified. It seems that IMSI as a routine application is not state of the art and the only confirmed indications for IMSI are recurrent implantation failure following ICSI and severe male factor.

The Different Calcium+2 Intensity Profile and Quality of Oocyte and Goat Sperms after Cryopreservation

NASA Astrophysics Data System (ADS)

Ciptadi, G.; Rahayu, S.; Fatchiyah; Wahyuningsih, S.; Budiarto, A.; Nasich, M.; Putri, A. R. I.; Mudawamah, M.; Ihsan, M. N.

2018-02-01

This research aims were to study the effect of the oocyte and sperms cryopreservation of Indonesian local goat on the post-thawing quality and profile or characters of Calcium+2 intensity in relating with their fertility capacity. A study was conducted to test the freezing method and post-thawing viability both stock cells stored in the deep freezer and liquid nitrogen (-80°C of vs -196°C). A fertility test of sperms has been conducted through in vitro of sperm quality, while the oocytes cryopreserved test was done by in vitro maturation (IVM) rate (%). The profile of Calcium 2+ was performed and analysis by Confocal Laser Scanned Microscope (CLSM). The result showed that IVM rate of goat oocyte is considered lower when cryopreserved in -80°C than in -196°C. Meanwhile, sperm is considered having a good quality in 2 methods of cryopreservation with post-thawing motility > 40 % (SNI 2014). There is an important difference between Calcium intensity of fresh and post-thawing both for oocyte and spermatozoa. Calcium +2 profiles is varied individually on the peak of intensity, but it considered expressed the same profile of each fresh and post-thawing cell. In vitro fertilization test need to be performed to complete the viability and fertility competence of these sperm and oocyte freezing stocks.

Aflatoxin B1 impairs sperm quality and fertilization competence.

PubMed

Komsky-Elbaz, A; Saktsier, M; Roth, Z

2018-01-15

Aflatoxins are poisonous byproducts of the soilborne fungus Aspergillus, involved in the decomposition of plant materials. Aflatoxins can be found in various food products, such as maize, sorghum, millet, rice and wheat. AFB1 is the most toxic of these, classified as a carcinogen and mutagen for both humans and animals. AFB1 has been detected in human cord blood and placenta; however, its toxic effect on sperm is less known. The current study examines sperm responses associated with AFB1 exposure. These included acrosome integrity and function, mitochondrial polarity, DNA fragmentation, fertilization competence and early embryonic development. Spermatozoa were obtained from bull ejaculate and epididymis and capacitated in vitro for 4h with 0, 0.1, 1, 10 and 100μM AFB1. Following capacitation, acrosome reaction (AR) was induced by Ca 2+ ionophore. The integrity and functionality of sperm were examined simultaneously by florescent staining. A Halosperm DNA fragmentation kit was used to evaluate DNA integrity. An in-vitro culture system was used to evaluate fertilization competence and blastocyst formation rate, using bovine oocytes. Findings indicate dose-responsive variation among compartments to AFB1 exposure. Sperm viability, expressed by integrity of the plasma membrane, was lower in sperm isolated from ejaculate or epididymis after culturing with AFB1. Exposure to AFB1 reduced the proportion of sperm from the epididymis tail undergoing acrosome reaction induced by Ca 2+ ionophore. AFB1 impaired mitochondrial membrane potential (ΔYm) in sperm isolated from ejaculate and the epididymis tail. Exposing ejaculated sperm to AFB1 increased the proportion of sperm with fragmented DNA and reduced the proportion of embryos that cleaved to the 2- to 4-cell stage, 42h postfertilization, however, the proportion of embryos that developed to blastocysts, 7days postfertilization, did not differ among groups. The findings explore the harmful effects of AFB1 on sperm viability, ΔΨm and DNA integrity associated with fertility competence. We postulate that AFB1-induced fragmentation in paternal DNA might have a carryover effect on the quality of developing embryos. Further evaluation for the quality of blastocysts derived from sperm exposed to AFB1 is warranted. Copyright © 2017 Elsevier B.V. All rights reserved.

Sperm chromatin alterations in fertile and subfertile bulls.

PubMed

Souza, Elisson Terêncio; Silva, Cláudio Vieira; Travençolo, Bruno Augusto Nassif; Alves, Benner Geraldo; Beletti, Marcelo Emílio

2018-06-01

Alterations in sperm chromatin have been related with subfertility in several mammals. In this study, chromatin alteration types (Base, Basal half, Central axis, Dispersed, and Whole) were assessed by toluidine blue (TB) staining, 6-diamidino-2-fenilindole (DAPI) and anti-protamine 1 antibody (anti-PR1) labeling in sperm samples of fertile and subfertile bulls. Semen samples were obtained from bulls kept in Artificial Insemination Center (fertile bulls) or from bulls subjected to scrotal insulation (subfertile bulls). The percentage of chromatin alterations identified by TB was similar (P > 0.05) in semen samples of fertile and subfertile bulls. In contrast, a greater (P < 0.01) chromatin decondensation and heterogeneity were recorded in semen samples of subfertile bulls. In DAPI and anti-PR1 methods, the subfertile bulls samples had a higher (P < 0.05) percentage of alteration in the base as well as overall chromatin alterations (P < 0.05). Moreover, the chromatin alterations recorded with TB, DAPI, and anti-PR1 were compared in semen samples of fertile and subfertile bulls. In fertile bulls, the overall chromatin alterations were similar (P > 0.05) among the methods In contrast, semen samples of subfertile bulls had a higher (P < 0.05) percentage of overall chromatin alterations when labeled with DAPI. In conclusion, our findings shown that all dye tested had specific sperm stainability and can be feasible to monitor subfertility condition in bulls. Also, different chromatin alteration types in sperm samples of fertile and suberftile bulls were recorded. Copyright © 2018 Society for Biology of Reproduction & the Institute of Animal Reproduction and Food Research of Polish Academy of Sciences in Olsztyn. Published by Elsevier B.V. All rights reserved.

Seasonal functional relevance of sperm characteristics in equine spermatozoa.

PubMed

Gamboa, S; Rodrigues, A S; Henriques, L; Batista, C; Ramalho-Santos, J

2010-04-15

A group of stallions with different reproductive indexes were used to study seasonal variations in sperm quality (Equus caballus). Semen samples were collected from late September to July and analyzed according to four seasonal periods: late September-December, January-March, late March-May, and June-July. Parameters monitored included sperm concentration, sperm motility, sperm morphology, sperm viability, acrosomal status, plasma membrane stability, and sperm mitochondrial membrane potential. Overall, seminal parameters monitored are affected mostly by time period, followed by animal and lastly by fertility, stressing the importance of individual variations in out-bred animal models. The analysis of multiple ejaculates from the same animals showed clear seasonal-based differences (P<0.05) with poor semen quality in winter and a noticeable improvement in sperm quality with increasing photoperiod. Better semen quality was observed between late March and May. Interactions between month period, animal, and fertility were evident (P<0.05) for sperm concentration, head and tail sperm anomalies, and acrosomal integrity. Thus, it may be advisable to adjust the use of stallion semen according to seasonal variations. Copyright 2010 Elsevier Inc. All rights reserved.

Testing the phenotype-linked fertility hypothesis in the presence and absence of inbreeding.

PubMed

Forstmeier, W; Ihle, M; Opatová, P; Martin, K; Knief, U; Albrechtová, J; Albrecht, T; Kempenaers, B

2017-05-01

The phenotype-linked fertility hypothesis suggests that females can judge male fertility by inspecting male phenotypic traits. This is because male sexually selected traits might correlate with sperm quality if both are sensitive to factors that influence male condition. A recent meta-analysis found little support for this hypothesis, suggesting little or no shared condition dependence. However, we recently reported that in captive zebra finches (Taeniopygia guttata) inbreeding had detrimental effects both on phenotypic traits and on measures of sperm quality, implying that variation in inbreeding could induce positive covariance between indicator traits and sperm quality. Therefore, we here assess empirically the average strength of correlations between phenotypic traits (courtship rate, beak colour, tarsus length) and measures of sperm quality (proportion of functional sperm, sperm velocity, sperm length) in populations of only outbred individuals and in mixed populations consisting of inbreds (F = 0.25) and outbreds (F = 0). As expected, phenotype sperm-trait correlations were stronger when the population contained a mix of inbred and outbred individuals. We also found unexpected heterogeneity between our two study populations, with correlations being considerably stronger in a domesticated population than in a recently wild-derived population. Correlations ranged from essentially zero among outbred-only wild-derived birds (mean Fisher's Zr ± SE = 0.03 ± 0.10) to moderately strong among domesticated birds of mixed inbreeding status (Zr ± SE = 0.38 ± 0.08). Our results suggest that, under some conditions, the phenotype-linked fertility hypothesis might apply. © 2017 European Society For Evolutionary Biology. Journal of Evolutionary Biology © 2017 European Society For Evolutionary Biology.

The Effect of Folate and Folate Plus Zinc Supplementation on Endocrine Parameters and Sperm Characteristics in Sub-Fertile Men: A Systematic Review and Meta-Analysis.

PubMed

Irani, Morvarid; Amirian, Malihe; Sadeghi, Ramin; Lez, Justine Le; Latifnejad Roudsari, Robab

2017-08-29

To evaluate the effect of folate and folate plus zinc supplementation on endocrine parameters and sperm characteristics in sub fertile men. We conducted a systematic review and meta-analysis. Electronic databases of Medline, Scopus , Google scholar and Persian databases (SID, Iran medex, Magiran, Medlib, Iran doc) were searched from 1966 to December 2016 using a set of relevant keywords including "folate or folic acid AND (infertility, infertile, sterility)".All available randomized controlled trials (RCTs), conducted on a sample of sub fertile men with semen analyses, who took oral folic acid or folate plus zinc, were included. Data collected included endocrine parameters and sperm characteristics. Statistical analyses were done by Comprehensive Meta-analysis Version 2. In total, seven studies were included. Six studies had sufficient data for meta-analysis. "Sperm concentration was statistically higher in men supplemented with folate than with placebo (P < .001)". However, folate supplementation alone did not seem to be more effective than the placebo on the morphology (P = .056) and motility of the sperms (P = .652). Folate plus zinc supplementation did not show any statistically different effect on serum testosterone (P = .86), inhibin B (P = .84), FSH (P = .054), and sperm motility (P = .169) as compared to the placebo. Yet, folate plus zinc showed statistically higher effect on the sperm concentration (P < .001), morphology (P < .001), and serum folate level (P < .001) as compared to placebo. Folate plus zinc supplementation has a positive effect on sperm characteristics in sub fertile men. However, these results should be interpreted with caution due to the important heterogeneity of the studies included in this meta-analysis. Further trials are still needed to confirm the current findings.

The fertilization ability and developmental competence of bovine oocytes grown in vitro

PubMed Central

MAKITA, Miho; UEDA, Mayuko; MIYANO, Takashi

2016-01-01

In vitro growth culture systems for oocytes are being developed in several mammalian species. In these growth culture systems, in vitro grown oocytes usually have lower blastocyst formation than in vivo grown oocytes after in vitro fertilization. Furthermore, there have been a few reports that investigated the fertilization ability of in vitro grown oocytes in large animals. The purpose of this study was to investigate the fertilization process and developmental competence of bovine oocytes grown in vitro. Oocyte-granulosa cell complexes collected from bovine early antral follicles (0.4−0.7 mm in diameter) were cultured for growth with 17β-estradiol and androstenedione for 14 days and matured in vitro. These oocytes were then inseminated for 6 or 12 h, and further cultured for development up to 8 days in vitro. After growth culture, oocytes grew from 95 µm to around 120 µm and acquired maturation competence (79%). Although fertilization rates of in vitro grown oocytes were low after 6 h of insemination, 34% of in vitro grown oocytes fertilized normally after 12 h of insemination, having two polar bodies and two pronuclei with a sperm tail, and 22% of these oocytes developed into blastocysts after 8 days of culture. The fertilization and blastocyst formation rates were similar to those of in vivo grown oocytes. In addition, blastocyst cell numbers were also similar between in vitro and in vivo grown oocytes. In conclusion, in vitro grown bovine oocytes are similar to in vivo grown oocytes in fertilization ability and can develop into blastocysts. PMID:27151093

The fertilization ability and developmental competence of bovine oocytes grown in vitro.

PubMed

Makita, Miho; Ueda, Mayuko; Miyano, Takashi

2016-08-25

In vitro growth culture systems for oocytes are being developed in several mammalian species. In these growth culture systems, in vitro grown oocytes usually have lower blastocyst formation than in vivo grown oocytes after in vitro fertilization. Furthermore, there have been a few reports that investigated the fertilization ability of in vitro grown oocytes in large animals. The purpose of this study was to investigate the fertilization process and developmental competence of bovine oocytes grown in vitro. Oocyte-granulosa cell complexes collected from bovine early antral follicles (0.4-0.7 mm in diameter) were cultured for growth with 17β-estradiol and androstenedione for 14 days and matured in vitro. These oocytes were then inseminated for 6 or 12 h, and further cultured for development up to 8 days in vitro. After growth culture, oocytes grew from 95 µm to around 120 µm and acquired maturation competence (79%). Although fertilization rates of in vitro grown oocytes were low after 6 h of insemination, 34% of in vitro grown oocytes fertilized normally after 12 h of insemination, having two polar bodies and two pronuclei with a sperm tail, and 22% of these oocytes developed into blastocysts after 8 days of culture. The fertilization and blastocyst formation rates were similar to those of in vivo grown oocytes. In addition, blastocyst cell numbers were also similar between in vitro and in vivo grown oocytes. In conclusion, in vitro grown bovine oocytes are similar to in vivo grown oocytes in fertilization ability and can develop into blastocysts.

Evaluation of human sperm chromatin status after selection using a modified Diff-Quik stain indicates embryo quality and pregnancy outcomes following in vitro fertilization.

PubMed

Tavares, R S; Silva, A F; Lourenço, B; Almeida-Santos, T; Sousa, A P; Ramalho-Santos, J

2013-11-01

Sperm chromatin/DNA damage can be measured by a variety of assays. However, it has been reported that these tests may lose prognostic value in Assisted Reproductive Technology (ART) cycles when assessed in post-prepared samples, possibly due to the normalizing effect promoted by sperm preparation procedures. We have recently implemented a modified version of the Diff-Quik staining assay that allows for the evaluation of human sperm chromatin status in native samples, together with standard sperm morphology assessment. However, the value of this parameter in terms of predicting in vitro fertilization (IVF) and Intracytoplasmic sperm injection (ICSI) outcomes after sperm selection is unknown. In this study, data from 138 couples undergoing in vitro fertilization (IVF) or Intracytoplasmic sperm injection (ICSI) treatments showed that sperm chromatin integrity was significantly improved after density gradient centrifugation and swim up (p < 0.001), but no correlations were found with fertilization or embryo development rates (p > 0.05). However, sperm samples presenting lower percentages of damaged chromatin were associated with better quality (Grade I) embryos in both ART procedures (p < 0.05) and clinical pregnancy among IVF couples (p < 0.05). Furthermore, regression analysis confirmed the clinical value of Diff-Quik staining in predicting IVF (but not ICSI) clinical pregnancy (OR: 0.927, 95% CI: 0.871-0.985, p = 0.015), and a threshold value of 34.25% for this parameter was established. The proportion of IVF couples achieving a clinical pregnancy was reduced 1.9-fold when the percentage of abnormal dark staining was ≥34.25% (p = 0.05). In conclusion, the Diff-Quik staining assay provides useful information regarding ART success, particularly in IVF cycles, where some degree of 'natural' sperm selection may occur; but not in ICSI, where sperm selection is operator dependent. This quick and low-cost assay is suggested as an alternative method to detect sperm chromatin status in minimal clinical settings, when no other well-established and robust assays (e.g. Sperm chromatin structure assay, terminal deoxynucleotidyl transferase-mediated dUDP nick-end labelling) are available. © 2013 American Society of Andrology and European Academy of Andrology.

Elevated aminopeptidase N affects sperm motility and early embryo development

PubMed Central

Ryu, Do-Yeal; Kwon, Woo-Sung

2017-01-01

Aminopeptidase N (APN) is a naturally occurring ectopeptidase present in mammalian semen. Previous studies have demonstrated that APN adversely affects male fertility through the alteration of sperm motility. This enzyme constitutes 0.5 to 1% of the seminal plasma proteins, which can be transferred from the prostasomes to sperms by a fusion process. In the present study, we investigated the molecular mechanism of action of APN and its role in regulating sperm functions and male fertility. In this in vitro study, epididymal mouse spermatozoa were incubated in a capacitating media (pH 7) containing 20 ng/mL of recombinant mouse APN for 90 min. Our results demonstrated that the supplementation of recombinant APN in sperm culture medium significantly increased APN activity, and subsequently altered motility, hyperactivated motility, rapid and medium swimming speeds, viability, and the acrosome reaction of mouse spermatozoa. These effects were potentially caused by increased toxicity in the spermatozoa. Further, altered APN activity in sperm culture medium affected early embryonic development. Interestingly, the effect of elevated APN activity in sperm culture medium was independent of protein tyrosine phosphorylation and protein kinase A activity. On the basis of these results, we concluded that APN plays a significant role in the regulation of several sperm functions and early embryonic development. In addition, increased APN activity could potentially lead to several adverse consequences related to male fertility. PMID:28859152

Beneficial effect of extracellular adenosine 5'-triphosphate treatment on the Indochinese leopard (Panthera pardus delacouri) sperm quality after cryopreservation.

PubMed

Thuwanut, P; Tipkantha, W; Siriaroonrat, B; Comizzoli, P; Chatdarong, K

2017-04-01

The Indochinese leopard (Panthera pardus delacouri) population, included in CITES Appendix I, has been declining for decades. Proper gamete preservation condition is critical for breeding programme management using artificial insemination or in vitro fertilization (IVF). The present study aimed at investigating the impact of post-thawing treatment of leopard semen with extracellular adenosine 5'-triphosphate (ATPe) on sperm quality (including morphological traits and ability to fertilize an oocyte). Semen from six adult male leopards was collected by electroejaculation (one ejaculation per cat). After the evaluation of the fresh sample quality, the semen was cryopreserved (10 × 10 6 cells per straw; two straws per cat). After thawing, the sperm sample from the first straw of each cat was divided into three aliquots: control (no ATPe), supplemented with 1.0 or 2.5 mM ATPe that were evaluated for sperm quality at 10, 30 min and 3 hr post-thawing. The sperm sample from the second straw, supplemented with 0, 1.0 or 2.5 mM ATPe for 30 min, was assessed for IVF with domestic cat oocytes. Sperm quality (all metrics) was negatively affected by the cryopreservation process (p ≤ .05). However, the percentage of sperm motility, level of progressive motility and percentage of plasma membrane integrity did not differ (p > .05) among post-thawing groups. The sperm mitochondrial membrane potential was enhanced (p ≤ .05) by ATPe treatment (1.0 and 2.5 mM; 10 min to 3 hr of incubation). Furthermore, incubation of ATPe (1.0 and 2.5 mM) for 30 min could promote sperm velocity patterns (curvilinear velocity; VCL and straight line velocity; VSL) (p ≤ .05). The percentage of pronuclear formation and cleaved embryos was increased (p ≤ .05) after 1.0 ATPe treatment (49.8 ± 2.8; 45.9 ± 1.5) compared to 0 mM (41.4 ± 3.3; 38.9 ± 0.5) whereas the number of sperm binding/oocyte did not significantly differ among groups. In summary, we suggest that ATPe activated the velocity of Indochinese leopard sperm motility that may lead to faster sperm/oocyte binding and sperm penetration (factors of successful embryo development). © 2016 Blackwell Verlag GmbH.

Artificial insemination with frozen-thawed boar sperm.

PubMed

Yeste, Marc; Rodríguez-Gil, Joan E; Bonet, Sergi

2017-09-01

Artificial insemination with frozen-thawed semen in pigs is not a routine technique; its use is restricted to specific cases, such as preservation of valuable genetic material (germplasm banks), safety strategies in case of natural disasters, long-distance transport of sperm, and in combination with sex-sorting. Cryoinjuries resulting from freeze-thawing protocols are a major concern with regard to the fertilization capacity of the treated sperm, which is lower than that of liquid-stored semen. Here, we provide an overview of artificial insemination using cryopreserved sperm, and summarize the factors that influence cryopreservation success before, during, and after freeze-thaw (i.e., sperm selection before starting the cryopreservation process, holding time, use of cryoprotectants, and rates of freezing and thawing) and that are driving the identification of biomarkers to predict sensitivity to cryodamage. Three different artificial insemination techniques (conventional or intracervical; intrauterine; and deep intrauterine) are also discussed with regards to their relevance when using frozen-thawed semen. Finally, we review the use of additives to freezing and thawing media, given reports that they may maintain and improve the quality and fertilizing capacity of frozen-thawed sperm. In sum, artificial insemination with frozen-thawed boar sperm can provide reasonable fertility outcomes, if freezable ejaculates, specific additives, and appropriate insemination techniques are used. © 2017 Wiley Periodicals, Inc.

Validation of the sperm class analyser CASA system for sperm counting in a busy diagnostic semen analysis laboratory.

PubMed

Dearing, Chey G; Kilburn, Sally; Lindsay, Kevin S

2014-03-01

Sperm counts have been linked to several fertility outcomes making them an essential parameter of semen analysis. It has become increasingly recognised that Computer-Assisted Semen Analysis (CASA) provides improved precision over manual methods but that systems are seldom validated robustly for use. The objective of this study was to gather the evidence to validate or reject the Sperm Class Analyser (SCA) as a tool for routine sperm counting in a busy laboratory setting. The criteria examined were comparison with the Improved Neubauer and Leja 20-μm chambers, within and between field precision, sperm concentration linearity from a stock diluted in semen and media, accuracy against internal and external quality material, assessment of uneven flow effects and a receiver operating characteristic (ROC) analysis to predict fertility in comparison with the Neubauer method. This work demonstrates that SCA CASA technology is not a standalone 'black box', but rather a tool for well-trained staff that allows rapid, high-number sperm counting providing errors are identified and corrected. The system will produce accurate, linear, precise results, with less analytical variance than manual methods that correlate well against the Improved Neubauer chamber. The system provides superior predictive potential for diagnosing fertility problems.

Involvement of a Na+/HCO-3 cotransporter in mouse sperm capacitation.

PubMed

Demarco, Ignacio A; Espinosa, Felipe; Edwards, Jennifer; Sosnik, Julian; De La Vega-Beltran, Jose Luis; Hockensmith, Joel W; Kopf, Gregory S; Darszon, Alberto; Visconti, Pablo E

2003-02-28

Mammalian sperm are incapable of fertilizing eggs immediately after ejaculation; they acquire fertilization capacity after residing in the female tract for a finite period of time. The physiological changes sperm undergo in the female reproductive tract that render sperm able to fertilize constitute the phenomenon of "sperm capacitation." We have demonstrated that capacitation is associated with an increase in the tyrosine phosphorylation of a subset of proteins and that these events are regulated by an HCO(3)(-)/cAMP-dependent pathway involving protein kinase A. Capacitation is also accompanied by hyperpolarization of the sperm plasma membrane. Here we present evidence that, in addition to its role in the regulation of adenylyl cyclase, HCO(3)(-) has a role in the regulation of plasma membrane potential in mouse sperm. Addition of HCO(3)(-) but not Cl(-) induces a hyperpolarizing current in mouse sperm plasma membranes. This HCO(3)(-)-dependent hyperpolarization was not observed when Na(+) was replaced by the non-permeant cation choline(+). Replacement of Na(+) by choline(+) also inhibited the capacitation-associated increase in protein tyrosine phosphorylation as well as the zona pellucida-induced acrosome reaction. The lack of an increase in protein tyrosine phosphorylation was overcome by the presence of cAMP agonists in the incubation medium. The lack of a hyperpolarizing HCO(3)(-) current and the inhibition of the capacitation-dependent increase in protein tyrosine phosphorylation in the absence of Na(+) suggest that a Na(+)/HCO(3)(-) cotransporter is present in mouse sperm and is coupled to events regulating capacitation.

Paper-Based Quantification of Male Fertility Potential.

PubMed

Nosrati, Reza; Gong, Max M; San Gabriel, Maria C; Pedraza, Claudio E; Zini, Armand; Sinton, David

2016-03-01

More than 70 million couples worldwide are affected by infertility, with male-factor infertility accounting for about half of the cases. Semen analysis is critical for determining male fertility potential, but conventional testing is costly and complex. Here, we demonstrate a paper-based microfluidic approach to quantify male fertility potential, simultaneously measuring 3 critical semen parameters in 10 min: live and motile sperm concentrations and sperm motility. The device measures the colorimetric change of yellow tetrazolium dye to purple formazan by the diaphorase flavoprotein enzyme present in metabolically active human sperm to quantify live and motile sperm concentration. Sperm motility was determined as the ratio of motile to live sperm. We assessed the performance of the device by use of clinical semen samples, in parallel with standard clinical approaches. Detection limits of 8.46 and 15.18 million/mL were achieved for live and motile sperm concentrations, respectively. The live and motile sperm concentrations and motility values from our device correlated with those of the standard clinical approaches (R(2) ≥ 0.84). In all cases, our device provided 100% agreement in terms of clinical outcome. The device was also robust and could tolerate conditions of high absolute humidity (22.8 g/m(3)) up to 16 weeks when packaged with desiccant. Our device outperforms existing commercial paper-based assays by quantitatively measuring live and motile sperm concentrations and motility, in only 10 min. This approach is applicable to current clinical practices as well as self-diagnostic applications. © 2015 American Association for Clinical Chemistry.

Understanding the effects of low salinity on fertilization success and early development in the sand dollar Echinarachnius parma.

PubMed

Allen, Jonathan D; Pechenik, Jan A

2010-04-01

Free-spawning marine invertebrates that live near shore or in estuaries may experience reduced fertilization success during low-salinity events. Although several studies have documented reproductive failure at reduced salinity in estuarine animals, few have looked at whether developmental failure is due to a failure of fertilization or to a failure of fertilized eggs to cleave. In this study, we examined the effects of salinities ranging from 18 to 32 psu on fertilization success and early development in the sand dollar Echinarachnius parma. In addition to decoupling the effects of low salinity on fertilization from its effects on early cleavage, we also assessed whether eggs or sperm were the weak link in accounting for reproductive failure. We found that both fertilization and cleavage failed at salinities below about 22 psu but that development could be partially rescued by returning zygotes to full-strength seawater. We also found that sperm remained active and capable of fertilizing eggs even after being exposed to low salinities for 30 min.. Taken together, these results suggest that reproductive failure at low salinities in E. parma is due more to an inability of the fertilized eggs to cleave than to an inability of sperm to fertilize eggs.

Zinc sparks induce physiochemical changes in the egg zona pellucida that prevent polyspermy

DOE Office of Scientific and Technical Information (OSTI.GOV)

Que, Emily L.; Duncan, Francesca E.; Bayer, Amanda R.

During fertilization or chemically-induced egg activation, the mouse egg releases billions of zinc atoms in brief bursts known as ‘zinc sparks.’ The zona pellucida (ZP), a glycoprotein matrix surrounding the egg, is the first structure zinc ions encounter as they diffuse away from the plasma membrane. Following fertilization, the ZP undergoes changes described as ‘hardening’, which prevent multiple sperm from fertilizing the egg and thereby establish a block to polyspermy. A major event in zona hardening is cleavage of ZP2 proteins by ovastacin; however, the overall physiochemical changes contributing to zona hardening are not well understood. Using x-ray fluorescence microscopy,more » transmission and scanning electron microscopy, and biological function assays, we tested the hypothesis that zinc release contributes to ZP hardening. We found that the zinc content in the ZP increases by 300% following activation and that zinc exposure modulates the architecture of the ZP matrix. Importantly, zinc-induced structural changes of the ZP have a direct biological consequence; namely, they reduce the ability of sperm to bind to the ZP. These results provide a paradigm-shifting model in which fertilization-induced zinc sparks contribute to the polyspermy block by altering conformations of the ZP matrix. Finally, this adds a previously unrecognized factor, namely zinc, to the process of ZP hardening.« less

Zinc sparks induce physiochemical changes in the egg zona pellucida that prevent polyspermy

DOE PAGES

Que, Emily L.; Duncan, Francesca E.; Bayer, Amanda R.; ...

2017-01-19

During fertilization or chemically-induced egg activation, the mouse egg releases billions of zinc atoms in brief bursts known as ‘zinc sparks.’ The zona pellucida (ZP), a glycoprotein matrix surrounding the egg, is the first structure zinc ions encounter as they diffuse away from the plasma membrane. Following fertilization, the ZP undergoes changes described as ‘hardening’, which prevent multiple sperm from fertilizing the egg and thereby establish a block to polyspermy. A major event in zona hardening is cleavage of ZP2 proteins by ovastacin; however, the overall physiochemical changes contributing to zona hardening are not well understood. Using x-ray fluorescence microscopy,more » transmission and scanning electron microscopy, and biological function assays, we tested the hypothesis that zinc release contributes to ZP hardening. We found that the zinc content in the ZP increases by 300% following activation and that zinc exposure modulates the architecture of the ZP matrix. Importantly, zinc-induced structural changes of the ZP have a direct biological consequence; namely, they reduce the ability of sperm to bind to the ZP. These results provide a paradigm-shifting model in which fertilization-induced zinc sparks contribute to the polyspermy block by altering conformations of the ZP matrix. Finally, this adds a previously unrecognized factor, namely zinc, to the process of ZP hardening.« less

Sperm dynamics in spiders (Araneae): ultrastructural analysis of the sperm activation process in the garden spider Argiope bruennichi (Scopoli, 1772).

PubMed

Vöcking, Oliver; Uhl, Gabriele; Michalik, Peter

2013-01-01

Storage of sperm inside the female genital tract is an integral phase of reproduction in many animal species. The sperm storage site constitutes the arena for sperm activation, sperm competition and female sperm choice. Consequently, to understand animal mating systems information on the processes that occur from sperm transfer to fertilization is required. Here, we focus on sperm activation in spiders. Male spiders produce sperm whose cell components are coiled within the sperm cell and that are surrounded by a proteinaceous sheath. These inactive and encapsulated sperm are transferred to the female spermathecae where they are stored for later fertilization. We analyzed the ultrastructural changes of sperm cells during residency time in the female genital system of the orb-web spider Argiope bruennichi. We found three clearly distinguishable sperm conditions: encapsulated sperm (secretion sheath present), decapsulated (secretion sheath absent) and uncoiled sperm (cell components uncoiled, presumably activated). After insemination, sperm remain in the encapsulated condition for several days and become decapsulated after variable periods of time. A variable portion of the decapsulated sperm transforms rapidly to the uncoiled condition resulting in a simultaneous occurrence of decapsulated and uncoiled sperm. After oviposition, only decapsulated and uncoiled sperm are left in the spermathecae, strongly suggesting that the activation process is not reversible. Furthermore, we found four different types of secretion in the spermathecae which might play a role in the decapsulation and activation process.

Long-term cryopreservation of sperm from Mandarin fish Siniperca chuatsi.

PubMed

Ding, Shuyan; Ge, Jiachun; Hao, Chen; Zhang, Mingsheng; Yan, Weihui; Xu, Zhiqiang; Pan, Jianlin; Chen, Songlin; Tian, Yongsheng; Huang, Yahong

2009-07-01

In order to develop cryopreservation techniques for long-term preserving the sperm of Mandarin fish Siniperca chuatsi, we examined the effects of various extender and cryopreservation on post-thaw motility. We found the optimal freezing procedures for the Mandarin fish sperm is diluting the semen in D-15 extender, chilling it to 4 degrees C, adding ME2SO to a final concentration of 10% (v/v), then transferring the semen in cryotubes, holding the cryotubes for 10 min at 6 cm (about -180 degrees C) above the surface of liquid nitrogen, for 5 min on the surface of liquid nitrogen, and finally plunged into liquid nitrogen. After thawed at 37 degrees C for 60s, the sperm had the highest post-thaw motility (96.00+/-1.73%). The optimal fertilization procedures for the frozen sperm is mixing the eggs with sperm, then adding 1 ml of swimming medium (SM=45 mM NaCl+5 mM KCl+20mM Tris-HCl, pH 8.0) immediately. At the sperm/egg ratio of 100,000:1, the fertilization rate and the hatching rate of the frozen sperm cryopreserved for 1 week or 1 year in liquid nitrogen (66.01+/-5.14% and 54.76+/-4.40% & 62.97+/-14.28% and 52.58+/-11.17%) were similar to that of fresh sperm (69.42+/-8.11% and 59.82+/-5.27%) (p>0.05). This is the first report that the Mandarin fish (S. chuatsi) sperm can successfully fertilized eggs after long-term cryopreservation.

Male infertility: an overview of causes and treatment options.

PubMed

Leaver, Rachel Busuttil

2016-10-13

It is estimated that 3.5 million people in the UK, that is one in every seven couples, have fertility problems. In the past, it was assumed that the cause always lay with the woman. However, developments in science brought a greater understanding of the process of sperm production and conception. It is now known that up to 30% of fertility problems may be because of the man alone and up to 90% of these are down to low sperm count or low sperm quality or both. This paper offers a review of the causes and potential factors that affect male fertility together with an overview of diagnosis, investigation and current treatment options for these men.

Inhibition of capacitation-associated tyrosine phosphorylation signaling in rat sperm by epididymal protein Crisp-1.

PubMed

Roberts, Kenneth P; Wamstad, Joseph A; Ensrud, Kathy M; Hamilton, David W

2003-08-01

Ejaculated sperm are unable to fertilize an egg until they undergo capacitation. Capacitation results in the acquisition of hyperactivated motility, changes in the properties of the plasma membrane, including changes in proteins and glycoproteins, and acquisition of the ability to undergo the acrosome reaction. In all mammalian species examined, capacitation requires removal of cholesterol from the plasma membrane and the presence of extracellular Ca2+ and HCO3-. We designed experiments to elucidate the conditions required for in vitro capacitation of rat spermatozoa and the effects of Crisp-1, an epididymal secretory protein, on capacitation. Protein tyrosine phosphorylation, a hallmark of capacitation in sperm of other species, occurs during 5 h of in vitro incubation, and this phosphorylation is dependent upon HCO3-, Ca2+, and the removal of cholesterol from the membrane. Crisp-1, which is added to the sperm surface in the epididymis in vivo, is lost during capacitation, and addition of exogenous Crisp-1 to the incubation medium inhibits tyrosine phosphorylation in a dose-dependent manner, thus inhibiting capacitation and ultimately the acrosome reaction. Inhibition of capacitation by Crisp-1 occurs upstream of the production of cAMP by the sperm.

A Specific Transitory Increase in Intracellular Calcium Induced by Progesterone Promotes Acrosomal Exocytosis in Mouse Sperm1

PubMed Central

Romarowski, Ana; Sánchez-Cárdenas, Claudia; Ramírez-Gómez, Héctor V.; Puga Molina, Lis del C.; Treviño, Claudia L.; Hernández-Cruz, Arturo; Darszon, Alberto; Buffone, Mariano G

2016-01-01

During capacitation, sperm acquire the ability to undergo the acrosome reaction (AR), an essential step in fertilization. Progesterone produced by cumulus cells has been associated with various physiological processes in sperm, including stimulation of AR. An increase in intracellular Ca2+ ([Ca2+]i) is necessary for AR to occur. In this study, we investigated the spatiotemporal correlation between the changes in [Ca2+]i and AR in single mouse spermatozoa in response to progesterone. We found that progesterone stimulates an [Ca2+]i increase in five different patterns: gradual increase, oscillatory, late transitory, immediate transitory, and sustained. We also observed that the [Ca2+]i increase promoted by progesterone starts at either the flagellum or the head. We validated the use of FM4-64 as an indicator for the occurrence of the AR by simultaneously detecting its fluorescence increase and the loss of EGFP in transgenic EGFPAcr sperm. For the first time, we have simultaneously visualized the rise in [Ca2+]i and the process of exocytosis in response to progesterone and found that only a specific transitory increase in [Ca2+]i originating in the sperm head promotes the initiation of AR. PMID:26819478

Nanobiotechnologies in the System of Farm Animals' Gene Pool Preservation

NASA Astrophysics Data System (ADS)

Kovtun, S. I.; Galagan, N. P.; Shcherbak, O. V.; Klymenko, N. Y.; Osypchuk, O. S.

It has been determined that sperm viability and mobility upon long storage in liquid nitrogen is being reduced. This issue is relevant for gene pool objects' preservation and for reproductive medicine. The use of nanomaterials (NM) in reproductive biotechnology can expand to the methodology of the rational gene pool preservation technology, especially of valuable biomaterial. Use of nanoparticles, based on ultrafine silica (UFS) with different agents located on its surface gives a positive effect on the thawed sperm mobility, increasing its activity and survival rate and leading to increased fertilization ability. After thawing, the sperm of bulls had an average activity level of 47 %. This activity index of gametes in control was being maintained for 30 min. In the experimental groups after 30 min, the most active gametes were those with UFS + sucrose (52 %). A lower activity compared with the control and UFS + sucrose had gametes with UFS + D-galactosamine. Sperm activity with UFS + D-galactosamine decreased by 14 % compared with the control and by 19 % compared to the UFS + sucrose. So, the feasibility of adding NM with UFS + sucrose at a concentration of 0.001 % to thawed bull sperm that has been cryopreserved for a long time was proved.

Genome-wide analysis identifies changes in histone retention and epigenetic modifications at developmental and imprinted gene loci in the sperm of infertile men.

PubMed

Hammoud, Saher Sue; Nix, David A; Hammoud, Ahmad O; Gibson, Mark; Cairns, Bradley R; Carrell, Douglas T

2011-09-01

The sperm chromatin of fertile men retains a small number of nucleosomes that are enriched at developmental gene promoters and imprinted gene loci. This unique chromatin packaging at certain gene promoters provides these genomic loci the ability to convey instructive epigenetic information to the zygote, potentially expanding the role and significance of the sperm epigenome in embryogenesis. We hypothesize that changes in chromatin packaging may be associated with poor reproductive outcome. Seven patients with reproductive dysfunction were recruited: three had unexplained poor embryogenesis during IVF and four were diagnosed with male infertility and previously shown to have altered protamination. Genome-wide analysis of the location of histones and histone modifications was analyzed by isolation and purification of DNA bound to histones and protamines. The histone-bound fraction of DNA was analyzed using high-throughput sequencing, both initially and following chromatin immunoprecipitation. The protamine-bound fraction was hybridized to agilent arrays. DNA methylation was examined using bisulfite sequencing. Unlike fertile men, five of seven infertile men had non-programmatic (randomly distributed) histone retention genome-wide. Interestingly, in contrast to the total histone pool, the localization of H3 Lysine 4 methylation (H3K4me) or H3 Lysine 27 methylation (H3K27me) was highly similar in the gametes of infertile men compared with fertile men. However, there was a reduction in the amount of H3K4me or H3K27me retained at developmental transcription factors and certain imprinted genes. Finally, the methylation status of candidate developmental promoters and imprinted loci were altered in a subset of the infertile men. This initial genome-wide analysis of epigenetic markings in the sperm of infertile men demonstrates differences in composition and epigenetic markings compared with fertile men, especially at certain imprinted and developmental loci. Although no single locus displays a complete change in chromatin packaging or DNA modification, the data suggest that moderate changes throughout the genome exist and may have a cumulative detrimental effect on fecundity.

Oviductal extracellular vesicles (oviductosomes, OVS) are conserved in humans: murine OVS play a pivotal role in sperm capacitation and fertility.

PubMed

Bathala, Pradeepthi; Fereshteh, Zeinab; Li, Kun; Al-Dossary, Amal A; Galileo, Deni S; Martin-DeLeon, Patricia A

2018-03-01

Are extracellular vesicles (EVs) in the murine oviduct (oviductosomes, OVS) conserved in humans and do they play a role in the fertility of Pmca4-/- females? OVS and their fertility-modulating proteins are conserved in humans, arise via the apocrine pathway, and mediate a compensatory upregulation of PMCA1 (plasma membrane Ca2+-ATPase 1) in Pmca4-/- female mice during proestrus/estrus, to account for their fertility. Recently murine OVS were identified and shown during proestrus/estrus to express elevated levels of PMCA4 which they can deliver to sperm. PMCA4 is the major Ca2+ efflux pump in murine sperm and Pmca4 deletion leads to loss of sperm motility and male infertility as there is no compensatory upregulation of the remaining Ca2+ pump, PMCA1. Of the four family members of PMCAs (PMCA1-4), PMCA1 and PMCA4 are ubiquitous, and to date there have been no reports of one isoform being upregulated to compensate for another in any organ/tissue. Since Pmca4-/- females are fertile, despite the abundant expression of PMCA4 in wild-type (WT) OVS, we propose that OVS serve a role of packaging and delivering to sperm elevated levels of PMCA1 in Pmca4-/- during proestrus/estrus to compensate for PMCA4's absence. Fallopian tubes from pre-menopausal women undergoing hysterectomy were used to study EVs in the luminal fluid. Oviducts from sexually mature WT mice were sectioned after perfusion fixation to detect EVs in situ. Oviducts were recovered from WT and Pmca4-/- after hormonally induced estrus and sectioned for PMCA1 immunofluorescence (IF) (detected with confocal microscopy) and hematoxylin and eosin staining. Reproductive tissues, luminal fluids and EVs were recovered after induced estrus and after natural cycling for western blot analysis of PMCA1 and qRT-PCR of Pmca1 to compare expression levels in WT and Pmca4-/-. OVS, uterosomes, and epididymal luminal fluid were included in the comparisons. WT and Pmca4-/- OVS were analyzed for the presence of known PMCA4 partners in sperm and their ability to interact with PMCA1, via co-immunoprecipitation. In vitro uptake of PMCA1 from OVS was analyzed in capacitated and uncapacitated sperm via quantitative western blot analysis, IF localization and flow cytometry. Caudal sperm were also assayed for uptake of tyrosine-phosphorylated proteins which were shown to be present in OVS. Finally, PMCA1 and PMCA4 in OVS and that delivered to sperm were assayed for enzymatic activity. Human fallopian tubes were flushed to recover luminal fluid which was processed for OVS via ultracentrifugation. Human OVS were negatively stained for transmission electron microscopy (TEM) and subjected to immunogold labeling, to detect PMCA4. Western analysis was used to detect HSC70 (an EV biomarker), PMCA1 and endothelial nitric oxide synthase (eNOS) which is a fertility-modulating protein delivered to human sperm by prostasomes. Oviducts of sexually mature female mice were sectioned after perfusion fixation for TEM tomography to obtain 3D information and to distinguish cross-sections of EVs from those of microvilli and cilia. Murine tissues, luminal fluids and EVs were assayed for PMCA1 (IF and western blot) or qRT-PCR. PMCA1 levels from western blots were quantified, using band densities and compared in WT and Pmca4-/- after induced estrus and in proestrus/estrus and metestrus/diestrus in cycling females. In vitro uptake of PMCA1 and tyrosine-phosphorylated proteins was quantified with flow cytometry and/or quantitative western blot. Ca2+-ATPase activity in OVS and sperm before and after PMCA1 and PMCA4 uptake was assayed, via the enzymatic hydrolysis rate of ATP. TEM revealed that human oviducts contain EVs (exosomal and microvesicular). These EVs contain PMCA4 (immunolabeling), eNOS and PMCA1 (western blot) in their cargo. TEM tomography showed the murine oviduct with EV-containing blebs which typify the apocrine pathway for EV biogenesis. Western blots revealed that during proestrus/estrus PMCA1 was significantly elevated in the oviductal luminal fluid (OLF) (P = 0.02) and in OVS (P = 0.03) of Pmca4-/-, compared to WT. Further, while PMCA1 levels did not fluctuate in OLF during the cycle in WT, they were significantly (P = 0.02) higher in proestrus/estrus than at metestrus/diestrus in Pmca4-/-. The elevated levels of PMCA1 in proestrus/estrus, which mimics PMCA4 in WT, is OLF/OVS-specific, and is not seen in oviductal tissues, uterosomes or epididymal luminal fluid of Pmca4-/-. However, qRT-PCR revealed significantly elevated levels of Pmca1 transcript in Pmca4-/- oviductal tissues, compared to WT. PMCA1 could be transferred from OVS to sperm and the levels were significantly higher for capacitated vs uncapacitated sperm, as assessed by flow cytometry (P = 0.001) after 3 h co-incubation, quantitative western blot (P < 0.05) and the frequency of immuno-labeled sperm (P < 0.001) after 30 min co-incubation. Tyrosine phosphorylated proteins were discovered in murine OVS and could be delivered to sperm after their co-incubation with OVS, as detected by western, immunofluorescence localization, and flow cytometry. PMCA1 and PMCA4 in OVS were shown to be enzymatically active and this activity increased in sperm after OVS interaction. None. Although oviductal tissues of WT and Pmca4-/- showed no significant difference in PMCA1 levels, Pmca4-/- levels of OVS/OLF during proestrus/estrus were significantly higher than in WT. We have attributed this enrichment or upregulation of PMCA1 in Pmca4-/- partly to selective packaging in OVS to compensate for the lack of PMCA4. However, in the absence of a difference between WT and Pmca4-/- in the PMCA1 levels in oviductal tissues as a whole, we cannot rule out significantly higher PMCA1 expression in the oviductal epithelium that gives rise to the OVS as significantly higher Pmca1 transcripts were detected in Pmca4-/-. Since OVS and fertility-modulating cargo components are conserved in humans, it suggests that murine OVS role in regulating the expression of proteins required for capacitation and fertility is also conserved. Secondly, OVS may explain some of the differences in in vivo and in vitro fertilization for mouse mutants, as seen in mice lacking the gene for FER which is the enzyme required for sperm protein tyrosine phosphorylation. Our observation that murine OVS carry and can modulate sperm protein tyrosine phosphorylation by delivering them to sperm provides an explanation for the in vivo fertility of Fer mutants, not seen in vitro. Finally, our findings have implications for infertility treatment and exosome therapeutics. The work was supported by National Institute of Health (RO3HD073523 and 5P20RR015588) grants to P.A.M.-D. There are no conflicts of interests.

Aberrant DNA methylation patterns of spermatozoa in men with unexplained infertility.

PubMed

Urdinguio, Rocío G; Bayón, Gustavo F; Dmitrijeva, Marija; Toraño, Estela G; Bravo, Cristina; Fraga, Mario F; Bassas, Lluís; Larriba, Sara; Fernández, Agustín F

2015-05-01

Are there DNA methylation alterations in sperm that could explain the reduced biological fertility of male partners from couples with unexplained infertility? DNA methylation patterns, not only at specific loci but also at Alu Yb8 repetitive sequences, are altered in infertile individuals compared with fertile controls. Aberrant DNA methylation of sperm has been associated with human male infertility in patients demonstrating either deficiencies in the process of spermatogenesis or low semen quality. Case and control prospective study. This study compares 46 sperm samples obtained from 17 normospermic fertile men and 29 normospermic infertile patients. Illumina Infinium HD Human Methylation 450K arrays were used to identify genomic regions showing differences in sperm DNA methylation patterns between five fertile and seven infertile individuals. Additionally, global DNA methylation of sperm was measured using the Methylamp Global DNA Methylation Quantification Ultra kit (Epigentek) in 14 samples, and DNA methylation at several repetitive sequences (LINE-1, Alu Yb8, NBL2, D4Z4) measured by bisulfite pyrosequencing in 44 sperm samples. A sperm-specific DNA methylation pattern was obtained by comparing the sperm methylomes with the DNA methylomes of differentiated somatic cells using data obtained from methylation arrays (Illumina 450 K) of blood, neural and glial cells deposited in public databases. In this study we conduct, for the first time, a genome-wide study to identify alterations of sperm DNA methylation in individuals with unexplained infertility that may account for the differences in their biological fertility compared with fertile individuals. We have identified 2752 CpGs showing aberrant DNA methylation patterns, and more importantly, these differentially methylated CpGs were significantly associated with CpG sites which are specifically methylated in sperm when compared with somatic cells. We also found statistically significant (P < 0.001) associations between DNA hypomethylation and regions corresponding to those which, in somatic cells, are enriched in the repressive histone mark H3K9me3, and between DNA hypermethylation and regions enriched in H3K4me1 and CTCF, suggesting that the relationship between chromatin context and aberrant DNA methylation of sperm in infertile men could be locus-dependent. Finally, we also show that DNA methylation patterns, not only at specific loci but also at several repetitive sequences (LINE-1, Alu Yb8, NBL2, D4Z4), were lower in sperm than in somatic cells. Interestingly, sperm samples at Alu Yb8 repetitive sequences of infertile patients showed significantly lower DNA methylation levels than controls. Our results are descriptive and further studies would be needed to elucidate the functional effects of aberrant DNA methylation on male fertility. Overall, our data suggest that aberrant sperm DNA methylation might contribute to fertility impairment in couples with unexplained infertility and they provide a promising basis for future research. This work has been financially supported by Fundación Cientifica de la AECC (to R.G.U.); IUOPA (to G.F.B.); FICYT (to E.G.T.); the Spanish National Research Council (CSIC; 200820I172 to M.F.F.); Fundación Ramón Areces (to M.F.F); the Plan Nacional de I+D+I 2008-2011/2013-2016/FEDER (PI11/01728 to AF.F., PI12/01080 to M.F.F. and PI12/00361 to S.L.); the PN de I+D+I 2008-20011 and the Generalitat de Catalunya (2009SGR01490). A.F.F. is sponsored by ISCIII-Subdirección General de Evaluación y Fomento de la Investigación (CP11/00131). S.L. is sponsored by the Researchers Stabilization Program from the Spanish National Health System (CES09/020). The IUOPA is supported by the Obra Social Cajastur, Spain. © The Author 2015. Published by Oxford University Press on behalf of the European Society of Human Reproduction and Embryology. All rights reserved. For Permissions, please email: journals.permissions@oup.com.

SPERM MOTILITY IN HSF1 KNOCKOUT MICE AFTER HEAT SHOCK IS ASSOCIATED WITH FERTILITY DEFICITS

EPA Science Inventory

SPERM MOTILITY IN HSF1 KNOCKOUT MICE AFTER HEAT SHOCK IS ASSOCIATED WITH FERTILITY DEFICITS. L.F. Strader*, S.D. Perreault, J.C. Luft*, and D.J. Dix*. US EPA/ORD, Reproductive Toxicology Div., Research Triangle Park, NC
Heat shock proteins (HSPs) protect cells from environm...

SLO3 auxiliary subunit LRRC52 controls gating of sperm KSPER currents and is critical for normal fertility

PubMed Central

Zeng, Xu-Hui; Yang, Chengtao; Xia, Xiao-Ming; Liu, Min; Lingle, Christopher J.

2015-01-01

Following entry into the female reproductive tract, mammalian sperm undergo a maturation process termed capacitation that results in competence to fertilize ova. Associated with capacitation is an increase in membrane conductance to both Ca2+ and K+, leading to an elevation in cytosolic Ca2+ critical for activation of hyperactivated swimming motility. In mice, the Ca2+ conductance (alkalization-activated Ca2+-permeable sperm channel, CATSPER) arises from an ensemble of CATSPER subunits, whereas the K+ conductance (sperm pH-regulated K+ current, KSPER) arises from a pore-forming ion channel subunit encoded by the slo3 gene (SLO3) subunit. In the mouse, both CATSPER and KSPER are activated by cytosolic alkalization and a concerted activation of CATSPER and KSPER is likely a common facet of capacitation-associated increases in Ca2+ and K+ conductance among various mammalian species. The properties of heterologously expressed mouse SLO3 channels differ from native mouse KSPER current. Recently, a potential KSPER auxiliary subunit, leucine-rich-repeat-containing protein 52 (LRRC52), was identified in mouse sperm and shown to shift gating of SLO3 to be more equivalent to native KSPER. Here, we show that genetic KO of LRRC52 results in mice with severely impaired fertility. Activation of KSPER current in sperm lacking LRRC52 requires more positive voltages and higher pH than for WT KSPER. These results establish a critical role of LRRC52 in KSPER channels and demonstrate that loss of a non-pore-forming auxiliary subunit results in severe fertility impairment. Furthermore, through analysis of several genotypes that influence KSPER current properties we show that in vitro fertilization competence correlates with the net KSPER conductance available for activation under physiological conditions. PMID:25675513

Genome-wide profiling of gene expression in the epididymis of alpha-chlorohydrin-induced infertile rats using an oligonucleotide microarray

PubMed Central

2010-01-01

Background As one of the chlorinated antifertility compounds, alpha-chlorohydrin (ACH) can inhibit glyceraldehyde-3-phosphate dehydrogenase (G3PDH) activity in epididymal sperm and affect sperm energy metabolism, maturation and fertilization, eventually leading to male infertility. Further studies demonstrated that the inhibitory effect of ACH on G3PDH is not only confined to epididymal sperm but also to the epididymis. Moreover, little investigation on gene expression changes in the epididymis after ACH treatment has been conducted. Therefore, gene expression studies may indicate new epididymal targets related to sperm maturation and fertility through the analysis of ACH-treated infertile animals. Methods Rats were treated with ACH for ten consecutive days, and then each male rat copulated with two female rats in proestrus. Then sperm maturation and other fertility parameters were analyzed. Furthermore, we identified epididymal-specific genes that are associated with fertility between control and ACH groups using an Affymetrix Rat 230 2.0 oligo-microarray. Finally, we performed RT-PCR analysis for several differentially expressed genes to validate the alteration in gene expression observed by oligonucleotide microarray. Results Among all the differentially expressed genes, we analyzed and screened the down-regulated genes associated with metabolism processes, which are considered the major targets of ACH action. Simultaneously, the genes that were up-regulated by chlorohydrin were detected. The genes that negatively regulate sperm maturation and fertility include apoptosis and immune-related genes and have not been reported previously. The overall results of PCR analysis for selected genes were consistent with the array data. Conclusions In this study, we have described the genome-wide profiles of gene expression in the epididymides of infertile rats induced by ACH, which could become potential epididymal specific targets for male contraception and infertility treatment. PMID:20409345

Genome-wide profiling of gene expression in the epididymis of alpha-chlorohydrin-induced infertile rats using an oligonucleotide microarray.

PubMed

Xie, Shuwu; Zhu, Yan; Ma, Li; Lu, Yingying; Zhou, Jieyun; Gui, Youlun; Cao, Lin

2010-04-22

As one of the chlorinated antifertility compounds, alpha-chlorohydrin (ACH) can inhibit glyceraldehyde-3-phosphate dehydrogenase (G3PDH) activity in epididymal sperm and affect sperm energy metabolism, maturation and fertilization, eventually leading to male infertility. Further studies demonstrated that the inhibitory effect of ACH on G3PDH is not only confined to epididymal sperm but also to the epididymis. Moreover, little investigation on gene expression changes in the epididymis after ACH treatment has been conducted. Therefore, gene expression studies may indicate new epididymal targets related to sperm maturation and fertility through the analysis of ACH-treated infertile animals. Rats were treated with ACH for ten consecutive days, and then each male rat copulated with two female rats in proestrus. Then sperm maturation and other fertility parameters were analyzed. Furthermore, we identified epididymal-specific genes that are associated with fertility between control and ACH groups using an Affymetrix Rat 230 2.0 oligo-microarray. Finally, we performed RT-PCR analysis for several differentially expressed genes to validate the alteration in gene expression observed by oligonucleotide microarray. Among all the differentially expressed genes, we analyzed and screened the down-regulated genes associated with metabolism processes, which are considered the major targets of ACH action. Simultaneously, the genes that were up-regulated by chlorohydrin were detected. The genes that negatively regulate sperm maturation and fertility include apoptosis and immune-related genes and have not been reported previously. The overall results of PCR analysis for selected genes were consistent with the array data. In this study, we have described the genome-wide profiles of gene expression in the epididymides of infertile rats induced by ACH, which could become potential epididymal specific targets for male contraception and infertility treatment.

Effects of nicotine on sperm characteristics and fertility profile in adult male rats: a possible role of cessation.

PubMed

Oyeyipo, Ibukun Peter; Raji, Yinusa; Emikpe, Benjamin Obukowho; Bolarinwa, Adeyombo Folashade

2011-07-01

Infertility is common among couples of child-bearing age and approximately half of known causes of primary infertility are attributable to male factor. It is still unclear whether the injurious effects of cigarette smoking on sperm characteristics and infertility are due to nicotine. Therefore, the present study investtigated the effects of orally administered of nicotine on sperm characteristics and libido in adult male albino rats. The study also sought nicotine effects on fertility rate, litter size and weight in female animals cohabited with nicotine treated male rats. Forty male and twenty-five female rats were used for the study. The male rats were divided into five groups and were treated for a period of 30 days with nicotine 0.5 mg/kg (low dose) and 1.0 mg/kg (high dose) per body weight while the control rats received 0.2 ml/kg normal saline. The fourth and fifth groups were gavaged with 0.5 mg/kg and 1.0 mg/kg body weight of nicotine but were left untreated for another 30 days. These groups served as the recovery groups. At the end of each experimental period, sperm analysis, fertility study, litter weight and size were determined. Sperm motility and count significantly decreased (P < 0.05) while the percentage of abnormality significantly increased (P < 0.05) in both treatment groups. However, there was an insignificant decrease (P > 0.05) in the viability and semen volume of the treated groups. Fertility studies revealed that nicotine reduced libido in male rats, litter weight and number delivered by the untreated female during the experiments. The present study showed that nicotine has a dose-dependent deleterious effect on the sperm characteristics and that fertility is ameliorated by nicotine cessation in male rats.

Sperm-egg penetration assay assessment of the contraceptive effects of glycerol and egg yolk in rooster sperm diluents.

PubMed

Abouelezz, F M K; Castaño, C; Toledano-Díaz, A; Esteso, M C; López-Sebastián, A; Campo, J L; Santiago-Moreno, J

2015-06-01

Glycerol (GLY) and egg yolk (EY) are good cryoprotectants of avian and mammalian sperm, but in birds, they strongly inhibit the eventual fertilization of ova. Using the sperm penetration (SP-holes) assay and fertility trials, the present study investigates (1) the possible mechanism by which this contraceptive effect occurs in chickens and (2) the maximum concentrations of GLY and EY tolerated by fresh rooster sperm. Seventy Black-Barred Andaluza hens (five per treatment) were inseminated four times (twice per week) with 0.1 mL of fresh semen from roosters of the same breed diluted 1:1 (v:v) with Lake and Ravie medium containing different concentrations of GLY or EY. No adverse effects on acrosome integrity, sperm motility, or viability were seen with any concentration of GLY or EY. The number of SP-holes on perivitelline layer samples taken from above the germinal disc became progressively lower at GLY concentrations of 1.5% or greater (P > 0.05). No holes caused by sperms were seen in unfertilized eggs. The corresponding fertility results showed similar reductions when the GLY concentration was 1.5% or greater. No changes in the number of SP-holes were seen with increasing EY concentrations (0%-7.5%), nor were any differences in fertility observed, except for a reduction when 15% EY was used. The results therefore reveal that GLY affects the transit of sperms through the oviduct in their attempt to reach the infundibulum area, limiting their access to the ovum perivitelline layer. Egg yolk had no such effect, nor did it influence acrosome reaction capacity; its mechanism of contraceptive action therefore remains unknown. The maximum GLY and EY concentrations tolerated by the rooster sperm were 0.75% and 7.5%, respectively. Copyright © 2015 Elsevier Inc. All rights reserved.

Iron defecation by sperm whales stimulates carbon export in the Southern Ocean

PubMed Central

Lavery, Trish J.; Roudnew, Ben; Gill, Peter; Seymour, Justin; Seuront, Laurent; Johnson, Genevieve; Mitchell, James G.; Smetacek, Victor

2010-01-01

The iron-limited Southern Ocean plays an important role in regulating atmospheric CO2 levels. Marine mammal respiration has been proposed to decrease the efficiency of the Southern Ocean biological pump by returning photosynthetically fixed carbon to the atmosphere. Here, we show that by consuming prey at depth and defecating iron-rich liquid faeces into the photic zone, sperm whales (Physeter macrocephalus) instead stimulate new primary production and carbon export to the deep ocean. We estimate that Southern Ocean sperm whales defecate 50 tonnes of iron into the photic zone each year. Molar ratios of Cexport ∶Feadded determined during natural ocean fertilization events are used to estimate the amount of carbon exported to the deep ocean in response to the iron defecated by sperm whales. We find that Southern Ocean sperm whales stimulate the export of 4 × 105 tonnes of carbon per year to the deep ocean and respire only 2 × 105 tonnes of carbon per year. By enhancing new primary production, the populations of 12 000 sperm whales in the Southern Ocean act as a carbon sink, removing 2 × 105 tonnes more carbon from the atmosphere than they add during respiration. The ability of the Southern Ocean to act as a carbon sink may have been diminished by large-scale removal of sperm whales during industrial whaling. PMID:20554546

The intimate genetics of Drosophila fertilization

PubMed Central

Loppin, Benjamin; Dubruille, Raphaëlle; Horard, Béatrice

2015-01-01

The union of haploid gametes at fertilization initiates the formation of the diploid zygote in sexually reproducing animals. This founding event of embryogenesis includes several fascinating cellular and nuclear processes, such as sperm–egg cellular interactions, sperm chromatin remodelling, centrosome formation or pronuclear migration. In comparison with other aspects of development, the exploration of animal fertilization at the functional level has remained so far relatively limited, even in classical model organisms. Here, we have reviewed our current knowledge of fertilization in Drosophila melanogaster, with a special emphasis on the genes involved in the complex transformation of the fertilizing sperm nucleus into a replicated set of paternal chromosomes. PMID:26246493

Assembly of the fluorescent acrosomal matrix and its fate in fertilization in the water strider, Aquarius remigis

PubMed Central

Miyata, Haruhiko; Noda, Naoki; Fairbairn, Daphne J.; Oldenbourg, Rudolf; Cardullo, Richard A.

2011-01-01

Animal sperm show remarkable diversity in both morphology and molecular composition. Here we provide the first report of intense intrinsic fluorescence in an animal sperm. The sperm from a semi-aquatic insect, the water strider, Aquarius remigis, contains an intrinsically fluorescent molecule with properties consistent with those of Flavin Adenine Dinucleotid (FAD) which appears first in the acrosomal vesicle of round spermatids and persists in the acrosome throughout spermiogenesis. Fluorescence recovery after photobleaching reveals that the fluorescent molecule exhibits unrestricted mobility in the acrosomal vesicle of round spermatids, but is completely immobile in the acrosome of mature sperm. Fluorescence polarization microscopy shows a net alignment of the fluorescent molecules in the acrosome of the mature sperm but not in the acrosomal vesicle of round spermatids. These results suggest that acrosomal molecules are rearranged in the elongating acrosome and FAD is incorporated into the acrosomal matrix during its formation. Further, we followed the fate of the acrosomal matrix in fertilization utilizing the intrinsic fluorescence. The fluorescent acrosomal matrix was observed inside the fertilized egg and remained structurally intact even after gastrulation started. This observation suggests that FAD is not released from the acrosomal matrix during the fertilization process or early development and supports an idea that FAD is involved in the formation of the acrosomal matrix. The intrinsic fluorescence of the A. remigis acrosome will be a useful marker for following spermatogenesis and fertilization. PMID:20857404

Semen evaluation and fertility assessment in a purebred dog breeding facility.

PubMed

Hesser, Andrea; Darr, Christa; Gonzales, Kris; Power, Heather; Scanlan, Tawny; Thompson, James; Love, Charles; Christensen, Bruce; Meyers, Stuart

2017-01-01

Semen quality in dogs has not been assessed in a longitudinal study that includes endpoints of female fertility and pregnancy. Although use of artificial insemination with chilled semen is increasingly used in canine reproduction, the resultant level of predictability and odds of fertile matings for dogs is still not fully understood. This research provides, for the first time, comprehensive semen evaluation in a large population of dogs in which fertility has been tracked. Duplicate ejaculates were obtained from 39 Labrador retriever males of the Guide Dogs for the Blind (San Rafael, CA, USA) breeding program. Sperm endpoints were determined in fresh semen and extended chilled semen at 48 hour after collection. Evaluation included total and progressive motility, average path velocity, morphology, membrane lipid peroxidation, presence of sperm reactive oxygen species, sperm chromatin structure, and mitochondrial DNA copy number. Male age ranged from 1 to 10 years and were grouped as young (Y; 1-3 years, n = 21), middle aged (M; 4-6 years, n = 13), and senior (S; 7 years or greater, n = 5) for analysis. The effects of age and sperm state (fresh vs. chilled) on the above sperm endpoints were determined using a linear mixed effects model. Semen endpoint values for all parameters were established for this group of fertile males. Progressive motility was only lower in the senior male chilled samples compared to all other groups, fresh and chilled (P < 0.05). Velocity decreased with increasing age and was lower overall in chilled samples (P < 0.05). Percent morphologically normal sperm was lower in senior dogs compared with the other age groups (P < 0.05). The presence of reactive oxygen species was lower in chilled samples compared with fresh (P < 0.05). For sperm chromatin structure, the senior-aged group had a higher %COMPα t than the middle-aged group (P < 0.05). Bayesian analysis determined that no differences were seen in total motility, membrane lipid peroxidation, and mitochondrial DNA copy number, with regard to conception rate or average litter size between age groups or between fresh and chilled samples. We observed no effects from semen quality on fertility or fecundity regardless of age, despite the differences found in semen quality. The use of advanced laboratory tests to evaluate sperm parameters beyond the standard motility, morphology, and concentration will open investigation to more specific and sensitive fertility tests in canine reproduction. Copyright © 2016 Elsevier Inc. All rights reserved.

Cryopreservation of epididymal sperm.

PubMed

Patrizio, P

2000-11-27

The advent of ICSI and the perfecting of freezing protocols for sperm samples that in the pre-ICSI era would not have been frozen, allows now routine cryopreservation of epididymal sperm regardless of their quality and quantity. There are two methods to retrieve epididymal sperm: microsurgical epididymal sperm aspiration (MESA) and percutaneous epididymal sperm aspiration (PESA). The majority of the literature has focused on the technique of MESA to obtain sperm on the claim that the amount of sperm retrieved with PESA might not be sufficient to allow cryopreservation. However, there are no data on cryopreservation and ICSI with epididymal sperm collected with PESA technique. In this study, a total of 68 consecutive cycles of PESA, of which 46 were performed with fresh epididymal sperm and 22 with frozen/thawed specimens were retrospectively analyzed. In the fresh epididymal group (n = 46), 446 eggs were injected and 207 cleaving embryos were obtained (fertilization rate of 46%). In the cryopreserved epididymal sperm group (n = 22), 216 eggs were injected and 115 cleaving embryos were obtained (fertilization rate of 53%, P = NS). There were 18 pregnancies (39%) with 17 (37%) delivered/ongoing in the fresh group, while there were 11 (50%) with 9 (41%) delivered/ongoing in the frozen group (P = NS). Epididymal sperm for cryopreservation was available in 44 of the 46 PESA cycles. Additionally, in the fresh group, 19 couples had excess embryos for cryopreservation while in the frozen group, ten couples had excess embryos for cryopreservation. A total of 17 frozen embryo transfer with epididymal sperm from PESA were analyzed. Of these, 12 FET were from embryos from the fresh epididymal group and three pregnancies with livebirths (25%) were recorded. Five FET were performed with extra embryos from frozen epididymal sperm and two (40%) pregnancies with livebirths were obtained. In summary, these data show that epididymal sperm obtained by PESA can be successfully cryopreserved in order to avoid future retrievals procedures and fertilization and pregnancy rates are similar between fresh and cryopreserved epididymal sperm. It is also reported for the first time that the transfer of frozen embryos obtained with either fresh or frozen thawed epididymal sperm leads to the same pregnancy'and delivery rate.

[Influence of the DNA integrity of optimized sperm on the embryonic development and clinical outcomes of in vitro fertilization and embryo transfer].

PubMed

Jiang, Wei-jie; Jin, Fan; Zhou, Li-ming

2016-05-01

To investigate the influence of the DNA integrity of optimized sperm on the embryonic development and clinical outcomes of in vitro fertilization and embryo transfer (IVF-ET). This study included 605 cycles of conventional IVF-ET for pure oviductal infertility performed from January 1, 2013 to December 31, 2014. On the day of retrieval, we examined the DNA integrity of the sperm using the sperm chromatin dispersion method. According to the ROC curve and Youden index, we grouped the cycles based on the sperm DNA fragmentation index (DFI) threshold value for predicting implantation failure, early miscarriage, and fertilization failure, followed by analysis of the correlation between DFI and the outcomes of IVF-ET. According to the DFI threshold values obtained, the 605 cycles fell into four groups (DFI value < 5%, 5-10%, 10-15%, and ≥ 15%). Statistically significant differences were observed among the four groups in the rates of fertilization, cleavage, high-quality embryo, implantation, clinical pregnancy, early miscarriage, and live birth (P < 0.05), but not in the rates of multiple pregnancy, premature birth, and low birth weight (P > 0.05). DFI was found to be correlated negatively with the rates of fertilization (r = -0.32, P < 0.01), cleavage (r = -0.19, P < 0.01), high-quality embryo (r = -0.40, P < 0.01), clinical pregnancy (r = -0.20, P < 0.01), and live birth (r = -0.09 P = 0.04), positively with the rate of early miscarriage (r = 0.23, P < 0.01), but not with the rates of multiple pregnancy (r = -0.01, P = 0.83), premature birth (r = 0.04, P = 0.54), and low birth weight (r = 0.03, P = 0.62). The DNA integrity of optimized sperm influences fertilization, embryonic development, early miscarriage, and live birth of IVF-ET, but its correlation with premature birth and low birth weight has to be further studied.

Isolation and Proteomic Characterization of the Mouse Sperm Acrosomal Matrix*

PubMed Central

Guyonnet, Benoit; Zabet-Moghaddam, Masoud; SanFrancisco, Susan; Cornwall, Gail A.

2012-01-01

A critical step during fertilization is the sperm acrosome reaction in which the acrosome releases its contents allowing the spermatozoa to penetrate the egg investments. The sperm acrosomal contents are composed of both soluble material and an insoluble material called the acrosomal matrix (AM). The AM is thought to provide a stable structure from which associated proteins are differentially released during fertilization. Because of its important role during fertilization, efforts have been put toward isolating the AM for biochemical study and to date AM have been isolated from hamster, guinea pig, and bull spermatozoa. However, attempts to isolate AM from mouse spermatozoa, the species in which fertilization is well-studied, have been unsuccessful possibly because of the small size of the mouse sperm acrosome and/or its fusiform shape. Herein we describe a procedure for the isolation of the AM from caput and cauda mouse epididymal spermatozoa. We further carried out a proteomic analysis of the isolated AM from both sperm populations and identified 501 new proteins previously not detected by proteomics in mouse spermatozoa. A comparison of the AM proteome from caput and cauda spermatozoa showed that the AM undergoes maturational changes during epididymal transit similar to other sperm domains. Together, our studies suggest the AM to be a dynamic and functional structure carrying out a variety of biological processes as implied by the presence of a diverse group of proteins including proteases, chaperones, hydrolases, transporters, enzyme modulators, transferases, cytoskeletal proteins, and others. PMID:22707618

Sperm yield after single layer centrifugation with Androcoll-E is related to the potential fertility of the original ejaculate.

PubMed

Morrell, J M; Stuhtmann, G; Meurling, S; Lundgren, A; Winblad, C; Macias Garcia, B; Johannisson, A

2014-05-01

Many attempts have been made to identify laboratory tests that are predictive of sperm fertility, both to improve the quality of stallion semen doses for artificial insemination (AI) and to identify potential breeding sires if no fertility data are available. Sperm quality at the stud is mostly evaluated by assessing subjective motility, although this parameter can be poorly indicative of fertility. Sperm morphology and chromatin integrity in Swedish stallions are correlated to pregnancy rate after AI. Because single layer centrifugation (SLC) selects for spermatozoa with normal morphology and good chromatin, retrospective analysis was carried out to investigate whether sperm yield after SLC is linked to potential fertility. Commercial semen doses for AI from 24 stallions (five stallions with four ejaculates each, 19 stallions with three ejaculates each; n = 77) obtained during the breeding season were cooled, and sent overnight to the Swedish University of Agricultural Sciences in an insulated box for evaluation, with other doses being sent to studs for commercial AI. On arrival at Swedish University of Agricultural Sciences, the semen was used for SLC and also for evaluation of sperm motility, membrane integrity, chromatin integrity, and morphology. The seasonal pregnancy rates for each stallion were available. The yield of progressively motile spermatozoa after SLC (calculated as a proportion of the initial load) was found to be highly correlated with pregnancy rate (r = 0.75; P < 0.001). Chromatin damage was highly negatively correlated with pregnancy rate (r = -0.69; P < 0.001). Pregnancy rate was also correlated with membrane integrity (r = 0.58; P < 0.01), progressive motility (r = 0.63; P < 0.01), and normal morphology (r = 0.45; P < 0.05). In conclusion, these preliminary results show that sperm yield after SLC is related to the potential fertility of the original ejaculate, and could be an alternative indicator of stallion fertility if breeding data are not available. Single layer centrifugation is fast (30 minutes) and does not require expensive equipment, whereas other assays require a flow cytometer and/or specialist skills. An additional option could be to transport semen doses to a laboratory for SLC if the stud personnel do not want to perform the procedure themselves. Copyright © 2014 Elsevier Inc. All rights reserved.

Factors and pathways involved in capacitation: how are they regulated?

PubMed Central

Jin, Shi-Kai; Yang, Wan-Xi

2017-01-01

In mammals, fertilization occurs via a comprehensive progression of events. Freshly ejaculated sperm have yet to acquire progressive motility or fertilization ability. They must first undergo a series of biochemical and physiological changes, collectively known as capacitation. Capacitation is a significant prerequisite to fertilization. During the process of capacitation, changes in membrane properties, intracellular ion concentration and the activities of enzymes, together with other protein modifications, induce multiple signaling events and pathways in defined media in vitro or in the female reproductive tract in vivo. These, in turn, stimulate the acrosome reaction and prepare spermatozoa for penetration of the egg zona pellucida prior to fertilization. In the present review, we conclude all mainstream factors and pathways regulate capacitation and highlight their crosstalk. We also summarize the relationship between capacitation and assisted reproductive technology or human disease. In the end, we sum up the open questions and future avenues in this field. PMID:27690295

Birth after human chorionic gonadotropin-primed oocyte in vitro maturation and fertilization with testicular sperm in a normo-ovulatory patient.

PubMed

González-Ortega, Claudia; Piña-Aguilar, Raul Eduardo; Cancino-Villareal, Patricia; Gutiérrez-Gutiérrez, Antonio Martin

2016-01-01

In this report, we present a case of in vitro maturation (IVM) with surgical retrieved testicular sperm in a normo-ovulatory female. Human chorionic gonadotropin-primed IVM, testicular biopsy for sperm retrieval and intracytoplasmic sperm injection with fresh sperm were performed. Fourteen cumulus-oocyte complexes were obtained in germinal vesicle or metaphase I stage, eight oocytes reached metaphase II, seven presumptive zygotes were obtained, and three cleavage stages embryos in day 2 were transferred producing a singleton pregnancy. A single healthy newborn was obtained. Our results suggest that IVM may be an alternative for in vitro fertilization in normo-ovulatory women even if surgical retrieval of sperm is needed. Further research is required to depict contributing factors to the success of IVM in indications different from polycystic ovaries syndrome and the role of male gamete.

PYK2: A Calcium-sensitive Protein Tyrosine Kinase Activated in Response to Fertilization of the Zebrafish Oocyte

PubMed Central

Sharma, Dipika; Kinsey, William H.

2012-01-01

Fertilization begins with binding and fusion of a sperm with the oocyte, a process that triggers a high amplitude calcium transient which propagates through the oocyte and stimulates a series of preprogrammed signal transduction events critical for zygote development. Identification of the pathways downstream of this calcium transient remains an important step in understanding the basis of zygote quality. The present study demonstrates that the calcium-calmodulin sensitive protein tyrosine kinase PYK2 is a target of the fertilization-induced calcium transient in the zebrafish oocyte and that it plays an important role in actin-mediated events critical for sperm incorporation. At fertilization, PYK2 was activated initially at the site of sperm-oocyte interaction and was closely associated with actin filaments forming the fertilization cone. Later PYK2 activation was evident throughout the entire oocyte cortex, however activation was most intense over the animal hemisphere. Fertilization-induced PYK2 activation could be blocked by suppressing calcium transients in the ooplasm via injection of BAPTA as a calcium chelator. PYK2 activation could be artificially induced in unfertilized oocytes by injection of IP3 at concentrations sufficient to induce calcium release. Functionally, suppression of PYK2 activity by chemical inhibition or by injection of a dominant-negative construct encoding the N-terminal ERM domain of PKY2 inhibited formation of an organized fertilization cone and reduced the frequency of successful sperm incorporation. Together, the above findings support a model in which PYK2 responds to the fertilization-induced calcium transient by promoting reorganization of the cortical actin cytoskeleton to form the fertilization cone. PMID:23084926

Inhibition of 19S proteasomal regulatory complex subunit PSMD8 increases polyspermy during porcine fertilization in vitro.

PubMed

Yi, Young-Joo; Manandhar, Gaurishankar; Sutovsky, Miriam; Jonáková, Vera; Park, Chang-Sik; Sutovsky, Peter

2010-03-01

The 26S proteoasome is a multi-subunit protease specific to ubiquitinated substrate proteins. It is composed of a 20S proteasomal core with substrate degradation activity, and a 19S regulatory complex that acts in substrate recognition, deubiquitination, priming and transport to the 20S core. Inhibition of proteolytic activities associated with the sperm acrosome-borne 20S core prevents fertilization in mammals, ascidians and echinoderms. Less is known about the function of the proteasomal 19S complex during fertilization. The present study examined the role of PSMD8, an essential non-ATPase subunit of the 19S complex, in sperm-ZP penetration during porcine fertilization in vitro (IVF). Immunofluorescence localized PSMD8 to the outer acrosomal membrane, acrosomal matrix and the inner acrosomal membrane. Colloidal gold transmission electron microscopy detected PSMD8 on the surface of vesicles in the acrosomal shroud, formed as a result of zona pellucida-induced acrosomal exocytosis. Contrary to the inhibition of fertilization by blocking of the 20S core activities, fertilization and polyspermy rates were increased by adding anti-PSMD8 antibody to fertilization medium. This observation is consistent with a possible role of PSMD8 in substrate deubiquitination, a process which when blocked, may actually accelerate substrate proteolysis by the 26S proteasome. Subunit PSMD8 co-immunoprecipitated with acrosomal surface-associated spermadhesin AQN1. This association indicates that the sperm acrosome-borne proteasomes become exposed onto the sperm surface following the acrosomal exocytosis. Since immunological blocking of subunit PSMD8 increases the rate of polyspermy during porcine fertilization, the activity of the 19S complex may be a rate-limiting factor contributing to anti-polyspermy defense during porcine fertilization. Copyright 2009. Published by Elsevier Ireland Ltd.

The evolution of polyandry: patterns of genotypic variation in female mating frequency, male fertilization success and a test of the sexy-sperm hypothesis.

PubMed

Simmons, L W

2003-07-01

The sexy-sperm hypothesis predicts that females obtain indirect benefits for their offspring via polyandy, in the form of increased fertilization success for their sons. I use a quantitative genetic approach to test the sexy-sperm hypothesis using the field cricket Teleogryllus oceanicus. Previous studies of this species have shown considerable phenotypic variation in fertilization success when two or more males compete. There were high broad-sense heritabilities for both paternity and polyandry. Patterns of genotypic variance were consistent with X-linked inheritance and/or maternal effects on these traits. The genetic architecture therefore precludes the evolution of polyandry via a sexy-sperm process. Thus the positive genetic correlation between paternity in sons and polyandry in daughters predicted by the sexy-sperm hypothesis was absent. There was significant heritable variation in the investment by females in ovaries and by males in the accessory gland. Surprisingly there was a very strong genetic correlation between these two traits. The significance of this genetic correlation for the coevolution of male seminal products and polyandry is discussed.

In vivo serial sampling of epididymal sperm in mice.

PubMed

Del Val, Gonzalo Moreno; Robledano, Patricia Muñoz

2013-07-01

This study was undertaken to refine the techniques of in vivo collection of sperm in the mouse. The principal objective was to offer a viable, safe and reliable method for serial collection of in vivo epididimary sperm through the direct puncture of the epididymis. Six C57Bl/6J males were subjected to the whole experiment. First we obtain a sperm sample of the right epididymis, and perform a vasectomy on the left side. This sample was used in an in vitro fertilization (IVF) experiment while the males were individually housed for 10 days to let them recover from the surgery, and then their fertility was tested with natural matings until we obtained a litter of each one. After that, the animals were subjected another time to the same process (sampling, recover and natural mating). The results of these experiments were a fertilization average value of 56.7%, and that all the males had a litter in the first month after the natural matings. This study documented the feasibility of the epididimary puncture technique to in vivo serial sampling of sperm in the mouse.

Sugar‐coated sperm: Unraveling the functions of the mammalian sperm glycocalyx

PubMed Central

Tecle, Eillen

2015-01-01

SUMMARY Mammalian spermatozoa are coated with a thick glycocalyx that is assembled during sperm development, maturation, and upon contact with seminal fluid. The sperm glycocalyx is critical for sperm survival in the female reproductive tract and is modified during capacitation. The complex interplay among the various glycoconjugates generates numerous signaling motifs that may regulate sperm function and, as a result, fertility. Nascent spermatozoa assemble their own glycans while the cells still possess a functional endoplasmic reticulum and Golgi in the seminiferous tubule, but once spermatogenesis is complete, they lose the capacity to produce glycoconjugates de novo. Sperm glycans continue to be modified, during epididymal transit by extracellular glycosidases and glycosyltransferases. Furthermore, epididymal cells secrete glycoconjugates (glycophosphatidylinositol‐anchored glycoproteins and glycolipids) and glycan‐rich microvesicles that can fuse with the maturing sperm membrane. The sperm glycocalyx mediates numerous functions in the female reproductive tract, including the following: inhibition of premature capacitation; passage through the cervical mucus; protection from innate and adaptive female immunity; formation of the sperm reservoir; and masking sperm proteins involved in fertilization. The immense diversity in sperm‐associated glycans within and between species forms a remarkable challenge to our understanding of essential sperm glycan functions. Mol. Reprod. Dev. 82: 635–650, 2015. © 2015 The Authors. Molecular Reproduction and Development published by Wiley Periodicals, Inc. PMID:26061344

Comparison of semen variables, sperm DNA damage and sperm membrane proteins in two male layer breeder lines.

PubMed

M, Shanmugam; T R, Kannaki; A, Vinoth

2016-09-01

Semen variables are affected by the breed and strain of chicken. The present study was undertaken to compare the semen quality in two lines of adult chickens with particular reference to sperm chromatin condensation, sperm DNA damage and sperm membrane proteins. Semen from a PD3 and White Leghorn control line was collected at 46 and 47 weeks and 55 weeks of age. The semen was evaluated for gross variables and sperm chromatin condensation by aniline blue staining. Sperm DNA damage was assessed by using the comet assay at 47 weeks of age and sperm membrane proteins were assessed at 55 weeks of age. The duration of fertility was studied by inseminating 100 million sperm once into the hens of the same line as well as another line. The eggs were collected after insemination for 15days and incubated. The eggs were candled on 18th day of incubation for observing embryonic development. The White Leghorn control line had a greater sperm concentration and lesser percentage of morphologically abnormal sperm at the different ages where assessments occurred. There was no difference in sperm chromatin condensation, DNA damage and membrane proteins between the lines. Only low molecular weight protein bands of less than 95kDa were observed in samples of both lines. The line from which semen was used had no effect on the duration over which fertility was sustained after insemination either when used in the same line or another line. Thus, from the results of the present study it may be concluded that there was a difference in gross semen variables between the lines that were studied, however, the sperm chromatin condensation, DNA damage, membrane proteins and duration over which fertility was sustained after insemination did not differ between the lines. Copyright © 2016 Elsevier B.V. All rights reserved.

Assessing the potential for egg chemoattractants to mediate sexual selection in a broadcast spawning marine invertebrate

PubMed Central

Evans, Jonathan P.; Garcia-Gonzalez, Francisco; Almbro, Maria; Robinson, Oscar; Fitzpatrick, John L.

2012-01-01

In numerous species, egg chemoattractants play a critical role in guiding sperm towards unfertilized eggs (sperm chemotaxis). Until now, the known functions of sperm chemotaxis include increasing the effective target size of eggs, thereby promoting sperm–egg encounters, and facilitating species recognition. Here, we report that in the broadcast spawning mussel, Mytilus galloprovincialis, egg chemoattractants may play an unforeseen role in sexual selection by enabling sperm to effectively ‘choose’ between the eggs of different conspecific females. In an initial experiment, we confirmed that sperm chemotaxis occurs in M. galloprovincialis by showing that sperm are attracted towards unfertilized eggs when given the choice of eggs or no eggs in a dichotomous chamber. We then conducted two cross-classified mating experiments, each comprising the same individual males and females crossed in identical male × female combinations, but under experimental conditions that offered sperm ‘no-choice’ (each fertilization trial took place in a Petri dish and involved a single male and female) or a ‘choice’ of a female's eggs (sperm were placed in the centre of a dichotomous choice chamber and allowed to choose eggs from different females). We show that male-by-female interactions characterized fertilization rates in both experiments, and that there was remarkable consistency between patterns of sperm migration in the egg-choice experiment and fertilization rates in the no-choice experiment. Thus, sperm appear to exploit chemical cues to preferentially swim towards eggs with which they are most compatible during direct sperm-to-egg encounters. These results reveal that sperm differentially select eggs on the basis of chemical cues, thus exposing the potential for egg chemoattractants to mediate mate choice for genetically compatible partners. Given the prevalence of sperm chemotaxis across diverse taxa, our findings may have broad implications for sexual selection in other mating systems. PMID:22438495

Pentoxifylline effects on capacitation and fertility of stallion epididymal sperm.

PubMed

Guasti, P N; Monteiro, G A; Maziero, R R D; Carmo, M T; Dell'Aqua, J A; Crespilho, A M; Rifai, E A; Papa, F O

2017-04-01

The aims of this study were to determinate whether pentoxifylline (PTX) increases the motion parameters of fresh and frozen-thawed equine epididymal spermatozoa, to evaluate the tyrosine phosphorylation of frozen-thawed epididymal sperm in the presence of PTX and to determine whether the PTX-treatment of stallion epididymal sperm prior to freezing improves the fertility response of mares to a reduced number of spermatozoa per insemination dose. Fifty epididymis were flushed with a skim milk based extender with or without PTX. The pre-treatment with PTX enhanced the sperm motility after being harvested (P<0.05); however the freeze-thaw process did not alter the sperm kinematics between control and treated samples (P>0.05). Plasma membrane integrity did not differ between control and PTX group after recovery and after thawing (P>0.05), as observed in tyrosine phosphorylation, which the PTX treatment did not alter the percentage of tail-associated immunofluorescence of cryopreserved epididymal sperm (P>0.05). For the fertility trial, different insemination groups were tested: 800×10 6 epididymal sperm (C800); 100×10 6 epididymal sperm (C100); 100×10 6 epididymal sperm recovered in an extender containing PTX (PTX100). The conception rates for C800; C100 and PTX100 were 68.7% (11/16); 31.5% (5/16) and 50% (8/16), respectively. The conception rate did not differ among groups (P>0.05), however, a low number of animals was used in this study. A trend toward significance (P=0.07) was observed between C800 and C100 groups. In conclusion, PTX has no deleterious effect on sperm motility, viability and capacitation of cryopreserved stallion epididymal sperm. The conventional artificial insemination with 100×10 6 sperm recovered with PTX ensures acceptable conception rates and maximize the limited number of doses of cryopreserved stallion epididymal sperm. Copyright © 2017 Elsevier B.V. All rights reserved.

Assessment of sperm DNA in patients submitted the assisted reproduction technology procedures.

PubMed

Tsuribe, Patrícia Miyuki; Lima Neto, João Ferreira; Golim, Marjorie de Assis; Dell'Aqua, Camila de Paula Freitas; Issa, João Paulo; Gobbo, Carlos Alberto Monte

2016-03-01

This study aimed to produce data on sperm quality while maintaining the integrity of sperm DNA samples taken from patients submitted to in vitro fertilization (IVF) procedures at our center, and determine whether increased levels of histones were associated with sperm DNA damage and decreased fertilization, cleavage, and pregnancy rates. Such findings might shed light on the physiology and outcomes of pregnancy. Semen samples from 27 patients divided into two groups were analyzed. The case group included individuals offered IVF; the control group had subjects with normal spermograms. Sperm DNA structure was assessed through phosphorylated histone H2AX analysis by flow cytometry. The patients with altered sperm parameters had more histones in sperm chromatin than the individuals with normal sperm parameters. Results indicated that increased levels of histone in sperm chromatin do not affect embryo production, but affect the cleavage rate, embryo quality, and might thus reduce pregnancy rates. The integrity of the paternal genome is of paramount importance in the initiation and maintenance of a viable pregnancy in patients treated with assisted reproduction technology procedures. Further studies on sperm diagnostic tests at a nuclear level might improve the treatment offered to infertile couples.

Effects of advanced selection methods on sperm quality and ART outcome.

PubMed

Yetunde, I; Vasiliki, M

2013-10-01

In assisted reproductive technology (ART), the role of spermatozoa has evolved over the years. In the past, early methods of selecting sperm for ART only focused on selecting motile and morphologically normal appearing sperm. It has become evident that these methods are inefficient in identifying the most suitable sperm for fertilization. Novel methods have thus been created to identify highly motile, morphologically normal, viable non-apoptotic spermatozoa with intact membranes and high DNA integrity for use in ART. These advanced methods of selection utilize our knowledge of unique characteristics of sperm, such as sperm surface charge, the presence of hyaluronic acid binding sites on sperm, sperm ultramorphology, markers of apoptosis and zona pellucida binding on sperm. These methods have shown potential promise in improving ART outcomes. Future developments may include Raman spectroscopy, confocal light absorption and scattering spectroscopic microscopy, and polarization microscopy. While these novel techniques have potential, they come with a cost burden and further studies are required to demonstrate their impact on ART outcomes. Furthermore, clinicians and human reproductive scientists need to continue to gather knowledge about human fertilization and determine the most physiological methods of sperm selection.

Long-lived sperm in the geothermal bryophyte Pohlia nutans

PubMed Central

Rosenstiel, Todd N.; Eppley, Sarah M.

2009-01-01

Non-vascular plants rely on sperm to cross the distance between male and female reproductive organs for fertilization and sexual reproduction to occur. The majority of non-vascular plants have separate sexes, and thus, this distance may be a few millimetres to many metres. Because sperm need water for transport, it has been assumed that sperm lifespans are short and that this type of sexual reproduction limits the expansion of non-vascular plants in terrestrial environments. However, little data is available on the lifespan of sperm in non-vascular plants, and none is available for bryophytes, the group thought to have first colonized terrestrial habitats. Here, we documented the lifespan of sperm of Pohlia nutans, collected from a geothermal spring's area, and tested the effects of variation under environmental conditions on this lifespan. Surprisingly, 20 per cent of the sperm were still motile after 100 h, and sperm lifespan was not significantly affected by temperature variation between 22 and 60°C. Lifespan was significantly affected by sperm dilution and temperatures above 75°C. These results suggest the need to reconsider the importance of sperm motility in bryophyte fertilization. PMID:19640871

Sperm Competition Selects for Sperm Quantity and Quality in the Australian Maluridae

PubMed Central

Rowe, Melissah; Pruett-Jones, Stephen

2011-01-01

When ejaculates from rival males compete for fertilization, there is strong selection for sperm traits that enhance fertilization success. Sperm quantity is one such trait, and numerous studies have demonstrated a positive association between sperm competition and both testes size and the number of sperm available for copulations. Sperm competition is also thought to favor increases in sperm quality and changes in testicular morphology that lead to increased sperm production. However, in contrast to sperm quantity, these hypotheses have received considerably less empirical support and remain somewhat controversial. In a comparative study using the Australian Maluridae (fairy-wrens, emu-wrens, grasswrens), we tested whether increasing levels of sperm competition were associated with increases in both sperm quantity and quality, as well as an increase in the relative amount of seminiferous tubule tissue contained within the testes. After controlling for phylogeny, we found positive associations between sperm competition and sperm numbers, both in sperm reserves and in ejaculate samples. Additionally, as sperm competition level increased, the proportion of testicular spermatogenic tissue also increased, suggesting that sperm competition selects for greater sperm production per unit of testicular tissue. Finally, we also found that sperm competition level was positively associated with multiple sperm quality traits, including the proportion of motile sperm in ejaculates and the proportion of both viable and morphologically normal sperm in sperm reserves. These results suggest multiple ejaculate traits, as well as aspects of testicular morphology, have evolved in response to sperm competition in the Australian Maluridae. Furthermore, our findings emphasize the importance of post-copulatory sexual selection as an evolutionary force shaping macroevolutionary differences in sperm phenotype. PMID:21283577

Sperm competition selects for sperm quantity and quality in the Australian Maluridae.

PubMed

Rowe, Melissah; Pruett-Jones, Stephen

2011-01-25

When ejaculates from rival males compete for fertilization, there is strong selection for sperm traits that enhance fertilization success. Sperm quantity is one such trait, and numerous studies have demonstrated a positive association between sperm competition and both testes size and the number of sperm available for copulations. Sperm competition is also thought to favor increases in sperm quality and changes in testicular morphology that lead to increased sperm production. However, in contrast to sperm quantity, these hypotheses have received considerably less empirical support and remain somewhat controversial. In a comparative study using the Australian Maluridae (fairy-wrens, emu-wrens, grasswrens), we tested whether increasing levels of sperm competition were associated with increases in both sperm quantity and quality, as well as an increase in the relative amount of seminiferous tubule tissue contained within the testes. After controlling for phylogeny, we found positive associations between sperm competition and sperm numbers, both in sperm reserves and in ejaculate samples. Additionally, as sperm competition level increased, the proportion of testicular spermatogenic tissue also increased, suggesting that sperm competition selects for greater sperm production per unit of testicular tissue. Finally, we also found that sperm competition level was positively associated with multiple sperm quality traits, including the proportion of motile sperm in ejaculates and the proportion of both viable and morphologically normal sperm in sperm reserves. These results suggest multiple ejaculate traits, as well as aspects of testicular morphology, have evolved in response to sperm competition in the Australian Maluridae. Furthermore, our findings emphasize the importance of post-copulatory sexual selection as an evolutionary force shaping macroevolutionary differences in sperm phenotype.

Liquid storage of miniature boar semen.

PubMed

Shimatsu, Yoshiki; Uchida, Masaki; Niki, Rikio; Imai, Hiroshi

2002-04-01

The effects of liquid storage at 15 degrees C on the fertilizing ability of miniature pig semen were investigated. Characterization of ejaculated semen from 3 miniature boars was carried out. Semen volume and pH were similar among these boars. In one of the boars, sperm motility was slightly low, and sperm concentration and total number of sperm were significantly lower than in the others (P < 0.01). Seminal plasma of the semen was substituted with various extenders (Kiev, Androhep, BTS and Modena) by centrifugation and semen was stored for 7 days at 15 degrees C. Sperm motility was estimated daily at 37 degrees C. For complete substitution of seminal plasma, Modena was significantly more efficient than the other extenders (P < 0.001) in retaining sperm motility. Semen from each of the 3 miniature boars that had been stored for 5 to 7 days at 15 degrees C in Modena was used for artificial insemination of 15 miniature sows. The farrowing rates were 100, 100 and 60%, and litter sizes were 6.4 +/- 1.5, 5.8 +/- 0.8 and 5.0 +/- 1.0 for each boar semen, respectively. The boar that sired the smallest farrowing rate was the same one that showed lower seminal quality with respect to sperm motility, sperm concentration and total number of sperm. These results suggest that miniature boar semen can be stored for at least 5 days at 15 degrees C by the substitution of seminal plasma with Modena extender.

Hybrid male sterility between Drosophila willistoni species is caused by male failure to transfer sperm during copulation.

PubMed

Civetta, Alberto; Gaudreau, Chelsea

2015-05-01

The biological concept of species stresses the importance of understanding what mechanisms maintain species reproductively isolated from each other. Often such mechanisms are divided into premating and postmating, with the latest being the result of either prezygotic or postzygotic isolation barriers. Drosophila willistoni quechua and Drosophila willistoni willistoni are two subspecies that experience reproductive isolation. When a D. w. quechua female is crossed with a D. w. willistoni male, the hybrid males (F1QW) are unable to father progeny; however, the reciprocal cross produces fertile hybrids. Thus, the mechanism of isolation is unidirectional hybrid male sterility. However, the sterile F1QW males contain large amounts of motile sperm. Here we explore whether pre-copulatory or post-copulatory pre-zygotic mechanisms serve as major deterrents in the ability of F1QW males to father progeny. Comparisons of parental and hybrid males copulation durations showed no significant reduction in copulation duration of F1QW males. Interrupted copulations of the parental species confirmed that sperm transfer occurs before the minimum copulation duration registered for F1QW males. However, we found that when females mate with F1QW males, sperm is not present inside the female storage organs and that the lack of sperm in storage is due to failure to transfer sperm rather than spillage or active sperm dumping by females. Sterility of F1QW hybrid males is primarily driven by their inability to transfer sperm during copulation.

Factors affecting storage of Slovak native rabbit semen in the gene bank.

PubMed

Kulíková, Barbora; Oravcová, Marta; Baláži, Andrej; Supuka, Peter; Chrenek, Peter

2017-10-01

In this study, fresh and frozen-thawed semen of Nitra and Zobor rabbit breeds were evaluated for potential inter-breed or inter-male differences in sperm quality traits. Individual male semen from four rabbits of each breed were diluted (v:v; 1:1) in a freezing medium composed of a commercial diluent, 16% of dimethyl sulphoxide (DMSO), 4% of Ficoll 70 and 2% of sucrose and frozen in liquid nitrogen vapours before being plunged into liquid nitrogen. Different motility traits, viability and plasma membrane integrity of fresh and frozen-thawed semen were evaluated in vitro using computer-assisted sperm analysis and flow cytometry. To evaluate the sperm fertilization ability, artificial insemination of fresh and frozen-thawed sperm was performed. Our results showed the effect of breed (P ≤ 0.05) on frozen-thawed sperm viability and plasma membrane integrity. Moreover, individual variability in semen quality among the rabbits was revealed (0.31 to 0.71 among quality traits). Our results thereby confirmed that the cryopreservation procedure could not ensure comparable sperm post-thaw survival for different breeds or males. Nevertheless, correlations between numbers of fresh total motile and progressively moving sperm and several quality parameters measured post thawing were revealed. Therefore, we suggest that the objective assessment of fresh rabbit sperm motility may be an effective indicator of frozen-thawed semen quality. Consequently, regular semen assessment is required in order to preserve good-quality insemination doses from native breeds.

Semen amyloids participate in spermatozoa selection and clearance

PubMed Central

Roan, Nadia R; Sandi-Monroy, Nathallie; Kohgadai, Nargis; Usmani, Shariq M; Hamil, Katherine G; Neidleman, Jason; Montano, Mauricio; Ständker, Ludger; Röcker, Annika; Cavrois, Marielle; Rosen, Jared; Marson, Kara; Smith, James F; Pilcher, Christopher D; Gagsteiger, Friedrich; Sakk, Olena; O’Rand, Michael; Lishko, Polina V; Kirchhoff, Frank

2017-01-01

Unlike other human biological fluids, semen contains multiple types of amyloid fibrils in the absence of disease. These fibrils enhance HIV infection by promoting viral fusion to cellular targets, but their natural function remained unknown. The similarities shared between HIV fusion to host cell and sperm fusion to oocyte led us to examine whether these fibrils promote fertilization. Surprisingly, the fibrils inhibited fertilization by immobilizing sperm. Interestingly, however, this immobilization facilitated uptake and clearance of sperm by macrophages, which are known to infiltrate the female reproductive tract (FRT) following semen exposure. In the presence of semen fibrils, damaged and apoptotic sperm were more rapidly phagocytosed than healthy ones, suggesting that deposition of semen fibrils in the lower FRT facilitates clearance of poor-quality sperm. Our findings suggest that amyloid fibrils in semen may play a role in reproduction by participating in sperm selection and facilitating the rapid removal of sperm antigens. DOI: http://dx.doi.org/10.7554/eLife.24888.001 PMID:28653619

Autoradiographic visualization of the mouse egg's sperm receptor bound to sperm

DOE Office of Scientific and Technical Information (OSTI.GOV)

Bleil, J.D.; Wassarman, P.M.

1986-04-01

The extracellular coat, or zona pellucida, of mammalian eggs contains species-specific receptors to which sperm bind as a prelude to fertilization. In mice, ZP3, one of only three zona pellucida glycoproteins, serves as sperm receptor. Acrosome-intact, but not acrosome-reacted, mouse sperm recognize and interact with specific O-linked oligosaccharides of ZP3 resulting in sperm-egg binding. Binding, in turn, causes sperm to undergo the acrosome reaction; a membrane fusion event that results in loss of plasma membrane at the anterior region of the head and exposure of inner acrosomal membrane with its associated acrosomal contents. Bound, acrosome-reacted sperm are able to penetratemore » the zona pellucida and fuse with the egg's plasma membrane (fertilization). In the present report, we examined binding of radioiodinated, purified, egg ZP3 to both acrosome intact and acrosome reacted sperm by whole-mount autoradiography. Silver grains due to bound 125I-ZP3 were found localized to the acrosomal cap region of heads of acrosome-reacted sperm. Under the same conditions, 125I-fetuin bound at only background levels to heads of both acrosome-intact and -reacted sperm, and 125I-ZP2, another zona pellucida glycoprotein, bound preferentially to acrosome-reacted sperm. These results provide visual evidence that ZP3 binds preferentially and specifically to heads of acrosome intact sperm; properties expected of the mouse egg's sperm receptor.« less

Uterosome-like vesicles prompt human sperm fertilizing capability.

PubMed

Franchi, A; Cubilla, M; Guidobaldi, H A; Bravo, A A; Giojalas, L C

2016-12-01

Does the rapid transit through the uterine environment modulate the sperm physiological state? The uterosome-like vesicles (ULVs) secreted by endometrial epithelial cells (EECs) in vitro are able to fuse with human spermatozoa, prompting their fertilizing capacity. Early studies suggest that sperm capacitation begins in the uterus and ends in the oviduct, and that a synergistic effect of both female organs may accelerate this process. Although it has been reported that co-incubation of human spermatozoa with endometrial cell-conditioned medium (CM) stimulates sperm capacitation, the mechanism mediating this communication is unknown. Human ULVs secreted by EECs were characterized and their effect on human sperm physiology was analysed. Spermatozoa were incubated with EEC-derived CM or ULV, after which sperm capacitation was evaluated at different time points. In addition, the interaction of spermatozoa with ULV was analysed. ULVs were isolated by ultracentrifugation and identified using electron microscopy and Western blotting to assess the presence of specific protein markers. Following seminal plasma removal, human spermatozoa were incubated CM or ULV, after which sperm capacitation was evaluated as the ability of the sperm to undergo the induced acrosome reaction and the level of protein tyrosine phosphorylation (PY) determined by Western blot and immunocytochemistry. The interaction of spermatozoa with labelled ULV was analysed by fluorescence microscopy. In all cases, at least three biological replicates from different sperm donors were performed for each set of experiments. Significant differences between mean values were determined by one-way ANOVA followed by Tukey's post hoc test. Differences between treatments were considered statistically significant at P ≤ 0.05. The level of capacitated spermatozoa and those recruited by chemotaxis increased 3- to 4-fold when spermatozoa were incubated in the presence of CM for 4 h. Even a 15 min incubation of spermatozoa with CM was also enough to increase the level of capacitated cells 3- to 4-fold (P < 0.05). Furthermore, a short co-incubation of spermatozoa with ULV stimulates sperm capacitation, as determined by the increase in the level of induced acrosome reaction and the induction of PY. In addition, after the co-incubation of spermatozoa with fluorescent labelled ULV, the sperm cells acquired the fluorescent staining which indicates that ULV might be transferred to the sperm surface by a fusion mechanism. This is an in vitro study performed with human biological material, spermatozoa and endometrial derived cells; the latter being a cell line originally isolated from a uterine adenocarcinoma. The capability of spermatozoa to briefly interact with ULVs supports the hypothesis that any step of sperm transport may have physiological consequences, despite the interaction lasting for only a limited period of time. This way of communication of spermatozoa with cell products of uterine origin opens new frontiers of investigation (e.g. the signalling molecules involved), shedding light on the sperm processes that prepare the male gamete for fertilization, which might have implications for human infertility treatment. N/A. The project was financially supported by SECyT-UNC. The authors declare no conflict of interest. © The Author 2016. Published by Oxford University Press on behalf of the European Society of Human Reproduction and Embryology. All rights reserved. For Permissions, please email: journals.permissions@oup.com.

Associations of hypoosmotic swelling test, relative sperm volume shift, aquaporin7 mRNA abundance and bull fertility estimates.

PubMed

Kasimanickam, R K; Kasimanickam, V R; Arangasamy, A; Kastelic, J P

2017-02-01

Mammalian sperm are exposed to a natural hypoosmotic environment during male-to-female reproductive tract transition; although this activates sperm motility in vivo, excessive swelling can harm sperm structure and function. Aquaporins (AQPs) is a family of membrane-channel proteins implicated in sperm osmoregulation. The objective was to determine associations among relative sperm volume shift, hypoosmotic swelling test (HOST), sperm aquaporin (AQP) 7 mRNA abundances, and sire conception rate (SCR; fertility estimate) in Holstein bulls at a commercial artificial insemination center. Three or four sires for each full point SCR score from -4 to +4 were included. Each SCR estimate for study bulls (N = 30) was based on > 500 services (mean ± SEM) of 725 ± 13 services/sire). Sperm from a single collection day (two ejaculates) from these commercial Holstein bulls were used. Relative mRNA expression of AQP7 in sperm was determined by polymerase chain reaction. Mean relative sperm volume shift and percentage of sperm reacted in a HOST (% HOST) were determined (400 sperm per bull) after incubating in isoosmotic (300 mOsm/kg) and hypoosmotic (100 mOsm/kg) solutions for 30 min. There was no correlation between %HOST and SCR (r = 0.28 P > 0.1). However, there was a positive correlation between relative sperm volume shift and SCR (r = 0.65, P < 0.05). Furthermore, AQP7 mRNA abundance was positively correlated to both relative volume shift (r = 0.73; P < 0.05) and to SCR (r = 0.67; P < 0.05). The mRNA expressions of AQP7 and relative sperm volume shift differed (P < 0.05) among low- (<2 SCR), average- (-2 to +2) and high- (>2) fertility sire groups. In conclusion, bulls with higher SCR had significantly greater AQP7 mRNA abundance in frozen-thawed sperm. This plausibly contributed to greater regulation of sperm volume shift, which apparently conferred protection from detrimental swelling and impaired functions. Copyright © 2016 Elsevier Inc. All rights reserved.

Acceleration of sperm transit time and reduction of sperm reserves in the epididymis of rats exposed to sibutramine.

PubMed

Bellentani, Fernanda F; Fernandes, Glaura S A; Perobelli, Juliana E; Pacini, Enio S A; Kiguti, Luiz R A; Pupo, André S; Kempinas, Wilma D G

2011-01-01

Sibutramine is a drug globally used for the treatment of obesity. The aim of this study was to investigate male reproductive disorders caused by sibutramine in adult rats. Wistar rats were treated for 28 consecutive days (gavage) with 10 mg/kg of sibutramine. Control animals received only vehicle (dimethylsulfoxide and saline). The rats were sacrificed for evaluation of body and reproductive organ weights, sperm parameters, hormone levels (luteinizing hormone, follicle-stimulating hormone, and testosterone), testicular and epididymal histopathology, sexual behavior, fertility and in vitro contractility of the epididymal duct. Sibutramine decreased (P < .05) weights of the epididymis and ventral prostate, but not of other reproductive organs. The sperm number and transit time in the epididymal cauda were decreased (P < .001), but the daily sperm production was not altered. Moreover, morphology and sperm motility, histopathology of the testes and epididymis, sexual behavior, fertility, and serum hormone levels were not altered by the treatment. Sibutramine increased the potency of norepinephrine and, per se, increased the mechanical activity of the epididymal duct in vitro. Thus, although sibutramine in these experimental conditions did not interfere with the reproductive process of rats, it provoked acceleration of the sperm transit time and a decrease in the sperm reserves in the epididymal cauda. This alteration is probably related to the sympathomimetic effect of this drug, as shown by the in vitro assays. In humans, use of this drug might present a threat for male fertility because sperm reserves in men are naturally lower than those in rats.

Reduction of centrifugation force in discontinuous percoll gradients increases in vitro fertilization rates without reducing bovine sperm recovery.

PubMed

Guimarães, A C G; Leivas, F G; Santos, F W; Schwengber, E B; Giotto, A B; Machado, C I U; Gonçalves, C G M; Folchini, N P; Brum, D S

2014-05-01

The objective of this study was to determine the effect of different centrifugation forces in bovine sperm separation by discontinuous Percoll gradients for in vitro fertilization IVF. The semen samples from each bull were pooled or each bull were centrifuged separately and centrifuged in discontinuous Percoll gradients (30, 60 and 90%) at different forces: F1 (9000×g), F2 (6500×g), F3 (4500×g) and F4 (2200×g), according experiment. The sperm samples were evaluated to determine the concentration, motility, vigor, morphology, reactive oxygen species (ROS), integrity of the plasma membrane, lipid peroxidation, antioxidants and embryo development were also evaluated. No difference was observed in the concentration of sperm submitted to different centrifugation forces. The total percentage of motile sperm was increased after centrifugation at F3 and F4, and the ROS production at F1 was greater than the other forces. When the bulls semen were processed individually, no significant differences were observed for the sperm quality parameters between F1 and F4, including lipid peroxidation, antioxidants, cleavage rate and average time to the first cleavage. This work demonstrated for the first time that centrifugation at 2200×g enhanced the sperm penetration and fertilization rates without reducing sperm recovery compared to the typical centrifugation force (9000×g) currently used by the commercial bovine IVF industry. Copyright © 2014 Elsevier B.V. All rights reserved.

Smoking and Male Infertility: An Evidence-Based Review

PubMed Central

Harlev, Avi; Gunes, Sezgin Ozgur; Shetty, Amit; du Plessis, Stefan Simon

2015-01-01

Many studies have reported that the contents of cigarette smoke negatively affect sperm parameters, seminal plasma, and various other fertility factors. Nevertheless, the actual effect of smoking on male fertility is not clear. The effect of smoking on semen parameters is based on the well-established biological finding that smoking increases the presence of reactive oxygen species, thereby resulting in oxidative stress (OS). OS has devastating effects on sperm parameters, such as viability and morphology, and impairs sperm function, hence reducing male fertility. However, not all studies have come to the same conclusions. This review sheds light upon the arguable association between smoking and male fertility and also assesses the impact of non-smoking routes of tobacco consumption on male infertility. It also highlights the evidence that links smoking with male infertility, including newly emerging genetic and epigenetic data, and discusses the clinical implications thereof. PMID:26770934

LOCALIZATION, FERTILITY INHIBITION, AND EPITOPE MAPS USING ANTIBODIES TO THE SPERM PROTEIN SP22

EPA Science Inventory

LOCALIZATION, FERTILITY INHIBITION, AND EPITOPE MAPS USING ANTIBODIES TO THE SPERM PROTEIN SP22. GR Klinefelter1, JE Welch*1, HDM Moore*2, K Bobseine*1, J Suarez*1 ,N Roberts*1 ,R Zucker *1 1U.S. EPA, NHEERL, Reproductive Toxicology Division, RTP, NC and 2University of Sheffield...

Improvement of common carp (Cyprinus carpio) sperm cryopreservation using a programable freezer.

PubMed

Bernáth, Gergely; Żarski, Daniel; Kása, Eszter; Staszny, Ádám; Várkonyi, Levente; Kollár, Tímea; Hegyi, Árpád; Bokor, Zoltán; Urbányi, Béla; Horváth, Ákos

2016-10-01

The applicability of a programmable freezer for the increased-scale cryopreservation of common carp sperm was investigated. The effect of different equilibration times, cryopreservation methods, extenders, dilution ratios, activating solutions on the post-thaw motility of common carp sperm was investigated. The suitable post-thaw storage time-interval as well as fertilizing capacity of cryopreserved sperm was also examined. The motility, curvilinear velocity (VCL) and straightness (STR) values did not decrease significantly during 60min of equilibration neither in equilibrated nor thawed groups. Motility parameters of thawed sperm were similar using a conventional cryopreservation technique using a polystyrene box [motility (33%), VCL (47μm/s) and STR (88%)] and a programmable freezer: [motility (32%), VCL (54μm/s) and STR (89%)]. The highest motility and VCL was measured with a sugar based extender (grayling extender) at a ratio 1:9 (motility: 52%, VCL: 76μm/s) and 1:20 (motility: 49%, VCL: 76μm/s). The activating solution for cyprinids (ASC) could prolong sperm movement up for 2min. A storage time of six hours following thawing did not have a significant effect on the motility parameters of thawed carp sperm. Agglutination was observed during cryopreservation of an elevated volume of sperm whereas motility 47%, VCL 62μm/s and STR 91% were measured after thawing. Fertilization rate with thawed sperm (32%) was significantly lower compared to the control group (73%). According to our results, the developed method using a programmable freezer is suitable for the cryopreservation of elevated number of straws. However, carp sperm agglutination during freezing may have a negative effect on the fertilizing capacity. Copyright © 2016 Elsevier Inc. All rights reserved.

Vitelline envelope of Bufo arenarum: biochemical and biological characterization.

PubMed

Barisone, Gustavo A; Hedrick, Jerry L; Cabada, Marcelo O

2002-04-01

Vitelline envelopes (VEs) of Bufo arenarum were isolated in order to study their composition and their role in fertilization. VEs are composed of four glycoproteins, with molecular masses of 120, 75, 41, and 38 kDa. To characterize its biological properties, we quantitatively determined sperm-VE binding and the induction of the acrosome reaction. Heterologous binding of B. arenarum sperm to Xenopus laevis VE components was observed with about one-third the efficiency of homologous binding. Equivalent binding of X. laevis sperm to the B. arenarum VE was observed. When B. arenarum sperm were incubated with fluorescein isothiocyanate-labeled VE, the labeled glycoproteins bound to the anterior end of the sperm head, showing a lateral distribution. Induction of the acrosome reaction was evaluated by incubating sperm in hypotonic saline media with VE glycoproteins. VEs induced the acrosome reaction in a time- and concentration-dependent manner. The acrosome reaction was maximal after 10 min. The half-maximal effect was obtained at a glycoprotein concentration of 1 microg/ml. Specificity was determined using fertilization envelope glycoproteins, which failed to induce the acrosome reaction. The B. arenarum VE is biochemically similar to other egg envelopes. It also seems that its biological properties are similar to other species in regard to sperm binding and induction of the acrosome reaction. However, as far as we are aware, this is the first observation of the VE inducing the sperm acrosome reaction in amphibians. The relatively small differences observed in heterologous sperm-VE binding in X. laevis and B. arenarum are inconsistent with the current paradigm that species specificity in fertilization is regulated at the sperm-VE binding step.

Development and current applications of assisted fertilization.

PubMed

Palermo, Gianpiero D; Neri, Queenie V; Monahan, Devin; Kocent, Justin; Rosenwaks, Zev

2012-02-01

Since the very early establishment of in vitro insemination, it became clear that one of the limiting steps is the achievement of fertilization. Among the different assisted fertilization methods, intracytoplasmic sperm injection emerged as the ultimate technique to allow fertilization with ejaculated, epididymal, and testicular spermatozoa. This work describes the early steps that brought forth the development of intracytoplasmic sperm injection and its role in assisted reproductive techniques. The current methods to select the preferential male gamete will be elucidated and the concerns related to the offspring of severe male factor couples will be discussed. Copyright © 2012. Published by Elsevier Inc.

Sperm chromatin structure integrity in liquid stored boar semen and its relationships with field fertility.

PubMed

Boe-Hansen, G B; Christensen, P; Vibjerg, D; Nielsen, M B F; Hedeboe, A M

2008-04-01

Extended semen doses from some boars used for AI have been shown to develop high levels of sperm DNA fragmentation during storage. Studies in other animals and humans have shown that if DNA damage is present in a certain percentage of the sperm cells the fertility potential of the semen sample is reduced. The objectives of the present study was to determine the relationship between sperm DNA fragmentation measured using the sperm chromatin structure assay (SCSA) in extended stored semen and field fertility in the boar. Three ejaculates from each of 145 boars were collected. Preparation of the semen doses included dilution with an EDTA extender and storage for up to 72 h post collection. The semen doses were assessed using flow cytometric methods for the percentage of viable sperm (PI/SYBR-14) and sperm DNA fragmentation (SCSA) at 0, 24, 48, and 72 h. A total of 3276 experimental inseminations in Danish breeding herds were conducted. The results showed that for 11 (7.6%) of the boars at least one of the three samples showed a value of DNA fragmentation index (DFI) above 20% within the storage period. Total number of piglets born (litter size) for Hampshire, Landrace and Danish Large White boars was, respectively, 0.5, 0.7 and 0.9 piglets smaller per litter when DFI values were above 2.1% as opposed to below this value. In conclusion the SCSA technique appears to be able to identify individuals with lower fertility with respect to litter size, and could in the future be implemented by the pig industry after a cost-benefit analysis.

The nuclear form of glutathione peroxidase 4 is associated with sperm nuclear matrix and is required for proper paternal chromatin decondensation at fertilization.

PubMed

Puglisi, Rossella; Maccari, Irene; Pipolo, Simona; Conrad, Marcus; Mangia, Franco; Boitani, Carla

2012-04-01

The nuclear isoform of the selenoprotein Phospholipid Hydroperoxide Glutathione Peroxidase (nGPx4) is expressed in haploid male germ cells, contains several cysteines and is able to oxidize protein thiols, besides glutathione. In this study we have investigated the subnuclear localization of this isoform in isolated mouse male germ cells at different steps of maturation. Immunoblotting and confocal microscopy analyses of subnuclear fractions showed that nGPx4 is localized to the nuclear matrix together with well known markers of this subnuclear compartment like lamin B and topoisomerase IIβ at all stages of germ cell differentiation. The peculiar nGPx4 distribution was confirmed by both biochemical and morphological analyses of COS-1 cells overexpressing Flag-tagged nGPx4. To test the functional role of nGPx4 in the process of chromatin assembly, sperm isolated from the caput and the cauda epididymides of wild-type (WT) and genetically deficient in nGPx4 (nGPx4-KO) mice were analyzed in an in vitro chromatin decondensation assay. Results showed that sperm from nGPx4-KO mice were more prone to decondense than those from WT mice at all stages of epididymal maturation, providing conclusive evidence that nGPx4 is required for a correct sperm chromatin compaction. We next addressed the issue of whether the lack of nGPx4 impacts on early events occurring at fertilization. Indeed, in vitro fertilization experiments showed an acceleration of sperm chromatin dispersion in oocytes fertilized by nGpx4-KO sperm compared with control. Overall these data indicate that the absence of nGPx4 leads to sperm nuclear matrix/chromatin instability that may negatively affect the embryo development. Copyright © 2011 Wiley Periodicals, Inc.

Poor Centrosomal Function of Cat Testicular Spermatozoa Impairs Embryo Development In Vitro after Intracytoplasmic Sperm Injection1

PubMed Central

Comizzoli, Pierre; Wildt, David E.; Pukazhenthi, Budhan S.

2007-01-01

In the domestic cat, morula-blastocyst formation in vitro is compromised after intracytoplasmic sperm injection (ICSI) with testicular compared to ejaculated spermatozoa. The aim of this study was to determine the cellular basis of the lower developmental potential of testicular spermatozoa. Specifically, we examined the influence of sperm DNA fragmentation (evaluated by TUNEL assay) and centrosomal function (assessed by sperm aster formation after ICSI) on first-cleavage timing, developmental rate, and morula-blastocyst formation. Because the incidences of DNA fragmentation were not different between testicular and ejaculated sperm suspensions, DNA integrity was not the origin of the reduced developmental potential of testicular spermatozoa. After ICSI, proportions of fertilized and cleaved oocytes were similar and not influenced by sperm source. However, observations made at 5 h post-activation clearly demonstrated that 1) zygotes generally contained a large sperm aster after ICSI with ejaculated spermatozoa, a phenomenon never observed with testicular spermatozoa, and 2) proportions of zygotes with short or absent sperm asters were higher after ICSI with testicular spermatozoa than using ejaculated spermatozoa. The poor pattern of aster formation arose from the testicular sperm centrosome, which contributed to a delayed first cleavage, a slower developmental rate, and a reduced formation of morulae and blastocysts compared to ejaculated spermatozoa. When a testicular sperm centrosome was replaced by a centrosome from an ejaculated spermatozoon, kinetics of first cell cycle as well as embryo development quality significantly improved and were comparable to data from ejaculated spermatozoa. Results demonstrate for the first time in mammals that maturity of the cat sperm centrosome (likely via epididymal transit) contributes to an enhanced ability of the spermatozoon to produce embryos that develop normally to the morula and blastocyst stages. PMID:16687647

Semen analysis (image)

MedlinePlus

The sperm count test is performed if a man's fertility is in question. It is helpful in determining if there is a problem in sperm production or quality of the sperm as a cause of infertility. The test may also be used after ...