scholarly journals Concepts in sperm heterogeneity, sperm selection and sperm competition as biological foundations for laboratory tests of semen quality

Reproduction ◽  
2004 ◽  
Vol 127 (5) ◽  
pp. 527-535 ◽  
Author(s):  
William V Holt ◽  
Katrien J W Van Look
Keyword(s):  
Sperm Competition ◽  
Laboratory Tests ◽  
Semen Quality ◽  
Sea Urchins ◽  
Selection Process ◽  
Sperm Quality ◽  
Genetic Material ◽  
Mendelian Inheritance ◽  
Competition Theory ◽  
Selection Processes

Stringent selection mechanisms, in both internal and external fertilisation systems, reject all but a significant minority of the spermatozoa released at ejaculation. Sperm competition theory provides circumstantial evidence that the selection process involves mechanisms by which the quality of the fertilising spermatozoon is controlled, thereby ensuring that females and their offspring receive high quality genetic material. In this review we examine some of these selection processes to see whether they could be exploited for the improvement of laboratory tests of sperm quality. Such tests are not only required for clinical and agricultural purposes, but are increasingly needed in fields such as reproductive and environmental toxicology where the species requirement is much broader. Despite many years of research, sperm quality assessment methods continue to provide imprecise data about fertility; here we suggest that this may be a consequence of using tests that focus on the spermatozoa that would normally be unable to fertilise under natural conditions. To achieve fertilisation a spermatozoon must be capable of responding appropriately to external signalling stimuli; those involving protein kinase-regulated flagellar function seem especially influential in governing effects ranging from non-Mendelian inheritance in mammals to sperm chemotaxis in sea urchins. Examination of the elicited responses reveals considerable heterogeneity in all species. Here we propose that this level of heterogeneity is meaningful both in terms of understanding how spermatozoa from some individuals possess fertility advantages over spermatozoa from their rivals in sperm competition, and in that the heterogeneity should be exploitable in the development of more accurate laboratory tests.

scholarly journals Dunnock social status correlates with sperm speed, but fast sperm does not always equal high fitness

2020 ◽  
Author(s):  
Carlos Esteban Lara ◽  
Helen Taylor ◽  
Benedikt Holtmann ◽  
Sheri Johnson ◽  
Eduardo S. A. Santos ◽  
...  
Keyword(s):  
Social Status ◽  
Sperm Competition ◽  
Wild Population ◽  
Sperm Quality ◽  
Sperm Cells ◽  
Competition Theory ◽  
The Social ◽  
Statistical Support ◽  
Mating Opportunities ◽  
Low Levels

Sperm competition theory predicts that males should modulate sperm investment according to their social status. Sperm speed (one proxy of sperm quality) also influences the outcome of sperm competition because fast sperm cells may fertilize eggs before slow sperm cells. We evaluated whether the social status of males predicted their sperm speed in a wild population of dunnocks (Prunella modularis). In addition to the traditional analysis of the average speed of sperm cells per sample, we systematically evaluated ranked groups of sperm, ranging from the 5-fastest sperm cells to the 100-fastest sperm cells in a sample. We further evaluated whether fitness, defined here as the number of chicks sired per male per breeding season, relates to the sperm speed in the same population. We found that males in monogamous pairings (i.e. low levels of sperm competition), produced the slowest sperm cells whereas subordinate males in polyandrous male-male coalitions, (i.e. high levels of sperm competition), produced the fastest sperm cells. This result was consistent across all the ranked groups of sperm, but statistical support was conditional on the number of sperm cells included in the analysis. Surprisingly, we found no significant relationship between fitness and sperm speed, contrary to theory – it is possible that the differential mating opportunities across social status leveled out any possible difference. Our study also suggests that it is important to identify biologically meaningful rankings of fastest sperm and cutoffs for inclusions for assessing sperm competition via sperm speed.

scholarly journals Pharmacological correction of technological stress in bulls and assessment of the influence of stress factors on semen quality

2021 ◽  
Vol 32 ◽  
pp. 04008
Author(s):  
Anastasiia Chaplynskikh ◽  
Ivan Nikulin
Keyword(s):  
Semen Quality ◽  
Sperm Quality ◽  
Genetic Material ◽  
Animal Husbandry ◽  
The Body ◽  
Stress Factors ◽  
Reproductive Capacity ◽  
Animal Reproduction ◽  
Leading Role ◽  
Technological Stress

The current conditions for the intensification of animal husbandry dictate a significant increase in the physiological and functional load on the body of productive animals, resulting in a failure of adaptive capacity, which manifest themselves in the violation of reproduction function and the development of pathological states. Research by domestic and foreign scientists has shown that stress plays a leading role in the etiology and pathogenesis of diseases leading to a reduction in animal reproduction [3, 4, 9]. Although the topic of stress is often covered in the scientific literature, some of its features are not fully explored. This is particularly true for male producers whose genetic material has a direct impact on livestock productivity and livestock production [1, 3, 4, 11]. Therefore, the study of the influence of stress factors on the reproductive capacity of males and their pharmaco-rectification is relevant. The aim of our research was to assess the degree of influence of technological stress factors on the reproduction function of the bull producers and to develop a pharmaco-correction scheme to prevent stress effects on sperm quality. In relation to the objective, the following objectives were proposed: 1. Study the reaction of the ox producers to the effects of technological stress; 2. Determine the influence of drugs Amber biostimulator, Azoxyvet on the quality of bull sperm.

The Prevalence of Bacteriospermia in Infertile Men and Association with Semen Quality in Southwestern Iran

2020 ◽  
Vol 20 (2) ◽  
pp. 198-202 ◽  
Author(s):  
Mohammad Motamedifar ◽  
Yalda Malekzadegan ◽  
Parisa Namdari ◽  
Behzad Dehghani ◽  
Bahia Namavar Jahromi ◽  
...  
Keyword(s):  
Semen Quality ◽  
Sperm Quality ◽  
Reproductive Function ◽  
World Health ◽  
Public Health Issue ◽  
Control Group ◽  
Microbiological Analysis ◽  
Male Reproductive Function ◽  
Infertile Men ◽  
Southwestern Iran

Introduction: Infertility considered as a social and public health issue and estimated that most of these infertile couples are residents of developing countries. Infectious diseases including the history of Sexually Transmitted Infections (STIs) may impact on male reproductive function. Therefore, the present study aimed to investigate the prevalence of bacterial contaminants of semen and probable association with sperm quality of infertile men in Iranian population. Methods: The study population consisted of 200 infertile men and 150 fertile men attending an infertility Center in southwestern Iran during the study period in 2015. The assessment of sperm parameters was according to the World Health Organization (WHO) guidelines. The presumptive pathogens were identified using standard microbiology tests and confirmed by specific PCR primers. Results: The prevalence of bacteriospermia in the semen of the infertile group was significantly higher than that in the fertile group (48% vs. 26.7%, P <0.001). The microbiological analysis of samples showed that the most abundant species of bacteria in semen of infertile men were Chlamydia trachomatis (12.5%) followed by Neisseria gonorrhoeae (11%). On the other hand, in the control group, Lactobacillus spp. (17.3%) was the most isolated pathogen. Results showed that the presence of N. gonorrhoeae, C. trachomatis, Mycoplasma genitalium, Haemophilus, and Klebsiella was significantly associated with sperm abnormality. Conclusion: Based on our findings, it seems that bacteriospermia is associated with alterations in the properties of semen which may lead to a decrease in the fertilization potential of sperm. Therefore, immediate and appropriate treatment is necessary before investigating every other possible cause of infertility.

Restraint stress of male mice triggers apoptosis in spermatozoa and spermatogenic cells via activating the TNF-α system

Zygote ◽  
2020 ◽  
Vol 28 (2) ◽  
pp. 160-169 ◽  
Author(s):  
Jie Zhang ◽  
De-Ling Kong ◽  
Bin Xiao ◽  
Hong-Jie Yuan ◽  
Qiao-Qiao Kong ◽  
...  
Keyword(s):  
Psychological Stress ◽  
Restraint Stress ◽  
Semen Quality ◽  
Sperm Quality ◽  
Fertilization Rate ◽  
Seminiferous Tubules ◽  
Spermatogenic Cells ◽  
Male Mice ◽  
Testicular Cells ◽  
Tnf Α

SummaryStudies have indicated that psychological stress impairs human fertility and that various stressors can induce apoptosis of testicular cells. However, the mechanisms by which psychological stress on males reduces semen quality and stressors induce apoptosis in testicular cells are largely unclear. Using a psychological (restraint) stress mouse model, we tested whether male psychological stress triggers apoptosis of spermatozoa and spermatogenic cells through activating tumour necrosis factor (TNF)-α signalling. Wild-type or TNF-α−/− male mice were restrained for 48 h before examination for apoptosis and expression of TNF-α and TNF receptor 1 (TNFR1) in spermatozoa, epididymis, seminiferous tubules and spermatogenic cells. The results showed that male restraint significantly decreased fertilization rate and mitochondrial membrane potential, while increasing levels of malondialdehyde, active caspase-3, TNF-α and TNFR1 in spermatozoa. Male restraint also increased apoptosis and expression of TNF-α and TNFR1 in caudae epididymides, seminiferous tubules and spermatogenic cells. Sperm quality was also significantly impaired when spermatozoa were recovered 35 days after male restraint. The restraint-induced damage to spermatozoa, epididymis and seminiferous tubules was significantly ameliorated in TNF-α−/− mice. Furthermore, incubation with soluble TNF-α significantly reduced sperm motility and fertilizing potential. Taken together, the results demonstrated that male psychological stress induces apoptosis in spermatozoa and spermatogenic cells through activating the TNF-α system and that the stress-induced apoptosis in spermatogenic cells can be translated into impaired quality in future spermatozoa.

scholarly journals Post-Thaw Sperm Quality and Functionality in the Autochthonous Pig Breed Gochu Asturcelta

Animals ◽  
2021 ◽  
Vol 11 (7) ◽  
pp. 1885
Author(s):  
José Néstor Caamaño ◽  
Carolina Tamargo ◽  
Inmaculada Parrilla ◽  
Felipe Martínez-Pastor ◽  
Lorena Padilla ◽  
...  
Keyword(s):  
Genetic Resource ◽  
Sperm Quality ◽  
Genetic Material ◽  
Mitochondrial Activity ◽  
Computer Assisted ◽  
Kinematic Parameters ◽  
Linear Mixed Effects ◽  
Sperm Analysis ◽  
Computer Assisted Sperm Analysis ◽  
Analysis System

Genetic resource banks (GRB) preserve the genetic material of endangered, valuable individuals or genetically relevant breeds. Semen cryopreservation is a crucial technique to reach these goals. Thus, we aimed to assess the sperm parameters of semen doses from the native pig breed Gochu Asturcelta stored at the GRB of Principado de Asturias (GRB-PA, Gijón, Spain), focusing on intrinsic and extrinsic (boar, season) factors. Two straws per boar (n = 18, 8–71 months of age) were thawed, pooled, and assessed after 30 and 150 min at 37 °C by CASA (computer-assisted sperm analysis system; motility and kinematic parameters) and flow cytometry (viability, acrosomal status, mitochondrial activity, apoptosis, reactive oxygen species, and chromatin status). The effects of age, incubation, and season on post-thawing quality were determined using linear mixed-effects models. Parameters were on the range for commercial boar breeds, with chromatin status (SCSA: fragmentation and immaturity) being excellent. Incubation decreased sperm quality and functionality. The boar age did not have a significant effect (p > 0.05), but the between-boar variability was significant (p < 0.001). The season significantly affected many parameters (motility, kinematics, viability, acrosomal status, mitochondrial activity), especially after 150 min of incubation. In general, samples collected in spring and summer showed higher quality post-thawing, the lowest in winter. In conclusion, the sperm doses from the Gochu Asturcelta breed stored at the GRB-PA showed excellent chromatin status and acceptable characteristics after thawing. Therefore, boar and seasonal variability in this autochthonous breed could be relevant for cryobank management.

scholarly journals Macro- and microelements in serum and seminal plasma as biomarkers for bull sperm cryotolerance

2021 ◽  
Vol 63 (1) ◽  
Author(s):  
Maja Zakošek Pipan ◽  
Petra Zrimšek ◽  
Breda Jakovac Strajn ◽  
Katarina Pavšič Vrtač ◽  
Tanja Knific ◽  
...  
Keyword(s):  
Seminal Plasma ◽  
Semen Quality ◽  
Sperm Quality ◽  
Membrane Integrity ◽  
Quality Characteristics ◽  
Freezing And Thawing ◽  
Additional Tool ◽  
Bull Semen ◽  
Bull Sperm ◽  
Fresh Semen

ABSTRACT Background Wide variation in fertility rates is observed when using frozen bull semen, even when the bulls have met quality standards for semen production. Therefore, a simple and reliable test to assess the freezing potential of bull semen based on the analysis of fresh semen or blood would be of great value. Attention is now turning to assessment of seminal plasma components such as proteins and elements. In the present study, the concentrations of macro- and microelements in fresh bull semen plasma and in serum and their correlation with quality characteristics of fresh semen and with semen quality after freezing and thawing were determined. Ejaculates were collected from 30 mature bulls, and semen volume, concentration, sperm motility, morphology, tail membrane integrity, plasma membrane permeability and DNA fragmentation were determined on the day of collection and after freezing and thawing. The concentrations of macroelements (Na, Mg, K and Ca) and microelements (Cu, Fe, Zn and Se) were determined in the seminal plasma and serum. The semen samples were classified into satisfactory and unsatisfactory groups according to the fresh semen quality. Results Zinc and Se levels measured in serum were associated with almost all fresh and frozen-thawed semen quality characteristics, while Fe levels were associated only with acrosomal defects in fresh semen. Zinc and Fe levels in fresh seminal plasma were associated with various quality characteristics of fresh and frozen-thawed semen, while Se level in fresh seminal plasma was not associated with any of the semen quality characteristics. Conclusions Microelements were shown to be useful as biomarkers involved in the analysis of bull sperm quality and could be used as an additional tool to predict bull semen quality after freezing and thawing. Our results confirm that the analysis of Zn and Se levels in serum and Zn, Cu and Fe levels in fresh seminal plasma can provide information to discriminate between bull semen samples with spermatozoa with high or low cryotolerance.

scholarly journals Predicting Rates of Inbreeding in Populations Undergoing Selection

Genetics ◽  
2000 ◽  
Vol 154 (4) ◽  
pp. 1851-1864 ◽  
Author(s):  
John A Woolliams ◽  
Piter Bijma
Keyword(s):  
Overlapping Generations ◽  
Linear Models ◽  
Selection Process ◽  
Correction Term ◽  
Random Mating ◽  
Nonrandom Mating ◽  
Selection Processes ◽  
Genetic Contributions ◽  
The Relationship

AbstractTractable forms of predicting rates of inbreeding (ΔF) in selected populations with general indices, nonrandom mating, and overlapping generations were developed, with the principal results assuming a period of equilibrium in the selection process. An existing theorem concerning the relationship between squared long-term genetic contributions and rates of inbreeding was extended to nonrandom mating and to overlapping generations. ΔF was shown to be ~¼(1 − ω) times the expected sum of squared lifetime contributions, where ω is the deviation from Hardy-Weinberg proportions. This relationship cannot be used for prediction since it is based upon observed quantities. Therefore, the relationship was further developed to express ΔF in terms of expected long-term contributions that are conditional on a set of selective advantages that relate the selection processes in two consecutive generations and are predictable quantities. With random mating, if selected family sizes are assumed to be independent Poisson variables then the expected long-term contribution could be substituted for the observed, providing ¼ (since ω = 0) was increased to ½. Established theory was used to provide a correction term to account for deviations from the Poisson assumptions. The equations were successfully applied, using simple linear models, to the problem of predicting ΔF with sib indices in discrete generations since previously published solutions had proved complex.

Fertilization dynamics of sperm from different male mating tactics in bluegill (Lepomis macrochirus)

2005 ◽  
Vol 83 (12) ◽  
pp. 1638-1642 ◽  
Author(s):  
Albrecht I Schulte-Hostedde ◽  
Gary Burness
Keyword(s):  
Sperm Competition ◽  
Lepomis Macrochirus ◽  
Fertilization Success ◽  
Male Mating ◽  
Motile Sperm ◽  
Mating Tactics ◽  
Sperm Activation ◽  
Competition Theory ◽  
Sperm Density ◽  
Over Time

Sperm competition results in the evolution of ejaculate characteristics such as high sperm density, high motility, and fast sperm swimming speed. A fundamental assumption of sperm competition theory is that ejaculates with high motility and fast-swimming sperm have an advantage with respect to fertilization success. We tested this assumption by studying the fertilization dynamics of alternative mating tactics (cuckolders and parentals) of male bluegill (Lepomis macrochirus Rafinesque, 1819). Sneakers (cuckolders) have faster swimming sperm and a higher proportion of motile sperm immediately following sperm activation than do parentals; however, these variables decline more quickly over time in sneaker sperm than in the sperm of parental males. We used a controlled fertilization experiment to test the prediction that parental males will have higher fertilization success than sneakers late in the sperm activation cycle because of the reduced rate of decline in ejaculate quality over time. We found that as the time from sperm activation increases parental sperm fertilizes more eggs than the sperm of sneakers. Our results support the idea that fertilization success is higher when ejaculates contain a higher proportion of either motile sperm or faster swimming sperm, all else being equal. In addition, after controlling for time from sperm activation, we found a significant bias in fertilization success toward parental males, suggesting that cryptic female choice might play a role in fertilization dynamics.

Preliminary comparative deep metabolomic analysis of spermatozoa from zebu and crossbred cattle suggests associations between metabolites, sperm quality and fertility

2021 ◽  
Vol 33 (6) ◽  
pp. 427
Author(s):  
Mohua DasGupta ◽  
Arumugam Kumaresan ◽  
Kaustubh Kishor Saraf ◽  
Gayathree Karthikkeyan ◽  
T. S. Keshava Prasad ◽  
...  
Keyword(s):  
Mass Spectrometry ◽  
Semen Quality ◽  
Sperm Quality ◽  
Tandem Mass ◽  
Metabolomic Analysis ◽  
Metabolomic Profile ◽  
Crossbred Cattle ◽  
Acetyl Coenzyme A ◽  
Chromatography Tandem Mass Spectrometry ◽  
Liquid Chromatography Tandem Mass

Poor semen quality and infertility/subfertility are more frequent in crossbred than zebu bulls. Using a high-throughput liquid chromatography–tandem mass spectrometry (LC-MS/MS)-based approach, we established the preliminary metabolomic profile of crossbred and zebu bull spermatozoa (n=3 bulls each) and identified changes in sperm metabolomics between the two groups. In all, 1732 and 1240 metabolites were detected in zebu and crossbred bull spermatozoa respectively. After excluding exogenous metabolites, 115 and 87 metabolites were found to be unique to zebu and crossbred bull spermatozoa respectively whereas 71 metabolites were common to both. In the normalised data, 49 metabolites were found to be differentially expressed between zebu and crossbred bull spermatozoa. The significantly enriched (P&lt;0.05) pathways in spermatozoa were taurine and hypotaurine metabolism (observed metabolites taurine and hypotaurine) in zebu and glycerophospholipid metabolism (observed metabolites phosphatidylcholine, phosphatidylethanolamine and phosphatidylserine) in crossbred bulls. The abundance of nitroprusside (variable importance in projection (VIP) score &gt;1.5) was downregulated, whereas that of l-cysteine, acetyl coenzyme A and 2′-deoxyribonucleoside 5′-diphosphate (VIP scores &gt;1.0) was upregulated in crossbred bull spermatozoa. In conclusion, this study established the metabolomic profile of zebu and crossbred bull spermatozoa and suggests that aberrations in taurine, hypotaurine and glycerophospholipid metabolism may be associated with the higher incidence of infertility/subfertility in crossbred bulls.

P–130 The effect of time of ejaculation and time of processing of semen on fertilization and ongoing pregnancy in IVF/ICSI treatments

2021 ◽  
Vol 36 (Supplement_1) ◽  
Author(s):  
A Badal ◽  
G Pilgram ◽  
D Diaz de Pool ◽  
L Van der Westerlaken
Keyword(s):  
Incubation Time ◽  
Room Temperature ◽  
Semen Quality ◽  
Sperm Quality ◽  
Gradient Centrifugation ◽  
Handling Time ◽  
Fertility Treatment ◽  
Ongoing Pregnancy ◽  
Ongoing Pregnancy Rate ◽  
Oocyte Vitrification

Abstract Study question Does time between ejaculation and processing, and time between processing and insemination/injection affect fertilization rate (FR) and ongoing pregnancy rate (OPR) in IVF/ICSI treatments? Summary answer Increasing time between processing and insemination significantly decreased the OPR after IVF. FRs after IVF/ICSI and OPR after ICSI were not affected by different time-intervals. What is known already The choice for IVF or ICSI depends on semen quality, however, this doesn’t affect the outcome of IVF/ICSI treatments (Mariappen et al 2018). After ejaculation, the percentage of motile spermatozoa decreases progressively at a rate of about 10%/hour (Makler 1979). According to the ESHRE-guideline, semen should be processed within 1 hour after ejaculation. In our laboratory, a validation was performed that confirmed a decrease in sperm motility after ejaculation. During incubation at 37 °C after processing, the sample remained stable in incubation medium (unpublished data). Therefore, we analyzed the effect of handling time and incubation time with regard to IVF/ICSI outcomes. Study design, size, duration This retrospective data analysis examines the effect of time between ejaculation and processing using density-gradient centrifugation (handling time) and time between processing and insemination (IVF)/injection (ICSI) (incubation time) on the FR and OPR, irrespective of the initial semen quality. A total of 1488 oocyte pickups (844 IVF, 644 ICSI) were included from 1060 patients undergoing fertility treatment between 2017 and 2019. Oocyte pickups without oocytes, with oocyte vitrification, or with donor oocytes were excluded. Participants/materials, setting, methods Anonymized data were obtained from the laboratory database ProMISe. Handling time and incubation time of the semen incubated at 37 °C and 5% CO2 were analyzed in relation to the occurrence of TFF (Total Fertilization Failure), FR and OPR. Linear and logistic regression was performed in SPSS version 25. In case of significant association, the data were adjusted for potential confounders, such as woman’s age, semen quality before and after preparation, and number of oocytes. Main results and the role of chance This study shows that increasing the incubation time of the semen significantly reduced the OPR per ET in IVF treatments (from 30,8% within 3,5 hours to 24,1% after 6 hours) even after adjusting for the potential confouders. However, the OPR in ICSI treatments was not significantly affected by the incubation time (rather, there was an opposite trend). Also, the handling time of the semen did not significant effect the FR per OPU and the OPR per ET in IVF/ICSI treatments. The overall percentage of TFF was 3,5% and did not differ significantly between the IVF and ICSI treatments. Both handling time and incubation time did not have a significant effect on the occurrence of TFF. An explanation for the decrease in OPR in IVF treatments may be that increasing the incubation time at 37 °C reduces the sperm quality as the capacitation reaction takes place too early, energy levels are reduced, DNA damage increases, or vacuoles arise in the sperm heads (Thijssen et al 2014, Jackson et al 2010, Peer et al 2007). Incubation at room temperature and reduction of the insemination time may improve OPR. Limitations, reasons for caution Retrospective study limitations (bias), no data on DNA fragmentation, incubation of semen only at 37 °C after preparation. Wider implications of the findings: Although it is recommended to produce semen at the IVF-department, our results show that an exception can be made, when production of a semen sample in a clinical setting is stressful, with no negative effect on the outcome. Furthermore, incubation-time at room temperature may have a positive effect on OPR. Trial registration number Not applicable

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