Poor Semen Quality Research Articles

Determinant genetic markers of semen quality in livestock.

The reproductive efficiency of livestock is crucial for agricultural productivity and economic sustainability. One critical factor in successful fertilization and the viability of offspring is the quality of semen. Poor semen quality, especially in frozen-thawed semen used in artificial insemination (AI) have been shown to influence conception outcomes, resulting a negative impact on livestock production. Recent advancements in genetic research have identified specific markers linked to semen quality traits in various livestock species, such as cattle, sheep, goats, pigs, buffalo, and equines. These genetic markers are essential in screening males for breeding suitability, which in turn enhances selective breeding programs. Understanding these markers is crucial for improving reproductive performance and increasing productivity in livestock populations. This review offers a comprehensive overview of the genetic markers associated with semen quality in key livestock. It explores the underlying genetic mechanisms and their practical implications in animal breeding and management. The review underscores the importance of integrating genetic insights into breeding strategies to optimize reproductive efficiency and ensure the sustainable development of livestock industries.

Effect of Adding Different Concentrations of Vitamin C and E to Improve Poor Semen Quality in Ram

Effect of Adding Different Concentrations of Vitamin C and E to Improve Poor Semen Quality in Ram

Russian Regional Differences in Allele Frequencies of CFTR Gene Variants: Genetic Monitoring of Infertile Couples.

A male factor, commonly associated with poor semen quality, is revealed in about 50% of infertile couples. CFTR gene (Cystic Fibrosis Transmembrane Conduction Regulator) variants are one of the common genetic causes of azoospermia-related male infertility. Notably, the spectrum and frequency of pathogenic CFTR variants vary between populations and geographical regions. In this work, we made an attempt to evaluate the allele frequency (AF) of 12 common CFTR variants in infertile Russian men and healthy individuals from different districts of Russia. Because of the limited number of population-based studies on Russian individuals, we characterized the population AFs based on data from the Registry of Russian cystic fibrosis (CF) patients. In addition to the CF patient registry, we estimated the local frequencies of the same set of variants based on the results of genotyping of CF patients in local biocollections (from St. Petersburg and Yugra regions). AFs of common CFTR variants calculated based on registry and biocollection data showed good concordance with directly measured population AFs. The estimated region-specific frequencies of CFTR variants allowed us to uncover statistically significant regional differences in the frequencies of the F508del (c.1521_1523del; p.Phe508del) and CFTRdele2,3(21kb) (c.54-5940_273+10250del21kb; p.Ser18ArgfsX) variants. The data from population-based studies confirmed previous observations that F508del, CFTRdele2,3(21kb), and L138ins (c.413_415dup; p.Leu138dup)variants are the most abundant among infertile patients, and their frequencies are significantly lower in healthy individuals and should be taken into account during genetic monitoring of the reproductive health of Russian individuals.

Effect of Glass Wool and Sephadex Sperm Separation Techniques on Improving the Poor Quality Semen of Iraqi Buffalo Bulls

This study investigated the effect of glass wool and Sephadex separation techniques on improving the poor semen quality of buffalo bulls. Semen had divided into four groups. The first and second groups used good (G1, positive control) and poor-quality semen (G2, negative control). Glass wool (G3) and Sephadex (G4) techniques had used to separate the poor semen quality in the 3rd-4th groups, respectively. The sperm concentration and total abnormalities were lower in the G3 and G4 groups than in the G2 group. Motility increased in the G4 group compared to the G2 group. Live sperm, normal morphology, plasma membrane, and acrosome integrity were higher in groups G4 and G3 than in the G2 group. In conclusion, after separation, there was a decrease in sperm concentration compared to non-separation. This decrease had compensated by a proportionate increase in other semen characteristics, which may improve the conception rate via artificial insemination with filtered semen.

Protein Profiles in Seminal Plasma of Iraqi Buffalo Bulls (Bubalus bubalis) Associated with Fresh and Cryopreserved Semen Quality

This study was undertaken to identify some protein profiles in the seminal plasma of Iraqi buffalo bulls and their correlation to the quality of fresh and cryopreserved semen. Semen was collected from eight buffalo bulls and divided according to the percentage of sperm individual motility into two groups. The first group (n=3) included good semen quality, while the second group (n=5) included poor semen quality. Seminal plasma was extracted from each semen sample by centrifugation and seminal proteins were resolved by sodium dodecyl sulfate-polyacrylamide gel electrophoresis (SDS-PAGE). Nine types of protein bands were observed in the seminal plasma of the buffalo bulls belonging to good semen quality, ranging from 10-68 kDa. The most abundant proteins in the overall presence of proteins in seminal plasma were 10 (100%), 14 (100%), 20 (100%), 26 (100%), 34 (100%), and 43 (37.5%) kDa. On the other hand, 14 types of protein bands resolved for the poor-quality semen, ranging from 10-155 kDa. The most abundant proteins in the overall presence of proteins in seminal plasma were 10 (100%), 14 (100%), 20 (100%), 26 (100%), 34 (87.5%), 130 (50%) and 155 (50%) kDa. A significant negative correlation was noticed among proteins with molecular weights of 28. 88 ± 3.26, 22.50 ± 2.85, and 12.00 ± 1.15 kDa, and the percentage of sperm individual motility and plasma membrane integrity. Moreover, there was a positive significant correlation between proteins whose molecular weight 22.50 ± 2.85 kDa and the percentages of total abnormalities and normal sperms. In conclusion, the identification of seminal proteins may be a useful tool in the future evaluation of spermatozoa and the prediction of fertility in Iraqi buffalo bulls.

Seasonal heat stress compromises testicular thermoregulation and semen quality of Dorper rams raised in a desert climate

Dorper rams are widely distributed throughout the world under different climatic conditions, however, little is known about their reproductive performance in desert regions. Ten Dorper rams were individually housed and exposed to thermoneutrality for 35 d in spring (23.6 ± 5.6 °C, mean ± SD) and outdoor heat stress (HS) for 35 d in summer (33.6 ± 2.0 °C) to evaluate the effect of seasonal HS on physiological responses, testicular biometry, and seminal quality under desert climatic conditions. Rectal temperature, respiration rate and coat surface temperatures in different body regions were measured every 7 d (0600, 1200, and 1800 h); also, testicular biometry was registered at 0600 h. Semen was collected via an artificial vagina 3 d after physiological variables were measured and seminal traits were evaluated. Rectal temperature, respiration rate and coat surface temperatures were higher (P < 0.01) at each hour of measurement in summer compared to spring. Overall, scrotal length and circumference, as well as testicular volume were higher (P < 0.01) in summer than in spring. Compared to spring conditions, summer HS caused lower (P ≤ 0.05) sperm concentration and viability combined with a higher percentage of sperm abnormalities without affecting ejaculate volume. Both mass and sperm motility were similar between seasons in the first two sampling weeks, and then decreased (P ≤ 0.03) due to summer HS. In conclusion, Dorper rams developed testicle hyperthermia and, consequently, showed poor semen quality due to the high environmental temperatures prevailing in desert regions.

Effect of leukocytes on semen quality in men from primary and secondary infertile couples: A cross-sectional study.

Leukocytospermia (LCS) is a known cause of male infertility. However, the relationship between seminal leukocytes and semen quality among infertile couples remains controversial. This study aims to investigate the association between semen quality and LCS in male partners of infertile couples. Semen samples were collected from 512 men who asked for a fertility evaluation in a reproductive center in China. Seminal leukocytes were counted following peroxidase staining with benzidine. Other semen parameters were compared in subfertile men with and without LCS. Poor semen quality (e.g., low semen volume, sperm concentration, and sperm progressive/total motility) was observed among men with LCS compared to those without LCS. Men with LCS had a higher risk of low sperm progressive motility (OR = 0.99, 95% CI = 0.98-0.99, p = 0.02) and total motility (OR = 0.99, 95% CI = 0.98-0.99, p = 0.02), even after adjustment for potential confounders (both OR = 0.99, 95% CI = 0.98-0.99, p = 0.03). Lower sperm viability was observed in LCS from male partners of secondary couples, while no significant difference in semen parameters was found between men with and without LCS in male partners of primary infertile couples. Low sperm motility and viability were associated with LCS in men from secondary infertile couples after adjusting for confounders (OR = 0.97, 95% CI = 0.95-0.99, p = 0.04; OR = 0.94, 95% CI = 0.89-0.99, p = 0.04, respectively). Our findings indicate that a higher risk of abnormal semen parameters was correlated with an increased number of leukocytes in men from secondary infertile couples.

60 Molecular Characterization of Boar Semen in Relation to Sperm Quality

Abstract Artificial insemination (AI) with fresh semen is the primary breeding tool in the swine industry. However, the heterogenous semen doses create challenges in boar studs due to the lack of consistent assessment criteria. Seminal plasma (SP) surrounding spermatozoa is a great source of reliable non-invasive biomarkers of sperm quality. It contains a wide array of bioactive molecules, whose dynamic compositions in response to extrinsic and intrinsic factors influence sperm motility and morphology. Therefore, we hypothesize that the miRNA content of extracellular vesicles (EVs) found in SP may reflect semen quality. Our study aimed to characterize poor vs. good quality semen and compare miRNA profiles of SP-derived EVs. Raw semen was collected (n = 75) from sexually mature Duroc boars at a commercial stud (Prestage Farms, MS) for 8 weeks. Semen samples were subjected to sperm motility and morphology analyses and subsequently classified as poor (n = 38) or good (n = 37) quality based on assessment criteria cut-offs (&amp;lt; 70% and ≥70%, respectively). Thereafter, raw semen samples were subjected to serial centrifugation to collect spermatozoa and SP. Samples were stored at -80oC until analyses. A subset of each frozen-thawed SP was used for NIRS absorbance analysis (ASD FieldSpec3 portable spectrometer – 1mm quartz cuvettes; 750-2500 nm). Other subsets of frozen-thawed SP were ultra-centrifugated to isolate EVs (SP-EV), followed by confirmations through transmission electron microscopy (TEM), dynamic light scattering (DLS), and immuno-western blotting. Five pools of three individual SP-EV samples, corresponding to extremely poor and extremely good quality semen, were constituted for total exosome RNA isolation, small RNA sequencing, miRNA detection, and differential miRNA expression. Messenger RNA targets of miRNA were searched and subjected to functional bioinformatic analyses using various software algorithms. Significant differences were set for P &amp;lt; 0.05. Poor and good quality samples had different spectrum profiles following NIRS analyses. Changes were explicitly observed in water structures at coordinates C1, C5, and C12 (nm), corresponding to water associations with chaotropic solutes (water asymmetrical stretching vibrations-ν3), free water, and kosmotropic solutes (increased H-bonding numbers and strength), respectively. The NIRS-LDA data contrasted two distinctive poor and good quality SP samples. All boar SP-EV were confirmed: round spherical structure; 30 to 400nm of diameter; and CD9+, CD63+, and CD81+ membrane markers. Totals of 281 and 271 miRNAs were identified in poor and good groups, respectively, and 15 were differentially expressed (DE). Only three DE miRNAs (ssc-miR-205, ssc-miR-493-5p, and ssc-miR-378b-3p) permitted targeting of 109 mRNA, which functional analyses indicated associations with nuclear and cytosol localization, as well as with functions, i.e., acetylation, Ubl conjugation, protein kinase binding, potentially altering sperm function. In conclusion, the study indicates that the NIRS tool can distinguish between good and poor semen quality, and the miRNA SP-EV content may reflect semen quality.

Exposure to Cumulus Cell Secretome Improves Sperm Function: New Perspectives for Sperm Selection In Vitro.

In the literature, there is a well-known correlation between poor semen quality and DNA sperm integrity, which can turn into negative outcomes in terms of embryo development and clinical pregnancy. Sperm selection plays a pivotal role in clinical practice, and the most widely used methods are mainly based on sperm motility and morphology. The cumulus oophorus complex (COC) during natural fertilization represents a barrier that spermatozoa must overcome to reach the zona pellucida and fertilize the oocyte. Spermatozoa that can pass through the COC have better structural and metabolic characteristics as well as enhanced acrosome reaction (AR). The present study aimed to evaluate the exposure of sperm to cumulus cell secretome during swim-up treatment (SUC) compared with the routinely used swim-up method (SU). To determine the effectiveness of this method, biological factors critical for the ability of sperm to fertilize an oocyte, including capacitation, AR, tyrosine phosphorylation signature, DNA integrity, and mitochondrial functionality, were assessed. The SUC selection assures recovery of high-quality spermatozoa, with enhanced mitochondrial functionality and motility compared with both SU-selected and unselected (U) sperm. Furthermore, using this modified swim-up procedure, significantly reduced sperm DNA damage (p < 0.05) was detected. In conclusion, the SUC approach is a more physiological and integrated method for sperm selection that deserves further investigation for its translation into clinical practice.

Non-targeted proteomic analysis of Asian elephant (Elephas maximus) seminal plasma using an in-solution digestion technique and liquid chromatography tandem-mass spectrometry.

Seminal plasma proteins have recently been reported to play a significant role as valuable materials for understanding male reproductive biology, identifying causes of fertility problems, and developing reproductive biomarkers. Proteomic analysis of seminal plasma holds promise in advancing the understanding of male Asian elephant reproductive biology. This study aims to explore seminal plasma proteins of Asian elephants and their probable functions to provide fundamental information about male reproduction in this species. The protein solution from pooled seminal plasma from 10 bulls (a total of 33 ejaculates) was digested into peptides and identified using LC-MS/MS. Out of 986 proteins, 597 were mapped and matched with 58 species in UniProt databases, including Elephas maximus. These mapped proteins were mostly involved in binding function, catalytic activity, cellular process, and metabolic process. Only 29 mapped proteins were recognized to be related in reproductive process, mainly associated in spermatogenesis and sperm capacitation. Additionally, several seminal plasma proteins related to fertility or semen quality in other mammals were also found in Asian elephant semen, such as keratin type I, aldose reductase, thrombospondon-1, fibronectin 1, platelet-activating factor acetyl hydrolase, mannosidase, and semenogelin-2. This discovery clearly reveals the beneficial protein profile in seminal plasma of the Asian elephant and serves as a crucial step in investigating infertility and poor semen quality in this valuable species.

Molecular study of the presence and transcriptional activity of HPV in semen

PurposeHuman Papillomavirus (HPV) in semen represents a controversial topic. Recent evidence suggests a correlation with poor semen quality, but its detection is still unstandardized in this biological fluid. Thus, the aims of this study were to verify the ability of nested PCR to reveal HPV-DNA in semen; to evaluate association of seminal HPV with sperm parameters and risk factors for infection; to investigate the rate of HPV-DNA positivity in patients with and without risk factors; to assess HPV transcriptional activity.MethodsWe enrolled sexually active men and collected clinical and anamnestic data during andrological and sexually transmitted infections (STIs) evaluation. For each patient, we performed semen analysis and nested PCR to detect HPV-DNA in semen. In positive semen samples, we proceeded with genotyping and RNA quantification to detect HPV transcriptional activity.ResultsWe enrolled 185 men (36.0 ± 8.3 years), of which 85 with (Group A) and 100 without HPV risk factors (Group B). Nested PCR was able to reveal HPV-DNA in semen, discovering a prevalence of 8.6% (11.8% in Group A and 6% in Group B, respectively). We observed no correlation between sperm quality and seminal HPV. Genital warts and previous anogenital infection were significantly associated with the risk of HPV positivity in semen. Moreover, no viral transcriptional activity was detected in positive semen samples.ConclusionsOur study suggests that searching for seminal HPV could be important in patients both with and without risk factors, especially in assisted reproduction where the risk of injecting sperm carrying HPV-DNA is possible.

Effects and possible mechanisms of combined exposure to noise and carbon monoxide on male reproductive system in rats.

Environmental hazards are an increasing concern due to the rapid pace of industrialization. Among these hazards, noise and carbon monoxide (CO) are common risk factors and have been shown to cause serious health problems. However, existing studies focused on the individual effects of noise and CO exposure and the combined effects of these two factors remain poorly understood. Our study aimed to examine the combined effects of noise and CO exposure on testicular function by constructing individual and combined exposure models. Our findings indicated that combined exposure to noise and CO was associated with a higher risk of testicular damage and male reproductive damage when compared to exposure alone. This was evidenced by poorer semen quality and more severe pathological damage to the testis. This combined exposure led to higher levels of oxidative stress and apoptosis in the testes, with bioinformatics analyses suggesting the signaling pathways involved in these responses. Specifically, activation of the P53 signaling pathway was found to contribute to the testicular damage caused by the combined exposure. Encouragingly, pterostilbene (PTE), a novel phytochemical, alleviated combined exposure-induced testicular damage by reducing oxidative stress and germ cell apoptosis. Overall, we identified joint reproductive toxicity resulting from the exposure to noise and CO, and found that PTE is a promising potential treatment for injuries caused by these factors. The cover image is based on the Research Article Effects and possible mechanisms of combined exposure to noise and carbon monoxide on male reproductive system in rats by Yingqing Li et al., https://doi.org/10.1002/tox.23927.

Endocrine disrupting chemicals and their effects on the reproductive health in men

Endocrine Disrupting Chemicals (EDCs) are harmful compounds that enter the environment naturally or through anthropogenic activities and disrupt normal endocrine functions in humans, adversely affecting reproductive health. Among the most significant sources of EDC contaminants are the pharmaceutical, cosmetic, and packaging industries. EDCs have been identified to have a deteriorating effect on male reproductive system, as evidenced by the increasing number of male infertility cases. A large number of case studies have been published in which men exposed to EDCs experienced testicular cancer, undescended testicles, a decrease in serum testosterone levels, and poor semen quality. Furthermore, epidemiological evidence suggested a link between prenatal EDC exposure and cryptorchidism or undescended testicles, hypospadias, and decreased anogenital distance in infants. The majority of these findings, however, are incongruent due to the lack of long-term follow-up studies that would demonstrate EDCs to be associated with male reproductive disorders. This review aims to provide an overview on recent scientific progress on the association of EDCs to male reproductive health with special emphasis on its toxicity and possible mechanism of EDCs that disrupt male reproductive system.

Oxido-Reduction Potential as a Method to Determine Oxidative Stress in Semen Samples.

There are different estimates for the incidence of infertility. Its occurrence may vary from area to area, but on average, it affects 15% of couples and 10-12% of men worldwide. Many aspects of infertility can be linked to reactive oxygen species (ROS) and the process of oxidative stress (OS). The association between poor semen quality and OS is well known. Unfortunately, there is no accepted protocol for the diagnosis and treatment of OS in andrology. Oxido-reduction potential (ORP) measurement is a new method for determining the ratio between oxidant and antioxidant molecules. Currently, ORP measurement is one of the fastest and most user-friendly methods of andrological OS determination and our goals were to confirm published correlations between ORP values and sperm parameters, examine how sperm concentration influences these results, and investigate whether intracellular ROS formations are also manifested in the ORP values or not after artificial ROS induction. Intracellular ROS formations were induced by menadione (superoxide anion inducer), hydrogen peroxide, and tert-butyl hydroperoxide (lipid peroxidation inducer) treatments; sperm parameters like motility and viability were determined with an SCA Scope system, and ORP changes were recorded by the Mioxsys system. Significant correlations were noticed among the ORP, spermatozoa concentration, motility, progressive motility, and viability. Nevertheless, only the ORP value after normalization with the sperm count correlated with these parameters. Due to normalization, very low and very high sperm concentrations can give misleading results. The means of the non-normalized ORP values were almost the same. All of the applied treatments resulted in decreases in the viability, motility, and progressive motility, and interestingly, altered ORP levels were detected. In addition, it was determined that seminal plasma had a significant protective effect on spermatozoa. The elimination of seminal plasma caused higher sensitivity of spermatozoa against used OS inducers, and higher ORP levels and decreased viabilities and motilities were measured. The ORP level could be a good indicator of male OS; however, in cases of low and high sperm counts, its result can be misleading. Overall, the conclusion can be drawn that ORP determination is a suitable method for detecting intracellular ROS accumulation, but it has limitations that still need to be clarified.

Heterologous Seminal Plasma Reduces the Intracellular Calcium and Sperm Viability of Cryopreserved Stallion Spermatozoa.

Despite the vital role of seminal plasma (SP) in maintaining sperm function and aiding gamete interaction in many species, SP is usually removed before cryopreservation of stallion sperm to improve cryosurvival of sperm. The present study assessed if the vital sperm functional parameters of genetically superior stallions producing poor quality semen can be enhanced by the supplementation of heterologous SP from the stallion producing high quality semen. Spermatozoa from poor quality semen producing stallions were divided into three aliquots: two aliquots were supplemented with SP obtained from good quality semen producing stallions at the rate of 20% and 30%, respectively, whereas the third aliquot remained as control (0% SP) and incubated at 37°C for 30 minutes. Sperm membrane integrity, mitochondrial membrane potential (MMP), mitochondrial superoxide (mtROS) generation, and intracellular calcium status were assessed at different time intervals during incubation by flow cytometry. It was observed that the dead sperm population increased (p < 0.01) during incubation in both the 20% and 30% SP-supplemented groups. However, no significant changes were observed in MMP in both the control and treatment groups at different time intervals. Interestingly, it was found that sperm mtROS production increased (p < 0.01) during incubation in the SP-supplemented groups compared with the control group. The proportion of live spermatozoa with high intracellular calcium was reduced (p < 0.01) during incubation in the SP-incubated groups. Collectively, heterologous SP addition could not repair the damages caused by the cryopreservation and further resulted in deterioration of semen quality as observed in our study by reducing viability, increasing reactive oxygen species (ROS) production possibly due to high proportion of dead cells, or some factors (yet to be identified) that are inducive of oxidative stress in stallion spermatozoa.

Environmental oestrogens disrupt testicular descent and damage male reproductive health: Mechanistic insight.

Environmental oestrogens (EEs) as environmental pollutants have been paid much attention due to their impact on congenital malformation of male genitourinary system. Exposure to EEs for prolonged time could hinder testicular descent and cause testicular dysgenesis syndrome. Therefore, it is urgent to understand the mechanisms by which EEs exposure disrupt testicular descent. In this review, we summarize recent advances in our understanding of the process of testicular descent, which is regulated by intricate cellular and molecular networks. Increasing numbers of the components of these networks such as CSL and INSL3 are being identified, highlighting that testicular descent is a highly orchestrated process that is essential to human reproduction and survival. The exposure to EEs would lead to the imbalanced regulation of the networks and cause testicular dysgenesis syndrome such as cryptorchidism, hypospadias, hypogonadism, poor semen quality and testicular cancer. Fortunately, the identification of the components of these networks provides us the opportunity to prevent and treat EEs induced male reproductive dysfunction. The pathways that play an important role in the regulation of testicular descent are promising targets for the treatment of testicular dysgenesis syndrome.

O-251 LIN28B gene expression is downregulated in spermatozoa of oligozoospermic men and associates with genetic variants previously linked to pubertal onset

Abstract Study question Is there an association between genetic polymorphisms in LIN28B with LIN28B expression and semen quality in spermatozoa from oligozoospermic men? Summary answer LIN28B is downregulated in spermatozoa of oligozoospermic men and explains 39% of sperm count variability. One SNP (rs314280) was associated with low LIN28B mRNA expression. What is known already Large-scale genomic studies have identified genetic variants in or near LIN28B to be robustly associated with pubertal traits such as age at menarche and age at voice break. The LIN28 family of genes are known to control cell division, growth and differentiation. The LIN28B orthologue is exclusively expressed at high levels in the testis and placenta; however, we have limited knowledge about the role of LIN28B in relationship to testicular function. Interestingly, other studies have showed that later onset of puberty is associated with poor semen quality, suggesting that pubertal development may influence adult testicular function. Study design, size, duration Twenty-nine oligozoospermic (cases) and fifty-four men with normal sperm concentration (controls) were recruited from patients seeking andrological work-up for male/couple infertility at a University Hospital. Subjects with abnormal karyotype, Yq-microdeletions, varicocele GIII-IV, hypogonadotropic hypogonadism, seminal infection, diabetes, BMI&amp;gt;35, excessive consumption of alcohol/drugs, testicular cancer, chemotherapy/radiotherapy were excluded. Semen samples were obtained for analysis (WHO, 2010) and sperm isolation by density gradient (PureSperm40®). Peripheral blood samples were analysed for reproductive hormones and used for DNA extraction. Participants/materials, setting, methods LIN28B and GAPDH-S mRNA abundance were measured by qRT-PCR (2-ΔCT method) in RNA isolated from purified sperm using SYBR® MasterMix (Takyon). Five SNPs in linkage disequilibrium (rs7759938, rs395962, rs314268, rs314277 and rs314280) were genotyped (TaqMan™ SNP Genotyping Assay). Statistical differences between groups were assessed by Mann-Whitney test and genetic association was analysed using “SNPassoc” package in R. Values are showed as median, Q1-Q3. Main results and the role of chance Cases and controls had similar age and BMI but as expected sperm concentration, morphology and vitality were differed between groups (9.9, 4.9-13.1 vs 82.8, 46.0-146.5 mill/ml; 1, 1-2 vs 3, 1-4% normal forms and 83%, 76-89 vs 86%, 82-90, respectively) (p &amp;lt; 0.05). No differences were observed in progressive motility, semen volume and days of abstinence. FSH and LH serum levels were higher in cases compared with controls (4.6, 2.6-7.8 vs 3.2, 2.5-4 mIU/ml and 4.2, 2.9-5.2 vs 3.1, 2.1-4.2 mIU/ml, respectively; p = 0.019 and p = 0.017). Relative expression of LIN28B was significantly diminished in cases compared with controls (0.0034, 0.0015-0.0103 vs 0.0446, 0.0122-0.1026; p &amp;lt; 0.001), while expression of the internal housekeeping control GAPDH-S was similar between groups. Linear regression model showed significant association of sperm concentration and total sperm count with LIN28B relative expression adjusted by age, abstinence time, % progressive motility and % normal morphology (beta=0.408, R2=0.241, p &amp;lt; 0.001 and beta=0.461, R2=0.393, p &amp;lt; 0.001). LIN28B rs314280 was associated with mRNA expression in the dominant model (p = 0.025) and two other SNPs (rs7759938, rs314268) showed the same trend (p = 0.09). Men with at least one minor allele of these 3 SNPs had a lower LIN28B mRNA abundance (p = 0.006; p = 0.07; p = 0.055). Limitations, reasons for caution Genotype frequency comparisons between cases and control were not conducted because of the small sample size. A larger cohort will be studied to address this assumption and association of genotypes with parameters of semen quality. Wider implications of the findings To our knowledge this study represents the first report on LIN28B expression and human testicular function. The significant direct association of LIN28B mRNA expression with sperm concentration suggests that LIN28B may be involved in spermatogonial proliferation. Trial registration number not applicable

Prenatal DEHP Exposure Induces Premature Testicular Aging by Promoting Leydig Cell Senescence through the MAPK Signaling Pathways.

Previous studies show that prenatal di-(2-ethylhexyl) phthalate (DEHP) exposure induces premature testicular aging. However, the evidence is weak, and the underlying mechanisms remain unclear. p38/extracellular signal-regulated kinase (ERK)/c-Jun NH(2)-terminal kinase (JNK) MAPK pathways participate in aging. Leydig cell (LC) senescence results in testicular aging. Whether prenatal DEHP exposure induces premature testicular aging by promoting LC senescence warrantsfurther study. Here, male mice undergo prenatal exposure to 500mg per kg per day DEHP, and TM3 LCs are treated with 200µm mono (2-ethylhexyl) phthalate (MEHP). MAPK pathways, testicular toxicity, and senescent phenotypes (β-gal activity, p21, p16, and cell cycle) of male mice and LCs are explored. Prenatal DEHP exposure induces premature testicular aging in middle-aged mice (poor genital development, reduced testosterone synthesis, poor semen quality, increased β-gal activity, and upregulated expression of p21 and p16). MEHP induces LCs senescence (cell cycle arrest, increased β-gal activity, and upregulated expression of p21). p38 and JNK pathways are activated, and the ERK pathway is inactivated. In conclusion, prenatal DEHP exposure induces premature testicular aging by promoting LC senescence through MAPK signaling pathways.

A North American study of anthropometric factors and semen quality

To evaluate the association between anthropometric measures and semen parameters. Cross-sectional study. Male participants aged ≥21 years. We analyzed data from 659 males (1185 samples) participating in a semen testing substudy of the Pregnancy Online Study (PRESTO), a North American preconception cohort study. After enrollment, we invited males aged ≥21 years to perform at-home semen testing using the Trak system. Participants reported selected anthropometric variables (current weight, height, waist circumference, and weight at age 17 years) and covariate data via an online baseline questionnaire. We used generalized estimating equations models to estimate the percent difference in mean log-transformed semen parameter values and 95% confidence intervals (CI) for associations between selected anthropometric variables and semen volume (mL), sperm concentration (million/mL), and total sperm count (million), adjusting for sociodemographics, lifestyle factors, and medical history. We also evaluated World Health Organization-defined thresholds for low semen quality. Percentage differences in mean log-transformed semen volume, sperm concentration, and total sperm count (95% CI) comparing current body mass index ≥35 vs. <25 kg/m2 were -6.3 (-15.8, 4.3), -6.4 (-24.6, 16.2), and -12.2 (-31.1, 11.8), respectively. Percentage differences (95% CIs) comparing waist circumferences of ≥42 vs. <31 inches were -4.2 (-15.0, 8.0), -6.4 (-27.6, 21.0), and -10.4 (-31.9, 17.9) for semen volume, sperm concentration, and total sperm count, respectively. Greater adult weight gain since age 17 years was associated with reduced semen volume (≥25 vs. <5 kg; percent difference, -9.7; 95% CI, -18.4, 0.1), but not sperm concentration or total sperm count. The highest categories of each anthropometric variable generally were associated with World Health Organization-defined low total sperm count (≤39 million). Selected anthropometric factors were associated modestly with poorer semen quality.

Defining an Optimal Range of Centrifugation Parameters for Canine Semen Processing.

Our objective was to determine a clinically relevant range of centrifugation parameters for processing canine semen. We hypothesized that higher gravitational (g) force and longer time of centrifugation would result in improved spermatozoa recovery rate (RR) but poorer semen quality. Cooled storage under standard shipping conditions was used as a stressor to evaluate long-term treatment effects. Individual ejaculates collected from 14 healthy dogs were split into six treatment groups (400 g, 720 g, and 900 g for 5 or 10 min). Sperm RR (%) was calculated post-centrifugation, and plasma membrane integrity (%, Nucleocounter® SP-100™), total and progressive motility (%, subjective and computer-assisted sperm analysis), and morphology (%, eosin-nigrosin staining) were assessed on initial raw semen (T0), post-centrifugation (T1), and 24 h (T2) and 48 h (T3) after cooling. Sperm losses were minimal, and RRs were similar across treatment groups (median >98%, p ≥ 0.062). Spermatozoa membrane integrity was not different between centrifugation groups at any time point (p ≥ 0.38) but declined significantly during cooling (T1 vs. T2/T3, p ≤ 0.001). Similarly, total and progressive motility did not differ across treatments but declined in all groups from T1 to T3 (p ≤ 0.02). In conclusion, our study showed that centrifugation within a range of 400 g-900 g for 5-10 min is appropriate for processing canine semen.