A single administration of carbetocin before electroejaculation increases the insemination doses produced from each ejaculate in rams

The aim of the study was to determine the effect of carbetocin administration (a long-acting analog of oxytocin) 20 or 10 min before electroejaculation (EE) on the duration of semen collection procedure, quantitative and qualitative characteristics of the ejaculate, and stress biomarkers in rams. Semen was collected from 12 Corriedale rams (age, 2.5-5.5 years old) with EE, in a Latin-square design, administrating carbetocin (0.2 mg/100 kg of body weight i.v.) 20 or 10 min before EE, or without carbetocin administration (CB-20, CB-10, and CON treatments, respectively). Each treatment was applied to different rams every 3-4 days, allowing all the rams to receive all three treatments. Carbetocin administered 20 or 10 min before EE increased the number of sperm ejaculated (P = 0.01), the semen concentration (P = 0.02), the number of insemination doses collected in a single collection (P = 0.01), and the number of insemination doses collected/electrical pulses administered (P = 0.05) compared to control rams. Carbetocin administered 20 or 10 min before semen collection prolonged the time required for EE and the number of pulses administered during EE compared to CON rams (P < 0.03 for both). The CB-10 rams required the administration of more electrical pulses during ejaculation than CON rams (P = 0.001), and CB-20 treatment tended to require more electrical pulses than CON rams (P = 0.06). The volume of the ejaculate was greater in CB-10 than in CON rams (P = 0.01), and that of CB-20 treatment tended to be greater than CON rams (P = 0.08). The percentage of sperm with intact membrane was greater in CB-20 than in CON rams (P = 0.01). Total protein, albumin, and globulin concentrations were lower immediately after carbetocin administration 20 or 10 min before EE. The treatments did not affect cortisol concentration, glycemia, rectal and surface temperatures, heart rate, and facial expressions. Carbetocin administration before EE of rams improved the quantitative and qualitative characteristics of the ejaculate, duplicating the number of insemination doses collected. It can be a promising treatment to obtain a greater quantity of doses to inseminate with a lower frequency of semen collections, reducing the negative impacts of EE on animal welfare.

Causal association between 25-Hydroxyvitamin D and risk of abnormal spermatozoa: A bidirectional Mendelian randomization study

Previous studies indicated conflicting findings regarding the association between vitamin D and abnormal spermatozoa. Herein, we assessed the causal association between circulating 25-Hydroxyvitamin D (25OHD) levels and the risk of abnormal spermatozoa by utilizing bidirectional Mendelian randomization (MR) analysis. Genome-wide association study summary statistics for 25OHD and abnormal spermatozoa were obtained from publicly accessible databases. Single nucleotide polymorphisms (SNPs) associated with 25OHD and SNPs associated with abnormal spermatozoa were used as instrumental variables (IVs) for forward MR analysis and reverse MR analysis, respectively. Inverse variance weighted (IVW) was the main MR approach, while weighted median, MR-Egger, and maximum likelihood methods were employed to supplement IVW. In addition, several sensitivity tests assessed the reliability of MR analysis. Forward MR analysis showed that elevated 25OHD levels significantly reduced abnormal spermatozoa risk (odds ratio [OR] = 0.75, 95 % confidence interval [CI]: 0.56-1.00, P = 4.98E-02), and the effect remained statistically significant after excluding SNPs associated with confounders (OR = 0.73, 95 % CI: 0.54-0.98, P = 3.83E-02) or only utilizing SNPs located near 25OHD-associated genes only as IVs (OR = 0.58, 95 % CI: 0.41-0.81, P = 1.67E-03). Reverse MR analysis indicated abnormal spermatozoa not affecting 25OHD level (P > 0.05). Sensitivity tests showed that MR analyses were not affected by heterogeneity and horizontal polytropy. Overall, the present MR study supports that elevated 25OHD levels reduce the risk of abnormal spermatozoa. Therefore, ensuring adequate vitamin D intake and maintaining stable levels of 25OHD may be effective strategies to optimize reproductive outcomes.

Exosomes from porcine serum as endogenous additive maintain function of boar sperm during liquid preservation at 17 °C in vitro

The supplementation of sperm culture media with serum is quite common, and improves both sperm survival and motility. However, the link between serum and sperm remains poorly understood. The present study is the first investigation of the effects on sperm quality and function of endogenous porcine serum exosomes in medium used for culturing boar sperm. Scanning electron microscopy (SEM) confirmed that serum-derived exosomes from both castrated boars (cbsExos) and sows (ssExos) exhibited typical nanostructural morphology and expressed CD63, CD9, and Alix, as shown by Western blotting. At 17 °C, the progressive motility and membrane integrity of sperm were significantly increased after incubation of fresh boar semen for 7 days with cbsExos-4 (8 × 1010 particles/mL) or ssExos-16 (32 × 1010 particles/mL). Moreover, cbsExos-4 and ssExos-16 were found to be effective sperm additives, improving mitochondrial transmembrane potential (ΔΨm) and adenosine triphosphate (ATP) content, total antioxidant activity (T-AOC), superoxide dismutase (SOD) activity, and glutathione peroxidase (GPx) activity while reducing reactive oxygen species (ROS) levels, and malondialdehyde (MDA) content following preservation at 17 °C after a 5-day incubation. Both fluorescence and SEM showed that the serum exosomes bound directly to the sperm membrane, suggesting an interaction that could influence sperm-zona pellucida binding. Overall, this study provides new insights into the potential benefits of adding cbsExos and ssExos to enhance the quality of boar sperm during ambient temperature preservation, which may lead to advancements in sperm preservation strategies.

Target silencing of porcine SPAG6 and PPP1CC by shRNA attenuated sperm motility

The quality of sperm significantly influences the reproductive efficiency of pig herds. High-quality sperm is necessary for efficient fertilization and to maximize the litter numbers in commercial pig farming. However, the understanding of genes regulating porcine sperm motility and viability is limited. In this study, we validated porcine sperm/Sertoli-specific promoters through the luciferase reporter system and identified vital genes for sperm quality via loss-of-function means. Further, the shRNAs driven by the ACE and SP-10 promoters were used to knockdown the SPAG6 and PPP1CC genes which were provisionally important for sperm quality. We assessed the effects of SPAG6 and PPP1CC knockdown on sperm motility by using the sperm quality analyzer and flow cytometry. The results showed that the ACE promoter is active in both porcine Sertoli cells and sperms, whereas the SP-10 promoter is operating exclusively in sperm cells. Targeted interference with SPAG6 and PPP1CC expression in sperm cells decreases the motility and increases apoptosis rates in porcine sperms. These findings not only offer new genetic tools for targeting male germ cells but also highlight the crucial roles of SPAG6 and PPP1CC in porcine sperm function.

Hyperbaric oxygen preconditioning normalizes scrotal temperature, sperm quality, testicular structure, and erectile function in adult male rats subjected to exertional heat injury

Testicular hyperthermia has been noted in men who work in high ambient temperatures. Scrotal temperatures above the normal range caused germ cell loss in the testes and resulted in male subfertility. In adult male rats, exercising at a higher environmental temperature (36 °C with relative humidity of 50%, 52 min) caused exertional heat stroke (EHS) characterized by scrotal hyperthermia, impaired sperm quality, dysmorphology in testes, prostates and bladders, and erectile dysfunction. Here, we aim to ascertain whether hyperbaric oxygen preconditioning (HBOP: 100% O2 at 2.0 atm absolute [ATA] for 2 h daily for 14 days consequently before the onset of EHS) is able to prevent the problem of EHS-induced sterility, testes, prostates, and bladders dysmorphology and erectile dysfunction. At the end of exertional heat stress compared to normobaric air (NBA or non-HBOP) rats, the HBOP rats exhibited lower body core temperature (40 °C vs. 43 °C), lower scrotal temperature (34 °C vs. 36 °C), lower neurological severity scores (2.8 vs. 5.8), higher erectile ability, (5984 mmHg-sec vs. 3788 mmHg-sec), higher plasma testosterone (6.8 ng/mL vs. 3.5 ng/mL), lower plasma follicle stimulating hormone (196.3 mIU/mL vs. 513.8 mIU/mL), lower plasma luteinizing hormone (131 IU/L vs. 189 IU/L), lower plasma adrenocorticotropic hormone (5136 pg/mL vs. 6129 pg/mL), lower plasma corticosterone (0.56 ng/mL vs. 1.18 ng/mL), lower sperm loss and lower values of histopathological scores for epididymis, testis, seminal vesicle, prostate, and bladder. Our data suggest that HBOP reduces body core and scrotal hyperthermia and improves sperm loss, testis/prostate/bladder dysmorphology, and erectile dysfunction after EHS in rats.

Vibration emissions affect the quality of liquid-preserved AI doses in stallions

Artificial insemination (AI) with liquid-preserved stallion semen is a widely used reproductive technology. As the demand for AI doses of high-class stallions is transnational, they are frequently exposed to long-distance transport. Since recent studies in boars indicated that vibration emissions caused by transport negatively affected sperm quality in vitro, this study questioned whether sperm quality in stallions is similarly impaired. Furthermore, we investigated stallion and extender-related differences in the spermatozoa's resistance to transport-related quality loss. Stallion ejaculates (n = 30) were collected at a German AI center, split in half, and subsequently diluted to a final sperm concentration of 50 × 106 sperm/mL using the semen extenders EquiPlus or Gent (both Minitüb GmbH, Germany). Four 12 mL aliquots of each sample were filled in plastic syringes according to a split-sample design and exposed to vibration (Displacement index Di = 3.0 ± 0.1) at 5 °C for 0 h (control), 3 h, 6 h or 9 h. All samples were stored for four days at 5 °C after transport simulation and analyzed for total sperm motility, thermo-resistance, membrane integrity, and mitochondrial activity determined by flow cytometry as well as the pH. After calculating generalized linear mixed models for each sperm quality trait, a negative impact of the duration of transport simulation could be shown on total sperm motility (P = 0.001), thermo-resistance (P = 0.030), and the pH (P = 0.001). Simulated transport for 6 h and 9 h diminished sperm quality (P ≤ 0.01), with 9 h reducing thermo-resistance by 5 ± 2.2% points (PP) for EquiPlus and sperm motility by 2.2 ± 1.7 PP for Gent compared to the control group. In contrast, samples exposed to vibration for 3 h showed no decline in sperm quality (P > 0.05). The individual stallion influenced every semen trait (P < 0.05) and transport-related losses in sperm thermo-resistance of up to 15.9 PP were demonstrated. Furthermore, EquiPlus was superior to Gent in all semen assessments (P < 0.001). We conclude that in vitro sperm quality is impaired by vibration. As the quality loss depends on the transport time, we recommend keeping shipping time as short as possible especially for spermatozoa of stallions that are susceptible to vibration-induced sperm quality loss.

Effect of probiotics and prebiotics on the composition of the equine fecal and seminal microbiomes and sperm quality: A pilot study

Probiotic and prebiotic effects on equine semen and gastrointestinal microbiome composition and sperm quality are unknown. This study aimed to evaluate the effects of pre-, pro- or synbiotic supplementation on fecal and semen microbiome composition and sperm quality parameters of stallions. This Latin square crossover trial involved four miniature pony stallions receiving control diet only, or addition of a pro-, pre- or synbiotic formulation. Full-length 16S rRNA gene amplicon sequencing was used to measure diversity of semen and fecal microbiomes. Total sperm count, total motility, progressive motility, DNA integrity, lipid peroxidation and mitochondrial oxidative stress, biomarkers of sperm quality, were measured after each intervention. A general linear model was employed to analyse and compare microbiome diversity measures and sperm quality data across four time points. Shannon's diversity index (alpha-diversity), and evenness of semen and gastrointestinal microbiomes were significantly different (p<0.001). A trend was observed for prebiotic effects on the diversity indices of the GI microbiome (p= 0.07). No effects of treatments were observed on either semen microbiome or sperm quality. Pre-, pro- and synbiotic supplements showed no negative effect on sperm quality parameters observed. This proof of concept provides preliminary data to inform future studies exploring the relationship between microbiomes and fertility.

Survey dataset on occupational stress, job satisfaction, and job performance among male fertility patients

This article presents data on occupational stress, job satisfaction, and job performance among male fertility patients. The data were collected from 11 November 2021 until 30 October 2022. A quantitative research approach was employed, involving a questionnaire development and survey. A sample of 309 was selected, using simple random sampling, from the pool of male patients that had undergone seminal fluid analysis (SFA) and received treatment from four private fertility clinics in Malaysia. Respondents were asked to give their consent by signing a consent form, for ethical research purposes. The questionnaire asked respondents about their demographics, sperm quality, occupational stress, job satisfaction, and job performance. The data could help other researchers to develop research on management issue in the context of male fertility, as well as organisations to maintain the health and welfare of their employees.

Effects of temperature anomaly on sperm quality: A multi-center study of 33,234 men

Backgrounds

Global fertility rates continue to decline and sperm quality is a prime factor affecting male fertility. Both extreme cold and heat have been demonstrated to be associated with decreased sperm quality, but no epidemiological studies have considered human adaptation to long-term temperature. Our aim was to conduct a multi-center retrospective cohort study to investigate exposure-response relationship between temperature anomaly (TA) that deviate from long-term climate patterns and sperm quality.

Methods

A total of 78,952 semen samples measured in 33,234 donors from 6 provincial human sperm banks in China were collected. This study considered heat and cold acclimatization to prolonged exposure in humans and explored the exposure-response relationship between TAs and sperm quality parameters (sperm concentrations, sperm count, progressive motility, progressive sperm count, total motility and total motile sperm count) during the hot and cold seasons, respectively. Linear mixed models and generalized linear models were built separately for specific centers to pool in a meta-analysis to obtain the pooled effect of TA on sperm quality, considering repeated measurements data structure and spatial heterogeneity.

Results

We identified an inverted U-shaped exposure-response relationship between TA and sperm quality during the hot season. Significant negative effect of anomalous cold on sperm quality during the hot season was found after additional adjustment for Body mass index, marital status and childbearing history. The heat-related TA in hot season was significantly negatively associated with sperm concentration, progressive sperm count and total motile sperm count (all P-values<0.05). After adjusting the relative humidity, the cold-related TA in cold season was negatively associated with the sperm total motility (P-values<0.05).

Conclusions

Our results suggest both heat-related and cold-related TAs are associated with decreased sperm quality. The findings highlight the importance of reducing exposure to anomalous temperatures to protect male fertility.

Effects of Calorie Restriction on Preserving Male Fertility Particularly in a State of Obesity

PURPOSE OF REVIEW

Highlight the importance of exploring nutritional interventions that could be applied as alternative or supplementary therapeutic strategies to enhance men's fertility.

RECENT FINDINGS

Lifestyle choices have prompted extensive discussions regarding its implications and applications as a complementary therapy. The growing concern over the decline in sperm quality underscores the urgency of investigating these alternative interventions. Calorie restriction (CR) has emerged as a promising strategy to improve male fertility. While the efficacy of CR depends on factors like age, ethnicity, and genetics, observational studies and clinical trials, such as CALERIE, have shown an improvement in serum testosterone level and sexual drive in men with or without obesity. Whereas, in a case-control study, a high intake of saturated and trans-fatty acids not improved sperm motility in astheno-zoospermic men. While vast data demonstrate that CR positively impacts sperm count and motility; however, its effects on sperm morphology and DNA fragmentation remain less clear, and the literature has shown discrepancies, mainly due to the nature of technical-dependent assessment tools. The review advocates a personalized approach to CR, considering individual health profiles to maximize its benefits. It underscores the need for routine, accessible diagnostic techniques in male reproductive health. It suggests that future research should focus on personalized dietary interventions to improve male fertility and overall well-being in individuals with or without obesity and unravel CR's immediate and lasting effects on semen parameters in men without obesity.

Effects of dietary basil (Ocimum basilicum) supplementation on reproductive hormones, semen parameters, and testicular development in Zandi male lambs

This study investigated the potential impact of feeding whole plant basil on sperm quality and the concentration of certain reproductive hormones in male lambs. A total of 18 Zandi male lambs with an initial weight of 28.8 ± 2.03 kg were included in a completely randomized design with three treatments and six repetitions. The experimental treatments included: 1) control (basal diet without basil), 2) diet containing 12.5 % basil, and 3) diet containing 25 % basil. The results showed that feeding basil to male lambs significantly increased testosterone concentration and decreased blood cortisol levels (P < 0.05). Additionally, feeding high levels of basil significantly improved sperm concentration, motility, and viability in the experimental samples, while reducing the level of complete abnormalities and malondialdehyde concentration (P < 0.05). The findings suggest that dietary supplementation of 25 % whole plant basil could be a useful strategy to improve sperm quality and increase testosterone secretion while reducing cortisol levels in male lambs.

Using Bayesian and weighted regression to evaluate the association of idiopathic oligoastenoteratozoospermia with seminal plasma metal mixtures

Idiopathic oligoastenoteratozoospermia (iOAT) affects 30% of infertile men of reproductive age. However, the associations between Cr, Fe, Cu, Se or Co levels and iOAT risk have not been determined. This research aimed to assess the associations between Cr, Fe, Cu, Se and Co levels as well as their mixtures in seminal plasma and the risk of iOAT and severe iOAT. Therefore, a case‒control study including 823 participants (416 iOAT patients and 407 controls) recruited from October 2021 to August 2022 at the reproductive medicine center of the First Affiliated Hospital of Anhui Medical University was conducted in Anhui, China. The concentrations of Cr, Fe, Cu, Se and Co in seminal plasma were detected via inductively coupled plasma‒mass spectrometry. Binary logistic regression models were used to assess the associations between the levels of Cr, Fe, Cu, Se and Co and the risk of iOAT and severe iOAT; additionally, Bayesian kernel machine regression (BKMR) and weighted quantile sum (WQS) regressions were performed to evaluate the joint effect of seminal plasma levels of Cr, Fe, Cu, Se and Co on the risk of iOAT and explore which elements contributed most to the relationship. We found significant associations between the concentrations of Fe, Cu and Se in seminal plasma and iOAT risk after adjusting for covariates (Fe, lowest tertile vs. second tertile: aOR = 1.86, 95% CI = 1.31, 2.64; Cu, lowest tertile vs. second tertile: aOR = 1.95, 95% CI = 1.37, 2.76; Se, lowest tertile vs. second tertile: aOR = 1.65, 95% CI = 1.17, 2.35). A lower Se concentration in seminal plasma (lowest tertile vs. second tertile: aOR = 1.84, 95% CI = 1.10, 3.10) was positively associated with the risk of severe iOAT. Additionally, we also observed an association between the concentration of Cr in seminal plasma and the risk of iOAT before adjusting for covariates (Cr, third tertile vs. lowest tertile: OR=1.44, 95% CI: 1.03, 2.02). According to the BKMR analyses, the risk of iOAT increased when the overall concentrations were less than the 25th percentile. The results from the WQS regression indicated that a negative WQS index was significantly associated with the iOAT risk, while a positive WQS index was not. Se and Fe had significant weights in the negative direction. In conclusion, lower Cu, Fe and Se levels in seminal plasma were positively associated with iOAT risk, while higher Cr levels in seminal plasma were positively associated with iOAT risk according to the single element model, and lower levels of Se were related to a greater risk of severe iOAT; when comprehensively considering all the results from BKMR and WQS regression, Fe, Se and Cr levels contributed most to this relationship.

Chlormequat chloride induced activation of calmodulin mediated PI3K/AKT signaling pathway led to impaired sperm quality in pubertal mice

Chlormequat chloride (CCC), as a widely used plant growth regulator, can cause impaired sperm quality and decreased testosterone synthesis in pubertal rats, but the underlying mechanism remains unclear. The purpose of this study was to elucidate the toxicokinetics and tissue distribution of CCC, as well as the possible mechanism of CCC-induced impairment in sperm quality. The concentration of CCC reached its peak 1 h after a single dose (200 mg/kg·bw) administration in mice plasma, and a bimodal phenomenon appeared in the testes, liver, and epididymis. In vivo, 200 mg/kg CCC caused testicular damage and impaired sperm quality in pubertal mice, and the expression of p-tyrosine and GSK3α decreased in cauda epididymidis, sperm and testes. CCC also caused the down-regulation of AKAP4 and the up-regulation of calmodulin (CaM), and activated the PI3K/AKT signaling pathway in the testes. In vitro, CCC reduced the levels of p-tyrosine, AKAP4 and GSK3α, increased the level of CaM and activated the PI3K/AKT signaling pathway in GC-1 cells. CaM antagonist (W-7 hydrochloride) and PI3K inhibitor (LY294002) can effectively improve the expression of GSK3α and AKAP4 by suppressing the PI3K/AKT signaling pathway in GC-1 cells treated with CCC. It was indicated that CCC induced impairment in sperm quality might be partially related to the activation of PI3K/AKT signaling pathway mediated by CaM.

Effects of different hormonal treatments on spermatogenesis advancement in hatchery-produced greater amberjack Seriola dumerili (Risso 1810)

In earlier studies, wild-caught greater amberjack Seriola dumerili (Risso, 1810) males reared in sea cages showed gametogenesis impairment and low sperm production and quality. Here, we (a) examined if F1 hatchery-produced males reared in sea cages also exhibit reproductive dysfunctions and (b) evaluated the effects of gonadotropin releasing hormone agonist (GnRHa) administration through injections (GnRHainj) or sustained-release implants (GnRHaimpl), and human chorionic gonadotropin (hGC) injections on spermatogenesis/spermiation enhancement. Fish were given a hormone treatment just prior to the spawning season, and were transferred to land-based tanks, according to an established spawning induction protocol. Blood samples (n = 6) were obtained on Days 0, 7 and 13 after treatment. Testis samples were obtained on Days 0 (n = 4) and 13 (n = 2 per treatment). The fish prior to their transfer from the sea cages to the land-based tanks, exhibited a low gonadosomatic index, altered sex steroid hormone profile and high density of testicular apoptotic cells. After transfer to tanks, there was a general depression of sex steroid plasma levels parallel to an increase in cortisol concentrations. Despite the negative effect on steroidogenesis by the transfer from the sea, the hormonal treatments increased the number of fish from where sperm could be obtained, as well as testis growth, and reduced testicular apoptosis. Treatment with hCG resulted in the most significant changes in spermatogenesis, while GnRHaimpl appeared to induce less intense, but likely longer-lasting effects. The study indicated that F1 hatchery-produced males also exhibited reproductive dysfunctions as wild-caught captive-reared greater amberjack, and that the observed positive effects of the hormone treatments on spermiation/spermatogenesis were likely mediated by factors other than sex steroid hormones.

Detrimental impact of cell phone radiation on sperm DNA integrity

Radiofrequency electromagnetic radiation (RF-EMR) from various sources may impact health due to the generation of frequency bands. Broad pulses emitted within frequency bands can be absorbed by cells, influencing their function. Numerous laboratory studies have demonstrated that mobile phones-generally the most widely used devices-can have harmful effects on sex cells, such as sperm and oocytes, by producing RF-EMR. Moreover, some research has indicated that RF-EMR generated by mobile phones can influence sperm parameters, including motility, morphology, viability, and (most critically) DNA structure. Consequently, RF-EMR can disrupt both sperm function and fertilization. However, other studies have reported that exposure of spermatozoa to RF-EMR does not affect the functional parameters or genetic structure of sperm. These conflicting results likely stem from differences among studies in the duration and exposure distance, as well as the species of animal used. This report was undertaken to review the existing research discussing the effects of RF-EMR on the DNA integrity of mammalian spermatozoa.

Changes in Sperm Parameters with Time in Men with Normal and Abnormal Baseline Semen Analysis

The association between paternal age and sperm quality in the population level has been previously studied. Only limited data exists regarding the intra-personal variations in semen parameters among fertile and infertile men over time. We aimed to assess trends over time in semen parameters among men with normal and abnormal baseline sperm parameters and investigate potential risk factors for sperm quality deterioration. This retrospective cohort study was conducted at a university-affiliated medical center in vitro fertilization (IVF) unit. Patients with at least two semen analyses (SA) performed > 1 year apart, with the last SA done between 2017 and 2021, were included. The study consisted of two main analyses-comparison of intra-patient's sperm parameters changes in men with normal and abnormal baseline SA (BSA) and analysis of risk factors for developing abnormal semen parameters over time in men who had normal BSA parameters. This study included a total of 902 men assessed for infertility with normal and abnormal BSA. The average time interval between tests was 1015 days (range 366-7709 days). Among individuals with normal BSA, there was a mild decline in most parameters-concentration (- 6.53 M/ml), motility (- 7.74%), and total motile count (TMC) (- 21.80 M) (p < 0.05 for all parameters). In contrast, a slight improvement in most parameters, except for concentration, was noted in men with abnormal BSA-volume (+ 0.21 ml), motility (+ 8.72%), and TMC (+ 14.38 M) (p < 0.05 for all parameters). Focusing on men with normal BSA, 33.5% of individuals developed abnormality in one or more of their sperm parameters over time, within a mean time of 1013 ± 661 days. We also found that only time between tests emerged as an independent prognostic factor for the development of abnormal SA later. Interestingly, sperm deterioration in participants in their third, fourth, and fifth decades of life with normal initial semen analysis was similar. Our study provides evidence of a decline in semen quality over time in individuals with normal BSA, in contrast to men with abnormal BSA. Longer time intervals between tests independently increase the risk of sperm abnormalities.

Association between diurnal temperature range and sperm quality: Evidence from a prospective cohort in Central China

Inter-day temperature variability has been reported to be associated with sperm quality in a city-level exposure assessment study. However, studies exploring the impact of temperature variability within a single day on sperm quality at individual level are still lacking. The present study aims to bridge this research gap by analyzing the linear and non-linear associations between diurnal temperature range (DTR) exposure and sperm quality, utilizing data from the Anhui Prospective Assisted Reproduction Cohort. The study included 15,112 males (totaling 28,267 tests) and assessed individual exposure to various environmental factors (residential greenness, ambient particulate matter, sulfur dioxide, relative humidity, ambient temperature, and DTR) during the 0-90 day period before semen analysis. A combination of a linear mixed model, natural cubic splines, and subgroup analysis was employed. Significant "U"-shaped non-linear associations were observed between DTR exposure and total motility, sperm concentration, sperm count, total motile sperm count, and progressive motile sperm count. Lower DTR levels negatively impacted these parameters, whereas higher DTR levels showed a positive effect. Notably, these associations were more pronounced at ambient temperatures below 16.5 °C, while absent in warmer conditions. Sperm quality demonstrates increased sensitivity to DTR exposure in cooler environments. Therefore, implementing effective individual temperature management strategies is crucial for mitigating decreased sperm quality associated with DTR exposure, highlighting the potential benefits of government policies aimed at achieving carbon neutrality to enhance overall sperm quality in the general population.

Effect of seawater temperature and pH on the sperm motility of the European eel

The current climate change situation could bring critical effects for marine species, especially those already considered endangered. Although some species can adapt fast to the environmental changes, it is necessary to get into the worst scenario and develop tools to anticipatedly assess the physiological effects of such environmental change. With this purpose, our study aims to determine the effect of a range of seawater temperatures and pHs on sperm motility in the European eel (Anguilla anguilla). Low seawater pH (6.5-7.4) decreased the eel sperm motility in comparison to the control (pH = 8.2). We also studied the combined effect of the pH of the artificial seminal plasma (the plasma where the sperm cells are suspended) with the pH of Artificial Sea Water (ASW, pH 7.8 or and 8.2). We did not find statistical differences in sperm motility and kinetic parameters caused by the artificial seminal plasma pH. However, seawater pH induced significantly higher values of total sperm motility, and the percentage of fast spermatozoa with a pH of 8.2 in comparison with a pH of 7.8. In contrast, the seawater temperature did not affect sperm motility parameters or sperm longevity. To study the effect of the interaction between seawater temperature and pH on sperm motility, two temperatures: 4 and 24 °C, and two pHs 7.8 and 8.2, were tested. There were significant differences between temperature and pH in several kinetic parameters and, in general, the lowest values were observed in the samples activated at low temperature and low pH (4 °C, pH 7.8). This work suggest that eel sperm motility and kinetics will not be affected by the expected changes in pH or temperature due to the climate change.

Cresyl Diphenyl Phosphate exposure induces reproductive functional defects in men and male mice

Cresyl Diphenyl Phosphate (CDP), as a novel organophosphate esters (OPEs), achieves widely used and exposed in multiple industries. However, its male reproductive toxicity and underlying mechanism remains unclear. In vivo, male mice were gavaged with CDP (0, 4, 20, or 100 mg/kg/d) for 8 weeks. And we treated TM3, TM4 and GC-2 cells with 0, 10, 25, and 50 μM CDP for 24 h to detect its reproductive toxicity effect in vitro. In our study, we revealed that CDP inhibited proliferation and induced apoptosis in mice testis and GC-2 cells, thereby leading to the decreased sperm quality. In mechanism, CDP trigger the oxidative stress and ROS production, thus partially causing DNA damage and cell apoptosis. Moreover, CDP exposure causes injury to Ledyig cells and Sertoli cells, thus disturbing the testicular microenvironment and inhibiting spermatogonia proliferation. In conclusion, this research reveals multiple adverse impacts of CDP on the male reproductive system and calls for further study of the toxicological effects of CDP on human health.

Effects of combined exposure to polystyrene microplastics and 17α-Methyltestosterone on the reproductive system of zebrafish

Polystyrene microplastics (PS-MPs) are important carriers of pollutants in water. 17α-Methyltestosterone (MT) is a synthetic environmental endocrine disrupting chemical (EDC) with androgenic effects. To study the effects of PS-MPs and MT on zebrafish reproductive systems, zebrafish were exposed to 0 or 50 ng L-1 MT, 0.5 mg∙L-1 PS-MPs, or 50 ng∙L-1 MT + 0.5 mg∙L-1 PS-MPs for 21 d. The results showed that the different exposure reagents caused varying degrees of damage to the reproductive systems in zebrafish, with the extent of damage increasing as the exposure duration increased. Histological analysis of the gonads revealed that the ratio of mature oocytes and mature spermatozoa in the gonad decreased gradually with increased exposure time, with the ratio being Control > PS-MPs > MT > MT + PS-MPs in decreasing order. The results of quantitative real-time PCR (qRT‒PCR) showed that in female fish treated for 7 d, the expression of cyp11a mRNA was significantly reduced in all three treatment groups(MT, PS-MPs, and MT + PS-MPs), while in the group treated for 14 d with MT + PS-MPs, the expression of cyp19a1a and StAR mRNA was significantly increased. In male fish exposed for 21 d, the expression of cyp11a, cyp17a1, cyp19a1a, StAR, 3β-HSD, and 17β-HSD3 mRNA was significantly decreased in MT + PS-MPs. ELISA results showed that after 14 d of exposure, the levels of E2, LH, and FSH in the ovaries of female fish were significantly reduced in all three treatment groups. Similarly, the levels of T, E2, LH, and FSH in the testis of male fish were significantly reduced after 14 d of exposure to PS-MPs and MT + PS-MPs. Offspring of zebrafish exposed to MT and MT + PS-MPs exhibited delayed incubation time and slow development. The cross-generational toxicity of PS-MPs themselves may be negligible, but it can exacerbate the toxicity of MT, making the cross-generational effects more pronounced in the offspring, causing offspring mortality and malformations. Offspring of zebrafish exposed to MT and MT + PS-MPs exhibited delayed incubation time and slow development. In addition, MT caused malformations such as pericardial edema, yolk cysts, and spinal deformities in zebrafish during the incubation period.

The effect of seminal pathogens on standard semen parameters, sperm kinematics and seminal inflammatory markers

This study evaluated the effects of urogenital pathogens on standard semen parameters, sperm kinematics and host inflammatory response in a cohort of asymptomatic subfertile men. There were six groups based on the results of bacterial culture, including Ureaplasma urealyticum (U. Urealyticum) (n = 27), mixed comprising two or more pathogenic species (n = 28), Gardnerella Vaginalis (G. Vaginalis) (n = 15), gram-positive cocci and bacilli (g+cocci/bacilli) (n = 15), gram-negative bacilli (g-bacilli) (n = 10) and Chlamydia trachomatis (C. trachomatis) (n = 2). One control group (n = 20) and one leukocytospermic group (n = 10) were also included. Sperm quality parameters, seminal leukocytes and interleukin (IL)-6 of all groups, apart from C. trachomatis, were compared to the control group. Standard semen parameters were significantly worse in all groups except for that with g-bacilli. Progressive motility, total motility and normal sperm morphology demonstrated the most significant differences, when U. Urealyticum, leukocytospermia and mixed pathogens were detected in semen. Among sperm kinematics, the concentration of progressive motile sperm cells (CPMS), the percentage of progressive motile sperm cells (PPMS) and straightness (STR) were manifested significant declines in the presence of seminal pathogens. CPMS was affected in all groups except for G. vaginalis. Moreover, the presence of g+cocci/bacilli and g-bacilli were associated with increased seminal IL-6. Seminal leukocytes were elevated significantly only when g-bacilli were cultured in semen. We conclude that seminal pathogens can negatively affect sperm quality. The most negative effect is related to U. Urealyticum. Moreover, g+cocci/bacilli and g-bacilli can initiate an inflammatory response.

Non-thermal plasma promotes boar sperm quality through increasing AMPK methylation

Boar sperm quality, as an important indicator of reproductive efficiency, directly affects the efficiency of livestock production. Here, this study was conducted to improve the boar sperm quality by using a non-thermal dielectric barrier discharge (DBD) plasma. Our results showed that DBD plasma exposure at 2.1 W for 15 s could improve boar sperm quality by increasing exon methylation level of adenosine monophosphate-activated protein kinase (AMPK) and thus improving the glycolytic flux, mitochondrial function, and antioxidant capacity without damaging the integrity of sperm DNA and acrosome. In addition, DBD plasma could rescue DNA methyltransferase inhibitor decitabine-caused low sperm quality through reducing the oxidative stress and mitochondrial damage. Therefore, the application of non-thermal plasma provides a new strategy for reducing sperm oxidative damage and improving sperm quality, which shows a great potential in assisted reproduction to solve the problem of male infertility.

SARS-CoV-2 vaccination and semen quality: a study based on sperm donor candidate data in southwest China

Background

The coronavirus disease 2019 (COVID-19) pandemic has been a global health crisis and continues to pose risk to population health at the present. Vaccination against this disease caused by the severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) virus has become a public health priority worldwide. Yet, limited information is available on the potential impact of such vaccines on human fertility.

Methods

To examine the relationship between COVID-19 vaccination and male fertility, we conducted an observational study on sperm donor candidates in China who received Chinese COVID-19 vaccines between January 1, 2020 to December 31, 2021.

Results

A total of 2,955 semen samples from 564 individuals were assessed along with vaccination information. Statistical analyses were conducted on both the entire study population and the subgroup of individuals who provided repeated semen samples before and after vaccination. While motility related parameters [progressive rate, curvilinear velocity (VCL), average path velocity (VAP), straight-line velocity (VSL), wobble (WOB), straightness (STR), linearity (LIN), amplitude of lateral head displacement (ALH), beat-cross frequency (BCF)] exhibited statistically significant difference before and after vaccination based on Welch two-sample test, mixed effects regression results based on repeated measures from the same individuals indicated that vaccination was not statistically associated with sperm quality parameters except for VCL, VAP, and VSL. Individual variability was the key determinant of sperm quality variance, with contribution ranging from 19% to 82%.

Conclusions

Findings from our study could help to enhance current understanding of male reproductive health in the context of the global pandemic.

Does COVID-19 affect sperm quality in males? the answer may be yes, but only temporarily

BACKGROUND

The Corona Virus Disease 2019 (COVID-19) pandemic has raised concerns regarding its potential impact on male reproductive health. However, the impact of COVID-19 on sperm quality remains uncertain. This retrospective study aimed to investigate the short-term and relatively long-term effects of COVID-19 infection on sperm quality.

METHODS

A total of 85 males with fertility requirements, who underwent semen evaluation at Guilin People's Hospital between June 2022 and July 2023, were included in the study. Changes in semen parameters were analyzed across three specific timeframes: within 6 months before COVID-19 infection, within 3 months after COVID-19 infection, and 3-6 months after COVID-19 recovery.

RESULTS

The results revealed that the sperm concentration and total sperm number were significantly lower after infection compared to before, while in the recovery period, the sperm concentration, total sperm count, progressive motility, and normal morphology significantly increased. Comparing the three periods, the most significant difference was observed in sperm concentration, which exhibited a significant decrease after infection but returned to normal levels after recovery from COVID-19.

CONCLUSIONS

These findings suggest that COVID-19 may exert some impact on sperm quality, particularly evidenced by decreased sperm concentration post-infection. Fortunately, these effects on semen parameters appear to be temporary, with gradual restoration of semen parameters within 3-6 months after recovery. However, further research is needed to explore the underlying mechanisms and long-term implications of these observed changes in semen parameters.

Outdoor artificial light at night and male sperm quality: A retrospective cohort study in China

Due to the worldwide increased rate of infertility among reproductive-age couples, there is a growing interest in the relationship between environmental stimuli and human sperm quality. While animal studies have demonstrated the detrimental effects of outdoor artificial light at night (ALAN) on sperm quality, investigations based on human data are lacking. Therefore, we conducted a retrospective cohort study involving 1991 sperm donor candidates and employed multivariate linear regression and restricted cubic spline models to quantify the association between outdoor ALAN and sperm quality. The aim was to determine whether there exists an association between exposure to outdoor ALAN and sperm quality. The study included 1991 sperm donor candidates with the following characteristics: mean [SD] age, 24.98 [4.78] years; mean [SD] BMI, 22.13 [2.60] kg/m2; mean [SD] sleep duration, 7.66 [1.07] hours/day. Outdoor ALAN exposure of study participants ranged from 0 to 100 nW/cm2/sr. Multiple regression analysis on chronic exposure (0-90 days before sperm donation) and human sperm quality revealed the following associations: for CASA primary motion parameters, every 100-unit (nW/cm2/sr) increase in chronic outdoor ALAN was associated with a change of -0.043 [95%CI: 0.073, -0.014] in Linearity (LIN), and -5.523 [95%CI: 9.100, -1.946] in Curvilinear velocity (VCL). For CASA secondary motion parameters, every 100-unit (nW/cm2/sr) increase in chronic outdoor ALAN was associated with a change of -3.873 [95%CI: 4.926, -2.748] in non-progressive motility rate (NP). Furthermore, the primary sperm quality parameter exhibited a decline of -4.740 [95%CI: 8.853, -0.628] in sperm motility rate per 100-unit (nW/cm2/sr) increase in chronic outdoor ALAN. Similar associations were also observed for acute exposure (0-9 days before sperm donation). This retrospective study suggests that poorer sperm quality is more prevalent among adult males residing in areas with higher levels of outdoor ALAN, with a particularly pronounced impact observed in males below the age of 25 years.

Physiological evaluation of seasonal sperm quality in a biannual spawner, Pacific abalone: Effects on in-vitro fertilization and cryotolerance

Pacific abalone, Haliotis discus hannai, is a highly valuable gastropod mollusk commonly found in Southeast Asia. The present study aims to analyze the seminal plasma quality, sperm quality, and cryotolerance of the Pacific abalone sperm during its reproductive season. The seminal plasma quality was evaluated by analyzing biochemical and metabolite composition, enzymatic activity (superoxide dismutase, catalase, and glutathione), and lipid peroxidation (LPO) activity. The sperm quality was evaluated by analyzing motility, concentration, volume, ATP content, acrosome integrity (AI), plasma membrane integrity (PMI), mitochondrial membrane potential (MMP), DNA integrity, and fertilization potential. The cryotolerance capacity was evaluated by analyzing post-thaw motility, AI, PMI, MMP, and DNA integrity. Seminal plasma osmolarity was significantly higher (1123.3 ± 1.5 mOsmL-1) in May compared to other reproductive periods, with Cl- (516.8 ± 0.5 mM) and Na+ (460.2 ± 0.4 mM) as the dominant ions. The seminal plasma pH remained constant at 6.8 throughout the reproductive season. Improved enzymatic activity and lower LPO were detected in May or June. Sperm quality indicators were similar in May and June, except for sperm production. The fertilization potential (May: 93.0 ± 4.4%, June: 86.0 ± 7.2%) and hatching rate (May: 86.6 ± 5.78%, June: 82.3 ± 3.2%) of Pacific abalone were significantly higher in May or June than they were in other reproductive seasons. The motility (May: 50.19 ± 2.35%, June: 49.96 ± 1.60%), AI (May: 44.02 ± 3.46%, June: 42.16 ± 3.61%), PMI (May: 54.12 ± 3.29%, June: 52.82 ± 2.58%), and MMP (May: 44.02 ± 3.46%, June: 42.16 ± 3.61%) of the cryopreserved sperm were similar in May and June compared with those preserved in other reproductive seasons. The DNA integrity of the cryopreserved sperm was similar in May (80.3 ± 6.7%) or June (78.9 ± 7.4%) and had a higher cryotolerance than in other reproductive seasons. Hence, it can be suggested that May and/or June are suitable periods for sperm physiology experiments, artificial reproduction, and sperm cryopreservation of Pacific abalone.

Ozone exposure associates with sperm quality indicators: Sperm telomere length as a potential mediating factor

Evidence linking O3 exposure and human semen quality is limited and conflicting and the mechanism underlying the association remains unclear. Therefore, we investigated the associations between ambient O3 exposure and sperm quality parameters and explored the mediating role of sperm mitochondrial DNA copy number (mtDNAcn) and sperm telomere length (STL) among 1068 potential sperm donors who provided 5002 repeated semen samples over approximately 90 days. We found that every 10 μg/m3 increase in O3 exposure was associated with a decrease in STL, sperm concentration, total count, total motile sperm number, and semen volume. However, O3 exposure was associated with increased total motility and progressive motility. The association for sperm quality parameters was stronger when exposure was measured at spermatogenesis stages I and II. For STL, the strongest association was observed when exposure was measured at spermatogenesis stage II. Additionally, we found that approximately 9% and 8% of the association between O3 exposure and sperm concentration and count was mediated by STL, respectively. In summary, our findings suggest that O3 pollution may affect sperm telomere length, eventually leading to reduced semen quality.

Effects of exposure to PM2.5 during pregnancy on the multigenerational reproductive outcomes of male mouse offspring and the role of Sertoli cells

There is a paucity of studies on the multigenerational reproductive toxicity of fine particle matter (PM2.5) exposure during pregnancy on male offspring and the underlying mechanisms. This study explored the effects of PM2.5 exposure during pregnancy on the spermatogenesis of three consecutive generations of male mouse offspring. We randomized pregnant C57BL/6 mice into the control group, the Quartz Fiber Membrane control group, and two experimental groups exposed to different concentrations of PM2.5 (4.8 and 43.2 mg/kg B.Wt.). Pregnant mice from experimental groups received intratracheal instillation of PM2.5 of different doses on a three-day basis until birth. F1 mature male offspring from PM2.5-exposed pregnant mice were mated with normal female C57BL/6 mice. Likewise, their F2 mature male followed the same to produce the F3 generation. The results showed that PM2.5 exposure during pregnancy led to decreased body and tail length, body weight, and survival rates, decreased sperm concentration and sperm motility, and increased sperm abnormality rates significantly in F1 male offspring. We barely observed significant impacts of PM2.5 on the birth number, survival rates, and index of testes in the F2 and F3 offspring. Further exploration showed that PM2.5 exposure during pregnancy caused the morphological abnormality of Sertoli cells, downregulated androgen receptor (AR) and connexin43, upregulated anti-Müllerian hormone (AMH), cytokeratin-18 (CK-18), caspase-3, and cleaved caspase-3, decreased thyroid-stimulating hormone (TSH) and testosterone (T), and increased triiodothyronine (T3) in F1 male mouse offspring. Overall, we hypothesize that PM2.5 exposure during pregnancy mainly negatively impacts spermatogenesis in the F1 offspring. The possible mechanism could be that PM2.5 exposure during pregnancy disrupts endocrine hormone release in the F1 generation, thereby influencing the maturation and proliferation of their Sertoli cells and hindering spermatogenesis. This study for the first time investigates the role of Sertoli cells in the reproductive toxicity of PM2.5 on offspring.

Persistent oligonecrozoospermia after asymptomatic SARS-CoV-2 infection. A case report and literature review

COVID-19 is known to have deleterious effects on different systems such as the respiratory, cardiovascular, central nervous, and gastrointestinal. However, conflicting data about the possible implications for male reproductive health and fertility have been reported. In addition, the long-term consequences of SARS-CoV-2 infection remain unclear. Herein, we report a case of a 42-year-old man with no known co-morbidities and normal baseline semen quality, who subsequently suffered an asymptomatic SARS-CoV-2 infection. Shortly after, the patient developed sudden oligoasthenozoospermia, even reaching azoospermia, which gradually evolved into persistent severe oligonecrozoospermia, accompanied by semen inflammation and oxidative stress. Remarkably, the latter occurred in the absence of urogenital infections, hormonal imbalances, tissue/organ obstruction/damage, medication or drug treatment, smoking, or exposure to toxins/pollutants, radiation, or high temperature. This case constitutes valuable clinical evidence that adds to the current knowledge in the field and highlights the need for further and longer follow-up studies to better understand the putative long-term consequences of SARS-CoV-2 infection on male fertility.

Human umbilical cord mesenchymal stem cells (hUC-MSCs) alleviate paclitaxel-induced spermatogenesis defects and maintain male fertility

Chemotherapeutic drugs can cause reproductive damage by affecting sperm quality and other aspects of male fertility. Stem cells are thought to alleviate the damage caused by chemotherapy drugs and to play roles in reproductive protection and treatment. This study aimed to explore the effects of human umbilical cord mesenchymal stem cells (hUC-MSCs) on alleviating paclitaxel (PTX)-induced spermatogenesis and male fertility defects. An in vivo PTX-induced mice model was constructed to evaluate the reproductive toxicity and protective roles of hUC-MSCs in male fertility improvement. A 14 day PTX treatment regimen significantly attenuated mice spermatogenesis and sperm quality, including affecting spermatogenesis, reducing sperm counts, and decreasing sperm motility. hUC-MSCs treatment could significantly improve sperm functional indicators. Mating experiments with normal female mice and examination of embryo development at 7.5 days post-coitum (dpc) showed that hUC-MSCs restored male mouse fertility that was reduced by PTX. In IVF experiments, PTX impaired sperm fertility and blastocyst development, but hUC-MSCs treatment rescued these indicators. hUC-MSCs' protective role was also displayed through the increased expression of the fertility-related proteins HSPA2 and HSPA4L in testes with decreased expression in the PTX-treated group. These changes might be related to the PTX-induced decreases in expression of the germ cell proliferation protein PCNA and the meiosis proteins SYCP3, MLH1, and STRA8, which were restored after hUC-MSCs treatment. In the PTX-treated group, the expression of testicular antioxidant proteins SIRT1, NRF2, CAT, SOD1, and PRDX6 was significantly decreased, but hUC-MSCs could maintain these expressions and reverse PTX-related increases in BAX/BCL2 ratios. hUC-MSCs may be a promising agent with antioxidant and anti-apoptosis characteristics that can maintain sperm quality following chemotherapy treatment.

Optimization of a non-activating medium for short-term chilled storage of barramundi (Lates calcarifer) testicular spermatozoa

Reliable short-term chilled sperm storage is a critical prerequisite to using advanced reproductive techniques for captive breeding of barramundi (Asian sea bass; Lates calcarifer). Marine Ringer's solution (MRS) is a common non-activating medium (NAM) and has previously been used to store sperm from wild-caught barramundi. However, MRS-stored spermatozoa from captive-bred barramundi were observed to lyse within 30 min incubation. Therefore, this study aimed to optimize the composition of NAM for short-term chilled storage by characterizing and mimicking the biochemical profile of seminal and blood plasma of captive-bred barramundi. To further understand the effect of each component, osmolality was first examined to determine its effect on sperm viability. Thereafter, the effects of NaHCO3, pH, and Na+ and K+ concentrations on sperm motility were investigated. Optimization of the NAM formula was achieved through iterative adaptions. The increase in NAM osmolality from 260 to 400 mOsm/kg led to a significant improvement in sperm viability. Moreover, using HEPES instead of NaHCO3 as buffering agent significantly enhanced sperm motility and velocity. As a result, sperm samples diluted with optimized NAM (185 mM NaCl, 5.1 mM KCl, 1.6 mM CaCl2·2H2O, 1.1 mM MgSO4·7H2O, 10.0 mM HEPES, 5.6 mM D+ glucose, 400 mOsm/kg, pH 7.4) and stored at 4 °C showed no significant loss in total motility for up to 48 h and retained progressive motility for up to 72 h. The optimized NAM developed in this study significantly extended the functional lifespan of spermatozoa during chilled storage, permitting the ongoing development of advanced reproductive technologies for barramundi.

Chronic exposure to tebuconazole alters thyroid hormones and plumage quality in house sparrows (Passer domesticus)

Triazoles belong to a family of fungicides that are ubiquitous in agroecosystems due to their widespread use in crops. Despite their efficiency in controlling fungal diseases, triazoles are also suspected to affect non-target vertebrate species through the disruption of key physiological mechanisms. Most studies so far have focused on aquatic animal models, and the potential impact of triazoles on terrestrial vertebrates has been overlooked despite their relevance as sentinel species of contaminated agroecosystems. Here, we examined the impact of tebuconazole on the thyroid endocrine axis, associated phenotypic traits (plumage quality and body condition) and sperm quality in wild-caught house sparrows (Passer domesticus). We experimentally exposed house sparrows to realistic concentrations of tebuconazole under controlled conditions and tested the impact of this exposure on the levels of thyroid hormones (T3 and T4), feather quality (size and density), body condition and sperm morphology. We found that exposure to tebuconazole caused a significant decrease in T4 levels, suggesting that this azole affects the thyroid endocrine axis, although T3 levels did not differ between control and exposed sparrows. Importantly, we also found that exposed females had an altered plumage structure (larger but less dense feathers) relative to control females. The impact of tebuconazole on body condition was dependent on the duration of exposure and the sex of individuals. Finally, we did not show any effect of exposure to tebuconazole on sperm morphology. Our study demonstrates for the first time that exposure to tebuconazole can alter the thyroid axis of wild birds, impact their plumage quality and potentially affect their body condition. Further endocrine and transcriptomic studies are now needed not only to understand the underlying mechanistic effects of tebuconazole on these variables, but also to further investigate their ultimate consequences on performance (i.e. reproduction and survival).

A novel technique for mass induction of propagation in small fish species: Hormone immersion

Due to the lack of environmental stimuli found in their natural habitat, not all species of tiny fish can reproduce naturally in the conditions of captivity. Silver rasbora (Rasbora argyrotaenia) was used as the model organism in this study, which is the first to successfully use the hormonal technique of immersion to mass induce spawning and spermiation in small fish species. In this study, in order to find out the effect of immersion hormone treatment, two separate experiments in which commercial hormone Ovaprim™ was used for spawning induction and Ovagold™ for spermiation induction were conducted. Four doses of hormones (0.0 mL/L, 0.7 mL/L, 1.4 mL/L, and 2.1 mL/L) were evaluated on 24 females and 40 males in total. According to the experimental findings of female breeders, 1.4 mL/L dose of Ovaprim™ showed best results on latency period (8.67 h) with a total number of eggs (6994 egg) and fertilization rate (99.22 %). In addition, hatching and larval survival rate have also increased. Milt volume and sperm concentration have also seen an increase to 4.25 μL/g bw and 42.71 10⁶ cell/μL respectively at 2.1 mL/L hormone concentration. The best results or responses were obtained by immersion treatments using Ovaprim™ doses of 1.4 mL/L on female and Ovagold™ concentrations of 2.1 mL/L on male. This new technique is a beneficial for breeding small fish species for either commercial or conservational culture condition.

Live motile sperm sorting device for enhanced sperm-fertilization competency: comparative analysis with density-gradient centrifugation and microfluidic sperm sorting

PURPOSE

A live motile sperm sorting device (LensHooke^® CA0) developed to prevent the deleterious effects of centrifugation was evaluated comparatively with conventional density-gradient centrifugation (DGC) and microfluidic-based device (Zymot) in sperm selection.

METHODS

Semen samples from 239 men were collected. CA0 under different incubation intervals (5, 10, 30, and 60 min) and temperatures (20, 25, and 37℃) was conducted. The sperm quality in CA0-, DGC-, and Zymot-processed samples was then comparatively evaluated. Semen parameters included concentration, motility, morphology, motion kinematics, DNA fragmentation index (DFI), and the rate of acrosome-reacted sperm (AR).

RESULTS

Total motility and motile sperm concentration increased in a time- and temperature-dependent manner and the total motility peaked for 30 min at 37℃. In paired analysis, CA0 showed significantly higher total motility (94.0%), progressive motility (90.8%), rapid progressive motility (83.6%), normal morphology (10.3%), and lower DFI (2.4%) and AR (4.7%) than the other two methods in normozoospermic samples (all p < 0.05). For non-normozoospermic samples, CA0 had significantly better results than the other two methods (total motility 89.2%, progressive motility 80.4%, rapid progressive motility 74.2%, normal morphology 8.5%, DFI 4.0%, and AR 4.0%; all p < 0.05).

CONCLUSION

CA0 yielded spermatozoa with enhanced sperm fertilization potentials; DFI was minimized in samples processed by CA0. CA0 was effective for both normal and abnormal semen samples due to its consistent selection efficiency.

The effect of dietary habits on oocyte/sperm quality

The effects of diet and nutritional habits on reproductive cells can be categorized in a variety of ways. In this review, the literature is divided, based on the dietary consumption effects on oocytes and sperm. Topics on dietary patterns and the intrauterine effect of maternal nutrition are covered. In general fruits, vegetables, whole greens, fish, legumes, and also dietary sources containing unsaturated fats can improve reproductive germ cell quality. In epidemiological studies, the food intake frequency questionnaire is one of the most common methods to assess diet. Due to methodological heterogeneity in dietary assessment and inadequacy in the measurement of dietary intake in the questionnaires used, several unreliable results may be reported. Thus, the quality of evidence needs to be improved, since nutritional diets may not be so simply objective and they are inadequate to explain obvious underlining mechanisms. In addition, various compounds that may be ingested can affect molecular mechanisms, influenced by other external factors (drugs, pesticides, smoking, alcohol) and changes in human nutritional parameters. Artificial Intelligence has recently gained widespread interest and may have a role in accurate analysis of dietary patterns for optimal nutritional benefit. Therefore, future prospective randomized studies and objective measurements, consisting of molecular level analysis of the impact on cells and clear-cut methods are needed for accurate assessment of the effect of dietary habits on reproductive treatment.

Use of the flavonoid taxifolin for sperm cryopreservation from the threatened Bermeya goat breed

Taxifolin is a plant flavonoid effective as an antioxidant. This study aimed to assess the effect of adding taxifolin to the semen extender during the cooling period before freezing on the overall post-thawing sperm variables of Bermeya goats. In the first experiment, a dose-response experiment was performed with four experimental groups: Control, 10, 50, and 100 μg/ml of taxifolin using semen from 8 Bermeya males. In the second experiment, semen from 7 Bermeya bucks was collected and extended at 20 °C using a Tris-citric acid-glucose medium supplemented with different concentrations of taxifolin and glutathione (GSH): control, 5 μM taxifolin, 1 mM GSH, and both antioxidants. In both experiments, two straws per buck were thawed in a water bath (37 °C, 30 s), pooled, and incubated at 38 °C. Motility (CASA) was assessed at 0, 2, and 5 h, and sperm physiology was assessed at 0 and 5 h by flow cytometry (viability, intact acrosome membrane, mitochondria membrane potential, capacitation, intracellular reactive oxygen species -ROS-, mitochondrial superoxide, and chromatin status). In experiment 2, an artificial insemination trial (AI) was included with 29 goats for testing the taxifolin 5-μM treatment on fertility. Data were analyzed with the R statistical environment using linear mixed-effects models. In experiment 1 and compared to the control, T10 increased progressive motility (P < 0.001) but taxifolin decreased total and progressive motility at higher concentrations (P < 0.001), both post-thawing and after the incubation. Viability decreased post-thawing in the three concentrations (P < 0.001). Cytoplasmic ROS decreased at 0 and 5 h at T10 (P = 0.049), and all doses decreased mitochondrial superoxide post-thawing (P = 0.024). In experiment 2, 5 μM taxifolin or 1 mM GSH (alone or combined) increased total and progressive motility vs. the control (P < 0.01), and taxifolin increased kinematic parameters such as VCL, ALH, and DNC (P < 0.05). Viability was not affected by taxifolin in this experiment. Both antioxidants did not significantly affect other sperm physiology parameters. The incubation significantly affected all the parameters (P < 0.004), overall decreasing sperm quality. Fertility after artificial insemination with doses supplemented with 5 μM taxifolin was 76.9% (10/13), not significantly different from the control group (69.2%, 9/13). In conclusion, taxifolin showed a lack of toxicity in the low micromolar range and could benefit goat semen cryopreservation.

Genome-wide assessment and mapping of inbreeding depression identifies candidate genes associated with semen traits in Holstein bulls

BACKGROUND

The reduction in phenotypic performance of a population due to mating between close relatives is called inbreeding depression. The genetic background of inbreeding depression for semen traits is poorly understood. Thus, the objectives were to estimate the effect of inbreeding and to identify genomic regions underlying inbreeding depression of semen traits including ejaculate volume (EV), sperm concentration (SC), and sperm motility (SM). The dataset comprised ~ 330 K semen records from ~ 1.5 K Holstein bulls genotyped with 50 K single nucleotide polymorphism (SNP) BeadChip. Genomic inbreeding coefficients were estimated using runs of homozygosity (i.e., F_ROH > 1 Mb) and excess of SNP homozygosity (F_SNP). The effect of inbreeding was estimated by regressing phenotypes of semen traits on inbreeding coefficients. Associated variants with inbreeding depression were also detected by regressing phenotypes on ROH state of the variants.

RESULTS

Significant inbreeding depression was observed for SC and SM (p < 0.01). A 1% increase in F_ROH reduced SM and SC by 0.28% and 0.42% of the population mean, respectively. By splitting F_ROH into different lengths, we found significant reduction in SC and SM due to longer ROH, which is indicative of more recent inbreeding. A genome-wide association study revealed two signals positioned on BTA 8 associated with inbreeding depression of SC (p < 0.00001; FDR < 0.02). Three candidate genes of GALNTL6, HMGB2, and ADAM29, located in these regions, have established and conserved connections with reproduction and/or male fertility. Moreover, six genomic regions on BTA 3, 9, 21 and 28 were associated with SM (p < 0.0001; FDR < 0.08). These genomic regions contained genes including PRMT6, SCAPER, EDC3, and LIN28B with established connections to spermatogenesis or fertility.

CONCLUSIONS

Inbreeding depression adversely affects SC and SM, with evidence that longer ROH, or more recent inbreeding, being especially detrimental. There are genomic regions associated with semen traits that seems to be especially sensitive to homozygosity, and evidence to support some from other studies. Breeding companies may wish to consider avoiding homozygosity in these regions for potential artificial insemination sires.

Shipping can be achieved but cargo arrives with damage - titanium dioxide nanoparticles affect the DNA of Pacific oyster sperm

Titanium dioxide nanoparticles (TiO₂ NP) were reported to be reprotoxic in humans and fish. However, the effects of these NP on the reproduction of marine bivalves, namely oysters, remain unknown. Thus, a short-term (1 h) direct exposure of sperm of the Pacific oyster (Crassostrea gigas) to two TiO₂ NP concentrations (1 and 10 mg.L-1) was performed, and sperm motility, antioxidant responses, and DNA integrity were evaluated. Although no changes occurred in sperm motility and the activities of the antioxidants, the genetic damage indicator increased at both concentrations, demonstrating that TiO₂ NP affects the DNA integrity of oyster sperm. Although DNA transfer can happen, it does not fulfill its biological mission since the transferred DNA is not intact and may compromise the reproduction and recruitment of the oysters. This vulnerability of C. gigas sperm towards TiO₂ NP highlights the importance of studying the effects of NPs exposure to broadcast spawners.

Review: Evaluation of bull fertility. Functional and molecular approaches

With the term "assisted reproduction technologies" in modern cattle farming, one could imply the collection of techniques that aim at the optimal use of bovine gametes to produce animals of high genetic value in a time- and cost-efficient manner. The accurate characterisation of sperm quality plays a critical role for the efficiency of several assisted reproduction-related procedures, such as sperm processing, in vitro embryo production and artificial insemination. Bull fertility is ultimately a collective projection of the ability of a series of ejaculates to endure sperm processing stress, and achieve fertilisation of the oocyte and production of a viable and well-developing embryo. In this concept, the assessment of sperm functional and molecular characteristics is key to bull fertility diagnostics and prognostics. Among others, functional features linked to sperm plasma membrane, acrosome and DNA integrity are usually assessed as a measure of the ability of sperm to express the phenotypes that will allow them to maintain their homeostasis and orchestrate-in a strict temporal manner-the course of events that will enable the delivery of their genetic content to the oocyte upon fertilisation. Nevertheless, measures of sperm functionality are not always adequate indicators of bull fertility. Nowadays, advancements in the field of molecular biology have facilitated the profiling of several biomolecules in male gametes. The molecular profiling of bovine sperm offers a deeper insight into the mechanisms underlying sperm physiology and, thus, can reveal novel candidate markers for bull fertility prognosis. In this review, the importance of three organelles (the nucleus, the plasma membrane and the acrosome) for the characterisation of sperm fertilising capacity and bull fertility is discussed at functional and molecular levels. In particular, information about sperm head morphometry, chromatin structure, viability as well as the ability of sperm to capacitate and undergo the acrosome reaction are presented in relation to the cryotolerance of male gametes and bull fertility. Finally, major spermatozoal coding and non-coding RNAs, and proteins that are involved in the above-mentioned aspects of sperm functionality are also summarised.

Introducing energy into marine environments: A lab-scale static magnetic field submarine cable simulation and its effects on sperm and larval development on a reef forming serpulid

Non-chemical sources of anthropogenic environmental stress, such as artificial lights, noise and magnetic fields, are still an underestimate factor that may affect the wildlife. Marine environments are constantly subjected to these kinds of stress, especially nearby to urbanized coastal areas. In the present work, the effect of static magnetic fields, associated with submerged electric cables, was evaluated in gametes and early life stages of a serpulid polychaete, namely Ficopomatus enigmaticus. Specifically, biochemical/physiological impairments of sperm, fertilization rate inhibition and incorrect larval development were assessed. We evaluated differences between two selected magnetic field induction values (0.5 and 1 mT) along a range of exposure times (30 min-48 h), for a sound evaluation on this species. We found that a magnetic induction of 1 mT, a typical value that can be found at distance of tens of cm from a submerged cable, may be considered a biologically and ecologically relevant for sessile organisms and for coastal environments more generally. This value exerted statistically significant effects on membranes, DNA integrity, kinetic parameters and mitochondrial activity of sperm cells. Moreover, a significant reduction in fertilization rate was observed in sperm exposed to the same magnetic induction level (1 mT) for 3 h, compared to controls. Regarding early larval stages, 48-h exposure did not affect the correct development. Our results represent a starting point for a future focus of research on magnetic field effects on early life stages of aquatic invertebrates, using model species as representative for reef-forming/encrusting organisms and ecological indicators of soft sediment quality.

N-acetylcysteine rescues meiotic arrest during spermatogenesis in mice exposed to BDE-209

Deca-bromodiphenyl ethers (BDE-209) has been widely used in electronic devices and textiles as additives to flame retardants. Growing evidence showed that BDE-209 exposure leads to poorer sperm quality and male reproductive dysfunction. However, the underlying mechanisms of BDE-209 exposure caused a decline in sperm quality remains unclear. This study aimed to evaluate the protective effects of N-acetylcysteine (NAC) on meiotic arrest in spermatocytes and decreased sperm quality in BDE-209-exposed mice. In the study, mice were treated with NAC (150 mg/kg BW) 2 h before administrated with BDE-209 (80 mg/kg BW) for 2 weeks. For the in vitro studies, spermatocyte cell line GC-2spd cells were pretreated with NAC (5 mM) 2 h before treated with BDE-209 (50 μM) for 24 h. We found that pretreatment with NAC attenuated the oxidative stress status induced by BDE-209 in vivo and in vitro. Moreover, pretreatment with NAC rescued the testicular histology impairment and decreased the testicular organ coefficient in BDE-209-exposed mice. In addition, NAC supplement partially promoted meiotic prophase and improved sperm quality in BDE-209-exposed mice. Furthermore, NAC pretreatment effectively improved DNA damage repair by recovering DMC1, RAD51, and MLH1. In conclusion, BDE-209 caused spermatogenesis dysfunction related to the meiotic arrest medicated by oxidative stress, decreasing sperm quality.

Impact of Alpinia galanga and zinc on semen quality and some reproductive hormone constituents in California rabbit bucks

The objective of the current study was to investigate the influence of synergism of the dry powder of Alpinia galanga rhizomes (AGR) and/or zinc sulfate in the diet on semen quality and reproductive traits of California rabbit bucks. The study was conducted in two stages. First stage: appreciation of semen characteristics, 36 California rabbit bucks (aged 5 months) with average body weights of 2980 g were divided randomly into six treatments (six individuals each). The treatment groups were: first group, control fed basal diet (C); second group, fed basal diet plus 1 g AGR/kg dry matter (DM) (AGR1); third group, fed basal diet plus 2 g AGR/kg DM (AGR2); fourth group, fed basal diet plus 200 mg Zn/litre drinking water (Zn); fifth group, fed basal diet plus 1 g AGR/kg DM and 200 mg Zn/litre drinking water (AGR1 + Zn); sixth group, fed basal diet plus 2 g AGR/kg DM and 200 mg Zn/litre drinking water (AGR2 + Zn). Second stage: the previous bucks were used to determine the efficiency of semen on reproductive fertility traits, 48 mature does (aged 6 months, nulliparous) with an average body weight of 3050 ± 20.7 g were divided randomly into six treatments and inseminated with previous groups of treated bucks. The results of the first stage, recorded high activity on gonadotropins hormones: follicle-stimulating hormone (FSH) and luteinizing hormone (LH), free testosterone (FT), progesterone (P₄) and oestrogen (E₂17β) concentrations for AGR1 + Zn and AGR2 + Zn compared with the control group. Groups AGR1, AGR2, AGR1 + Zn and AGR2 + Zn had significantly lowered concentrations of triglycerides, total cholesterol, low-density lipoprotein, and malondialdehyde (MDA), whereas high-density lipoprotein and total antioxidant capacity (TAC) were increased significantly compared with the control group. The group supplemented with AGR with or without Zn had significantly improved ejaculate volume, advanced motility, sperm concentration, and cell integrity. Fertility rate and litter size were improved in all groups compared with the control. It was concluded that supplementing diets with Alpinia galanga and Zn significantly increased sperm percentage, motility and reproductive hormones (testosterone, FSH, LH, E₂17β, P₄). This suggested that this plant when used may be favourable for improved sperm quality and fertility parameters.

Extension of the equilibration period up to 24 h maintains the post-thawing quality of Holstein bull semen frozen with OPTIXcell®

Semen cryopreservation in bovine livestock is well established, but logistics often require deviations from standard protocols. Extending the equilibration time to the following day is convenient in many situations. To improve our knowledge of the effects of this modification, we studied the post-thawing and post-incubation (4 h, 38 °C) sperm quality after freezing with 4 or 24-h extension in the OPTIXcell extender by using an ample panel of analyses: CASA for motility; flow cytometry for viability, physiology, oxidative stress, and chromatin parameters (DNA fragmentation, chromatin compaction, and thiol groups status); and spectrometry for malondialdehyde production. Semen was obtained from 12 Holstein bulls. The 24-h equilibration time showed few significant effects, with only a tiny decrease in progressive motility and a positive impact on chromatin structure. The incubation removed some of these effects, with the pattern for chromatin compaction remaining the same. No detrimental oxidative stress or increase in apoptotic or capacitation markers was detected. Additionally, the individual bull interacted with the effects of the incubation and the equilibration, especially regarding the chromatin status. Whereas this interaction did not critically affect sperm quality, it could be relevant in practice. Bull fertility as non-return rates (NRR56) was associated with some sperm parameters (especially with an improved chromatin structure) but not in the 4-h post-thawing analysis. Our study supports that extending the equilibration time by at least 24-h is feasible for bull semen freezing with the OPTIXcell extender.

Both selenium deficiency and excess impair male reproductive system via inducing oxidative stress-activated PI3K/AKT-mediated apoptosis and cell proliferation signaling in testis of mice

Selenium (Se) deficiency or excess impairs testicular development and spermatogenesis, while the underlying mechanisms in this regard remain unclear. This study was designed to explore the molecular biology of Se deficiency or excess in spermatogenesis in mice. Three-week-old male mice (n = 10 mice/diet) were fed with Se-deficient diet (SeD, 0.02 mg Se/kg), adequate-Se diet (SeA, 0.2 mg Se/kg), or excess-Se diet (SeE, 2.0 mg Se/kg) for 5 months. Compared with SeA, SeD reduced (P < 0.05) the body weight (10.4%) and sperm density (84.3%) but increased (P < 0.05) sperm deformity (32.8%); SeE decreased (P < 0.05) the sperm density (78.5%) and sperm motility (35.9%) of the mice. Meanwhile, both SeD and SeE increased (P < 0.05) serum FSH concentrations (10.4-25.6%) and induced testicular damage in mice in comparison with the SeA. Compared with SeA, SeD increased (P < 0.05) the 8-OHdG concentration by 25.5%; SeE increased (P < 0.05) both MDA and 8-OHdG concentrations by 118.8-180.3% in testis. Furthermore, transcriptome analysis showed that there 1325 and 858 transcripts were altered (P < 0.05) in the testis by SeD and SeE, respectively, compared with SeA. KEGG pathway analysis revealed that these differentially expressed genes were mainly enriched in the PI3K-AKT signaling pathway, which is regulated by oxidative stress. Moreover, western blotting analysis revealed that SeD and SeE dysregulated PI3K-AKT-mediated apoptosis and cell proliferation signaling, including upregulating (P < 0.05) caspase 3, cleaved-caspase 3, BCL-2 and (or) P53 and downregulating (P < 0.05) PI3K, p-AKT, p-mTOR, 4E-BP1, p-4E-BP1 and (or) p-p70S6K in the testis of mice compared with SeA. Additionally, compared with SeA, both SeD and SeE increased (P < 0.05) GPX3 and SELENOO; SeD decreased (P < 0.05) GPX1, TXRND3 and SELENOW, but SeE increased (P < 0.05) production of three selenoproteins in the testis. Conclusively, both Se deficiency and excess impairs male reproductive system in mice, potentially with the induction of oxidative stress and activation of PI3K/AKT-mediated apoptosis and cell proliferation signaling in the testis.

Initial assessment of the toxicologic effects of leachates from 3-dimensional (3-D) printed objects on sperm quality in two model fish species

The use of 3-dimensional (3-D) printing is gaining popularity in life sciences and driving innovation in fields including aquatic sperm cryopreservation. Yet, little is known about the effects leachates from these objects may have on biological systems. In this study, we investigated if exposure to leachates from 3-D printed objects fabricated from different photo-curable resins could affect sperm quality in two model fish species, zebrafish (Danio rerio) and goldfish (Carassius auratus). Leachates were collected following contact periods of 10 min and 22 h with objects manufactured using a mask LCD resin printer and three different commercially available resins (i.e., standard, eco-friendly, and impact-resistant). Sperm cells were exposed to the leachates for 18 min, and parameters related to sperm motility, cell count, and membrane integrity were evaluated. All experiments were blinded. Leachate originating from contact with impact-resistant resin for 10 min significantly reduced the cell count of zebrafish sperm, while leachate originating from contact with standard resin for 22 h significantly increased the beat cross frequency of goldfish sperm. The changes were not observed across species and no adverse effects were recorded in percent motility, velocity, amplitude of lateral head movement, or membrane integrity of sperm. Our findings demonstrate that exposure to leachates from certain 3-D printed resins can affect sperm quality, while other resins may support sperm quality evaluation. Further investigations are warranted to assess other parameters, effects, and their biological relevance for a variety of aquatic species.

Do phthalates and their metabolites cause poor semen quality? A systematic review and meta-analysis of epidemiological studies on risk of decline in sperm quality

A systematic review and meta-analysis were conducted to understand the association of phthalates and their metabolites with sperm quality in humans. By June 30, 2022, relevant literature on the effects of phthalates and their metabolites on sperm quality were searched and collected using three English-language databases including PubMed, EMbase, and Web of Science. Two researchers independently screened literature, extracted data, and assessed risk of bias. Stata 11 and RevMan 5.3 were used to conduct meta-analysis, test publication bias, and sensitivity analysis. A total of 12 literature were included for meta-analysis, excluding literature with different effect sizes. The results of meta-analysis indicated that monobutyl phthalate (MBP) and monobenzyl phthalate (MBzP) in urine were negatively correlated with semen concentration, and the results were statistically significant (MBP, pooled odds ratio (OR), 95% confidence interval (CI): 2.186 (1.471, 3.248), P < 0.05) and (MBzP, pooled OR (95%CI): 1.882 (1.471, 3.248), P < 0.05). Furthermore, the level of Di-(2-ethylhexyl) phthalate (DEHP) in semen was negatively correlated with semen concentration and the combined effect size was (pooled correlation coefficients (r) (95%CI): -0.225 (-0.319, -0.192), P < 0.05). However, the associations between MBP and MBzP with sperm motility and sperm morphology were not statistically significant (P > 0.05). And there was also no significant correlation between monoethyl phthalate (MEP), monomethyl phthalate (MMP), and mono-2-ethylhexyl phthalate (MEHP) and semen parameters, including semen concentration, sperm motility, and sperm morphology (P > 0.05). In summary, this current study provides moderate-certainty evidence for the data demonstrated that is a negative correlation between urine MBP levels, urine MBzP levels, and semen DEHP levels with semen concentration. In the future, more longitudinal cohort studies are needed to help elucidate the overall association.

Comment on 'Importance of real-time measurement of sperm head morphology in intracytoplasmic sperm injection' by Fumiaki Itoi et al

We present a commentary on the article published in the Zygote FirstView: 'Importance of real-time measurement of sperm head morphology in intracytoplasmic sperm injection' by Fumiaki Itoi and colleagues. We comment on the importance of providing the microscope setup details whenever sperm morphology visualization is discussed. The claim of ×6000-10,000 magnification is misleading as such levels of magnification are impossible to achieve.

Epigenetic programming of TBX2/CX43 mediates lower sperm quality in male offspring induced by prenatal dexamethasone exposure

Decreased sperm quality is the main cause of male infertility. Studies have found that prenatal dexamethasone exposure (PDE) decreases sperm quality in male offspring after birth, but the mechanism is unclear. Wistar pregnant rats were subcutaneously injected with 0.1, 0.2 and 0.4 mg/kg.d dexamethasone at gestational day 9-20. The testes and sperm of first-generation (F1) offspring were collected, and F1 offspring were mated with wild-type female rats to obtain F2. Compared with the control group, F1 offspring in PDE group had lower sperm count and motility after birth, and the deformity rate increased. F2 fetal rats' body length and weight decreased, and the intrauterine growth retardation rate increased. Meanwhile, PDE decreased the expression of connexin 43 (CX43) in offspring testes, while T-box transcription factor 2 (TBX2) promoter region histone 3 lysine 9 acetylation (H3K9ac) level and its expression were increased. Traced back to F1 fetus testes, PDE increased the expression of glucocorticoid receptor (GR) and P300, activated GR protein into the nucleus, and made GR act on the TBX2 promoter region. Further, a series of Sertoli cell interventions confirmed that dexamethasone promoted GR to recruit P300, increased the H3K9ac level of TBX2 promoter region and its expression, and inhibited the expression of CX43. This study confirmed that PDE decreased sperm quality of male offspring, which is related to the epigenetic programming of TBX2/CX43 in the Sertoli cells, provided a theoretical and experimental basis for guiding the rational use of drugs during pregnancy.

BDE-209 disrupted the blood-testis barrier integrity by inhibiting estrogen receptor α signaling pathway in Sprague-Dawley rats

Deca brominated diphenyl ether (BDE-209) is a widely used flame retardant with endocrine-disrupting activity which reportedly caused sperm quality decline and damaged blood-testis barrier (BTB). However, whether BDE-209 exposure led to BTB integrity dysfunction through affecting microtubule cytoskeletal organization and junctions was not well-elucidated. This study aimed to investigate the role of estrogen receptor α (ERα) in BDE-209-mediated perturbation of BTB integrity. Male rats and primary culture Sertoli cells were co-treated with BDE-209 and propylpyrazoletriol (PPT). The data demonstrated that BDE-209 impaired BTB integrity by reducing crucial tight junction-related proteins with ZO-1 and Occludin. Furthermore, the data suggested that BDE-209 diminished the apical ectoplasmic specialization markers with Eps8 and Formin1. In addition, BDE-209 damaged BTB ultrastructure including tight junctions and ectoplasmic specialization structures with broken tight junctions and the absence of actin microfilaments. Further experiments revealed that ERα was triggered in BDE-209-treated Sertoli cells. Unexpectedly, we found that PPT rescued BDE-209-mediated disruption of BTB integrity including tight junction and apical ectoplasmic specialization by activating ERα in Sertoli cells. Taken together, these findings indicated that intratesticular BDE-209 exposure perturbed BTB integrity and destroyed BTB structure by blocking ERα pathway. Our findings provide a new therapeutic target for male reproductive dysfunction.

Changes in Organ Weight, Sperm Quality and Testosterone Levels After Aluminum (Al) and Indium (In) Administration to Wistar Rats

BACKGROUND

Aluminum and indium are widely used in industrial manufacturing, in pharmaceutical products, in medical treatments, and in food packaging, so they could reach organisms by different way. In order to clarify whether these elements are dangerous, we already demonstrated the ultrastructural modifications observed in the testicles, the epididymides, and the seminal vesicles of rat. Their pro-oxidative effect was also confirmed concomitantly to a decrease in anti-oxidant defenses in the blood, the testicles, and the liver. Thus, it seemed very logic to evaluate damages in the reproductive organs, especially on the exocrine and endocrine functions of the testicles.

METHODS

Aluminum and indium were intraperitoneally administered to male Wistar rats. Sperm solution was obtained from cauda epididymides. Motility, viability, density, and malformation of spermatozoa solution were assessed. Serum total unconjugated testosterone concentrations were measured using RIA technique.

RESULTS

Our results showed a decrease in weight of the testicles, epididymides, and seminal vesicles of indium-treated rats and an increase in the weight of their kidneys. A decrease in motility, viability, and density of epididymides stored sperm as well as generation of many spermatozoa malformations was also observed especially in indium-treated rats. Testosterone levels were increased in indium but were enhanced in aluminum group. This confirmed our previous studies showing that aluminum and indium are toxic for the testicular tissues. This could be explained by the generation of reactive oxygen species (ROS) affecting strongly the exocrine and the endocrine functions of the testicles.

CONCLUSION

Aluminum and indium are disturbing elements for the exocrine and endocrine functions of rat testicles.