Poor Semen Quality Research Articles

Toll-like receptors (TLR) 2 and 4 on human sperm recognize bacterial endotoxins and mediate apoptosis

Bacterial infections of the genital tract are one of the most serious causes of infertility in males. In some human patients with poor semen quality, leukocytospermia has been observed. Because leukocytes express the bacterial-lipopolysaccharide (LPS) responsive Toll-like receptor (TLR) signaling cascade and secrete tumor necrosis factor-α, secreted cytokines comprise one, but probably not the only, class of factors that can impact sperm motility. In this study, we documented that bacterial endotoxins, LPS and peptidoglycan, can be detected in human semen. Furthermore, the addition of endotoxins in the absence of leukocytes directly and significantly reduced the motility and increased the apoptotic rate of both human and mouse sperm and suppressed fertilization by mouse sperm both in vivo and in vitro. The well-known LPS receptor, TLR4, and peptidoglycan receptor, TLR2, were expressed in human and mouse sperm. In Tlr2/4(-/-) double-mutant mice, the negative effects of endotoxins on sperm functions were blocked, suggesting that the bacterial endotoxins mediated activation of TLR-dependent pathways in sperm leading to apoptosis. Sperm can recognize bacterial endotoxins by TLRs present in their membranes. The activated TLRs reduce sperm motility, induce sperm apoptosis and significantly impair the potential for fertilization.

Knowledge and perceived risks in couples undergoing genetic testing after recurrent miscarriage or for poor semen quality

Couples with recurrent miscarriage (RM) and men with poor semen quality may undergo genetic testing as part of the diagnostic work-up. This study explored their knowledge and perception of genetic testing, evaluated psychological wellbeing and identified associated variables. A prospective questionnaire study was conducted in seven clinical genetics centres and referring gynaecological departments in couples with RM or poor semen quality. Questionnaires were completed before disclosure of genetic test results. Main outcome measures were knowledge, perceived risk, anxiety and depression. Of 439 participants, 256 were not aware genetic testing was part of the diagnostic work-up. One-third (36% RM, 33% poor semen quality) indicated they had not received information about the genetic test from their doctor. Perceived risk of receiving an abnormal genetic test result was higher than objective risk. Anxiety was highly correlated with perceived risk. Women with RM were more anxious than women in the poor semen quality group or men ( P < 0.01). These couples undergoing genetic testing have a suboptimal understanding of the nature of testing, overestimate the risks of receiving an abnormal result and some show high levels of anxiety. The results of this study can be used to improve patient counselling before genetic testing. Couples with recurrent miscarriage (RM) and couples with men with poor semen quality, may undergo genetic testing as part of the diagnostic work-up to establish the cause. We explored the knowledge and perception of genetic testing in these couples and evaluated their psychological wellbeing. We provided questionnaires in seven clinical genetics centres and referring gynaecological departments to couples with RM or poor semen quality. The questionnaires were completed before receiving the result of the genetic test. We asked couples about knowledge, perceived risk, anxiety and depression. Of 439 participants, 256 said they were not aware genetic testing was part of the diagnostic work-up. One-third (36% RM, 33% poor semen quality) indicated they had not received information about the genetic test from their doctor. Almost all participants overestimated their risk of receiving an abnormal genetic test result. The overestimation was highest in participants who were more anxious. Women with RM were more anxious than women in the poor semen quality group or men ( P < 0.01). These couples undergoing genetic testing have a suboptimal understanding of the nature of testing, overestimate the risks of receiving an abnormal result and some indicate high levels of anxiety. The results of this study can be used to improve patient counselling before genetic testing.

Density gradient centrifugation of sperm from a subfertile stallion and effect of seminal plasma addition on fertility

Stallions are not selected for fertility but for other criteria (pedigree, conformation, performances, progeny), therefore valuable but subfertile stallions with poor semen quality are frequently used in commercial breeding programs. The object of this study was to evaluate whether sperm selection through a silane-coated silica colloid gradient centrifugation, with or without the addition of seminal plasma of a high fertile stallion, could improve the pregnancy rates of an oligospermic valuable stallion in a commercial breeding program. In 2008 breeding season (experiment 1, n = 104 mares), simple centrifugation and density gradient centrifugation of the sperm were compared. In 2009 and 2010 breeding seasons (experiment 2, n = 125 mares), the effect of the addition of 5% seminal plasma to the extender after sperm selection was evaluated. In all mares deep horn uterine insemination was performed with 1 ml containing 50 × 10 6 morphologically normal progressive motile spermatozoa, 24–30 h after induction of ovulation with hCG. Pregnancy diagnosis by ultrasonography was performed 14 days following ovulation. Results showed a higher per cycle pregnancy rate ( P > 0.05) when sperm selection through a density gradient was used (62% vs. 42.3%, exp 1), while the addition of 5% seminal plasma did not influence the outcome (45.9% vs. 47.6%, exp 2) ( P > 0.05). An age-related decrease in the fertility of the stallion was observed when comparing the results from the different breeding seasons ( P < 0.05). In conclusion, sperm selection through a discontinuous density gradient enabled a normal per cycle pregnancy rate to be achieved from an oligospermic-subfertile stallion in a commercial breeding program, and no differences were observed regarding the addition of seminal plasma.

Endocrine Assessment of Prepubertal Boys With a History of Cryptorchidism and/or Hypospadias: A Pilot Study

Four disorders, including poor semen quality, testicular cancer, cryptorchidism and hypospadias, are thought to represent testicular dysgenesis syndrome and have been hypothesized to share a common etiology. We predicted testicular function in prepubertal boys with a history of cryptorchidism and/or hypospadias by measuring serum hormone levels. A total of 82 prepubertal boys who underwent orchiopexy and/or hypospadias repair in childhood were enrolled in the study. Patients were surgically treated for cryptorchidism (23 in group 1), hypospadias (49 in group 2), cryptorchidism and hypospadias (10 in group 3), and hydrocele testis (7 in control group 4). Serum hormones, including luteinizing hormone, follicle-stimulating hormone and total testosterone, were measured separately by age less than 12.5, 12.5 to 13.5 and greater than 13.5 years, and by Tanner pubertal stage. Follicle-stimulating hormone in group 3 was significantly higher than in groups 1, 2 and 4 at ages 12.5 to 13.5 and greater than 13.5 years, and for Tanner stages 2 and 3 (p <0.05). However, luteinizing hormone and testosterone did not differ among the groups regardless of age or Tanner stage. Group 3 patients had significantly higher follicle-stimulating hormone regardless of the severity of cryptorchidism or hypospadias. Data suggest that testicular function in patients with cryptorchidism plus hypospadias is more severely impaired than that in patients with cryptorchidism or hypospadias, lending clinical support to the testicular dysgenesis syndrome hypothesis of a common origin.

Correlation between blood growth hormone profile and reproduction performance in Arabic rams

The aim of this study was to evaluate the seasonal variations of growth hormone concentration in serum and its association with semen characteristics and testosterone level in Arabic rams. The study was carried out with six adult Arabic rams aged 2 to 3 years old. The experiments showed a seasonal variation in growth hormone level. The concentration of growth hormone in breeding season was significantly higher than that in the non-breeding season. In both breeding and non-breeding seasons, there was a positive correlation between serum growth hormone concentration and spermatozoa quality parameters include motility, concentration and viability as well as testosterone concentration. Controversy, a negative correlation was revealed between growth hormone value and abnormal sperm percent in both seasons. Thus, seasonal variation of growth hormone concentration was accompanied with marked alterations in semen characteristics and testosterone level. It can be concluded that one reason for low concentration of testosterone and poor semen quality in the non-breeding season can likely be due to low concentration of blood growth hormone.

Basal Levels and GnRH-induced Responses of Peripheral Testosterone and Estrogen in Holstein Bulls with Poor Semen Quality

The present study investigated the basal levels and GnRH-induced responses of peripheral testosterone and estrogen in Holstein bulls with poor semen quality. On the basis of semen parameters, bulls (n=5) having poor semen quality were selected as experimental bulls, and good semen quality bulls (n=4) were used as control bulls. Both groups were treated intramuscularly once with GnRH (250 µg of fertirelin acetate). Blood samples were collected at -1 day (d), -30 min and 0 h (treatment) followed by every 30 min for 5 h and 1, 3 and 5 d post-GnRH treatment (PGT), and LH, testosterone and estradiol-17β (E(2)) concentrations were measured. The pretreatment concentrations were used as basal levels. The percentage increments based on the 0-h levels were calculated per bull for each sampling time until 5 h PGT, and differences were compared between the experimental and control groups. The PGT concentrations of testosterone and basal and PGT concentrations of E(2) were significantly lower in the experimental group. The testosterone increment in the experimental group was delayed and significantly lower from 1 to 5 h PGT than those in the control group. It can be suggested that bulls with poor semen quality have delayed and lower GnRH-induced testosterone response and may also have lower estrogen levels.

The IMSI procedure improves poor embryo development in the same infertile couples with poor semen quality: A comparative prospective randomized study

BackgroundSperm of poor quality can negatively affect embryo development to the blastocyst stage. The aim of this comparative prospective randomized study was to evaluate the role of an intracytoplasmic morphologically selected sperm injection (IMSI) in the same infertile couples included in the programme of intracytoplasmic sperm injection (ICSI) due to their indications of male infertility which had resulted in all arrested embryos following a prolonged 5-day culture in previous ICSI cycles.MethodsCouples exhibiting poor semen quality and with all arrested embryos following a prolonged 5-day culture in previous ICSI cycles were divided into two groups: Group 1: IMSI group (n = 20) with IMSI performed in a current attempt and Group 2: ICSI group (n = 37) with a conventional ICSI procedure performed in a current attempt of in vitro fertilization. Fertilization rate, embryo development, implantation, pregnancy and abortion rates were compared between current IMSI and conventional ICSI procedures, and with previous ICSI attempts.ResultsThe IMSI group was characterized by a higher number of blastocysts per cycle than the ICSI group (0.80 vs. 0.65) after a prolonged 5-day embryo culture. There was a significantly lower number of cycles with all arrested embryos and cycles with no embryo transfer in the IMSI group versus the ICSI group (0% vs. 27.0%, p = 0.048). After the transfer of embryos at the blastocyst or morula stage (on luteal day 5) a tendency toward higher implantation and pregnancy rates per cycle was achieved in the IMSI group compared to the ICSI group (17.1% vs. 6.8%; 25.0% vs. 8.1%, respectively), although not statistically significant. After IMSI, all pregnancies achieved by the blastocyst transfer were normally on-going, whereas after ICSI, two of three pregnancies ended in spontaneous abortion. After IMSI, two pregnancies were also achieved by the morula stage embryos, whereas after the conventional ICSI procedure, embryos at the morula stage did not implant.ConclusionsThe IMSI procedure improved embryo development and the laboratory and clinical outcomes of sperm microinjection in the same infertile couples with male infertility and poor embryo development over the previous ICSI attempts.

Molecular cloning and sequence analysis of follicle-stimulating hormone beta polypeptide precursor cDNA from the bovine pituitary gland

Follicle-stimulating hormone (FSH) plays an essential role in mammalian spermatogenesis and follicular development. In a previous study, we demonstrated that some bulls carry numerous linked mutations in the FSH beta-subunit (FSHB) gene, and that these bulls have poor-quality semen, low fertility, and slightly lower serum FSH concentration compared to those without such mutations. Here, we identified the different FSHB mRNA transcripts in such individuals and analyzed the evolutionary pattern of the FSHB open reading frame (ORF) in different species. Two different lengths of FSHB mRNA transcripts corresponding to two different polyadenylation sites in the 3'-UTR were detected in wild-type bull pituitary glands, and four different mRNA transcripts resulting from the different polyadenylation sites and linked mutations were identified in mutation-bearing bull pituitaries. All transcripts had almost the same putative FSHB precursor molecule. When the ORF sequences of wild-type and mutation-bearing genes were compared with those of other tetrapod species, the leopard frog had the lowest level of homology (57.8 and 58.1%) and the buffalo had the highest level (95.9 and 96.7%), respectively. These results indicated that the bovine FSHB gene transcribes at least two classes of mRNA in the wild-type and four classes of mRNA in the mutation-bearing individuals, which provides a new insight into the bovine FSHB evolutionary pattern. In addition, these findings lay a foundation for further study of gene expression regulation and the effects of mutations on male fertility traits in cattle.

Selenium&amp;ndash;vitamin E supplementation in infertile men: effects on semen parameters and pregnancy rate

ObjectivesInfertility is an important medical and social problem that has an impact on well-being. A significant development in the last 10 years in the study of human infertility has been the discovery that oxidative sperm DNA damage has a critical role in the etiology of poor semen quality and male infertility. Selenium (Se) is an essential element for normal testicular development, spermatogenesis, and spermatozoa motility and function. The predominant biochemical action of Se in both humans and animals is to serve as an antioxidant via the Se-dependent enzyme glutathione peroxidase and thus protect cellular membranes and organelles from peroxidative damage. We explored the efficacy of Se in combination with vitamin E for improving semen parameters and pregnancy rates in infertile men.Materials and methodsThe study included 690 infertile men with idiopathic asthenoteratospermia who received supplemental daily Se (200 μg) in combination with vitamin E (400 units) for at least 100 days. The mean age of cases was 28.5 years (range 20–45), and the median age was 30 years. These cases had presented with male factor infertility (primary or secondary) for at least 1 year. The longest and shortest duration of infertility was 10 years and 1 year, respectively. The median time of diagnosis of infertility was 1 year with a mean of 2.5 years.ResultsWe observed 52.6% (362 cases) total improvement in sperm motility, morphology, or both, and 10.8% (75 cases) spontaneous pregnancy in comparison with no treatment (95% confidence interval: 3.08 to 5.52). No response to treatment occurred in 253 cases (36.6%) after 14 weeks of combination therapy. Mean difference between semen analyses of cases before and after treatment was 4.3% with a standard deviation of 4.29. On the basis of paired t-test results, combination therapy with oral Se and vitamin E was effective for treatment of asthenospermia or asthenoteratospermia or induction of spontaneous pregnancy (P ≤ 0.001).ConclusionsSupplemental Se and vitamin E may improve semen quality and have beneficial and protective effects, especially on sperm motility. We advocate their use for the treatment of idiopathic male infertility diagnosed with asthenoteratospermia or asthenospermia in semen analysis.

Are serum levels of vitamin D associated with semen quality? Results from a cross-sectional study in young healthy men

To examine the association between low serum vitamin D concentration and estimates of male reproductive function. Cross-sectional study. University hospital. From a Danish pregnancy cohort established in 1984-1987, 347 sons were selected for a study conducted in 2005-2006. Semen parameters and reproductive hormones were related to vitamin D concentrations in 307 men. Semen characteristics and reproductive hormones. A high vitamin D level was unexpectedly associated with lower crude median total sperm count and percentage of normal morphology sperm and a high level of crude median sex hormone-binding globulin and FSH. After adjustment, the associations attenuated to nonsignificant associations, except for sex hormone-binding globulin. Additionally, adjusted free androgen index was lower at higher vitamin D levels, and men with high vitamin D had 11% (95% confidence interval, 1%-20%) lower free androgen index compared with men with low vitamin D. These results do not indicate that low vitamin D is a risk factor for poor semen quality in a population of young healthy men, but we may not have enough men with low vitamin D levels to detect an effect. New studies should include a larger proportion of vitamin D-deficient men.

Artificial insemination in geese

Currently most breeds and lines of geese in use at a commercial scale are derived from two wild species; the swan goose (Anser cygnoides L.) and the true goose-greylag (Anser anser L.). Interestingly, local selections performed for centuries from these two ancestors have resulted in strains or breeds expressing large differences for a range of phenotypic traits including size, body weight, feather colour, behaviour and physiology (including reproductive performance), along with carcass characteristics, flavour and chemical composition of the meat.When compared with other poultry species, the main factors that have limited geese production and geese meat consumption in Europe are the seasonality of its reproduction and the low fertility of breeder flocks (e.g. egg production, fertility and hatchability rates, low male to female ratio, poor semen quality) associated with, on average, relatively high proportions of lipid tissues in the carcasses of their progeny. Some of the above problems can be eliminated or at least reduced by the application of artificial insemination procedures and by selective breeding on fertility and seasonality.The present paper reviews the main particularities of artificial insemination techniques developed in the goose with regards to the morphology and physiology of male reproductive organs. The main characteristics of ejaculates along with some morphological aspects of sperm morphology, semen collection procedures and semen quality assessment are also described. Finally, geese insemination procedures along with their interests and limits are discussed.

Regulation of Translational Suppression in Post-Meiotic Germ Cells: Crosstalk Between MicroRNAs and Actin-Associated Proteins.

During male germ cell development, the vast majority of mRNAs is translationally repressed at the post-meiotic stage. While individual components implicated in the transcriptional and posttranscriptional control of specific germ cell gene expression have been identified, the mechanism that coordinates widespread translational suppression during germ cell differentiation remains unclear. In this study, we established that the cross-talk between miRNAs and actin-associated protein sets the tone for the mRNA-specific as well as general uncoupling of transcription and translation during post-meiotic germ cell maturation. Our study reveals that loss of the miRNA-processing enzyme Dicer function in haploid spermatids causes altered translational activation of several post-meiotic germ cell-specific transcripts, resulting in abnormal chromatin compaction and impaired fertility. We identified a specific miRNA-targeted actin-associated protein 2/3 complex (Arpc) subunit that plays a crucial role in this process as it sequesters germ cell-specific transcripts through their 3' UTR into translationally inert RNP complexes, and making them inaccessible to translational machinery. Interestingly, this actin-associated protein mediates translational suppression by interacting with GW182, a component of processing and chromatoid bodies, discrete cytoplasmic foci in the somatic and germ cells, respectively, believed to play an instrumental role in the storage and degradation of translationally suppressed mRNA. Collectively, our findings suggest that miRNAs are important checkpoint regulators that control timely expression of genes critical for post-meiotic germ cell differentiation and add a new dimension to the increasing role of actin and actin-associated proteins in post-transcriptional gene regulation. In light of recent studies showing an association between altered expression of actin-binding proteins and poor semen quality in human males, we propose that miRNA(s) targeting this Arpc subunit may serve as novel biomarkers for defective sperm and impaired male fertility. This research is funded by the NIH (HD053774-03). (platform)

GnRH Induced Testosterone Response in Poor Semen Quality Holstein Bulls.

GnRH Induced Testosterone Response in Poor Semen Quality Holstein Bulls.

Hypercholesterolemia impaired sperm functionality in rabbits.

Hypercholesterolemia represents a high risk factor for frequent diseases and it has also been associated with poor semen quality that may lead to male infertility. The aim of this study was to analyze semen and sperm function in diet-induced hypercholesterolemic rabbits. Twelve adult White New Zealand male rabbits were fed ad libitum a control diet or a diet supplemented with 0.05% cholesterol. Rabbits under cholesterol-enriched diet significantly increased total cholesterol level in the serum. Semen examination revealed a significant reduction in semen volume and sperm motility in hypercholesterolemic rabbits (HCR). Sperm cell morphology was seriously affected, displaying primarily a “folded head”-head fold along the major axe-, and the presence of cytoplasmic droplet on sperm flagellum. Cholesterol was particularly increased in acrosomal region when detected by filipin probe. The rise in cholesterol concentration in sperm cells was determined quantitatively by Gas chromatographic-mass spectrometric analyses. We also found a reduction of protein tyrosine phosphorylation in sperm incubated under capacitating conditions from HCR. Interestingly, the addition of Protein Kinase A pathway activators -dibutyryl-cyclic AMP and iso-butylmethylxanthine- to the medium restored sperm capacitation. Finally, it was also reported a significant decrease in the percentage of reacted sperm in the presence of progesterone. In conclusion, our data showed that diet-induced hypercholesterolemia adversely affects semen quality and sperm motility, capacitation and acrosomal reaction in rabbits; probably due to an increase in cellular cholesterol content that alters membrane related events.

Electroejaculatory Stimulation for Male Infertility Secondary to Spinal Cord Injury: The Irish Experience in National Rehabilitation Hospital

To examine the success rate of electroejaculatory stimulation in patients with acquired spinal injuries in a single Irish institution. The use of electroejaculatory stimulation is of benefit in patients with spinal cord injury who wish to have children. A retrospective review of the Hospital In-Patient Enquiry scheme database and the patients' medical notes was performed. Any patient who had undergone electroejaculatory stimulation in the past 14 years was included. The quality of semen obtained and the pregnancy rate were assessed in relation to several variables, including patient age and level of spinal injury. From 1994 to 2008, 31 patients (29 patients with acquired spinal injury and 2 patients with a congenital spinal abnormality) had undergone electroejaculatory stimulation as a method of providing semen for assisted conception. Of the 31 patients, 6 had requested cryopreservation of their semen for future use and were therefore excluded from the pregnancy rate analysis. Of the 25 patients who had used the semen, 9 (36%) were successful in achieving pregnancy that resulted in living offspring. The semen analysis results were available for 15 patients. Three patients (one each with contaminated semen, poor semen quality, and an abandoned procedure) required testicular biopsy to extract viable sperm and subsequently achieved pregnancy. Lower spinal lesions (below T10) were associated with lower rates of pregnancy after electroejaculatory stimulation. One patient developed autonomic dysreflexia during the procedure, which was therefore abandoned. Electroejaculatory stimulation is an effective method of obtaining semen for reproductive purposes and is an option for fertility preservation in patients with spinal cord injury-related anejaculation.

Can Altered Expression of HSPA2 in Varicocele Patients Lead to Abnormal Spermatogenesis?

Background Heat shock protein A2 (HSPA2) is correlated with sperm maturity and function. Therefore, dysfunctional expression of this gene results in abnormal spermatogenesis. On the other hand, DNA damage in spermatozoa is considered to be an important cause of male infertility, and the presence of sperm with DNA fragmentation and chromatin abnormalities in human ejaculates is well documented, in particular in men with poor semen quality. Therefore, the aim of this study is to evaluate HSPA2 expression and its relation with DNA fragmentation, protamine deficiency involved in DNA packaging and semen parameters in varicocele patients in comparison to fertile men before and after varicocelectomy. Materials and methods This study included 52 fertile individuals as the control group and 70 infertile individuals with varicocele as the experimental group. Sperm DNA fragmentation, protamine deficiency and relative HSPA2 expression were evaluated by the sperm chromatin dispersion test, chromomycin A3 staining and RT-PCR, respectively. Results The mean values of abnormal morphology, protamine deficiency and DNA fragmentation were significantly lower in varicocele individuals following varicocelectomy when compared to fertile individuals. The correlation between these parameters were studied and discussed in the text. Conclusion There is a decrease in relative HSPA2 expression which is possibly due to chronic induced hyperthermia in varicocele individuals. Removal of this stress increases HSPA2 expression and results in the proper folding of proteins involved in spermatogenesis; therefore resulting in improved DNA packaging, as well as better sperm morphology and motility which may indirectly reduce sperm DNA fragmentation.

Easy sperm processing technique allowing exclusive accumulation and later usage of DNA-strandbreak-free spermatozoa

Sperm DNA fragmentation is increased in poor-quality semen samples and correlates with failed fertilization, impaired preimplantation development and reduced pregnancy outcome. Common sperm preparation techniques may reduce the percentage of strandbreak-positive spermatozoa, but, to date, there is no reliable approach to exclusively accumulate strandbreak-free spermatozoa. To analyse the efficiency of special sperm selection chambers (Zech-selectors made of glass or polyethylene) in terms of strandbreak reduction, 39 subfertile men were recruited and three probes (native, density gradient and Zech-selector) were used to check for strand breaks using the sperm chromatin dispersion test. The mean percentage of affected spermatozoa in the ejaculate was 15.8 ± 7.8% (range 5.0–42.1%). Density gradient did not significantly improve the quality of spermatozoa selected(14.2 ± 7.0%). However, glass chambers completely removed 90% spermatozoa showing strand breaks and polyethylene chambers removed 76%. Both types of Zech-selectors were equivalent in their efficiency, significantly reduced DNA damage (P < 0.001) and,with respect to this, performed better than density gradient centrifugation (P < 0.001). As far as is known, this is the first report ona sperm preparation technique concentrating spermatozoa unaffected in terms of DNA damage. The special chambers most probably select for sperm motility and/or maturity.

Cryptorchidism and hypospadias as a sign of testicular dysgenesis syndrome (TDS): Environmental connection

Cryptorchidism and hypospadias are common genital birth defects that affect 2-9% and 0.2-1% of male newborns, respectively. The incidence of both defects shows large geographic variation, and in several countries increasing trends have been reported. The conditions share many risk factors, and they are also interlinked to the risk of testis cancer and poor semen quality. Testicular Dysgenesis Syndrome (TDS) may underlie many cases of all these male reproductive health problems. Genetic defects in androgen production or action can cause both cryptorchidism and hypospadias, but these are not common. A monogenic reason for cryptorchidism or hypospadias has been identified only in a small proportion of all cases. Environmental effects appear to play a major role in TDS. Exposure to several persistent chemicals has been found to be associated with the risk of cryptorchidism, and exposure to anti-androgenic phthalates has been shown to be associated with hormonal changes predisposing to male reproductive problems. Despite progress in identification of endocrine-disrupting substances, we are still far from knowing all the risk factors for these birth defects, and advice for prevention must be based on precautionary principles.

Effect of cryopreservation on sperm chromatin integrity and fertilizing potential in bovine semen

The present study was conducted on 83 bulls belonging to three species/breeds (Karan Fries crossbred and Sahiwal purebred cattle and Murrah buffalo). The bulls were selected based on their unacceptable semen parameters (poor semen quality and freezability) for comparative analysis with control bulls for assessing uncompensable seminal parameters, namely, detection of sperm chromatin maturity (using acidic aniline blue staining) and fragmentation level (comet assay of sperm nuclear DNA) along with production of 8-hydroxy-2′-deoxyguanosine (8-OHdG) (detected by high performance liquid chromatography of 8-OHdG) in cryopreserved semen specimen. The acidic aniline blue assay revealed that neither the fertility groups nor the species/breeds differed significantly, however, for comet assay only the fertility groups differed significantly (P < 0.05). High performance liquid chromatography analysis could detect the presence of the adduct (8-OHdG) in semen specimen of only three cattle breeding bulls. The results suggest that weekly collection of semen does not induce immature sperm production in dairy bulls. The cryopreservation of semen induces sperm DNA fragmentation which is comparatively higher in that of bulls with poor semen quality. 8-OHdG was not significantly produced and thereby is not a matter of serious concern for dairy bulls reared under stall-fed condition. It can be concluded that comet assay may be used for quality assessment of the cryopreserved semen samples especially which are to be used for inseminating the elite cows or for assisted reproduction.

Copper Metabolism Disorders Affect Testes Structure and Gamete Quality in Male Mice

In the present study, animals with a genetic defect in copper metabolism were used as a model organism to study the role of copper in reproduction and to determine whether the disturbances in copper and zinc metabolism affect the testicular tissue and gamete quality in males. Mice with an X-linked mosaic mutation (Atp7amo-ms) exhibit pathological features characteristic of affected copper metabolism. This mutation usually leads to lethality of the mutant males which generally expire on about day 16. Only 4% of mutant animals survive the critical period, achieve maturity, and become fertile. To improve the mutants' viability they were treated with subcutaneous injections of cupric chloride. We measured copper and zinc concentration in the gonads of young (14-day-old) and adult (5-month-old) mutant and control males. Results indicate that copper content was increased but zinc was decreased in the mutant testes. Analysis of the morphology of the testis of the young animals indicate that apoptosis (characteristic for the gonads of young males) was increased in the gonads of the 14-day-old mutants. This process was less advanced in the group of 14-day-old copper treated control males. Apoptosis was also increased in the testes of the adult mutants. Moreover in adult mutants we observed pathological changes in testes morphology (atrophic and sclerotic tubules). Copper and zinc disorders also negatively influenced semen quality parameters, including sperm motility, head morphology, tail cytoplasmic membrane integrity, and number of viable spermatozoa. Poor semen quality of the mutant males seems to be responsible for affected in vivo fertilization efficiency. Treatment with cupric chloride did not influence semen quality except in maturation rate, which was even slower in both mutant and control males after treatment. Additionally, in mutants, copulatory plugs and fertile copulation outcome were decreased after copper treatment.