Predictors Of Male Fertility Research Articles

Clusterin expression and distribution in spermatozoa as predictor of male fertility.

Clusterin (CLU), one of the main glycoproteins in mammalian semen and the male reproductive tract, plays a role in spermatogenesis and sperm maturation. Given the poor reliability of classic seminal studies in determining male-fertilizing capacity and the differences in CLU abundance between normal and abnormal spermatozoa, we investigated the potential value of mRNA-CLU levels and protein distribution in spermatozoa as markers of sperm quality and predictors of male fertility. This multicenter study included 90 patients undergoing in vitro fertilization (IVF) treatment with their partners, and a control group of 36 fertile males with normal seminograms. We assessed the relationship between IVF treatment outcomes, seminogram variables, mRNA-CLU levels byquantitative real-time-PCR and CLU distribution by immunostaining in spermatozoa. Our study reveals CLU staining in the acrosome (p = 0.002, OR 14.8, 95% CI: 2.7-79.3) and mRNA-CLU levels (p = 0.005, OR 10.85, 95% CI: 2.0-57.4) as independent risk factors for pregnancy failure, irrespective of traditional seminogram variables. Additionally, our results suggest that CLU, and specially its secreted isoform, constitutes a component of the protein pool that human spermatozoa can produce during its maturation process, exhibiting a variable abundance and distribution in spermatozoa from fertile men compared to those in patients with altered seminograms and infertile patients with normal seminograms. Our study is the first to identify mRNA-CLU levels and CLU immunostaining in the spermatozoa acrosome as independent risk factors for pregnancy failure, with distribution patterns correlating with sperm maturity and seminogram alterations.

Religion and ethnicity interaction as a predictor of male fertility in Nigeria: Evidence from a national representative sample.

High fertility constitutes a challenge to men's health conditions in Nigeria, a low-income country. Religion and ethnicity are central to the current Male Fertility (MF) level in Nigeria. This study determined the relationship between Male Fertility (MF) and Religion Ethnic Interaction (REI) amidst other socio-demographic characteristics in Nigeria. Nigeria Demographic and Health Survey data, 2018 was used. Men aged 15-59 years [n = 8,786] were sampled using a multi-stage approach. Fertility was measured by the number of Children Ever Born (CEB). REI was generated using the combination of religion and ethnic groups; Hausa/Fulani Muslim, Igbo Christian, Yoruba Christian, and Yoruba Muslim. However, Hausa/Fulani Christians and Igbo Muslims were excluded from this study because a few men in these categories were available in the original sample. Weighted data were analyzed using the Negative Binomial (NB) model (α0.05). The mean age and CEB of the men were 32.9±12.0 years and 3.18±4.4 respectively. The mean CEB among men aged 45-59 years was highest among Hausa/Fulani Muslims (x = 11.57±5.98), but least among Yoruba Christians (x = 4.44±2.67). About 33.4% of the Hausa/Fulani Muslims had had ≥5 children, while 13.7% were reported among the Yoruba Christian men (p<0.001). The fertility Incidence Rate Ratio (IRR) was higher among Hausa/Fulani Muslims, but less among Igbo Christians, and Yoruba Christians than Yoruba Muslims. Restricting the analyzed data to only monogamous men revealed no significant differences in the fertility IRR of Yoruba Christians and Yoruba Muslims, but the fertility IRR was significantly higher among the Hausa/Fulani Muslims than Yoruba Muslims. A disparity exists in MF across the REI groups with the Hausa/Fulani Muslims being the major contributors to high MF. Therefore, bridging the gap in access to fertility control measures and programmes that might have resulted from religion and ethnic differences will reduce male fertility level in Nigeria.

Serum Nerve Growth Factor Levels as a Predictor of Bull Candidate Semen Quality of Madura Cattle.

Madura cattle are the germplasm of native cattle on the verge of extinction because of crossbreeding. Therefore, the present study was aimed to determine the serum nerve growth factor (NGF) concentration as a predictor of fresh ejaculate fertility parameters in Madura bull candidates. Eleven Madura bull candidates used for frozen semen production were selected for the study. Blood samples were collected using a vacutainer from the jugular vein for analyzing serum NGF and testosterone levels. Meanwhile, semen collection was conducted using an artificial vagina for sperm motility, viability, and concentration assessment. Data were analyzed to determine the correlation among variables and the linear regression of NGF concentration to other significant variables. The result showed that NGF had a significant correlation (p < 0.05) with testosterone levels, sperm motility, viability, and concentration. A significant correlation was observed between testosterone levels, sperm concentration, and sperm viability. The regression equation among significantly correlated variables was determined. For artificial insemination, suitable bull ejaculates for obtaining frozen semen should reach at least 2.12 ng/mL of NGF levels, with sperm viability, sperm concentration, and testosterone levels of more than 78.63%, 1,462.177 million/mL ejaculate, and 25.67 ng/mL, respectively. This is the first study to identify NGF as a predictor of male fertility in bull candidates of Madura cattle. Therefore, NGF levels could be used as a marker of male fertility in Madura bull cattle candidates. Thus, based on the minimum NGF levels, the ejaculate of Madura bull candidate that meets the requirements for frozen semen production could predict fertility.

Male Accessory Glands Infections: Mechanisms of Influence on Male Fertility

Male accessory glands infections (MAGI) are considered one of the causes of male infertility. Chronic prostatitis is the most prevalent form of MAGI. Researches that assessed the influence of chronic prostatitis on conventional semen parameters have shown contradictory results, so the debate regarding this issue continues. Conventional semen parameters are imperfect markers of male fertility, as many men remain infertile despite being normozoospermic. The search for reliable predictors of male fertility continues to this day. Oxidative stress is considered one of the main pathogenetic mechanisms of male infertility. Free radical oxidation is the leading cause of spermatozoa DNA damage. Spermatozoa DNA fragmentation caused by oxidative stress was associated with a number of unsuccessful reproductive outcomes. There are several factors that are responsible for making spermatozoa vulnerable to free radical damage including abnormal maturation characterized by insufficient chromatin protamination. Acrosin activity defines the ability of spermatozoa to penetrate the ovum membrane and is therefore an independent marker of spermatozoa fertilizing capacity. Possible mechanisms of chronic prostatitis influence on male fertility and current scientific data regarding its association with novel predictors of male infertility are discussed in this article.The study did not have sponsorship. The authors have declared no conflicts of interest.

Acrosome reaction and sperm DNA fragmentation as predictors of male fertility and the relationship with environmental factors

Acrosome reaction and sperm DNA fragmentation as predictors of male fertility and the relationship with environmental factors

Intramale variation in sperm size: functional significance in a polygynous mammal.

Studies concerning the relationships between sperm size and velocity at the intraspecific level are quite limited and often yielded contradictory results across the animal kingdom. Intramale variation in sperm size may represent a meaningful factor to predict sperm velocity, due to its relationship with the level of sperm competition among related taxa. Because sperm phenotype is under post-copulatory sexual selection, we hypothesized that a reduced intramale variation in sperm size is associated with sperm competitiveness in red deer. Our results show that low variation in sperm size is strongly related to high sperm velocity and normal sperm morphology, which in turn are good predictors of male fertility in this species. Furthermore, it is well known that the red deer show high variability in testicular mass but there is limited knowledge concerning the significance of this phenomenon at intraspecific level, even though it may reveal interesting processes of sexual selection. Thereby, as a preliminary result, we found that absolute testes mass is negatively associated with intramale variation in sperm size. Our findings suggest that sperm size variation in red deer is under a strong selective force leading to increase sperm function efficiency, and reveal new insights into sexual selection mechanisms.

Cryopreserved Bovine Spermatozoal Transcript Profile as Revealed by High-Throughput Ribonucleic Acid Sequencing1

Ejaculated bovine spermatozoa retain a pool of RNAs that may have a function in early embryogenesis and be used as predictors of male fertility. The bovine spermatozoal transcript profile remains incomplete because previous studies have relied on hybridization-based techniques, which evaluate a limited pool of transcripts and cannot identify full-length transcripts. The goal of this study was to sequence the complete cryopreserved bovine spermatozoal transcript profile using Illumina RNA-Sequencing (RNA-Seq). Spermatozoal RNA was pooled from nine bulls with conception rate scores ranging from -2.9 to 3.5 and confirmed to exclude genomic DNA and somatic cell mRNA. After selective amplification of poly(A)(+) RNA and high-throughput sequencing, 6166 transcripts were identified via alignment to the bovine genome (UMD 3.1/bosTau6). RNA-Seq transcript levels (n = 9) were highly correlated with quantitative PCR copy number (r(2) = 0.9747). The bovine spermatozoal transcript profile is a heterogeneous population of degraded and full-length predominantly nuclear-encoded mRNAs. Highly abundant spermatozoal transcripts included PRM1, HMGB4, and mitochondrial-encoded transcripts. Full-length transcripts comprised 66% of the top 368 transcripts (fragments per kilobase of exon per million fragments mapped [FPKM] > 100) and amplification of the full-length transcript or 5' and 3' ends was confirmed for selected transcripts. In addition to the identification of transcripts not previously reported in spermatozoa, several known spermatozoal transcripts from various species were also found. Gene ontology analysis of the FPKM > 100 spermatozoal transcripts revealed that translation was the most predominant biological process represented. This is the first report of the spermatozoal transcript profile in any species using high-throughput sequencing, supporting the presence of mRNA in spermatozoa for further functional and fertility studies.

A two-tailed Comet assay for assessing DNA damage in spermatozoa

DNA fragmentation is considered an important parameter of semen quality, and of significant value as a predictor of male fertility. Poor quality chromatin is closely associated with, and highly indicative of, some fertility problems. Many methodologies to assess DNA fragmentation in spermatozoa are available, but they are all unable to differentiate between single-stranded DNA breaks (SSB) and double-stranded DNA breaks (DSB) in the same sperm cell. The two-tailed Comet assay (2T-Comet) protocol overcomes this limitation. A modification of the original Comet assay was developed for the simultaneous evaluation of DNA SSB and DSB in human spermatozoa. The 2T-Comet assay is a fast, sensitive, and reliable procedure for the quantification and characterization of DNA damage in spermatozoa. It is an innovative method for assessing sperm DNA integrity, which has important implications for human fertility and andrological pathology.

Sperm-DNA Fragmentation Measured by Sperm Chromatin Structure Assay as an Independent Predictor of Male Fertility In Vivo.

Sperm-DNA Fragmentation Measured by Sperm Chromatin Structure Assay as an Independent Predictor of Male Fertility In Vivo.