Sperm creatine kinase activity in normospermic and oligozospermic Hungarian men

Genome-wide association study for carcass weight in pasture-finished beef cattle in Hawai'i

Introduction: Genome-wide association studies (GWAS) have identified genetic markers for cattle production and reproduction traits. Several publications have reported Single Nucleotide Polymorphisms (SNPs) for carcass-related traits in cattle, but these studies were rarely conducted in pasture-finished beef cattle. Hawai'i, however, has a diverse climate, and 100% of its beef cattle are pasture-fed. Methods: Blood samples were collected from 400 cattle raised in Hawai'i islands at the commercial harvest facility. Genomic DNA was isolated, and 352 high-quality samples were genotyped using the Neogen GGP Bovine 100 K BeadChip. SNPs that did not meet the quality control standards were removed using PLINK 1.9, and 85 k high-quality SNPs from 351 cattle were used for association mapping with carcass weight using GAPIT (Version 3.0) in R 4.2. Four models were used for the GWAS analysis: General Linear Model (GLM), the Mixed Linear Model (MLM), the Fixed and Random Model Circulating Probability Unification (FarmCPU), the Bayesian-Information and Linkage-Disequilibrium Iteratively Nested Keyway (BLINK). Results and Discussion: Our results indicated that the two multi-locus models, FarmCPU and BLINK, outperformed single-locus models, GLM and MLM, in beef herds in this study. Specifically, five significant SNPs were identified using FarmCPU, while BLINK and GLM each identified the other three. Also, three of these eleven SNPs ("BTA-40510-no-rs", "BovineHD1400006853", and "BovineHD2100020346") were shared by multiple models. The significant SNPs were mapped to genes such as EIF5, RGS20, TCEA1, LYPLA1, and MRPL15, which were previously reported to be associated with carcass-related traits, growth, and feed intake in several tropical cattle breeds. This confirms that the genes identified in this study could be candidate genes for carcass weight in pasture-fed beef cattle and can be selected for further breeding programs to improve the carcass yield and productivity of pasture-finished beef cattle in Hawai'i and beyond.

Creatine in Health and Disease

Although creatine has been mostly studied as an ergogenic aid for exercise, training, and sport, several health and potential therapeutic benefits have been reported. This is because creatine plays a critical role in cellular metabolism, particularly during metabolically stressed states, and limitations in the ability to transport and/or store creatine can impair metabolism. Moreover, increasing availability of creatine in tissue may enhance cellular metabolism and thereby lessen the severity of injury and/or disease conditions, particularly when oxygen availability is compromised. This systematic review assesses the peer-reviewed scientific and medical evidence related to creatine's role in promoting general health as we age and how creatine supplementation has been used as a nutritional strategy to help individuals recover from injury and/or manage chronic disease. Additionally, it provides reasonable conclusions about the role of creatine on health and disease based on current scientific evidence. Based on this analysis, it can be concluded that creatine supplementation has several health and therapeutic benefits throughout the lifespan.

Unravelling the genomic architecture of bull fertility in Holstein cattle

BACKGROUND

Fertility is considered an important economic trait in dairy cattle. Most studies have investigated cow fertility while bull fertility has received much less consideration. The main objective of this study was to perform a comprehensive genomic analysis in order to unravel the genomic architecture underlying sire fertility in Holstein dairy cattle. The analysis included the application of alternative genome-wide association mapping approaches and the subsequent use of diverse gene set enrichment tools.

RESULTS

The association analyses identified at least eight genomic regions strongly associated with bull fertility. Most of these regions harbor genes, such as KAT8, CKB, TDRD9 and IGF1R, with functions related to sperm biology, including sperm development, motility and sperm-egg interaction. Moreover, the gene set analyses revealed many significant functional terms, including fertilization, sperm motility, calcium channel regulation, and SNARE proteins. Most of these terms are directly implicated in sperm physiology and male fertility.

CONCLUSIONS

This study contributes to the identification of genetic variants and biological processes underlying sire fertility. These findings can provide opportunities for improving bull fertility via marker-assisted selection.

The effect of cigarette smoking on human sperm creatine kinase activity: as an ATP buffering system in sperm

BACKGROUND

Spermatozoa are a group of cells that consume adenosine triphosphate (ATP) rapidly. Creatine kinase (CK), produced by creatine phosphate, is an energy reservoir for the rapid buffering and regeneration of ATP and can play an important role in sperm motility. Therefore, this study investigates the effects of cigarette smoking on human sperm CK activity in males who smoke.

MATERIALS AND METHODS

In this case - control study, we obtained semen samples from male smokers (n=64) and nonsmokers (n=83). Smokers were categorized as light, moderate, or heavy smokers according to the daily number of cigarettes smoked and the number of years they have smoked. Data were analyzed by the independent t test and Pearson's analysis.

RESULTS

This investigation showed significantly lower sperm CK activity and movement in male smokers compared to nonsmokers. In addition, it was demonstrated that cigarette smoking had a dose-dependent effect on these parameters. There was a positive relation, although not significant, between sperm CK activity and its motility in male smokers.

CONCLUSION

Smoking, by diminishing sperm CK activity, may potentially impair sperm energy homeostasis and have an association with damage to sperm motility. This effect can be an important mechanism that may cause infertility in male smokers. However, further research is necessary to elucidate the underlying mechanism of sperm motility damage caused by cigarette smoking.

Biochemical properties of bull spermatozoa separated in iodixanol density solution

Bull spermatozoa samples contain variable portion of motile and normal morphology spermatozoa along with spermatozoa incapable of fertilization due to their pathologic changes. As semen quality is influenced by biochemical and morphological characteristics of all spermatozoa, the aim of the study was to separate spermatozoa in discontinuous iodixanol density gradient solution and to determine their cholesterol, phospholipid, triacylglycerol and lipid peroxide concentrations and creatine kinase activity. The study was performed in winter and included seven Simmental bulls aged 1.5-3.5 years. Semen samples were collected by use of artificial vagina. Upon evaluation of semen quality (volume, concentration and progressive sperm motility), the samples were centrifuged in iodixanol density solution to obtain two sperm fractions. The two fractions included sperms with progressive motility greater than 90% and less than 20%, respectively. A statistically significantly higher lipid peroxide concentration was determined in sperm fraction with <20% progressive motility. Different sperm subpopulations can be obtained by separating bull spermatozoa in different iodixanol density gradient solutions, while monitoring their biochemical properties can help assess the sperm quality.

Creatine kinase as an indicator of sperm quality and maturity in men with oligospermia

OBJECTIVES

To determine the differences among the creatine kinase (CK) levels in the spermatozoa of subfertile men with mild, moderate, or severe oligospermia and to examine the differences in CK activity between infertile patients with various clinical diagnoses and a group of normal healthy donors (control). CK is a marker of sperm maturity that correlates with the sperm fertilizing capacity. Elevated levels are associated with an increased rate of functional abnormalities and increased cytoplasmic retention.

METHODS

We compared the CK levels in 51 oligospermic men who could not initiate a pregnancy. Patients were categorized according to their degree of oligospermia as defined by the total sperm count: mild (greater than 10 to 40 x 10(6); n = 30), moderate (5 to 10 x 10(6); n = 11), and severe (less than 5 x 10(6); n = 10). These patients were further classified according to their diagnosis (ie, varicocele, n = 24; unexplained infertility, n = 17; vasectomy reversal, n = 9; and unknown diagnosis, n = 1). A separate group consisting of 25 healthy donors was included as a control group. A computer-assisted semen analyzer assessed the sperm characteristics, and the CK levels were measured using a CK test kit after the enzyme was extracted with Triton-X.

RESULTS

The CK levels were significantly higher in the sperm of the severely oligospermic group (8.8 +/- 6.5 IU/10(8) sperm) than in the moderate (0.50 +/- 0.19 IU/10(8) sperm) and mild (0.49 +/- 0.15 IU/10(8) sperm) groups (P <0.0001). The mean CK level in the severely oligospermic group was 18-fold higher than that in the moderate (P = 0.03) and mild (P <0.001) groups. The CK levels were significantly higher in all three infertile groups compared with the donor group (0.06 +/- 0.01 IU/10(8) sperm). Patients with varicocele had the highest CK level (3.42 +/- 2.56 IU/10(8) sperm) compared with patients in the vasectomy reversal group (1.73 +/- 0.98 IU/10(8) sperm) and the idiopathic infertility group (0.26 +/- 0.08 IU/10(8) sperm).

CONCLUSIONS

Elevated CK levels are associated with severe oligospermia, irrespective of the clinical diagnosis. CK may be a sensitive indicator of sperm quality and maturity in the follow-up of patients treated for male factor infertility.

The search is on: finding accurate molecular markers of male fertility

Diagnosis of the fertility potential of a semen sample is essential for consistently high reproductive efficiency. The use of subfertile or infertile semen can have devastating consequences for those selling or using the semen. Therefore it is crucial to develop and use accurate diagnostic tests to determine the fertility of males and of individual semen samples. These diagnostic tests must be economically practical and provide consistent results. The goal of this review is to explore areas of fertility diagnostic research, including what we have termed functional and molecular tests, and consider the accuracy of each test. In this article, literature from several species is cited, and it is noteworthy that each diagnostic test may not be valuable in all species. Multiple functional and molecular tests will likely be needed to effectively characterize male fertility in each species.