The Role of Number of Copies, Structure, Behavior and Copy Number Variations (CNV) of the Y Chromosome in Male Infertility

The Odad3 Gene Is Necessary for Spermatozoa Development and Male Fertility in Mice

Odad3 gene loss-of-function mutation leads to Primary Ciliary Dyskinesia (PCD), a disease caused by motile cilia dysfunction. Previously, we demonstrated that knockout of the Odad3 gene in mice replicates several features of PCD, such as hydrocephalus, defects in left-right body symmetry, and male infertility, with a complete absence of sperm in the reproductive tract. The majority of Odad3 knockout animals die before sexual maturation due to severe hydrocephalus and failure to thrive, which precludes fertility studies. Here, we performed the expression analysis of the Odad3 gene during gonad development and in adult testes. We showed that Odad3 starts its expression during the first wave of spermatogenesis, specifically at the meiotic stage, and that its expression is restricted to the germ cells in the adult testes, suggesting that Odad3 plays a role in spermatozoa formation. Subsequently, we conditionally deleted the Odad3 gene in adult males and demonstrated that even partial ablation of the Odad3 gene leads to asthenoteratozoospermia with multiple morphological abnormalities of sperm flagella (MMAF) in mice. The analysis of the seminiferous tubules in Odad3-deficient mice revealed defects in spermatogenesis with accumulation of seminiferous tubules at the spermiogenesis and spermiation phases. Furthermore, analysis of fertility in heterozygous Odad3+/- knockout mice revealed a reduction in sperm count and motility as well as abnormal sperm morphology. Additionally, Odad3+/- males exhibited a shorter fertile lifespan. Overall, these results suggest the important role of Odad3 and Odad3 gene dosage in male fertility. These findings may have an impact on the genetic and fertility counseling practice of PCD patients carrying Odad3 loss-of-function mutations.

Using Selenium-enriched Mutated Probiotics as Enhancer for Fertility Parameters in Mice

Increasing fertility rates have become one of the factors that concern all people in the world. Therefore, the study aims to use two mutated strains of probiotics enriched with selenium (PSe40/60/1 and BSe50/20/1) to improve fertility. Thirty Swiss albino male mice were divided into three groups; control, LP + S was given Lactobacillus plantarum PSe40/60/1 plus selenium, and BL + S was given Bifidobacterium longum BSe50/20/1 plus selenium. Free testosterone, LH, and FSH were measured in serum by biochemical analysis. Testicular tissues were examined by histopathological analysis. The count and motility of sperm, and sperm abnormalities were determined by microscopic examination. The method of qRT-PCR was used to detect gene expression of Tspyl1, Hsd3b6, and Star genes. The biochemical results showed that serum content of free testosterone (FT) hormone had significantly increase in the BL + S and LP + S groups compared with control. Levels of LH and FSH hormones were the highest in the BL + S group. The treated groups showed all developmental stages of spermatogenesis, including spermatogenesis, spermatocytes, and seminiferous tubule spermatids, as well as intact Sertoli cells and Leydig cells without changes. When compared to the control group, sperm count and motility increased in the BL + S group, while sperm abnormalities decreased. The expression of Tspyl1 gene in testicular tissues decreased in the LP + S and BL + S groups, while the expression of Star and Hsd3b6 genes was higher in the BL + S group and lower in the LP + S group compared with the control group. Therefore, Bifidobacterium longum BSe50/20/1 enriched with selenium could be useful in enhancing male fertility.

Teachers' Well-Being Forced to Work from Home Due to COVID-19 Pandemic: Work Passion as a Mediator

BACKGROUND

This study examines the relationship between perceived demands (workload and organizational constraints) of teachers' work during the online period of schooling during the COVID-19 crisis and well-being (emotions, engagement, and job crafting), with work passion as a mediator.

METHODS

The survey was carried out on a sample of 383 teachers during the first wave of the COVID-19 pandemic. The Scale of Organizational Constraints and the Workload Scale, the Passion Scale adapted for work, the Job Crafting Questionnaire, the Utrecht Scale of Work Engagement, and the Scale of Positive and Negative Experience was used.

RESULTS

Harmonious passion strengthened the positive relationships between workload and organizational constraints and job crafting and weakened the negative relationship with positive emotions and the positive one with negative emotions. The positive relationship between workload and engagement has been strengthened by harmonious passion. The negative relationship between organizational constraints and engagement became positive and weaker. Relationships between variables were weakened, i.e., workload and engagement, organizational constraints and job crafting, or strengthened, i.e., organizational constraints and engagement, by an obsessive passion. In tested models, obsessive passion has the opposite effect and is weaker than harmonious passion.

CONCLUSION

The structural equation modeling (SEM) confirmed that work passion, mainly harmonious, is a mechanism explaining the relationship between the demands of forced work from home with teachers' well-being.

Repetitive DNA Sequences in the Human Y Chromosome and Male Infertility

The male-specific Y chromosome, which is well known for its diverse and complex repetitive sequences, has different sizes, genome structures, contents and evolutionary trajectories from other chromosomes and is of great significance for testis development and function. The large number of repetitive sequences and palindrome structure of the Y chromosome play an important role in maintaining the stability of male sex determining genes, although they can also cause non-allelic homologous recombination within the chromosome. Deletion of certain Y chromosome sequences will lead to spermatogenesis disorders and male infertility. And Y chromosome genes are also involved in the occurrence of reproductive system cancers and can increase the susceptibility of other tumors. In addition, the Y chromosome has very special value in the personal identification and parentage testing of male-related cases in forensic medicine because of its unique paternal genetic characteristics. In view of the extremely high frequency and complexity of gene rearrangements and the limitations of sequencing technology, the analysis of Y chromosome sequences and the study of Y-gene function still have many unsolved problems. This article will introduce the structure and repetitive sequence of the Y chromosome, summarize the correlation between Y chromosome various sequence deletions and male infertility for understanding the repetitive sequence of Y chromosome more systematically, in order to provide research motivation for further explore of the molecules mechanism of Y-deletion and male infertility and theoretical foundations for the transformation of basic research into applications in clinical medicine and forensic medicine.

Infertility in Men: Advances towards a Comprehensive and Integrative Strategy for Precision Theranostics

Male infertility is an increasing and serious medical concern, though the mechanism remains poorly understood. Impaired male reproductive function affects approximately half of infertile couples worldwide. Multiple factors related to the environment, genetics, age, and comorbidities have been associated with impaired sperm function. Present-day clinicians rely primarily on standard semen analysis to diagnose male reproductive potential and develop treatment strategies. To address sperm quality assessment bias and enhance analysis accuracy, the World Health Organization (WHO) has recommended standardized sperm testing; however, conventional diagnostic and therapeutic options for male infertility, including physical examination and semen standard analysis, remain ineffective in relieving the associated social burden. Instead, assisted reproductive techniques are becoming the primary therapeutic approach. In the post-genomic era, multiomics technologies that deeply interrogate the genome, transcriptome, proteome, and/or the epigenome, even at single-cell level, besides the breakthroughs in robotic surgery, stem cell therapy, and big data, offer promises towards solving semen quality deterioration and male factor infertility. This review highlights the complex etiology of male infertility, especially the roles of lifestyle and environmental factors, and discusses advanced technologies/methodologies used in characterizing its pathophysiology. A comprehensive combination of these innovative approaches in a global and multi-centric setting and fulfilling the suitable ethical consent could ensure optimal reproductive and developmental outcomes. These combinatorial approaches should allow for the development of diagnostic markers, molecular stratification classes, and personalized treatment strategies. Since lifestyle choices and environmental factors influence male fertility, their integration in any comprehensive approach is required for safe, proactive, cost-effective, and noninvasive precision male infertility theranostics that are affordable, accessible, and facilitate couples realizing their procreation dream.

Advanced molecular approaches in male infertility diagnosis

In the recent years a special attention has been given to a major health concern namely to male infertility, defined as the inability to conceive after 12 months of regular unprotected sexual intercourse, taken into account the statistics that highlight that sperm counts have dropped by 50-60% in recent decades. According to the WHO, infertility affects approximately 9% of couples globally, and the male factor is believed to be present in roughly 50% of cases, with exclusive responsibility in 30%. The aim of this manuscript is to present an evidence-based approach for diagnosing male infertility that includes finding new solutions for diagnosis and critical outcomes, retrieving up-to-date studies and existing guidelines. The diverse factors that induce male infertility generated in a vast amount of data that needed to be analysed by a clinician before a decision could be made for each individual. Modern medicine faces numerous obstacles as a result of the massive amount of data generated by the molecular biology discipline. To address complex clinical problems, vast data must be collected, analysed, and used, which can be very challenging. The use of artificial intelligence (AI) methods to create a decision support system can help predict the diagnosis and guide treatment for infertile men, based on analysis of different data as environmental and lifestyle, clinical (sperm count, morphology, hormone testing, karyotype, etc.) and "omics" bigdata. Ultimately, the development of AI algorithms will assist clinicians in formulating diagnosis, making treatment decisions, and predicting outcomes for assisted reproduction techniques.

Copy number variation of the SRY gene showed an association with disorders of sex development in Yorkshire Terrier dogs

The molecular background of disorders of sex development (DSD) in dogs is poorly understood. Several copies of the SRY genes have been reported in the dog genome. We used droplet digital PCR with the aim of determining variability in SRY copy number and its association with DSD in dogs. Altogether 19 DSD male dogs (XY DSD) of 10 breeds and 87 control dogs of eight breeds were analyzed. Moreover, we performed a comparative analysis of SRY copy number in other canids: wolves (3), red foxes (16), and Chinese raccoon dogs (10). We found that the modal number of SRY copies in dogs, wolves, red foxes, and Chinese raccoon dogs was 3, 3, 1, and 3 respectively. Variability of copy number was only observed in Yorkshire Terriers (two or three copies) and red foxes (one or two copies). An analysis of six DSD Yorkshire Terriers and 38 control males of this breed showed that 50% of the DSD dogs had two copies, while the incidence of this variant was significantly lower in the control dogs (10.5%). Searching for the copy number of the coding and 5'-flanking fragments revealed full concordance with the copy number. These fragments were also sequenced in DSD (19) and control (24) dogs, and no DNA variants were found. We conclude that, in the dog, two or three functional copies of the SRY gene are present, and a smaller number of copies showed an association with the risk of DSD phenotype in Yorkshire Terriers.

The Y chromosome and its impact on health and disease

The Y chromosome is the most gene-deficient chromosome in the human genome (though not the smallest chromosome) and has largely been sequestered away from large-scale studies of the effects of genetics on human health. Here I review the literature, focusing on the last 2 years, for recent evidence of the role of the Y chromosome in protecting from or contributing to disease. Although many studies have focused on Y chromosome gene copy number and variants in fertility, the role of the Y chromosome in human health is now known to extend too many other conditions including the development of multiple cancers and Alzheimer's disease. I further include the discussion of current technology and methods for analyzing Y chromosome variation. The true role of the Y chromosome and associated genetic variants in human disease will only become clear when the Y chromosome is integrated into larger studies of human genetic variation, rather than being analyzed in isolation.

An NGS-based approach to identify Y-chromosome variation in non-obstructive azoospermia

Copy number variations (CNVs), including deletions and duplications on the Y chromosome, are known genetic factors in azoospermia. Therefore, it is important to identify novel pathogenic CNVs related to azoospermia. In this study, we compared CNVs detected by STS-PCR and NGS in 107 individuals with nonobstructive azoospermia (NOA). STS-PCR analysis revealed that 8.14% (9/107) of patients had AZF deletions. The highest percentage of deletions was located in the AZFc region, followed by AZFa and AZFb+c. Positive CNVs, including four duplications, six deletions and three complex CNVs, were detected using NGS methods in 12.15% (13/107) of NOA patients. Both the duplications and deletions detected in q11.223 were confirmed to increase the genetic risk for NOA. A comparison between the STS-PCR results and NGS methods revealed concordant CNV-positive results in 4 of 107 cases (3.74%). The discrepancies included 6 cases with CNVs identified by NGS but not detected by STS-PCR, and two cases were detected by STS-PCR but not by NGS. Notably, four duplications were not identified and three complex CNVs were detected as simple deletions using STS-PCR analysis. The NGS method provides comprehensive results in detecting Y chromosome-linked CNVs, including deletions and duplications, which might broaden our understanding of NOA.

Eef2k is not required for fertility in male mice

Background

Eukaryotic elongation factor-2 kinase (Eef2k) is a protein kinase associated with the calmodulin-induced signaling pathway and an atypical alpha-kinase family member. Eef2k-mediated phosphorylation of eukaryotic translation elongation factor 2 (Eef2) can inhibit the functionality of this protein, altering protein translation. Prior work suggests Eef2k to be overexpressed in breast, pancreatic, brain, and lung cancers wherein it may control key processes associated with apoptosis, autophagy, and cell cycle progression. The functional importance of Eef2k in the testes of male mice, however, has yet to be clarified.

Methods

A CRISPR/Cas9 approach was used to generate male Eef2k-knockout mice, which were evaluated for phenotypic changes in epididymal or testicular tissues through histological and immunofluorescent staining assays. In addition, TUNEL staining was conducted to assess the apoptotic death of cells in the testis. Fertility, sperm counts, and sperm motility were further assessed.

Results

Male Eef2k-knockout mice were successfully generated, and exhibited normal fertility and development. No apparent differences were observed with respect to spermatogenesis, sperm counts, or germ cell apoptosis when comparing male Eef2k ^-/- and Eef2k ^+/+ mice.

Conclusions

Male Eef2k-knockout mice remained fertile and were free of any evident developmental or spermatogenic abnormalities, suggesting Eef2k to be dispensable in the context of male fertility.

Genome-wide selective sweep analysis of the high-altitude adaptability of yaks by using the copy number variant

The domestic yak (Bos grunniens) from the Qinghai-Tibet Plateau is an important animal model in high-altitude adaptation studies. Here, we performed the genome-wide selective sweep analysis to identify the candidate copy number variation (CNV) for the high-altitude adaptation of yaks. A total of 531 autosomal CNVs were determined from 29 yak genome-wide resequencing data (15 high- and 14 low-altitude distributions) by using a CNV caller with a CNV identification interval > 5 kb, CNV silhouette score > 0.7, and minimum allele frequency > 0.05. Most high-frequency CNVs were located at the exonic (44.63%) and intergenic (46.52%) regions. In accordance with the results of the selective sweep analysis, 7 candidate CNVs were identified from the interaction of the top 20 CNVs with highest divergence from the F _ST and V _ST between the low (LA) and high (HA) altitudes. Five genes (i.e., GRIK4, IFNLR1, LOC102275985, GRHL3, and LOC102275713) were also annotated from the seven candidate CNVs and their upstream and downstream ranges at 300 kb. GRIK4, IFNLR1, and LOC102275985 were enriched in five known signal pathways, namely, glutamatergic synapse, JAK-STAT signaling pathway, cytokine-cytokine receptor interaction, neuroactive ligand-receptor interaction, and olfactory transduction. These pathways are involved in the environmental adaptability and various physiological functions of animals, especially the physiological regulation under a hypoxic environment. The results of this study advanced the understanding of CNV as an important genomic structure variant type that contributes to HA adaptation and helped further explain the molecular mechanisms underlying the altitude adaptability of yaks.

Y RNA: An Overview of Their Role as Potential Biomarkers and Molecular Targets in Human Cancers

Y RNA are a class of small non-coding RNA that are largely conserved. Although their discovery was almost 40 years ago, their function is still under investigation. This is evident in cancer biology, where their role was first studied just a dozen years ago. Since then, only a few contributions were published, mostly scattered across different tumor types and, in some cases, also suffering from methodological limitations. Nonetheless, these sparse data may be used to make some estimations and suggest routes to better understand the role of Y RNA in cancer formation and characterization. Here we summarize the current knowledge about Y RNA in multiple types of cancer, also including a paragraph about tumors that might be included in this list in the future, if more evidence becomes available. The picture arising indicates that Y RNA might be useful in tumor characterization, also relying on non-invasive methods, such as the analysis of the content of extracellular vesicles (EV) that are retrieved from blood plasma and other bodily fluids. Due to the established role of Y RNA in DNA replication, it is possible to hypothesize their therapeutic targeting to inhibit cell proliferation in oncological patients.

The heat shock protein family gene Hspa1l in male mice is dispensable for fertility

Background

Heat shock protein family A member 1 like (Hspa1l) is a member of the 70kD heat shock protein (Hsp70) family. HSPA1L is an ancient, evolutionarily conserved gene with a highly conserved domain structure. The gene is highly abundant and constitutively expressed in the mice testes. However, the role of Hspa1l in the testes has still not been elucidated.

Methods

Hspa1l-mutant mice were generated using the CRISPR/Cas9 system. Histological and immunofluorescence staining were used to analyze the phenotypes of testis and epididymis. Apoptotic cells were detected through TUNEL assays. Fertility and sperm motilities were also tested. Quantitative RT-PCR was used for analyzing of candidate genes expression. Heat treatment was used to induce heat stress of the testis.

Results

We successfully generated Hspa1l knockout mice. Hspa1l ^-/- mice exhibited normal development and fertility. Further, Hspa1l ^-/- mice shown no significant difference in spermatogenesis, the number of apoptotic cells in testes epididymal histology, sperm count and sperm motility from Hspa1l ^+/+ mice. Moreover, heat stress does not exacerbate the cell apoptosis in Hspa1l ^-/- testes. These results revealed that HSPA1L is not essential for physiological spermatogenesis, nor is it involved in heat-induced stress responses, which provides a basis for further studies.