Integration of omics studies indicates that species-dependent molecular mechanisms govern male fertility

Background Comparative and comprehensive omics studies have recently been conducted to provide a comprehensive understanding of the biological mechanisms underlying infertility.However,because these huge omics datasets often contain irrelevant information,editing strategies for summarizing and filtering the data are necessary prerequisite steps for identifying biomarkers of male fertility.Here,we attempted to integrate omics data from spermatozoa with normal and below-normal fertility from boars and bulls,including transcriptomic,proteomic,and metabolomic data.Pathway enrichment analysis was conducted and visualized using g:Profiler,Cytoscape,EnrichmentMap,and AutoAnnotation to determine fertility-related biological functions according to species.Results In particular,gamete production and protein biogenesis-associated pathways were enriched in bull spermatozoa with below-normal fertility,whereas mitochondrial-associated metabolic pathways were enriched in boar spermatozoa with normal fertility.These results indicate that below-normal fertility may be determined by aberrant regulation of protein synthesis during spermatogenesis,and the modulation of reactive oxygen species generation to maintain capacitation and the acrosome reaction governs boar sperm fertility.Conclusion Overall,this approach demonstrated that distinct molecular pathways drive sperm fertility in mammals in a species-dependent manner.Moreover,we anticipate that searching for species-specific signaling pathways may aid in the discovery of fertility-related biomarkers within large omics datasets.

Heat shock protein family D member 1 in boar spermatozoa is strongly related to the litter size of inseminated sows

Background:Sperm quality evaluation is the logical first step in increasing field fertility.Spermatozoa contain cytoplasmic organelles and biomolecules known as sperm-intrinsic factors,which play key roles in sperm maturation,sperm-oocyte fusion,and embryo development.In particular,sperm membrane proteins[e.g.,arginine vasopressin receptor 2,beta-actin,prohibitin,and heat shock protein family D member 1(HSPD1)]and RNA could be used as functional indicators of male fertility.We sought to clarify the effects of differential mRNA expression of selected genes on several fertilisation parameters,including sperm motility,motion kinematics,capacitation,and litter size,in a porcine model.Results:Our results demonstrated that HSPD1 expression was significantly correlated with male fertility,as measured by the litter size of inseminated sows.The expression of HSPD1 mRNA was linked to sperm motility and other motion kinematic characteristics.Furthermore,HSPD1 had a 66.7%overall accuracy in detecting male fertility,and the high-litter size group which was selected with the HSPD1 marker had a 1.34 greater litter size than the lowlitter size group.Conclusions:Our findings indicate that HSPD1 might be a helpful biomarker for superior boar selection for artificial insemination,which could boost field fertility.

Establishment of a male fertility prediction model with sperm RNA markers in pigs as a translational animal model

Background:Male infertility is an important issue that causes low production in the animal industry.To solve the male fertility crisis in the animal industry,the prediction of sperm quality is the most important step.Sperm RNA is the potential marker for male fertility prediction.We hypothesized that the expression of functional genes related to fertilization will be the best target for male fertility prediction markers.To investigate optimum male fertility prediction marker,we compared target genes expression level and a wide range of field data acquired from artificial insemination of boar semen.Results:Among the genes related to acrosomal vesicle exocytosis and sperm–oocyte fusion,equatorin(EQTN),zona pellucida sperm-binding protein 4(ZP4),and sperm acrosome membrane-associated protein 3 exhibited high accuracy(70%,90%,and 70%,respectively)as markers to evaluate male fertility.Combinations of EQTN-ZP4,ZP4-protein unc-13 homolog B,and ZP4-regulating synaptic membrane exocytosis protein 1(RIMS1)showed the highest prediction value,and all these markers are involved in the acrosome reaction.Conclusion:The EQTN-ZP4 model was efficient in clustering the high-fertility group and may be useful for selection of animal that has superior fertility in the livestock industry.Compared to the EQTN-ZP4 model,the ZP4-RIMS1 model was more efficient in clustering the low-fertility group and may be useful in the diagnosis of male infertility in humans and other animals.The appointed translational animal model and established biomarker combination can be widely used in various scientific fields such as biomedical science.

Regulation of epithelial function, differentiation, and remodeling in the epididymis

The epididymis is a single convoluted tubule lined by a pseudostratified epithelium. Specialized epididymal epithelial cells, the so-called principal, basal, narrow, and clear cells, establish a unique luminal environment for the maturation and storage of spermatozoa. The epididymis is functionally and structurally divided into several segments and sub-segments that create regionally distinct luminal environments. This organ is immature at birth, and epithelial cells acquire their fully differentiated phenotype during an extended postnatal period, but the factors involved in this complex process remain incompletely characterized. In the adult epididymis, the establishment of an acidic luminal pH and low bicarbonate concentration in the epididymis contributes to preventing premature activation of spermatozoa during their maturation and storage. Clear cells are proton-secreting cells throughout the epididymis, but principal cells have distinct acid/base transport properties, depending on their localization within the epididymis. Basal cells are located in all epididymal segments, but they have a distinct morphology depending on the segment and species examined. How this structural plasticity of basal cells is regulated is discussed here. Also, the role of luminal factors and androgens in the regulation of epithelial cells is reviewed in relation to their respective localization in the proximal versus distal regions of the epididymis. Finally, we describe a novel role for CFTR in tubulogenesis and epithelial cell differentiation.