Spatiotemporal expression patterns of natriuretic peptides in rat testis and epididymis during postnatal development

Sperm Functional Genome Associated With Bull Fertility

Bull fertility is an important economic trait in sustainable cattle production, as infertile or subfertile bulls give rise to large economic losses. Current methods to assess bull fertility are tedious and not totally accurate. The massive collection of functional data analyses, including genomics, proteomics, metabolomics, transcriptomics, and epigenomics, helps researchers generate extensive knowledge to better understand the unraveling physiological mechanisms underlying subpar male fertility. This review focuses on the sperm phenomes of the functional genome and epigenome that are associated with bull fertility. Findings from multiple sources were integrated to generate new knowledge that is transferable to applied andrology. Diverse methods encompassing analyses of molecular and cellular dynamics in the fertility-associated molecules and conventional sperm parameters can be considered an effective approach to determine bull fertility for efficient and sustainable cattle production. In addition to gene expression information, we also provide methodological information, which is important for the rigor and reliability of the studies. Fertility is a complex trait influenced by several factors and has low heritability, although heritability of scrotal circumference is high and that it is a known fertility maker. There is a need for new knowledge on the expression levels and functions of sperm RNA, proteins, and metabolites. The new knowledge can shed light on additional fertility markers that can be used in combination with scrotal circumference to predict the fertility of breeding bulls. This review provides a comprehensive review of sperm functional characteristics or phenotypes associated with bull fertility.

Study on the region-specific expression of epididymis mRNA in the rams

The epididymis is divided into three regions including the caput, corpus and cauda. Gene expression profiles in different regions indicate the different functions of epididymis which are crucial for sperm maturation. In this study, three one-year-old rams was used as the experimental animal. Transcriptome sequencing technology was used to sequence mRNA in the caput, corpus and cauda of the epididymis. Based on the spatiotemporal-specific expression pattern in the epididymis, the mRNA expression profiles of the three parts of the epididymis were analysed. Region-specifically expressed genes were analysed by GO and KEGG analyses to screen the key genes involved in sheep sperm maturation. We obtained 129, 54 and 99 specifically expressed genes in the caput, corpus and cauda, respectively. And twenty specific expressed genes related to sperm maturation were used to construct functional networks. The heatmap showed that 6 genes of LCN protein family were highly expressed in the head of epididymis of sheep. We infer that sperm maturation is gradual in the epididymis and that there are significant differences in epididymal gene expression patterns between different species. This provides a data resource for analysing the regulatory mechanism of epididymis genes related to sperm maturation in rams.

Expression profile of Toll-like receptor 4 in rat testis and epididymis throughout postnatal development

Toll-like receptors (TLRs) belonging to pattern recognition receptors are involved in maintaining testicular and epididymal immune homeostasis. The purpose of the current study was to investigate TLR4 expression in rat testis and epididymis throughout postnatal development. Weak staining was detected in peritubular myoid cells and immature Sertoli cells while no staining was observed in gonocytes during prepubertal period. However, TLR4 expression began to appear in spermatocytes in pubertal period and gradually increased in spermatids. An intense staining was observed in steps 5-19 spermatids in post pubertal and mature periods. Similarly, TLR4 expression in the testes steadily increased from pubertal period to mature period. Puberty also caused a significant increase in TLR4 expression in epididymis. TLR4 expression in cauda epididymis was lower as compared to those of other epididymal segments. The majority of epididymal epithelial cells exhibited apical TLR4 expression, whereas basal cells showed intense intracytoplasmic immunoreaction. We detected an intense staining in epididymal smooth muscle cells. The expression levels of TLR4 showed dynamic changes in both spermatogenic cells, and entire testicular and epididymal tissues during postnatal development. These results suggest that TLR4 expression contributes not only to inflammation but also to the development of spermatogenic cells.