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BackgroundSpermatogenesis is a highly complicated biological process that occurs in the epithelium of the seminiferous tubules. It is regulated by a complex network of endocrine and paracrine factors and juxtacrine testicular cross-talk . Sertoli cells (SCs) play a key role in spermatogenesis due to their production of trophic, differentiation and immune-modulating factors. However, many of the molecular pathways of SCs action remain controversial and unclear. Recently, research has focused on exosomes as an important mechanism of intercellular communication. ResultsW e found that the exosomes derived from SCs ( SC-Exos ) significantly inhibited the apoptosis of the primary spermatogonial stem cells (SSCs). Total of 1016 miRNAs in SCs and 556 miRNAs in SC-Exos were detected using microRNA (miRNA) high-throughput sequencing. Further, 294 miRNAs were differentially expressed between SCs and SC-Exos. Based on the GO and KEGG analyses, the target genes of 37 (high-expressed in exosomes and RPM>1000) selected miRNAs were involved in multiple biological pathw ays, including the MAPK signaling pathway and PI3K/AKT signaling pathway. And miR-10b is one of the top ten exosomes with relatively large enrichment of microRNA. In addition, the overexpression of miR-10b down-regulated expression of the target KLF4 to reduce spermatogonial apoptosis in SSCs or C18-4 cell line. ConclusionsThe study indicated a large number of small RNAs loaded in exosomes was secreted form the donor SCs to target spermatogonial regulated the apoptosis. And miR-10b inhibits the apoptosis of spermatogonia through the target gene KLF4.

Musk secreted by Chinese forest musk deer (FMD; Moschus berezovskii) is a highly valuable ingredient in the fields of perfumery and medicine, and the main factor affecting the production of musk is the androgen level of male FMD. To clarify whether the musk gland of FMD can synthesize androgen, we compared and analyzed the expression patterns of steroid hormone biosynthesis-related genes in the musk gland and testis of FMD by RNA-seq and RT-qPCR. We obtained 33,308 and 38,602 unigenes from the musk gland and testis, respectively, and 26,780 co-expressed unigenes. Analysis of co-expressed genes revealed that 12,647 genes were annotated to 11,484 Gene Ontology terms and 10,941 genes were annotated to 6120 pathways, including several pathways important in metabolic and synthetic activity. Next, 21 steroid hormone synthesis-related genes were screened from the transcriptome of the musk gland of 4-month-old FMD. The expression levels of three key genes of steroid hormone biosynthesis (CYP11A1, CYP17A1, and HSD3B) in the musk gland differed from their expression levels in the testis based on RT-qPCR. Furthermore, immunohistochemistry indicated that CYP11A1, CYP17A1, and HSD3B were localized in the glandular tubular columnar cells of the musk gland. These results suggested that the musk gland of male FMD has the potential to locally synthesize steroid hormone and thus plays a critically important role in musk secretion.

Melatonin (MLT) is an efficient antioxidant that protects spermatozoa against damages caused by oxidative stress. In this study, to maintain good function of Onychostoma macrolepis spermatozoa during semen preservation invitro at 4°C, different concentrations of MLT (0.5, 1 and 2μM) were added to the semen. After storage (0, 24, 48 and 72h), 1μM MLT in semen markedly improved sperm quality, as reflected by better plasma membrane integrity, the relative steady level of reactive oxygen species (ROS) and slower rate of decrease in mitochondrial membrane potential. Activated spermatozoa in semen with 1μM MLT had higher kinematic performance (i.e. percentage of motile and progressive spermatozoa and the beat cross frequency; P

This study focuses on the effect of outer membrane vesicles (OMVs) in gram-negative bacteria on boar sperm function during in vitro storage. In the 40 ejaculates collected from Guangzhong Black boar, six gram-negative bacterial species were detected by 16S rDNA sequencing, of which Proteus mirabilis was the main contaminating bacterium. The OMVs of P. mirabilis were isolated by gradient ultracentrifugation. To reveal the effect of OMVs on boar sperm, different OMV concentrations were added to the Modena medium during sperm storage at 17 °C. Even after 3 days of storage, it was noted that low OMV dose (5 μg/mL) in the extender did not significantly reduce sperm quality as compared with that in the control semen samples; however, sperm motility and sperm morphology were significantly altered in the extender owing to a high OMV dose (10 μg/mL). The relative ROS level successively increased with OMV dose in sperm samples and storage time. Meanwhile, OMVs dramatically elevated the mitochondrial potential of sperm. OMVs could bind with the sperm membrane to further influence the capacity of sperm-oocyte binding; they also increased the expression of LC3 and caspase 3 and decreased that of anti-apoptosis-related protein, Bcl2, in sperm. It was concluded that OMVs of P. mirabilis influenced the function of boar sperm by inducing sperm membrane reconstruction as well as autophagy and apoptosis of sperm.