The testis-specific gene 1700102P08Rik is essential for male fertility.

Male infertility is a rising problem around the world. Often the cause of male infertility is unclear, and this hampers diagnosis and treatment. Spermatogenesis is a complex process under sophisticated regulation by many testis-specific genes. Here, we report the testis-specific gene 1700102P08Rik is conserved in both the human and mouse and highly expressed in spermatocytes. To investigate the role of 1700102P08Rik in male fertility, knockout mice were generated by CRISPR-Cas9. 1700102P08Rik knockout male mice were infertile with smaller testis and epididymis, but female knockout mice retained normal fertility. Spermatogenesis in the 1700102P08Rik knockout male mouse was arrested at the spermatocyte stage, and no sperm were found in the epididymis. The deletion of 1700102P08Rik causes apoptosis in the testis but did not affect the serum concentration of testosterone, luteinizing hormone, and follicle-stimulating hormone or the synapsis and recombination of homologous chromosomes. We also found that 1700102P08Rik is downregulated in spermatocyte arrest in men. Together, these results indicate that the 1700102P08Rik gene is essential for spermatogenesis and its dysfunction leads to male infertility.

[Expressions of the adenylate kinase family in asthenospermia].

OBJECTIVE: To investigate the expressions of the adenylate kinase (AK) family in the sperm of asthenospermia patients. METHODS: We collected semen samples from 30 asthenospermia patients and another 30 normal healthy males, detected the mRNA and protein expressions of AKs by RT-PCR and Western blot, localized the AKs by immunofluorescence assay and immunohistochemistry, and analyzed their association with sperm motility. RESULTS: RT-PCR and Western blot showed that AKs 1－9 were expressed in the sperm of all the subjects, and the mRNA and protein expressions of AK1, AK6 and AK7 were significantly lower in the asthenospermia patients than in the normal males. In the testis, AK1 and AK7 were expressed in the cytoplasm while AK6 in the nucleus, and in the sperm, the former two were localized in the flagella while the latter one in the sperm head. Antibody blocking experiments showed that none of the AK1, AK6 and AK7 antibodies had any significant effect on the total or progressive motility of the sperm while cultured with each alone, but co-culturing with the three antibodies markedly reduced the total sperm motility (ï¼»80.5 ± 2.4ï¼½%) and progressive sperm motility (ï¼»60.6 ± 3.6ï¼½%) in comparison with those in the control group (ï¼»87.6 ± 3.3ï¼½% and ï¼»70.2 ± 2.3ï¼½%) (P < 0.05). CONCLUSIONS: The mRNA and protein expressions of AK1, AK6 and AK7 are significantly down-regulated in the sperm of asthenospermia patients, which may be closely related with reduced sperm motility.

The expression of the new epididymal luminal protein of PDZ domain containing 1 is decreased in asthenozoospermia.

Spermatozoa are not mature until they transit the epididymis where they acquire motility and the ability to fertilize an egg through sequential modifications. The epididymis has three functional regions, caput, corpus, and cauda, and the luminal proteins of the epididymis play important roles in the above modifications. However, the proteins with differential enrichment between the caput and cauda are still largely unknown. To reveal the functions of the caput and cauda during sperm maturation, luminal proteins from caput and cauda of mice were analyzed by isobaric tag for relative and absolute quantitation (iTRAQ). Overall, 128 differentially enriched proteins were found, of which 46 were caput enriched and 82 were cauda enriched. Bioinformatic analysis showed that lipid metabolism was active in the caput; while anion- and cation-binding activity and phosphorus and organophosphate metabolism were active in the cauda. A new epididymal luminal protein, the caput-enriched PDZ domain containing 1 (Pdzk1), also named Na+/H+ exchange regulatory cofactor 3 (NHERF3), which plays a critical role in cholesterol metabolism and carnitine transport, was found in the lipid metabolism. Western blotting and immunofluorescence analyses showed that Pdzk1 was expressed in the epididymis but not in the testis, and localized at the middle piece of the sperm tail. Pdzk1 protein level was also reduced in the spermatozoa in case of asthenozoospermic patients compared with that in normozoospermic men, suggesting that Pdzk1 may participate in sperm maturation regulation and may be associated with male infertility. These results may provide new insights into the mechanisms of sperm maturation and male infertility.