The Functional And Mechanism Study Of Human DNAJB13Gene In Sperm Motility

The incidence of infertility is as high as10%-15%in our country,50%of whom caused by male. Spermato genic failure is confirmed to be a significant one, which typified by idiopathic asthenozoospermia. If genes are missing or broken, these alterations are passed on to human offspring. Therefore, it is necessary to understand the mechanism of spermatogenesis.In the past research result, a novel testis overexpressed gene DNAJB13related to human spermatogenesis and its mouse homologue Dnajb13have been mapped and cloned by our research group. RT-PCR results showed that DNAJB13expressed in adult testis tissue as well as the adult sperm. In-situ hybridization experiment showed that DNAJB13is mainly expressed in primary and secondary spermatocyte.Objective&Methods:The location、the function and mechanism of DNAJB13in spermatogenesis without any conclusion. Jointing immunoblot and immunofluorescence, immune electron microscopy to clarify expression and positioning of DNAJB13in human mature sperm. Detecting DNAJB13by direct sequencing, to study the relationship beween mutation and polymorphism within DNAJB13gene with idiopathic asthenozoospermia.Combline immunoprecipitation with liquid mass spectrometry, to identify whether there are other proteins interacting with DNAJB13. Result:①Western Blot shows DNAJB13expression in normal adult sperm; using immunofluorescence we find out that DNAJB13protein is localized on mature sperm flagellum; IEM of DNAJB13,we localized the protein to the part of the middle piece of sperm flagellum, corresponding to the location of outer doublet microtubules、radial spokes and the outer dense fibres (ODFs)、mitochondrial sheath.(2)It is the first time that we found2missense mutation in the exon2of gene DNAJB13(c.857T>C、c.912T>C) on the international,detected3SNPs in the exon2of gene DNAJB13(including rs10793069, rs10793068and rs199547235);2SNPs in the exon3of gene DNAJB13(including rs653263, rs=145909750);3SNPs in the exon8of gene DNAJB13(including rs2306820,rs2306819,72982975),③We identified some kinds of proteins including HKI, LDHC, may be interact with DNAJB13in human sperm.Conclusion:The fact that DNAJB13localized to the part of the middle piece of sperm flagellum, corresponding to the location of outer doublet microtubules、radial spokes and the outer dense fibres (ODFs)、 mitochondrial sheath suggests gene function related to sperm motility; mutation and polymorphism of DNAJB13gene may lead the idiopathic asthenozoospermia; DNAJB13interacts with LDHC、HK1that takes part in the glycometabolism process of human sperm.