To Characterize the Developmental Roles of SLC9A3 in Epididymis and Testis by Knockout Model

• Main Authors: CHENG, CHIAO-YIN, 鄭喬尹
• Other Authors: LIN, YING-HUNG
• Format: Others
• Language: zh-TW
• Published: 2016
• Online Access: http://ndltd.ncl.edu.tw/handle/65865552072186941987

碩士 === 輔仁大學 === 基礎醫學研究所碩士班 === 104 === Between 10% and 15% of couples are affected by reduced fertility, and defects of men in roughly half of the cases. Congenital Bilateral Absent of the Vas Deference (CBAVD) accounted for 1% ~ 2% of male infertility and 95% caused by Cystic Fibrosis Transmembrane Conductance Regulator (CFTR) mutation in Caucasians. However, in our study, 42.9% (27/63) CBAVD cases in Taiwan don't exist the CFTR mutation. Recently, we found another CBAVD-related gene, SLC9A3 (Solute Carrier Family 9, Subfamily, A Sodium/Hydrogen Exchanger), by array-CGH (Comparative Genomic Hybridization). SLC9A3 is major expressed on epithelial cells in gastrointestinal tract, kidney, epididymis, and vas deference. N-terminal of SLC9A3 mediates sodium and hydrogen exchange and in the C-terminal of SLC9A3 regulates the sodium/hydrogen exchange activity and interacts with its regulated proteins e.g., NHERF1 (SLC9A3 regulator 1) and CFTR. The major functional studies of SLC9A3 focus on epithelial cells in gastrointestinal tract and kidney. Recently, we confirmed male SLC9A3-dificent mice are infertile. However, the developmental roles of SLC9A3 in testis and epididymis are unclear. First, we characterized that SLC9A3 expressed at the acrosomal granule and acrosome during post-spermatogenesis process located on the apical stereocilia of epididymal epithelium of cauda of epididymis and epithelium of vas deference at 60 days-old mice through immunofluorescence staining. Second, we also confirmed the sterility of Slc9a3-/- male mice through routine mating about 1-2 months. Further, according to H&E staining and nuclear staining, we found the ratio of exist mature sperm in the lumen, was reduced. The structures of interstitial tissue and seminiferous tubules were disrupted from 35 and 60 days-old Slc9a3 -/- mice compared with wild-type. Further, number of round spermtid reduced in Slc9a3 -/- mice through acrosomal marker staining. The testicular section of KO mice reveals hypo-spermatogenesis-like phenotype. Third, most lumens in caput of epididymis was absent mature sperm. The liquid hoarded in the lumens of epididymis in Slc9a3 -/- mice increased accompanied with aging. The liquid hoarding reveled in the epididymis from 35 days-old of KO mice consists with the beginning expression of SLC9A3 at 35 days-old wild-type mice. In addition, loss of SLC9A3 also affected the location of NHERF1 in epididymis at 35 and 60 days through immunofluorescence staining. This study indicated that SLC9A3 is required for maintaining the arrangement and numbers of male germ cells during spermatogenic process and transport the spermatozoa in epididymis.