Shen Qunshan, Martinez Guillaume, Liu Hongbin, Beurois Julie, Wu Huan, Amiri-Yekta Amir, Liang Dan, Kherraf Zine-Eddine, Bidart Marie, Cazin Caroline, Celse Tristan, Satre Véronique, Thierry-Mieg Nicolas, Whitfield Marjorie, Touré Aminata, Song Bing, Lv Mingrong, Li Kuokuo, Liu Chunyu, Tao Fangbiao, He Xiaojin, Zhang Feng, Arnoult Christophe, Ray Pierre F, Cao Yunxia, Coutton Charles
Reproductive Medicine Center, Human Sperm Bank, Department of Obstetrics and Gynecology, the First Affiliated Hospital of Anhui Medical University, Hefei, 230022, China.
NHC Key Laboratory of Study on Abnormal Gametes and Reproductive Tract (Anhui Medical University), Hefei, 230032, China.
Hum Genet. 2021 Sep;140(9):1367-1377. doi: 10.1007/s00439-021-02313-z. Epub 2021 Jul 13.
Spermatozoa are polarized cells with a head and a flagellum joined together by the connecting piece. Flagellum integrity is critical for normal sperm function, and flagellum defects consistently lead to male infertility. Multiple morphological abnormalities of the flagella (MMAF) is a distinct sperm phenotype consistently leading to male infertility due to a reduced or absent sperm motility associated with severe morphological and ultrastructural flagellum defects. Despite numerous genes recently described to be recurrently associated with MMAF, more than half of the cases analyzed remain unresolved, suggesting that many yet uncharacterized gene defects account for this phenotype. By performing a retrospective exome analysis of the unsolved cases from our initial cohort of 167 infertile men with a MMAF phenotype, we identified one individual carrying a homozygous frameshift variant in CFAP206, a gene encoding a microtubule-docking adapter for radial spoke and inner dynein arm. Immunostaining experiments in the patient's sperm cells demonstrated the absence of WDR66 and RSPH1 proteins suggesting severe radial spokes and calmodulin and spoke-associated complex defects. Using the CRISPR-Cas9 technique, we generated homozygous Cfap206 knockout (KO) mice which presented with male infertility due to functional, structural and ultrastructural sperm flagellum defects associated with a very low rate of embryo development using ICSI. Overall, we showed that CFAP206 is essential for normal sperm flagellum structure and function in human and mouse and that bi-allelic mutations in CFAP206 cause male infertility in man and mouse by inducing morphological and functional defects of the sperm flagellum that may also cause ICSI failures.
精子是极化细胞，其头部和鞭毛通过连接段连接在一起。鞭毛的完整性对于正常精子功能至关重要，鞭毛缺陷一直会导致男性不育。鞭毛多重形态异常（MMAF）是一种独特的精子表型，由于与严重的形态和超微结构鞭毛缺陷相关的精子活力降低或缺失，一直会导致男性不育。尽管最近有许多基因被描述与MMAF反复相关，但超过一半的分析病例仍未得到解决，这表明许多尚未表征的基因缺陷导致了这种表型。通过对我们最初的167名具有MMAF表型的不育男性队列中的未解决病例进行回顾性外显子组分析，我们鉴定出一名个体在CFAP206中携带纯合移码变异，CFAP206是一个编码用于放射辐条和内动力蛋白臂的微管对接适配器的基因。对患者精子细胞进行的免疫染色实验表明，WDR66和RSPH1蛋白缺失，提示存在严重的放射辐条以及钙调蛋白和辐条相关复合体缺陷。使用CRISPR-Cas9技术，我们生成了纯合Cfap206基因敲除（KO）小鼠，这些小鼠由于功能性、结构性和超微结构性精子鞭毛缺陷以及使用卵胞浆内单精子注射（ICSI）时胚胎发育率极低而出现雄性不育。总体而言，我们表明CFAP206对于人和小鼠的正常精子鞭毛结构和功能至关重要，并且CFAP206中的双等位基因突变通过诱导精子鞭毛的形态和功能缺陷导致人和小鼠的雄性不育，这些缺陷也可能导致ICSI失败。
