Abstract：
OBJECTIVE: Is the novel homozygous nonsense variant of AK7 associated with multiple morphological abnormalities of the sperm flagella (MMAF), a specific type of oligoasthenoteratozoospermia leading to male infertility?
METHODS: Whole-exome sequencing and Sanger sequencing were performed to identify potential gene variants. Immunoblotting and immunofluorescence were applied to confirm the relationship between mutated genes and disease phenotypes. The concentration of reactive oxygen species and the rate of apoptosis were measured to evaluate the mitochondrial function of spermatozoa. Transmission electron microscopy and scanning electron microscopy were employed to observe sperm ultrastructure.
RESULTS: A novel homozygous nonsense variant of AK7, c.1153A>T (p. Lys385*), was identified in two infertile siblings with asthenoteratozoospermia through whole-exome sequencing. Both immunoblotting and immunofluorescence assays showed practically complete absence of AK7 in the patient\'s spermatozoa. Additionally, the individual with the novel AK7 variant exhibited a phenotype characterized by severe oxidative stress and apoptosis caused by mitochondrial metabolic dysfunction of spermatozoa. Notably, remarkable flagellar defects with multiple axonemes in uniflagellate spermatozoa, accompanied by mitochondrial vacuolization, were observed; this has not been reported previously in patients with other AK7 variants.
CONCLUSIONS: This study found that a novel identified homozygous nonsense variant of AK7 may be associated with MMAF-related asthenoteratozoospermia. The observed functional associations between mitochondria and sperm flagellar assembly provide evidence for potential mutual regulation between AK7 and flagella-associated proteins during spermatogenesis.
METHODS: Whole-exome sequencing and Sanger sequencing were performed to identify potential gene variants. Immunoblotting and immunofluorescence were applied to confirm the relationship between mutated genes and disease phenotypes. The concentration of reactive oxygen species and the rate of apoptosis were measured to evaluate the mitochondrial function of spermatozoa. Transmission electron microscopy and scanning electron microscopy were employed to observe sperm ultrastructure.
RESULTS: A novel homozygous nonsense variant of AK7, c.1153A>T (p. Lys385*), was identified in two infertile siblings with asthenoteratozoospermia through whole-exome sequencing. Both immunoblotting and immunofluorescence assays showed practically complete absence of AK7 in the patient\'s spermatozoa. Additionally, the individual with the novel AK7 variant exhibited a phenotype characterized by severe oxidative stress and apoptosis caused by mitochondrial metabolic dysfunction of spermatozoa. Notably, remarkable flagellar defects with multiple axonemes in uniflagellate spermatozoa, accompanied by mitochondrial vacuolization, were observed; this has not been reported previously in patients with other AK7 variants.
CONCLUSIONS: This study found that a novel identified homozygous nonsense variant of AK7 may be associated with MMAF-related asthenoteratozoospermia. The observed functional associations between mitochondria and sperm flagellar assembly provide evidence for potential mutual regulation between AK7 and flagella-associated proteins during spermatogenesis.
摘要：
目的：是与精子鞭毛（MMAF）的多种形态异常相关的AK7的新型纯合无义变体，导致男性不育的特定类型的少弱精子症?
方法:进行全外显子组测序和Sanger测序以鉴定潜在的基因变异.应用免疫印迹法和免疫荧光法来证实突变基因与疾病表型之间的关系。测量活性氧浓度和凋亡率，以评估精子的线粒体功能。采用透射电镜和扫描电镜观察精子超微结构。
结果：AK7的一种新型纯合无义变体，c.1153A>T（p。Lys385*),通过全外显子组测序在两个患有弱精子症的不育兄弟姐妹中发现。免疫印迹和免疫荧光测定均显示患者精子中几乎完全不存在AK7。此外,具有新型AK7变体的个体表现出一种表型,其特征是精子线粒体代谢功能障碍引起的严重氧化应激和细胞凋亡.值得注意的是,单鞭毛精子中有多个轴突的明显鞭毛缺陷，伴随着线粒体空泡化，被观察到；这在其他AK7变异的患者中没有报道过。
结论：本研究发现一种新的鉴定的AK7纯合无义变体可能与MMAF相关的弱精子症有关。观察到的线粒体和精子鞭毛组装之间的功能关联为精子发生过程中AK7和鞭毛相关蛋白之间的潜在相互调节提供了证据。
方法:进行全外显子组测序和Sanger测序以鉴定潜在的基因变异.应用免疫印迹法和免疫荧光法来证实突变基因与疾病表型之间的关系。测量活性氧浓度和凋亡率，以评估精子的线粒体功能。采用透射电镜和扫描电镜观察精子超微结构。
结果：AK7的一种新型纯合无义变体，c.1153A>T（p。Lys385*),通过全外显子组测序在两个患有弱精子症的不育兄弟姐妹中发现。免疫印迹和免疫荧光测定均显示患者精子中几乎完全不存在AK7。此外,具有新型AK7变体的个体表现出一种表型,其特征是精子线粒体代谢功能障碍引起的严重氧化应激和细胞凋亡.值得注意的是,单鞭毛精子中有多个轴突的明显鞭毛缺陷，伴随着线粒体空泡化，被观察到；这在其他AK7变异的患者中没有报道过。
结论：本研究发现一种新的鉴定的AK7纯合无义变体可能与MMAF相关的弱精子症有关。观察到的线粒体和精子鞭毛组装之间的功能关联为精子发生过程中AK7和鞭毛相关蛋白之间的潜在相互调节提供了证据。
