Liu Wenqiang, Li Kunming, Bai Dandan, Yin Jiqing, Tang Yuanyuan, Chi Fengli, Zhang Linfeng, Wang Yu, Pan Jiaping, Liang Shanshan, Guo Yi, Ruan Jingling, Kou Xiaochen, Zhao Yanhong, Wang Hong, Chen Jiayu, Teng Xiaoming, Gao Shaorong
Clinical and Translational Research Center of Shanghai First Maternity and Infant Hospital, Shanghai Key Laboratory of Signaling and Disease Research, School of Life Sciences and Technology, Tongji University, Shanghai, 200092, China.
Hum Genet. 2017 Aug;136(8):975-985. doi: 10.1007/s00439-017-1822-7. Epub 2017 Jun 24.
The zona pellucida (ZP) is an extracellular matrix universally surrounding mammalian eggs, which is essential for oogenesis, fertilization, and pre-implantation embryo development. Here, we identified two novel heritable mutations of ZP2 and ZP3, both occurring in an infertile female patient with ZP-abnormal eggs. Mouse models with the same mutations were generated by CRISPR/Cas9 gene editing system, and oocytes obtained from female mice with either single heterozygous mutation showed approximately half of the normal ZP thickness compared to wild-type oocytes. Importantly, oocytes with both heterozygous mutations showed a much thinner or even missing ZP that could not avoid polyspermy fertilization, following the patient's pedigree. Further analysis confirmed that precursor proteins produced from either mutated ZP2 or ZP3 could not anchor to oocyte membranes. From these, we conclude that ZP mutations have dosage effects which can cause female infertility in humans. Finally, this patient was treated by intracytoplasmic sperm injection (ICSI) with an improved culture system and successfully delivered a healthy baby.
透明带（ZP）是普遍包裹哺乳动物卵子的细胞外基质，对卵子发生、受精和植入前胚胎发育至关重要。在此，我们鉴定出ZP2和ZP3的两个新的可遗传突变，均发生在一名患有ZP异常卵子的不孕女性患者身上。通过CRISPR/Cas9基因编辑系统构建了具有相同突变的小鼠模型，与野生型卵母细胞相比，从具有单个杂合突变的雌性小鼠获得的卵母细胞显示出约一半的正常ZP厚度。重要的是，具有两个杂合突变的卵母细胞显示出更薄甚至缺失的ZP，无法避免多精受精，这与患者的家系情况一致。进一步分析证实，由突变的ZP2或ZP3产生的前体蛋白无法锚定到卵母细胞膜上。由此，我们得出结论，ZP突变具有剂量效应，可导致人类女性不孕。最后，该患者通过改进的培养系统进行了胞浆内单精子注射（ICSI）治疗，并成功产下一名健康婴儿。
