A novel homozygous mutation of phospholipase C zeta leading to defective human oocyte activation and fertilization failure
A novel homozygous mutation of phospholipase C zeta leading to defective human oocyte activation and fertilization failure
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磷脂酶 C zeta 的新型纯合突变导致人类卵母细胞活化缺陷和受精失败
DOI：
10.1093/humrep/dez293
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发表时间：
2020
影响因子：
6.1
通讯作者：
Qiao Jie
中科院分区：
文献类型：
--
作者：
Yuan Peng;Yang Cen;Ren Yixin;Yan Jie;Nie Yanli;Yan Liying;Qiao Jie
研究问题：一种新的纯合子磷脂酶C zeta（PLC zeta），c.1658 G>C; p.R553P突变是否与ICSI后复发性受精失败的结局相关？总结回答：PLC zeta，c.1658 G>C导致人类卵母细胞激活缺陷和受精失败，而PLC zeta的C2结构域中的这种突变不损害精子的浓度、活力和染色体倍性。已知信息：精子特异性PLC zeta现在被广泛认为是引起细胞内钙（Ca 2+）振荡的生理刺激，这是哺乳动物受精过程中卵子激活所必需的。到目前为止，很少有遗传学研究表明PLC zeta基因的不同点突变与男性不育有关。研究设计、规模、持续时间：这是一项基础医学研究，旨在评估人类受精过程中PLC zeta C2结构域新突变的致病性。对象/材料，地点，方法：应用单细胞组学技术分析受精失败卵母细胞DNA甲基化状态和患者精子倍体。分析患者的全基因组测序数据中PLC zeta的突变。桑格测序证实了一种罕见的变异体的存在，然后注射突变体和野生型PLC zeta mRNA以观察卵母细胞活化。主要结果和机会的作用：受精失败的卵母细胞（n=4）是三倍体，缺乏适当的DNA去甲基化。全基因组测序分析揭示了PLC zeta，c.1658 G>C; p.R553P中的一种新的错义纯合突变，其导致精氨酸553转化为脯氨酸。这种点突变不影响精子中相应蛋白质的产生。然而，显微注射从PLC zeta R553 P突变基因转录的mRNA未能触发卵母细胞激活和随后的胚胎发育。局限性，预防原因：由于其罕见的发病率，只有1例PLC zeta突变患者可用。这些发现的更广泛的意义：值得注意的是，我们发现了PLC zeta中的一种新的纯合突变，这导致PLC zeta蛋白的C2结构域的异常构象。我们的研究结果表明PLC zeta在人类受精和PLC zeta介导的生理功能的C2结构域的正常结构的要求的重要作用。
STUDY QUESTION: Is a novel homozygous phospholipase C zeta (PLC zeta), c.1658 G>C; p. R553P mutation in the C2 domain associated with the outcomes of recurrent fertilization failure after ICSI? SUMMARY ANSWER: PLC zeta, c.1658 G>C led to defective human oocyte activation and fertilization failure, while this mutation in the C2 domain of PLC zeta did not compromise concentration, motility and chromosome ploidy of sperm. WHAT IS KNOWN ALREADY: Sperm-specific PLC zeta is now widely considered to be the physiological stimulus that evokes intracellular calcium (Ca2+) oscillations, which are essential for egg activation during mammalian fertilization. Thus far, few genetic studies have shown that different point mutations in the PLC zeta gene are associated with male infertility. STUDY DESIGN, SIZE, DURATION: This was a basic medical research to assess pathogenicity for novel mutation in the C2 domain of PLC zeta during human fertilization. PARTICIPANTS/MATERIALS, SETTING, METHODS: Single-cell omics were applied to analyze the DNA methylation state of the fertilization failure oocytes and the ploidy of the patient's sperm. Whole genome sequencing data for the patient were analyzed for mutations in PLC zeta. Sanger sequencing confirmed the presence of a rare variant, and then the mutant and wild-type PLC zeta mRNA were injected to observe oocyte activation. MAIN RESULTS AND THE ROLE OF CHANCE: The fertilization failure oocytes (n=4) were triploid and lacking proper DNA demethylation. The whole genome sequencing analysis revealed a novel missense homozygous mutation in PLC zeta, c.1658 G>C; p. R553P, which leads to the conversion of arginine 553 to proline. This point mutation does not affect the production of the corresponding protein in sperm. However, microinjection of the mRNA transcribed from the PLC zeta R553P mutation gene failed to trigger oocyte activation and the subsequent embryo development. LIMITATIONS, REASONS FOR CAUTION: Only one patient with PLC zeta mutations was available because of its rare incidence. WIDER IMPLICATIONS OF THE FINDINGS: Notably, we discovered a novel homozygous mutation in PLC zeta, which results in an abnormal conformation at the C2 domain of the PLC zeta protein. Our findings indicate an essential role of PLC zeta in human fertilization and the requirement of a normal structure of C2 domain in PLC zeta-mediated physiological function.