母源基因对早期胚胎发育起重要的作用，纺锤体的组装对卵母细胞成熟、染色体正常倍性的维持及胚胎早期发育至关重要，但纺锤体组装相关的母源基因在人类早期胚胎发育中的作用机制还缺乏深入研究。申请者前期利用单细胞转录组测序技术对人类早期胚胎进行研究，检测出2万多个母源基因，发现其中有三个纺锤体组装相关基因TUBB8、NUF2、BUB1B，在成熟卵、原核期及二细胞期胚胎均有高表达，但在四细胞期明显下降，八细胞期及之后表达量基本为零，提示其在卵成熟及胚胎早期发育过程中发挥重要作用。本项目拟在此基础上，降低或增加小鼠卵母细胞相应基因表达，观察卵母细胞成熟及胚胎发育情况以及纺锤体组装与卵母细胞遗传信息，并进一步利用人未成熟卵进行验证，从而初步探讨临床上反复卵不成熟、早期胚胎发育停滞的原因。该研究将有助于进一步加深对人类早期胚胎发育的认识，为生殖医学临床上疑难病例诊疗提供新的思路和手段。

Maternal genes play critical roles in the initial phases of embryonic development. Spindle assembly is crucial for embryonic euploidy and pre-implantation embryo development. However, the role of spindle organization associated maternal gene hasn’t been clearly known. Applicant has applied single-cell RNA sequencing (RNA-seq) analysis to individual cells from human preimplantation embryos. More than 20,000 maternal expressed genes were detected, involved three spindle organization associated maternal genes, TUBB8, NUF2 and BUB1B. All of them are highly expressed in mature oocyte, zygote and 2-cell embryo, but their expression significantly decreased in 4-cell embryo. After 8-cell stage, the expression of these genes could hardly been detected. The changes of gene expression indicate that TUBB8, NUF2 and BUB1B are essential during egg maturation and early embryo development. Based on the previous study, applicant will deregulate the expression of these genes by intracytoplasmic siRNA injection to mouse oocytes( include inmature and mature oocytes), then observe the progress of egg maturation , embryonic development, as well as spindle assembly, and detect the genome of oocytes. The conclusion will be verified with human inmature oocyte, to find the pathogenic mechanism of repeatedly egg maturation arrest or pre-implantation embryo development arrest and to provide a scientific basis for clinical diagnosis and treatment.