中文摘要：

染色体编辑工具例如定期聚类短 palindromic 重复(CRISPR ) 联系了的 interspaced 系统(Cas ) 广泛地被用来包括动物接合子和人的房间在模型系统修改基因，并且为基本研究和临床的应用保持巨大的诺言。迄今为止，严肃的知识差距在人的早胚胎，并且在效率和在人的培植前胚胎使用象 CRISPR/Cas9 那样的技术的潜在的离开目标效果留在我们 DNA 修理机制的理解。在这份报告，我们使用了推进的接合子调查 CRISPR/Cas9-mediated 基因在人的房间编辑的 tripronuclear (3PN ) 。我们发现 CRISPR/Cas9 能有效地劈开内长的 -globin 基因(HBB ) 。然而，相应再结合的效率指导了 HBB 的修理(HDR ) 是低的，编辑胚胎是马赛克。离开目标劈开在由 T7E1 试金并且 whole-exome 定序揭示了的这些 3PN 接合子也是明显的。而且，内长的 delta-globin 基因(HBD ) 对 HBB 相应，与外长的施主 oligos 竞争了充当修理模板，导致倔强的变化。我们的数据也显示在这些胚胎的 HBB 地点的修理通过非转线路 HDR 小径优先地发生了。一起拿，我们的工作加亮紧迫的需要进一步改进 CRISPR/Cas9 平台的忠实和特性，为编辑的 CRSIPR/Cas9-mediated 的任何临床的应用程序的一个前提。

英文摘要：

Genome editing tools such as the clustered regularly interspaced short palindromic repeat （CRISPR）-associated system （Cas） have been widely used to modify genes in model systems including animal zygotes and human cells, and hold tremendous promise for both basic research and clinical applications. To date, a serious knowledge gap remains in our understanding of DNA repair mechanisms in human early embryos, and in the efficiency and potential off-target effects of using technologies such as CRISPR/Cas9 in human pre-implantation embryos. In this report, we used tripronuclear （3PN） zygotes to further investigate CRISPR/Cas9-mediated gene editing in human cells. We found that CRISPR/Cas9 could effectively cleave the endogenous β-globin gene （HBB）. However, the efficiency of homologous recombination directed repair （HDR） of HBB was low and the edited embryos were mosaic. Off-target cleavage was also apparent in these 3PN zygotes as revealed by the T7E1 assay and whole-exome sequencing. Furthermore, the endogenous delta-globin gene （HBD）, which is homologous to HBB, competed with exogenous donor oligos to act as the repair template, leading to untoward mutations. Our data also indicated that repair of the HBB locus in these embryos occurred preferentially through the non-crossover HDR pathway. Taken together, our work highlights the pressing need to further improve the fidelity and specificity of the CRISPR/Cas9 platform, a prerequisite for any clinical applications of CRSIPR/Cas9-mediated editing.