动物克隆能快速地扩繁良种家畜、生产基因编辑动物。然而动物克隆的效率较低，严重制约了该技术在育种中的推广。克隆是一个复杂的过程，除去操作等人为因素，在卵母细胞和供核细胞中还存在着许多影响克隆效率的因子。因此，我们希望通过鉴定这些因子，明确它们在克隆胚中参与的生物学过程，从而助于我们增强对体细胞核移植这一过程的理解，提高核移植效率。我们的前期研究发现，在牛的体细胞克隆胚发育过程中，微小RNA miR-125b通过抑制KMT1A减少H3K9me3的分布，促进克隆囊胚形成。但是miR-125b/KMT1A产生的这种作用会影响哪些生物学进程，这些进程哪些又对于miR-125b促进囊胚形成这一表型最为关键，干预后形成的囊胚质量是否有明显变化。这些问题还需要我们进一步的实验来阐明。弄清这些问题将进一步加强我们对于微小RNA在体细胞核移植过程中的作用机制的理解，为体细胞克隆技术体系的改进提供理论依据。

Animal cloning can be used to expand numbers of superior livestock. However, these technologies are plagued with inefficiencies making them too costly for the average livestock producer. Cloning is a complex process. Exclude Human Factors, there still have bio-factors in donor cells and oocytes which affect the clone efficiency. To identify these biology-factor and clarify the biological process they involved will help us to understand the cloning and improve its efficiency. Previously, we indentified that miR-125b is essential for promoting successful somatic nuclear transfer (SCNT) reprogramming and its overexpression improve the SCNT blastocyst development. miR-125b regulated the histone H3 lysine-9 tri-methylation (H3K9me3) in SCNT embryos by directly targeting the KMT1A and promoted SCNT embryos development. However, the biological process underlying the miR-125b/KMT1A axis is yet to be defined, especially for preimplantation and blastocyst formation. These questions need further experiments to expound. This research will not only increase our understanding of the microRNA’s role in nuclear transfer but also provide a theoretical base for improving nuclear transfer systems.