中国畜牧兽医 ›› 2026, Vol. 53 ›› Issue (2): 819-836.doi: 10.16431/j.cnki.1671-7236.2026.02.028

• 遗传繁育 • 上一篇    下一篇

华西牛MSTN基因编辑细胞及胚胎的效率优化研究

杜志雯1(), 高雨馨1, 刘淑琴1, 马海滨2, 杨磊1, 宋丽爽1, 白春玲1, 魏著英1, 李光鹏1(), 苏广华1()   

  1. 1.内蒙古大学生命科学学院,省部共建草原家畜生殖调控与繁育国家重点实验室,呼和浩特 010071
    2.内蒙古奥科斯牧业有限公司,锡林郭勒 026321
  • 收稿日期:2025-05-27 出版日期:2026-02-20 发布日期:2026-01-27
  • 通讯作者: 李光鹏,苏广华 E-mail:dzw15133339850@163.com;gpengli@imu.edu.cn;guanghuasu@imu.edu.cn
  • 作者简介:杜志雯,E-mail:dzw15133339850@163.com
  • 基金资助:
    肉牛内蒙古自治区“揭榜挂帅”项目(2022JBGS0018);内蒙古自治区自然科学基金-面上项目(2024MS03001);自治区科技领军人才团队项目(2022LJRC0006);内蒙古自治区重大专项(2021ZD0009)

Efficiency Optimization of MSTN Gene Editing in Huaxi Cattle Cells and Embryos

DU Zhiwen1(), GAO Yuxin1, LIU Shuqin1, MA Haibin2, YANG Lei1, SONG Lishuang1, BAI Chunling1, WEI Zhuying1, LI Guangpeng1(), SU Guanghua1()   

  1. 1.State Key Laboratory of Reproductive Regulation and Breeding of Grassland Livestock (Jointly Built by the Ministry of Science and Technology and Inner Mongolia Autonomous Region),College of Life Sciences,Inner Mongolia University,Hohhot 010071,China
    2.Inner Mongolia Aokesi Animal Husbandry Co. ,Ltd. ,Xilingol 026321,China
  • Received:2025-05-27 Online:2026-02-20 Published:2026-01-27
  • Contact: LI Guangpeng, SU Guanghua E-mail:dzw15133339850@163.com;gpengli@imu.edu.cn;guanghuasu@imu.edu.cn

摘要:

目的 对华西牛肌肉生长抑制素(myostatin,MSTN)基因进行精准编辑,以提升其产肉性能,同时建立高效的基因编辑技术体系,为中国肉牛生物育种提供理论依据和技术支撑。 方法 利用CRISPR/Cas9系统设计6条靶向MSTN基因外显子1和2的sgRNAs,构建Cas9敲除载体,并通过电转法将其转染至华西牛胎儿成纤维细胞。采用流式荧光分选技术筛选突变单克隆细胞株,并通过Sanger测序验证编辑效果。利用Western blotting检测野生型及编辑后的华西牛胎儿成纤维细胞中MSTN蛋白表达水平,评估基因编辑效率。通过Cas-OFFinder软件预测脱靶位点,并在单克隆细胞株中进行测序验证。此外,以体外受精(IVF)合子为材料,使用不同的电穿孔参数,将Cas9核糖核蛋白(RNP)导入胚胎,检测卵裂率和囊胚率,并通过巢式PCR和测序验证胚胎编辑效果。 结果 试验成功构建6种Cas9敲除载体,转染效率稳定在12.7%~18.6%之间。流式荧光分选获得35株MSTN基因敲除单克隆细胞株,其中E2-3单载体和E2(2+3)双载体编辑效率最高,分别为57.9%和55.6%。Western blotting结果显示,编辑组MSTN蛋白表达量与野生型相比极显著降低(P<0.01);脱靶检测未发现明显脱靶效应,验证了编辑系统的高特异性。在胚胎编辑试验中,优化后的电穿孔参数(25 V、6个脉冲、2.5 ms)使囊胚率达到18.7%,显著高于其他参数处理组(P<0.05)。巢式PCR和测序分析证实,编辑后的囊胚在外显子1和2中分别发生单碱基突变和多碱基突变。 结论 试验成功建立了华西牛MSTN基因编辑技术体系,实现了高效的基因敲除和胚胎编辑,为华西牛的遗传改良提供了可靠的技术方案。优化的电穿孔参数和双载体策略提升了编辑效率,且未检测到脱靶效应,为肉牛生物育种的进一步发展奠定了重要基础。

关键词: 华西牛; MSTN基因; CRISPR/Cas9系统; 基因编辑; 胚胎电转

Abstract:

Objective This study aimed to precisely edit myostatin (MSTN) gene in Huaxi cattle to enhance meat production performance, and establish an efficient gene editing technology system to provide a theoretical basis and technical support for the biotechnological breeding of beef cattle in China. Method Six sgRNAs targeting exons 1 and 2 of MSTN gene were designed using CRISPR/Cas9 system. Cas9 knockout vector was constructed and transfected into Huaxi cattle fetal fibroblast cells via electroporation. Fluorescence-activated cell sorting (FACS) was employed to screen monoclonal cell lines with mutations, and the editing outcomes were validated by Sanger sequencing. Western blotting was used to detect MSTN protein expression in both wild-type and edited Huaxi cattle fetal fibroblast cells to evaluate the gene editing efficiency. Potential off-target sites were predicted using the Cas-OFFinder software and verified by sequencing in the monoclonal cell lines. Additionally, in vitro fertilization (IVF) zygotes were utilized to deliver Cas9 ribonucleoprotein (RNP) complexes under different electroporation parameters. Cleavage and blastocyst formation rates were assessed, and the editing efficiency in embryos was verified by nested PCR and sequencing. Result Six types of Cas9 knockout vectors were successfully constructed, with transfection efficiency consistently ranging from 12.7% to 18.6%. A total of 35 monoclonal cell lines with MSTN gene knockout were obtained through FACS. Among these, the E2-3 single-vector and E2(2+3) dual-vector strategies achieved the highest editing efficiencies, reaching 57.9% and 55.6%, respectively. Western blotting results showed that MSTN protein expression in the edited groups were extrenely significantly reduced compared with wild-type group (P<0.01). No significant off-target effects were detected, confirming the high specificity of the editing system. In the embryonic editing experiments, the optimized electroporation parameters (25 V, 6 pulses, and 2.5 ms) resulted in a blastocyst formation rate of 18.7%, which was significantly higher than that of other parameter-treated groups (P<0.05). Conclusion The experiment successfully established a gene editing technology system for MSTN gene in Huaxi cattle, achieving highly efficient gene knockout and embryonic editing, thereby providing a reliable technical solution for the genetic improvement of Huaxi cattle. The optimized electroporation parameters and dual-vector strategy enhanced editing efficiency, with no detectable off-target effects, laying an important foundation for the further development of biotechnological breeding in beef cattle.

Key words: Huaxi cattle; MSTN gene; CRISPR/Cas9 system; gene editing; embryo electroporation

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