利用TALENs技术制备myostatin基因敲除策勒黑羊的研究

策勒黑羊是一个优良的多胎地方绵羊品种,其突出特征为全年发情和繁殖率高。然而，策勒黑羊的产肉性能较低，有待进一步改良。肌肉生长抑制素(myostatin，MSTN)是骨骼肌生长发育的负调控因子。MSTN基因敲除小鼠的肌肉重量大约增加了2倍，这为通过敲除绵羊MSTN基因，以提高绵羊产肉性能提供了很好的动物模型。因此，本项目以高繁殖力策勒黑羊MSTN基因为靶基因，采用转录激活子样效应因子核酸酶（TALENs）基因敲除技术，从各方面优化TALENs基因敲除条件的基础上，结合本实验室成熟的转基因克隆绵羊制作平台，构建MSTN基因敲除的策勒黑羊，并对该基因敲除策勒黑羊的产肉性能进行分析。本研究目标的实现，不仅将建立一条有效提高绵羊产肉性能的新途径，为培育肉用多胎绵羊新品种奠定基础，而且可探索一套高效的大动物基因敲除技术路线，为构建各种具有重要经济性状的基因定点突变绵羊奠定基础。

Cele black sheep is a fecundity local breed, being prominent characteristic of high fecundity and annual estrus. However, meat performance of Cele black sheep is low and need to be further enhanced. Myostatin (MSTN) functions as a negative regulator of skeletal muscle development and growth. Mutation in the MSTN gene in mice results in an increase of meat performance by 200%, which provides a good animal model for enhancing meat performance of sheep by knockouting sheep MSTN. Therefore, this project will target MSTN gene of Cele black sheep and construct myostatin knockout Cele black sheep by optimal transcription activator-like effector nucleases (TALENs) and somatic cell nuclear transfer technology. Meat performance and quality will be analyzed for myostatin knockout Cele black sheep. Our study will not only establish a new way for enhancing meat performance of sheep, which will lay foundation for breeding new strain of mutton and prolific sheep, but also establish a new technical route for gene knockout in the large mammals, which will lay foundation for constructing some important economic character of gene mutation sheep.