Rtn4-A/B基因敲除小鼠模型的制备

Construction of Rtn4-A/Bknockout mouse model

目的通过制备Rtn4-A/B基因敲除小鼠,探索Rtn4-B基因的生物学功能。方法用细菌人工染色体(BAC)载体构建Rtn4-A/B基因打靶载体并使其线性化,通过电转化法将其转入129SvEv品系雄性小鼠胚胎干细胞(embryonic stem cell,ES细胞)。将正确同源重组的ES细胞注射入C57BL/6J小鼠囊胚腔,繁育出嵌合体小鼠后,进一步繁殖以获得杂合子小鼠。抽提小鼠尾尖组织DNA,采用PCR法鉴定小鼠的基因型。结果基因打靶后,得到14个发生双臂正确同源重组ES细胞克隆。利用阳性ES细胞克隆进行囊胚内显微注射,得到5只嵌合率大于50%的雄鼠,最终繁育得到4只Rtn4-A+/-B+/-杂合子小鼠。结论利用ES细胞基因打靶、同源重组等方法,成功获得Rtn4-A/B基因敲除杂合子小鼠。

Objective To generate Rtn4-A/B knockout mouse model and to explore the biological function of the Rtn4 B gene. Methods The targeting construct for inactivating Rtn4-A/B gene was prepared by bacterial artificial chromosome （BAC）. The vector was linearized and electroporated into 129SvEv mouse embryonic stem cells （ES cells）. Then the Rtn4 A/B knockout ES cells were microinjected into blastula of C57BL/6J mice after superovulation. F1 hybrid mice were bred to obtain mouse aggregation chimeras, and were identified by PCR amplification of tail genomic DNA. Results Fourteen clones of gene-targeted ES cells were identified after gene knockout and five male chimeras with a higher than 50 chimeric ratio were produced after microinjection into the blastula. Finally four Rtn4-A/B hybrid mice were obtained. Conclusion A Rtn4-A/B deficient mouse strain has been successfully generated by homologous recombination using genetically modified ES cells.