乙基亚硝基脲诱导转基因小鼠基因突变的研究

Study on Ethylnitrosourea-Induced Gene Mutations in Transgenic Mice

[目的 ]用乙基亚硝基脲 (ENU)进一步验证携带xylE基因的转基因小鼠在体内基因突变研究中的应用价值。 [方法 ]用ENU对转基因小鼠进行诱变处理 (i.p .5 0mg/(kg·d) ,连续 5d)后 ,从脾脏组织DNA中回收带有靶基因xylE的pESnx质粒 ,通过电穿孔法转化大肠杆菌 ,筛选突变体 ,检测突变率 ,并对突变靶基因进行测序分析以确定突变类型。 [结果 ] (1)ENU诱发转基因小鼠脾脏组织xylE基因的突变率为 1 2 48× 10 -4 ,显著高于自发突变率 ;(2 )ENU诱发基因突变的类型包括碱基的颠换、转换以及由于碱基的缺失或插入所引起的移码突变。 [结论 ]该转基因小鼠是检测体内基因突变的一种有效的动物模型。

Objective] Ethylnitrosourea (ENU) was used as mutagen to further verify the practical value of transgenic mouse model containing xylE gene in detecting gene mutations in vivo . [Methods] ENU was administered to transgenic mice by i.p.injection (5 daily injections at a dose of 50mg/kg). Target gene xylE carried on pESnx plasmid was recovered from DNA of spleens and transferred into Escherichia coli by electroporation. Mutants were detected and the types of mutation were identified by sequence analysis. [Results] (1)ENU induced mutant frequency in spleen is 1.248×10 -4 with significant difference from the spontaneous one; (2)ENU induced predominantly transversions,while some transitions and frameshift mutations caused by base delection or insertion were also observed. [Conclusion] The results demonstrated that this transgenic mouse model can be applied feasibly and effectively to detect gene mutations in vivo .