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目的 研究酵母TEL1基因在毛细血管扩张 运动共济失调症 (ataxia telangiectasia ,A T)A T细胞中的异位表达对辐射诱发A T细胞染色体畸变的影响。方法 稳定转染酵母TEL1全基因序列、酵母TEL1基因片断和pRep5空载体的AT TEL1、AT deltaTEL1、AT rep、GM rep细胞分别在含10 0 μg ml潮霉素的DMEM培养液中培养 ;A T细胞和正常对照的GM6 39细胞分别在DMEM培养液中常规培养。应用6 0 Co源对处于指数生长期的上述细胞进行γ射线照射 ,吸收剂量分别为 0 ,1和 3Gy。应用常规染色体技术制片 ,并进行染色体畸变分析。结果 传代培养的AT TEL1、AT del taTEL1、AT rep、A T、GM6 39、GM rep细胞的染色体数目均是非整倍体 ;无论是A T细胞染色体自发畸变率还是辐射诱发的染色体畸变率均明显高于正常对照的GM6 39纤维母细胞 ;A T细胞的高染色体畸变率主要是由于染色体双着丝粒体和染色体断片所至的染色体型畸变 ;稳定转染酵母TEL1全基因序列的AT TEL1细胞染色体自发畸变率与A T细胞之间差异无显著性 (P >0 0 5 ) ;辐射诱发AT TEL1细胞的染色体畸变率明显低于A T细胞 (P <0 0 1) ;辐射诱发AT deltaTEL1、AT rep细胞染色体畸变率则高于A T细胞。结论 酵母TEL1基因在A T细胞中的异位表达 ,能够明显降低电离辐射诱发?
Objective To investigate the effect of ectopic expression of yeast TEL1 gene on the chromosome aberration of A T cells induced by ataxia telangiectasia (A T) A T cells. METHODS: AT TEL1, AT deltaTEL1, AT rep and GM rep cells stably transfected with yeast TEL1 gene, TEL1 gene fragment of yeast and pRep5 empty vector were respectively cultured in DMEM containing 100 μg of hygromycin. AT cells And normal control GM6 39 cells were cultured in DMEM culture medium. The 60Co source was used to gamma-irradiate the above cells in exponential growth phase with absorbed doses of 0, 1, and 3 Gy, respectively. Produced using conventional chromosomal techniques and analyzed for chromosomal aberrations. Results The chromosome numbers of AT TEL1, AT del taTEL1, AT rep, AT, GM6 39 and GM rep cells in subculture were all aneuploid. Both the spontaneous aberration rate of AT cell chromosome and the chromosome aberration rate induced by radiation were significantly higher Normal control GM639 fibroblasts; AT cell high chromosome aberration rate is mainly due to chromosomal duplication and chromosomal chromosome fragments of chromosomal aberrations; stably transfected yeast TEL1 whole genome AT TEL1 cell chromosome chromosomal aberrations (P> 0.05). The chromosome aberration rate of AT TEL1 cells induced by radiation was significantly lower than that of AT cells (P <0.01). The chromosome aberrations of AT deltaTEL1 and AT rep cells induced by radiation Rate is higher than AT cells. Conclusion Ectopic expression of yeast TEL1 gene in A T cells can significantly reduce the ionizing radiation induced?