摘要
目的为研究马兜铃酸(Aristolochic Acid,AA)的致突变机制提供实验依据。方法挑取对照组和100μg/ml AA处理小鼠淋巴瘤L5178Y tk+/--3.7.2-细胞得到的胸苷激酶(Thymidine kinase,tk)基因突变克隆,提取DNA,用基于PCR的杂合性缺失(Loss of heterozygosity,LOH)的分析方法检测含功能性tk基因(tk+)的11号染色体(11 b)上的断裂情况。结果100μg/ml AA诱导的突变体中tk+基因缺失率为99.01%,其中所有的小克隆(Small Clone,SC)都失去了tk+基因,而大克隆(Large Clone,LC)的LOH发生率为96.6%。进一步分析11号染色体上的分布的3个微卫星位点(D11Mit42,D11Mit29,D11Mit74)的LOH状况如下:6 cm长度的DNA断裂频率为76%,38 cm长度DNA即超过染色体一半长度的DNA断裂频率为34%,整条染色体的缺失率为16%。另外LC在3个微卫星位点(D11Mit42,D11Mit29,D11Mit74)上的LOH发生率分别是:88%,60%和24%;SC的分别为:64%,8%和8%。结论AA是一个强染色体断裂剂。在11b染色体上LC的染色体断裂情况比LC严重。
Objective To elucidate the mutngenic effects of aristolochic acid（AA） on the tk ^＋/- locus of 1-5178Y tk ^＋/- -3.7.2- mouse lymphoma cells. Methods DNA isolated from tit mutants in the control group and 100 μg/ml AA treatment group were analyzed by a PCR-based method to detect loss of beterozygosity （LOH） and identify the clastogenic events on the tk^＋ -bearing chromosome 11 b. Results The total percentage of LOH in mutants induced by 100 μg/ml AA was 99.01% ; All the small colony mutants had lost the tklb allele, while the frequency of LOH in large colony mutants was 96.6% . The percentage of LOH on the other three microsatellite loci （D11Mit42, D11Mit29, D11Mit74） distributed along chromosome lib was further analyzed. 76% of mutants showed damage that reach to 6 centimorgan（cm） in the chromosome length; 34% of mutants had a damage of DNA reached 38 cm which was larger than half of chromosome 11; 16% of mutants had lost the entire chromosome. The percentage of LOH at the three loci in large colony mutants were 88%, 60%, 24% respectively, while in small colony mutants those were 64%, 8%, 8%. Conclusion AA is a strong clastogen. The damage of DNA on chromosome llb induced by AA in large colonies seemed more extensive than that in small colonies.
出处
《毒理学杂志》
CAS
CSCD
北大核心
2007年第2期81-83,共3页
Journal of Toxicology
基金
国家自然科学基金项目(30472110)
