摘要
利用寡核苷酸芯片检测方法分析CYP1A1单核苷酸多态性 (SNP)和GSTM1缺失与否 ,实验结果证明了寡核苷酸芯片技术可并行、准确、高效地检测基因的单核苷酸多态性和其他类型的基因多态型 ,可为疾病遗传易感性及单体型的研究提供强有力的研究工具。采用该寡核苷酸芯片 ,检测了 84份正常人的血液DNA样本 ,其中GSTM1基因缺失率达到 4 7 6 % ,接近报道数值。统计分析发现 ,CYP1A1m1 m2的 3种基因型组合TT AG、TT GG和TC GG的发生频率都为 0 ,而根据实验得到的m1和m2各自基因型数据计算 ,它们的发生频率应是11 4 %、2 6 %和 3 1% ,所以推测在所检测的样本中没有T(m1位点 )和G(m2位点 )的连锁组合 ,即m1和m2位点的组合只有 3种单体型 :T A、C A和C G ,其发生频率分别是 6 9 6 %、7 7%和 2 2 6 %。
Cytochrome P4501A1 plays a major role in the bioactivation of a number of tobacco procarcinogens.Glutathione S-transferase(GSTM1),a member of the class of GST gene family,has been shown to be polymorphic because of gene deletion resulting in a failure to express the GSTM1 gene in 50%～60% of individuals.Some CYP1A1/GSTM1 null genotype combinations seem to predispose the lung,esophagus,and oral cavity of smokers to an even higher risk for cancer or DNA damage,requiring,however,confirmation.An easy and reliable oligonuleotide microarray approach validated through direct sequencing method is developed in order to accurately detect single nucleotide polymorphisms of CYP1A1 gene and discriminate the presence and absence of GSTM1 gene.The m1(MspⅠ) and m2(Ile462Val) polymorphisms of CYP1A1 gene and GSTM1 null genotype were also determined in a random population of 84 healthy,unrelated volunteers with developed microarray-based method.Of 84 cases,47.6% were calssified as GSTM1 null,close to the published data.It's interesting that there lack three genotypes of m1-m2 locus in the population: TT-AG,TT-GG and TC-GG.However,according to the data of the genotype frequencies independently happened at both m1 and m2 site,the combination frequencies of above three genotypes are 11.4%,2.6%,and 3.1% respectively.Therefore we assume that the haplotypes of m1-m2 are only T-A,C-A and C-G,but not T-G,as it were,there is no recombination happened between m1 site and m2 site.The frequencies of three haplotypes of T-A,C-A and C-G,calculated through corresponding genotypes,are 69.6%,7.7% and 22.6% respectively.
基金
国家高技术研究发展计划资助项目 ("863计划") (No .2 0 0 2AA2Z2 0 0 2 )~~
关键词
单核苷酸多态性
CYP1A1
GSTM1
寡核苷酸芯片
单体型
single nucleotide polymorphism
CYP1A1(cytochrome P4501A1)
GSTM1(glutathione S-transferase M1)
oligonucleotide microarray
haplotypes
