摘要
目的 调查 2 5例老年痴呆患者血细胞线粒体中细胞色素C氧化酶亚基Ⅱ基因的突变情况 ,探讨线粒体DNA突变与阿尔茨海默病 (AD)性老年痴呆发生发展的关系。 方法 采用微量法提取血细胞总DNA直接作为PCR模板 ,进行巢式PCR扩增 ,最后采用DNA序列分析鉴定突变。 结果 在正常老人组 ,只扩增了 2 80bp的线粒体细胞色素C氧化酶亚基Ⅱ基因 (COX2 )扩增片段 ,而在老年痴呆患者中出现了 4 6 4bp和 2 80bp的多态性扩增片段 ,并且发现了 1个 32 0bp的新的线粒体DNA缺失片段 ,1位AD患者的COX2基因存在一种新的缺失后重组现象 ,COX2基因的 1条单链在np75 0 3处断裂 ,另 1条单链在np7785处断裂 ,这两个断裂的游离片段通过插入 1个额外的胞嘧啶核苷酸重新连接起来。 结论 老年痴呆患者中的COX2基因存在片段扩增多态性。
Objective To investigate the deletiones of mitochondrial cytochrome C oxidase subunit Ⅱ gene in blood cells from 25 patients with Alzheimer disease(AD). We tried to explore the relationship between the mutations of mitochondrial cytochrome oxidase subunit Ⅱ gene and the development of AD. Methods Trace DNA of blood cells was isolated and used as the DNA template for PCR directly. The first PCR products were used as template for nested-PCR. Molecular cloning of nested-PCR products and DNA sequencing were used to identify the mutations of mitochondrial DNA. Results Two different amplified polymorphic DNA fragments,464bp and 280bp, were amplified in blood cells of eight patients with AD. Besides, and additional 320bp fragment was also found in a patient with AD by cloning method. The 320bp amplified fragment was proved to be a new type of deletion of COX2 gene.A new deletion of COX2 gene was found in a patient with AD, and one single chain of COX2 gene was broken at the spot of np7503, while another complement chain was broken at the spot of np7785. The two broken fragments were re-jointed to form an enclosed structure through inserting an additional dC base between them.Conclusion The results show that there appear amplified polymorphic DNA fragments in the patients with AD
出处
《解剖学报》
CAS
CSCD
北大核心
2005年第1期57-61,共5页
Acta Anatomica Sinica
基金
广东省专项课题 (A3 0 2 0 2 0 40 1)
广东省科技攻关项目 (2KM0 5 5 0 3S)
广州市科技攻关项目 (ZD0 2 2K2 0 170 1)
