Contribution of de novo point mutations to the overall mutational burden in mitochondrial DNA of adult rats
Contribution of de novo point mutations to the overall mutational burden in mitochondrial DNA of adult rats
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DOI：
10.1016/j.exger.2005.02.007
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发表时间：
2005-05-01
影响因子：
3.9
通讯作者：
Reis, RJS
中科院分区：
文献类型：
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作者：
Khaidakov, A;Chavannes-Turesky, N;Reis, RJS
本研究分析了年轻（6 个月）和老年（24 个月）雄性 F344 大鼠大脑和肌肉组织线粒体 DNA 点突变的发生率。经过高保真 PCR 扩增和变性梯度凝胶电泳 (DGGE) 测定克隆，然后对检测到的突变体进行测序，检测到 NADH 脱氢酶基因亚基 5 的编码序列突变。总共分析了大脑和肌肉样本中近千个单独的克隆。平均而言，脑组织 mtDNA 的突变频率随着年龄的增长而增加 66%（2.3 +/- 1.9 vs. 3.8 +/- 4.5 X 10(-4) 突变/bp，平均值 +/- SD），但未能达到统计学显着性（p=0.45）。肌肉组织产生的突变体要少得多，年轻和年老大鼠的平均突变频率几乎比脑组织中的相应值低 10 倍（分别为 0.3 +/- 0.4 和 0.5 +/- 0.6 X 10-4）。在年轻组中，肌肉和大脑之间的突变积累差异非常显着（卡方 = 9.7，p
This study analyzed the incidence of point mutations in mitochondrial DNA of brain and muscle tissues from young (6-month) and old (24-month) male F344 rats. Coding sequence mutations in subunit 5 of the NADH dehydrogenase gene were detected after high-fidelity PCR amplification and cloning by denaturing gradient gel electrophoresis (DGGE) assay followed by sequencing of detected mutants. In total, almost a thousand individual clones were analyzed both in brain and muscle samples. On average, mtDNA from brain tissue showed a 66% increase with age in mutation frequencies (2.3 +/- 1.9 vs. 3.8 +/- 4.5 X 10(-4) mutations/bp, mean +/- SD), which failed to reach statistical significance (p=0.45). Muscle tissues yielded substantially fewer mutants with average mutant frequencies for both young and old rats almost 10 times lower than the corresponding values in the brain tissue (0.3 +/- 0.4 and 0.5 +/- 0.6 X 10-4, respectively). The difference in mutation accumulation between muscle and brain was highly significant in both the younger group (Chi-squared = 9.7, p