Transcription-associated mutational asymmetry in mammalian evolution
Transcription-associated mutational asymmetry in mammalian evolution
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DOI：
10.1038/ng1103
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发表时间：
2003-04-01
期刊：
影响因子：
30.8
通讯作者：
Green, ED
中科院分区：
文献类型：
--
作者：
Green, P;Ewing, B;Green, ED
Although mutation is commonly thought of as a random process, evolutionary studies show that different types of nucleoticle substitution occur with widely varying rates that presumably reflect biases intrinsic to mutation and repair mechanisms(1-4). A strand asymmetry(5,6), the occurrence of particular substitution types at higher rates than their complementary types, that is associated with DNA replication has been found in bacteria(7) and mitochondria(8). A strand asymmetry that is associated with transcription and attributable to higher rates of cytosine deamination on the coding strand has been observed in enterobacteria(9-11). Here, we describe a qualitatively different transcription-associated strand asymmetry in mammals, which may be a byproduct of transcription-coupled repair(12) in germline cells. This mutational asymmetry has acted over long periods of time to produce a compositional asymmetry, an excess of G+T over A+C on the coding strand, in most genes. The mutational and compositional asymmetries can be used to detect the orientations and approximate extents of transcribed regions.
