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复制和转录机器会同时使用相同的DNA区域作为模板,因此复制和转录不可避免地以头对头或追尾方式相互碰撞.头对头碰撞和追尾碰撞均会导致复制机器停留,从而造成DNA损伤和基因组不稳定.就基因组完整性而言,头对头碰撞比追尾碰撞的后果更严重.本文回顾总结了复制-转录冲突的解决机制和进化影响.相对于前导链,滞后链上非同义(氨基酸改变)突变的发生率更高,并且滞后链上基因的高频诱变取决于转录本和基因大小,因此较快的适应性突变发生在滞后链上.头对头基因的高度转录增加了复制过程中响应压力的突变率.无论是头对头还是追尾模式,复制-转录冲突都可能是适应性进化的驱动力.“,”The replication and transcription machinery concurrently use the same DNA region as template so that the machineries inevitably collide with each other in the manner of either head-on or co-directional.Both head-on and co-directional collisions lead to a pause of replication fork,thereby DNA damage and genome instability.The head-on collision is more detrimental than the co-directional in respect of genome integrity.Here we review the resolving mechanisms and evolutionary impact of the replication-transcription collisions.The rate of nonsynonymous (amino-acid-changing) mutations on the lagging is higher relative to that on the leading strand and the high frequency mutagenesis in genes on the lagging strand is dependent on transcriptions and gene sizes,thus faster adaptive mutations occur on the lagging strand.Highly transcribing of head-on oriented genes increases the mutation rates responding to stress during active replication.It is likely that the replication-transcription collision no matter in the head-on or co-directional mode is a driving force for adaptive evolution.