Saturday, March 28, 2009

Human mutation rate associated with DNA replication timing, by Stamatoyannopoulos

Human mutation rate associated with DNA replication timing, Nature Genetics, 41: 393-395, 2009
Eukaryotic DNA replication is highly stratified, with different genomic regions shown to replicate at characteristic times during S phase. Here we observe that mutation rate, as reflected in recent evolutionary divergence and human nucleotide diversity, is markedly increased in later-replicating regions of the human genome. All classes of substitutions are affected, suggesting a generalized mechanism involving replication time-dependent DNA damage. This correlation between mutation rate and regionally stratified replication timing may have substantial evolutionary implications.

This paper supports the maximum genetic diversity (MGD) hypothesis. Late replicating DNAs are in heterochromatin state and are enriched with non-coding sequences. They are under less functional constraint than euchromatins and are expected to show higher maximum genetic diversity. So, in fact, mutation rate has little to do with the result reported in this paper.

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