Jørgensen Frank Grønlund, Schierup Mikkel H
Department of Genetics and Ecology, Aarhus University, Denmark.
Trends Genet. 2009 Dec;25(12):523-7. doi: 10.1016/j.tig.2009.10.002. Epub 2009 Oct 23.
Gene density and orientation of genes in eukaryotes seem to be correlated with the replication origin and the mutation rate is greater in late replicating regions; however, the reason for these patterns is unknown. Here, we investigate predicted replication origins in the human genome and find that levels of polymorphism as well as divergence from the chimpanzee genome are greater in genes transcribed on the lagging strand than those on the leading strand. This might be caused by interference between RNA and DNA polymerases, and avoidance of collisions between these enzymes might be an evolutionary force shaping gene orientation and density surrounding replication start sites. Physical constraints might have a larger influence on genome evolution than previously thought.
真核生物中基因的密度和方向似乎与复制起点相关，且在复制后期的区域突变率更高；然而，这些模式的原因尚不清楚。在这里，我们研究了人类基因组中预测的复制起点，发现与滞后链上转录的基因相比，前导链上转录的基因的多态性水平以及与黑猩猩基因组的差异更大。这可能是由RNA和DNA聚合酶之间的干扰引起的，避免这些酶之间的碰撞可能是塑造复制起始位点周围基因方向和密度的一种进化力量。物理限制对基因组进化的影响可能比之前认为的更大。
