Bechhoefer John, Marshall Brandon
Department of Physics, Simon Fraser University, Burnaby, B.C., V5A 1S6, Canada.
Phys Rev Lett. 2007 Mar 2;98(9):098105. doi: 10.1103/PhysRevLett.98.098105. Epub 2007 Feb 27.
DNA replication in Xenopus laevis is extremely reliable, failing to complete before cell division no more than once in 10 000 times; yet replication origin sites are located and initiated stochastically. Using a model based on 1D theories of nucleation and growth and using concepts from extreme-value statistics, we derive the distribution of replication times given a particular initiation function. We show that the experimentally observed initiation strategy for Xenopus laevis meets the reliability constraint and is close to the one that requires the fewest resources of a cell.
非洲爪蟾的DNA复制极其可靠，在细胞分裂前未能完成复制的情况每10000次中不超过一次；然而，复制起始位点是随机定位和起始的。我们基于成核与生长的一维理论构建模型，并运用极值统计的概念，推导出给定特定起始函数时的复制时间分布。我们表明，实验观察到的非洲爪蟾的起始策略满足可靠性约束，并且接近细胞所需资源最少的策略。
