Algebraic Distribution of Segmental Duplication Lengths in Whole-Genome Sequence Self-Alignments

Distributions of duplicated sequences from genome self-alignment are characterized, including forward and backward alignments in bacteria and eukaryotes. A Markovian process without auto-correlation should generate an exponential distribution expected from local effects of point mutation and selection on localised function; however, the observed distributions show substantial deviation from exponential form – they are roughly algebraic instead – suggesting a novel kind of long-distance correlation that must be non-local in origin.

本研究对基因组自比对（genome self-alignment）所产生的重复序列分布特征进行了系统表征，涵盖细菌与真核生物的正向及反向自比对结果。无自相关（auto-correlation）的马尔可夫过程（Markovian process）本应生成由点突变（point mutation）的局部效应以及针对局域功能的选择作用所预期的指数分布（exponential distribution）；但实际观测到的序列分布与指数形式存在显著偏离，反而近似呈现代数分布特征，这表明存在一类起源于非局域机制的新型长程关联（long-distance correlation）。