Dependence structure of noncoding DNA regions

Abstract

Various models of dependence structure in genetic sequences have been proposed. Most current stochastic models of noncoding DNA sequence evolution assume that neighbouring nucleotides evolve independently [1]. This considerably simplifies calculations. On the other hand the importance of neighbour dependencies in the substitution process has long been recognized, and several models of these dependencies have been proposed [1,2]. The properties they impose on the sequences (Markovity, reversibility, long range dependence, ect.) are rather contradictory [4]. The validity of these properties in noncoding sequences of bacterial genomes is tested by making use of statistical methods [3].