Search of regions with periodicity using random position weight matrices in the genome of c. Elegans

Abstract

A mathematical method was developed in this study to determine tandem repeats in a DNA sequence. A multiple alignment of periods was calculated by direct optimization of the position-weight matrix (PWM) without using pairwise alignments or searching for similarity between periods. Random PWMs were used to develop a new mathematical algorithm for periodicity search. The developed algorithm was applied to analyze the DNA sequences of C. elegans genome. 25360 regions having a periodicity with length of 2 to 50 bases were found. On the average, a periodicity of ~4000 nucleotides was found to be associated with each region. A significant portion of the revealed regions have periods consisting of 10 and 11 nucleotides, multiple to 10 nucleotides and periods in the vicinity of 35 nucleotides. Only ~30% of the periods found were discovered early. This study discussed the origin of periodicity with insertions and deletions.