Sequence-based structural signatures of genome evolution

Among the multitude of methods available for the study of origin and evolut ion of various life forms on Earth, the phylogenetic approach, i.e. the del ineation of natural genetic relatedness amongst different groups of organis ms, has been of particular interest to evolutionary biologists. An approach towards analysing phylogeny is the comparison of genome sequences of extan t organisms by a variety of computational techniques. These studies rely mo stly on the similarity or dissimilarity in global character of the genome i n terms of sequence, without any consideration to its structure. In this wo rk, we report a potentially new methodology towards elucidation of molecula r phylogeny. The approach considers a structural parameter of the genome, n amely its flexibility, and uses it to compare the small subunit ribosomal r ibonucleic acid (SSU rRNA) gene from a cross-section of species. We fmd tha t the flexibility pattern of the genome is strikingly similar in organisms that are closer in evolutionary distance than the ones that are separated. This method of comparison thus might be utilised in constructing phylogenet ic trees from flexibility patterns derived from nucleotide sequence.