Abstract
Comparative genomics based on synteny relies on sequence homology of genes within a selected set of genomes, but the increase in evolutionary distance reduces the estimation of orthology. In this study, we use homolog groups instead of orthologs. We also estimate correlations of gene locations between genomes. We obtained 16 cyanobacterial datasets from the Gclust server (http://gclust.c.u-tokyo.ac.jp) developed by N. Sato. As a result, significant correlation of gene location was found within a window of fifty genes. Based on such correlations, the cyanobacteria are classified into marine group, fresh water group and Anabaena family. In addition, the results of hierarchical clustering using these data are consistent basically with molecular phylogeny. These results show that the application of our method is not restricted to cyanobacteria.
