Genome Complexity Browser: estimation and visualization of prokaryote genome variability

Motivation Comparative genomics studies may be used to acquire new knowledge about chromosomal architecture - the rules to combine a set of genes in a genome of a living organism. Hundreds of thousands of prokaryote genomes were sequenced and assembled. Still, there is a lack of computational tools able to compare hundreds of genomes simultaneously, i.e. to find hotspots of genome rearrangements and horizontal gene transfer or to analyze which part of an operon is conservative and which is variable. Results We developed Genomic Complexity Browser (GCB), a tool that allows to visualize gene contexts in a graph form and evaluate genome variability of different parts of a prokaryotic chromosome. We introduce a measure called complexity, which is an indirect measure of genome variability. Intraspecies and interspecies comparisons reveal that regions with high complexity tend to be located in a similar context in different strains and species. While many of such hot spots are associated with prophages and pathogenicity islands, some of them lack these determinants and mechanisms that govern their dynamics are to be elucidated. Availability GCB is freely available as a web server at and as a stand-alone application at Contact paraslonic{at}gmail.com