Prokaryote distribution of IS4 subgroups and emerging families. A. Three dimensional histogram of the number of distinct elements belonging to IS4 subgroups and emerging families, as they can be found among major prokaryotic clades. Each IS subgroup/family is represented by a different color. Iso-forms (which we defined as elements that show a divergence of less than 2% in the amino acid sequence of their potential proteins) were not included. The line 'Others' stands for Aquificae, Chlamydiae/Verrucomicrobia, Chloroflexi, Chrysiogenetes, Dictyoglomi, Fusobacteria, Nitrospirae, Spirochetes, Thermodesulfobacteria and Thermotogae. For interpretation, see main text. B. To avoid misinterpretation triggered by unequal sequencing efforts between different microbial groups, the number of genome projects, as of 1st April 2007, is depicted by histogram.
De Palmenaer et al. BMC Evolutionary Biology 2008 8:18 doi:10.1186/1471-2148-8-18