(C − G)/(C + G) counts in sliding windows of 50 kb with 5-kb displacement (solid line) and 10 kb with 1-kb displacement (dashed line) in complete genomes of E. coli, B. subtilis, H. influenzae, H. pylori, M. genitalium, M. pneumoniae, Synechocystis PCC6803, M. jannaschii, M. thermoautotrophicum, and A. fulgidus. The value of (C − G)/(C + G) is assigned to the position at the middle of the window. The arrows indicate locations of the origin of replication (when known).