Figure 1

Z-scores of the frequency of poly(A) and poly(T) HTs with 5 to 9 bases in the coding genes of 99 selected prokaryotic genomes. Each bar represents one bacterial genome; genomes are sorted by increasing G+C content in the coding genes (a list of genomes in the order displayed here is available as Additional File 5). Bacterial genomes are represented by white bars while black bars represent archaeal genomes. Horizontal lines indicate ± 1.96 standard deviations (the cut-off for significant [P < 0.05] over or under-representation). Bars with Z-scores > 0 indicate an overrepresentation, while Z-scores < 0 indicate underrepresentation of the HTs in the sequences analyzed. Vertical lines at the bottom of each graph show the approximate GC content of the organisms.