Figure 1From: Quantitative analysis of mutation and selection pressures on base composition skews in bacterial chromosomesScatter-plot analysis of base composition skews – χG vs. χA. The χG values and χA values of 185 bacterial chromosomes are plotted against each other. The symbols for the 19 groups of bacterial chromosomes (1–19) are listed on the right. The 'Keto Excess' and the 'Purine Excess' trends in Quadrant I and II are indicated.Back to article page