Figure 1.
Correspondence analysis of relative synonymous usage for genes of (A) Escherichia coli, (B) Bacillus subtilis, (C) Thermotoga maritima, and (D) Methanobacterium thermoautotrophicum. Triangles correspond to genes proposed as being acquired by horizontal gene transfer and included in regions with a low G+C content. Circles correspond to genes proposed as being acquired by HGT and included in regions with a high G+C content. Dots correspond to genes that are not proposed as being acquired by HGT. For the sake of clarity, genes proposed as being acquired by HGT that do not belong to a region that is high or low in the G+C content are not shown.
