Figure 3

Heterogeneity of positional background nucleotide compositions in E. coli (2,766 genes in M9 medium), S. cerevisiae (5,142 genes), D. melanogaster (1,651 genes), C. elegans (12,184 genes), and A. thaliana (1,332 genes). Heterogeneities of positional GC contents are represented by absolute differences between overall GC content and its positional contents: GC-GC1 for the first position (panel A), GC-GC2 for the second position (panel B), and GC-GC3 for the third position (panel C), respectively. Likewise, heterogeneities of positional purine content are absolute differences between overall purine (AG) content and its positional contents: AG-AG1 for the first position (panel D), AG-AG2 for the second position (panel E), and AG-AG3 for the third position (panel F), respectively.