Figure 1.

The distribution of GC contents in rice and Arabidopsis genes. The GC content of the 14,005 rice genes (shown in red) has a bimodal distribution, while the GC distribution of the 25,625 Arabidopsis genes (shown in blue) is unimodal. The vertical line (at 60% G+C) shows the point where we separated the rice genes into two classes: high GC and low GC rice genes.