Fig. 3.

Distribution of GC in the coding region of corn, Arabidopsis and rice. The GC content in the coding region of corn cDNAs is bimodal and the high GC content can be explained by the abundance of GC in the third position of the codons. A similar result is observed for rice but Arabidopsis is unimodal. GC indicates the ratio of GC versus AT. GC12 represent the ratio of GC versus AT in the 1st and 2nd positions of the codons. GC3 represents the ratio of GC versus AT in the 3rd position of the codons