Figure 4.

A linear regression plot between mean position of the tRNA genes and mean usage of the corresponding codon. The data points represent the average of each of tRNA across the mt-genome sequences from (A) 33 species with evolutionarily stable gene order, (B) 14 species with rearranged gene orders within lower taxa, and (C) all of the 47 species selected (Table 2). Data points for the tRNA genes that specify hydrophobic and hydrophilic amino acids are colored magenta and blue, respectively; exceptionally, the data points for the tRNA-Leu (CUN) and tRNA-Thr are colored light pink and light blue, respectively. The regression lines were derived from the all data points in the plot.