Fig. 7.

Codon usage bias in organelle genomes of 58 species. (A) The effective number of codons (ENc) distribution in high and low altitude species. (B) The GC content at the third position of codons (GC3s) distribution in high and low altitude species. (C) Relative synonymous codon usage (RSCU) values showing significant differences between high and low altitude species. (D) The PCA plot based on absolute codon usage frequency (absCUFs) of mitogenomes. (E) The PCA plot based on synonymous codon usage frequency (synCUFs) of mitogenomes. (F) The PCA plot based on absolute codon usage frequency (absCUFs) of plastomes. (G) The PCA plot based on synonymous codon usage frequency (synCUFs) of plastomes. ns represents no significance. P represents P-value from the Wilcoxon Signed-Rank Test