Fig. 3
From: Nucleotide composition of the Zika virus RNA genome and its codon usage
Codon ENC analysis of ZIKV RNA. The effective number of codons (ENC-values, Y-axis) of the single ZIKV ORF (3420 codons) was plotted against the GC-content at the 3rd synonymous codon positions (GC3-values, X-axis). The continuous grey line represents theoretical ENC values for random codon usage as a function of GC3. Deviation from this line in the direction of lower ENC-values points to selection of a preferred set of codons. We analyzed codon usage for several ZIKV isolates and the two host species (homo sapiens and Aedes aegypti). The latter two values are based on the following numbers of codons (with the number of genes in parentheses, see [25]): human: 40,662,582 (93,487) and Aedes aegypti: 257,935 (585)