Fig. 4From: Genomic analysis of codon usage shows influence of mutation pressure, natural selection, and host features on Marburg virus evolutionNeutrality plot analysis of the GC1,2S and that of the third codon position (GC3S). GC1,2S stands for the average value of GC content in the first and second position of the codons (GC1S and GC2S). While GC3S refers to the GC content in the third position. The solid red line is the linear regression of GC1,2S against GC3S Back to article page