Figure 1From: Mutational pressure dictates synonymous codon usage in freshwater unicellular α - cyanobacterial descendant Paulinella chromatophora and β - cyanobacterium Synechococcus elongatus PCC6301 Diagrammatic representation of three clades in the Prochlorococcus / Synechococcus clade. SCU variation in marine Synechococcus is shaped by selection but in marine Prochlorococcus, mutational pressure shapes the SCU pattern. SCU: Synonymous codon usage.Back to article page