plosone-phylo
pone.0033547.g004.png
The proportion of overrepresented identical codon pairs can be variable even at genus level.
Two phylogenetic trees of Mycobacterium and Rickettsia species were constructed separately, based on molecular data. For each species, its genome size, the total numbers of overused identical codon pairs and overused non-identical codon pairs in the secondary-favored group were shown. A: Genus Mycobacterium represents an example with overall high level of codon pairing pattern. The most reduced genome, found in M. leprae, has the lowest level of overrepresented codon pairs in the genus. B: Genus Rickettsia represents an example that has an overall low level of codon pairing. The early-diverging lineage of R. bellii has the highest level of overrepresented codon pairs, while other species in the genus, with reduced genomes to variable extents, also possess variant levels of overrepresented codon pairs.
pone.0033547.g004.png
The proportion of overrepresented identical codon pairs can be variable even at genus level.
Two phylogenetic trees of Mycobacterium and Rickettsia species were constructed separately, based on molecular data. For each species, its genome size, the total numbers of overused identical codon pairs and overused non-identical codon pairs in the secondary-favored group were shown. A: Genus Mycobacterium represents an example with overall high level of codon pairing pattern. The most reduced genome, found in M. leprae, has the lowest level of overrepresented codon pairs in the genus. B: Genus Rickettsia represents an example that has an overall low level of codon pairing. The early-diverging lineage of R. bellii has the highest level of overrepresented codon pairs, while other species in the genus, with reduced genomes to variable extents, also possess variant levels of overrepresented codon pairs.