Fig. 1From: The evolutionary dynamics of tRNA-gene copy number and codon-use in E. coli.tRNA and SGE genes frequently have multiple copies in E. coli. a. The phylogenetic relationship of the E. coli strains used in this study, as established by Touchon et al. 2009. b. The bars show the numbers of duplicate copies of tRNA genes and SGE genes in each E. coli strainBack to article page