Nucleotide sequence asymmetry and codon adaptation index (CAI) for 15 SSD pairs in the S. cerevisiae genome. The sequence asymmetry measure on the x axis was calculated as the difference between unique nucleotide sites at the ancestral copy and the derived copy. The y axis represents the difference in CAI values between the ancestral copy and the derived copy for the same SSD pair. There was no significant association between differences in rate asymmetry and CAI values for SSD pairs (Kendall's tau = 0.226; p = 0.25).
Bu et al. BMC Evolutionary Biology 2011 11:279 doi:10.1186/1471-2148-11-279