1. Gene-wise Tajima’s D values and gene lengths.
Gene-wise Tajima’s D values and gene lengths. Repetitive regions of the alignment were masked. Gene lengths have been log transformed (base 2). We added a constant value of 3 to all Tajima’s D values to make them positive and log transformed (base 2) the Tajima’s D values. We log transformed (base 2) the gene lengths. The linear regression line is plotted in blue. Genes with regression values in the lower 5% are highlighted in green. Drug resistance-associated genes in this group are labeled. While negative Tajima’s D values are normally associated with purifying selection or a recent selective sweep, we find that drug resistance genes with negative Tajima’s D values also have high nucleotide diversity. We hypothesize that patterns of diversity at these genes have been affected by relaxation of purifying selection and positive selection for drug resistance.
Tatum D. Mortimer et al. mSystems 2018; doi: /mSystems