Frequencies of mutations in the nadR gene.

<p>(a) population 18. (b) population 19. (c) population 20. Δ, deletion; +, insertion. Numbers following gene names indicate the affected codon within the gene. FS, SS1, etc. in parentheses indicate which clones (if any) have the mutation. The <i>nadR</i>-290 mutation is identical in populations 19 and 20; <i>nadR</i>-290 in population 18 is a different mutation in the same codon. The <i>nadR</i>-294 mutation is identical in populations 18 and 20; <i>nadR</i>-294 in population 19 is a different mutation in the same codon. Note that the highest frequency on the <i>y</i>-axis is 0.35.