TABLE 2.
Genetic variations in the three sequenced loci
| Gene | No. of sequences | Fragment size (bp) | No. of alleles | No. of polymorphic sites (%) | No. of synonymous base substitutionsa | Range of nucleotide differences between alleles (% range) | Mean % of G+C content | dN/dSb |
|---|---|---|---|---|---|---|---|---|
| tcdC | 57 | 600 | 10 | 30 (5.0) | 10 | 1-20 (0.2-3.0) | 29.4 | 0.1875 |
| tcdR | 23 | 385 | 6 | 23 (6.0) | 4 | 2-14 (0.5-3.6) | 20.3 | 0.1697 |
| cdtR | 21 | 720 | 5 | 36 (5.0) | 17 | 3-22 (0.4-3.0) | 22.9 | 0.2709 |
a
Synonymous base substitutions are nucleotide changes which did not result in amino acid changes.
b
dN/dS, average frequencies of synonymous substitutions per potential synonymous site (dS) over nonsynonymous substitutions per potential nonsynonymous site (dN) were calculated with START software to test the degree of selection on a locus.