Article Figures & Data
Figures
- Fig. 1.
Phylogeny of S. pneumoniae and related species, based on 1,380 bases of the rpoB sequence. The tree is the single most parsimonious phylogeny, created using the exhaustive search algorithm of PAUP, version 3.1.1 (D. L. Swofford, PAUP. Phylogenetic analysis using parsimony, version 4, Sinauer Associates, Sunderland, Mass., 1998). Branching confidence values are based on 1,000 bootstrap replicates. DNA sequence divergences between each donor strain and the S. pneumoniae recipients are shown on the right. The above phylogeny agrees with results obtained by analysis of 16S rRNA and sodA genes, with the notable exception thatS. anginosus clusters here with S. constellatus, whereas earlier results show it to be more closely related to S. intermedius. The high bootstrap confidence value of this grouping suggests a possible recombination event at rpoB.
- Fig. 2.
Log10 (sexual isolation) versus sequence divergence between each donor and recipient. Sexual isolation values were calculated by dividing the frequency of homogamic recombination (using the donor's own Rifr DNA) by the frequency of heterogamic recombination (using a divergent donor's DNA). The sexual isolation shown for the wild-type recipients is the average value for the two wild-type recipient strains, Pn16 and R6. The sexual isolation in the absence of mismatch repair is the result of transformation of the R6Δ3 hexA mutant. φwt and φHex− are the slopes of the regression of log10 (sexual isolation) on sequence divergence for the wild type and the Hex− mutant, respectively.
Tables
- Table 1.
List of strains
Species Strain Source Relevant genotype S. pneumoniae Pn16 C. G. Dowson wta S. pneumoniae R6 C. G. Dowson wt S. pneumoniae R6Δ3 C. G. Dowson ΔhexA S. pneumoniae 96129 C. G. Dowson wt S. mitis NCTC 10712 NCTC Type strain S. oralis NCTC 11427 NCTC Type strain S. sanguis NCTC 7863 NCTC Type strain S. parasanguis ATCC 15912 ATCC Type strain S. crista NCTC 12479 NCTC Type strain S. anginosus ATCC 9895 ATCC Type strain S. constellatus NCTC 11063 NCTC Type strain S. intermedius ATCC 27335 ATCC Type strain S. adjacens ATCC 49175 ATCC Type strain ↵a wt, wild type.
- Table 2.
Sequence identity matrix for Streptococcusstrains based on a partial rpoB sequence
Species or strain % DNA sequence identity or divergencea compared to: S. pneumoniae strain Pn16 S. pneumoniae strain 91629 S. mitis S. oralis S. parasanguis S. crista S. sanguis S. anginosus S. constellatus S. intermedius S. adjacens S. pneumoniae strain Pn16 99.3 94.9 93.3 86.4 86.3 85.0 83.9 83.4 81.8 72.6 S. pneumoniae strain 91629 0.7 94.6 93.3 86.1 86.1 84.7 83.6 83.0 81.7 72.4 S. mitis 5.1 5.4 92.3 85.2 86.1 84.7 82.7 82.2 80.8 71.8 S. oralis 6.7 6.7 7.7 85.2 85.6 85.3 83.3 81.9 81.5 72.4 S. parasanguis 13.6 13.9 14.8 14.8 85.6 84.4 82.2 83.4 81.9 70.4 S. crista 13.7 13.9 13.9 14.4 14.4 92.2 83.6 83.5 83.7 71.4 S. sanguis 15.0 15.3 15.4 14.7 15.6 7.8 84.9 85.5 84.2 72.2 S. anginosus 16.1 16.4 17.3 16.7 17.8 16.4 15.1 92.9 88.4 70.3 S. constellatus 16.6 17.0 17.8 18.1 16.6 16.5 14.6 7.1 88.6 71.9 S. intermedius 18.2 18.3 19.2 18.5 18.1 16.3 15.8 11.7 11.4 70.5 S. adjacens 27.4 27.6 28.2 27.6 29.6 28.6 27.8 29.7 28.1 29.5 ↵a Percentages above and to the right of the diagonal formed by the blank entries represent DNA sequence identity; those below and to the left represent sequence divergence.
- Table 3.
Transformation frequencies, log10 transformed
Source of donor DNA Transformation frequencya for recipient strain: Pn16 R6 R6Δ3 S. pneumoniaePn16 −2.59 ± 0.32 −3.26 ± 0.24 −2.70 ± 0.34 S. pneumoniaeR6 −2.79 ± 0.50 −3.33 ± 0.27 −2.81 ± 0.24 S. pneumoniae91629 −2.64 ± 0.42 −3.65 ± 0.22 −2.59 ± 0.22 S. mitis −3.61 ± 0.23 −4.59 ± 0.22 −3.24 ± 0.11 S. oralis −3.37 ± 0.28 −4.15 ± 0.07 −3.30 ± 0.28 S. parasanguis −4.73 ± 0.50 −5.97 ± 0.21 −3.92 ± 0.31 S. crista −4.72 ± 0.62 −5.89 ± 0.14 −4.17 ± 0.50 S. sanguis −5.63 ± 0.54 −6.80 ± 0.26 −4.71 ± 0.52 S. anginosus −5.04 ± 0.22 −6.00 ± 0.20 −4.14 ± 0.20 S. constellatus −6.17 ± 0.29 −6.74 ± 0.35 −4.91 ± 0.34 S. intermedius −5.49 ± 0.35 −6.26 ± 0.44 −4.50 ± 0.12 S. adjacens No transformants No transformants −5.62 ± 0.12 ↵a Log10 (frequency of transformation) ± standard error, based on four or more experimental trials.
- Table 4.
Sexual isolation (log10 transformed) between the S. pneumoniae recipients and the donor strains
Source of donor DNA Log10 (sexual isolation) ± SEb for recipient strain: Pn16 R6 R6Δ3 S. pneumoniaePn16 0a −0.08 ± 0.23 −0.11 ± 0.16 S. pneumoniaeR6 0.21 ± 0.22 0 0 S. pneumoniae91629 0.06 ± 0.10 0.32 ± 0.11 −0.04 ± 0.28 S. mitis 1.00 ± 0.19 0.95 ± 0.17 0.48 ± 0.26 S. oralis 1.16 ± 0.28 0.73 ± 0.23 0.88 ± 0.13 S. parasanguis 2.13 ± 0.23 2.64 ± 0.44 1.11 ± 0.23 S. crista 2.07 ± 0.27 2.56 ± 0.36 1.80 ± 0.08 S. sanguis 3.04 ± 0.42 3.47 ± 0.24 1.91 ± 0.28 S. anginosus 2.45 ± 0.16 2.67 ± 0.34 1.27 ± 0.36 S. constellatus 3.58 ± 0.22 3.41 ± 0.27 2.10 ± 0.42 S. intermedius 3.06 ± 0.33 2.78 ± 0.29 2.01 ± 0.40 S. adjacens No transformants No transformants 3.39 ± 0.15 ↵a The sexual isolation between a recipient and its own Rifr mutant is defined to be zero.
↵b Sexual isolation values and standard errors are based on at least four experimental trials. Note that the values are obtained by dividing the homogamic transformation frequency by the heterogamic frequency for each trial for each donor-recipient pair and then averaged. Since not all donor-recipient comparisons were carried out in the same experimental trial, sexual isolation values will not in general be equal to the results of simply dividing the average transformation frequencies from Table 3.
