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17720781[PMID] - PMC - NCBI

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1.
FIG. 1.

FIG. 1. From: Genome-Wide Transcriptional Changes in Streptococcus gordonii in Response to Competence Signaling Peptide .

Transformability of strain CH1 cells in response to CSP. At time0 100 ng/ml CSP was added to aliquots of log phase cells (OD600 = 0.4). Replicative plasmid DNA carrying an erythromycin resistance determinant was added to individual aliquots of cells at various time points (abscissa). Two units of DNase were added 9 min after the addition of DNA. All procedures were carried out at 36°C. Cell mixtures were incubated for 1 h and plated on Todd-Hewitt agar containing 10 μg/ml erythromycin. Transformation frequencies for CSP-induced cells at each time point, calculated as the number of erythromycin-resistant colonies/ml divided by the number of viable CFU/ml on antibiotic-free Todd-Hewitt agar, are shown on the ordinate. Limits of detection were <5 × 10−8. No erythromycin-resistant colonies were detected in any parallel control cultures without CSP at any time point. Results shown are representative of three independent experiments.

M. M. Vickerman, et al. J Bacteriol. 2007 Nov;189(21):7799-7807.
2.
FIG. 2.

FIG. 2. From: Genome-Wide Transcriptional Changes in Streptococcus gordonii in Response to Competence Signaling Peptide .

Colorimetric representation of relative expression levels of CSP-induced S. gordonii genes. Transcript levels as measured by cDNA hybridized to a sixfold redundant S. gordonii microarray and averaged for two replicate hybridizations are shown at 5, 15, and 40 min after CSP induction. Results for 185 up-regulated gene loci (expression ratio, >2; induced/uninduced) were ordered vertically based upon their position in the chromosome (). Temporally invariant genes (expression levels averaging ≤2 over the course of the experiment) were omitted. Color codes represent cDNA levels at each time point as indicated at the top of the columns, over the range from ≤2 (black) to 30.4 (bright red). Enlarged side panels show expression patterns for representative genes. For numerical values for all up-regulated genes, see Table S1 in the supplemental material. The “>” (5′-3′) and “<” (3′-5′) symbols following the name of each genetic locus indicate the direction of transcription with reference to the chromosomal origin of replication.

M. M. Vickerman, et al. J Bacteriol. 2007 Nov;189(21):7799-7807.
3.
FIG. 3.

FIG. 3. From: Genome-Wide Transcriptional Changes in Streptococcus gordonii in Response to Competence Signaling Peptide .

S. gordonii gene clusters up-regulated in response to CSP at 15 min and preceded by a putative combox regulatory site (). Putative proteins encoded by each gene are shown. (A) Late gene consensus sequences. Genetic loci and proteins encoded by the first up-regulated ORF downstream of the combox sequence are listed. Comparison to the consensus combox sequence and the distances to the putative start codon of the ORF immediately downstream of the consensus sequence are shown. In the case of the combox upstream of the bacteriocin SthA, the distance to SGO_0117, encoding a hypothetical protein (HP) that was not expressed in any of the experiments, as well as the distance to SGO_0116, encoding the SthA bacteriocin, are both shown. S. pneumoniae homologs in strains TIGR4 (gene loci SP) and R6 (gene loci SPR) for the S. gordonii loci are shown. All S. pneumoniae homologs except SPR2021 are preceded by a similar combox sequence () and have been shown to be up-regulated in response to CSP in both strains R6 and Rx (, ). SGO_2094 does not have a significant homolog in S. pneumoniae strain TIGR4, whereas strain R6 does carry a GSP781 homolog (SPR2021); the gene encoding this protein has not been implicated in the S. pneumoniae competence response (). (B) S. gordonii gene clusters with identified comboxes. Clusters of genes up-regulated at 15 min after CSP exposure and positioned downstream of the combox consensus sequence (C) are shown. Gene loci are designated by the SGO number above each arrow; putative encoded proteins are shown within the arrows. Directions of the arrows indicate the 5′→3′ direction of each ORF in relation to the chromosomal origin of replication. Arrow sizes are not to scale. Arrows with dashed lines do not represent 15-min CSP-responsive ORFs and either were classified as representing early-response competence genes (encoding ComA, ComB, and ComX) or were not expressed in the microarray under any of the conditions tested (HP encoded by SGO_0117).

M. M. Vickerman, et al. J Bacteriol. 2007 Nov;189(21):7799-7807.

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