| Comments |
P.3312 right column 2nd & 3rd paragraph (but see updated value in "correction" at bottom): "The bacterial endosymbionts, B. aphidicola and C. ruddii, harbor small genomes (450 and 190 kb, respectively) and have very high substitution rates, as a consequence of both their lack of several repair mechanisms (Fig. S1) and the reduced efficacy of selection due to their small effective population sizes. These features are also expected to augment rates of transcription errors, so [investigators] assayed the transcription error rates in these endosymbionts using methods identical to those used for E. coli. For the replicate samples of B. aphidicola, [they] detected a total of 169 transcription errors in total mRNA, yielding a transcription error rate of 2.69 ± 0.73 (SEM) × 10^−5, which is not significantly different from the rate that [they] obtained for E. coli mRNA [two-tailed t test, t(8) = 2.527, P > 0.05 Fig. 3A] … Unlike C. ruddii and B. aphidicola, the E. coli genome possesses multiple polymorphic rRNA operons, making it unfeasible to estimate rRNA transcription error rates in E. coli. [They] detected a total of 1,014 errors in C. ruddii rRNAs and 4,377 errors in B. aphidicola rRNAs, yielding rRNA transcription error rates of 5.13 × 10^−5 for C. ruddii and 3.37 × 10^−5 for B. aphidicola (Fig. 3A). [Their] estimates of bacterial transcription error rates are, in descending order, 5.13 × 10^−5 for C. ruddii rRNA, 4.63 × 10^−5 for E. coli mRNA, 3.37 × 10^−5 for Buchnera rRNA, and 2.69 × 10^−5 for Buchnera mRNA. The transcription error rates for B. aphidicola mRNA and rRNA do not differ significantly from one another." See Correction PMID 27402746 link |