RT Journal Article
SR Electronic
T1 Replication-transcription conflicts promote adaptive evolution
JF bioRxiv
FD Cold Spring Harbor Laboratory
SP 2020.06.23.167650
DO 10.1101/2020.06.23.167650
A1 Merrikh, Christopher N.
A1 Harris, Leonard A.
A1 Mangiameli, Sarah
A1 Merrikh, Houra
YR 2020
UL http://biorxiv.org/content/early/2020/06/25/2020.06.23.167650.abstract
AB In 2013, we discovered that encounters between the replication and transcription machineries allow bacteria to evolve at an accelerated rate by promoting mutagenesis in lagging strand genes. Though we proposed that this process is adaptive, it is also possible that the increased mutation frequency in lagging strand genes could be the result of reduced purifying selection (neutral selection).Due to the low number of available genome sequences at the time of publication, we were unable to distinguish between these two models with a high level of confidence. Here, we utilized the wealth of newly available bacterial genome sequences to examine these two possibilities. To test the adaptive hypothesis, we analyzed convergent mutation patterns. To test the neutral hypothesis, we performed in silico modeling. Our results clearly demonstrate that the neutral model cannot explain the increased mutagenesis of lagging strand genes. Additionally, our evolutionary convergence data strongly support the adaptive hypothesis. We conclude that encounters between the replication and transcription machineries in lagging strand gene accelerate the discovery of beneficial mutations.Competing Interest StatementThe authors have declared no competing interest.