Bacterial genomes experience lots of mutations that result from a complex mix of DNA damage, errors made by DNA polymerase, and errors repaired or made by repair enzymes. Do these processes leave a tell-tale signature in the genome, and can we use it to infer which processes were most important? A new paper in Genome Biology and Evolution, with contributions from Mrudula and Deepa, shows that the mutational signatures observed in wild type E coli strains are dominated by DNA polymerase errors. Surprisingly, various DNA repair enzymes – which are quite dynamic in evolutionary time (e.g., see Sane et al 2023) – appear to have only transient effects on the genome. It remains to be seen why these effects are transient, and for what timescales do they linger on in genomes. Check out the paper and the nice cover image (below) by Sonya Garushyants and Sarah Stone!
AdaptationLab 