A near-deterministic mutational hotspot in Pseudomonas fluorescens is constructed by multiple interacting genomic
M J Shepherd1, J S Horton1, T B Taylor1
1Milner Centre for Evolution, Department of Biology & Biochemistry, University of Bath, Claverton Down, Bath BA2 7AY, UK.
Molecular Biology and Evolution
|June 16, 2022
Summary
Evolutionary hotspots in Pseudomonas fluorescens are driven by genomic location, sequence, and DNA repair proteins. Understanding these factors allows prediction of predictable evolutionary outcomes and deterministic evolution.
Area of Science:
- Evolutionary biology
- Microbial genetics
Background:
- Mutations, while random, often occur at specific genomic locations, leading to predictable evolutionary patterns when combined with natural selection.
- The bacterium Pseudomonas fluorescens (SBW25) exhibits a mutational hotspot enabling a specific mutation (ntrB A289C) in over 95% of independent lines re-evolving motility.
Purpose of the Study:
- To identify the genomic features responsible for creating potent mutational hotspots.
- To develop a framework for predicting and locating hotspots that can enforce near-deterministic evolution.
Main Methods:
- Investigated the interplay of genomic location, local nucleotide sequence, gene strandedness, and mismatch repair proteins.
- Analyzed the formation of a specific mutational hotspot in Pseudomonas fluorescens.
Main Results:
- Genomic location, local nucleotide sequence, gene strandedness, and mismatch repair proteins collectively facilitate the formation of mutational hotspots.
- Identified key factors contributing to a highly repeatable evolutionary outcome in Pseudomonas fluorescens.
Conclusions:
- A combination of genomic features dictates the formation of mutational hotspots.
- This understanding provides a framework for predicting evolutionary trajectories and identifying genetic loci prone to specific mutations.
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