Madeleine Oman's 1st Authored Paper in Prestigious Genome Biology & Evolution
Madeleine Oman, PhD student, from Ness Lab, published her 1st Authored paper in the prestigious Genome Biology & Evolution.
How Sequence Context-Dependent Mutability Drives Mutation Rate Variation in the Genome
The rate of mutations varies >100-fold across the genome, altering the rate of evolution, and susceptibility to genetic diseases. The strongest predictor of mutation rate is the sequence itself, varying 75-fold between trinucleotides. The fact that DNA sequence drives its own mutation rate raises a simple but important prediction; highly mutable sequences will mutate more frequently and eliminate themselves in favour of sequences with lower mutability, leading to a lower equilibrium mutation rate. However, purifying selection constrains changes in mutable sequences, causing higher rates of mutation. We conduct a simulation using real human mutation data to test if (1) DNA evolves to a low equilibrium mutation rate and (2) purifying selection causes a higher equilibrium mutation rate in the genome’s most important regions. We explore how this simple process affects sequence evolution in the genome, and discuss the implications for modelling evolution and susceptibility to DNA damage.