Rates of spontaneous mutation among RNA viruses.

TLDR

Published mutant frequencies show a wide range of RNA virus mutation rates per genome per replication because mutational targets are small and poorly sample average base mutability. The study presents simple methods to estimate spontaneous mutation rates from mutant frequencies and population parameters in RNA viruses. The authors calculate rates by analyzing mutant frequencies together with population parameters. Lytic RNA viruses have a central mutation rate of about one per genome per replication, roughly 300 times higher than DNA microbes and near the viability limit, while retroviruses mutate at about one‑tenth that rate.

Abstract

Simple methods are presented to estimate rates of spontaneous mutation from mutant frequencies and population parameters in RNA viruses. Published mutant frequencies yield a wide range of mutation rates per genome per replication, mainly because mutational targets have usually been small and, thus, poor samples of the mutability of the average base. Nevertheless, there is a clear central tendency for lytic RNA viruses (bacteriophage Q beta, poliomyelitis, vesicular stomatitis, and influenza A) to display rates of spontaneous mutation of approximately 1 per genome per replication. This rate is some 300-fold higher than previously reported for DNA-based microbes. Lytic RNA viruses thus mutate at a rate close to the maximum value compatible with viability. Retroviruses (spleen necrosis, murine leukemia, Rous sarcoma), however, mutate at an average rate about an order of magnitude lower than lytic RNA viruses.