Evolution at a high imposed mutation rate: adaptation obscures the load in phage T7.

ABSTRACT: Evolution at high mutation rates is expected to reduce population fitness deterministically by the accumulation of deleterious mutations. A high enough rate should even cause extinction (lethal mutagenesis), a principle motivating the clinical use of mutagenic drugs to treat viral infections. The impact of a high mutation rate on long-term viral fitness was tested here. A large population of the DNA bacteriophage T7 was grown with a mutagen, producing a genomic rate of 4 nonlethal mutations per generation, two to three orders of magnitude above the baseline rate. Fitness-viral growth rate in the mutagenic environment-was predicted to decline substantially; after 200 generations, fitness had increased, rejecting the model. A high mutation load was nonetheless evident from (i) many low- to m

SUBMITTER: Springman R 

PROVIDER: S-EPMC2815918 | biostudies-literature | 2010 Jan

REPOSITORIES: biostudies-literature