Adaptive molecular evolution for 13,000 phage generations: a possible arms race.

ABSTRACT: Bacteriophage phiX174 was evolved on a continuous supply of sensitive hosts for 180 days ( approximately 13,000 phage generations). The average rate of nucleotide substitution was nearly 0.2% (11 substitutions)/20 days, and, surprisingly, substitutions accumulated in a clock-like manner throughout the study, except for a low rate during the first 20 days. Rates of silent and missense substitutions varied over time and among genes. Approximately 40% of the 71 missense changes and 25% of the 58 silent changes have been observed in previous adaptations; the rate of parallel substitution was highest in the early phase of the evolution, but 7% of the later changes had evolved in previous studies of much shorter duration. Several lines of evidence suggest that most of the changes were adaptive,

SUBMITTER: Wichman HA 

PROVIDER: S-EPMC1449705 | biostudies-literature | 2005 May

REPOSITORIES: biostudies-literature