Frequent beneficial mutations during single-colony serial transfer of Streptococcus pneumoniae.

ABSTRACT: The appearance of new mutations within a population provides the raw material for evolution. The consistent decline in fitness observed in classical mutation accumulation studies has provided support for the long-held view that deleterious mutations are more common than beneficial mutations. Here we present results of a study using a mutation accumulation design with the bacterium Streptococcus pneumoniae in which the fitness of the derived populations increased. This rise in fitness was associated specifically with adaptation to survival during brief stationary phase periods between single-colony population bottlenecks. To understand better the population dynamics behind this unanticipated adaptation, we developed a maximum likelihood model describing the processes of mutation and station

SUBMITTER: Stevens KE 

PROVIDER: S-EPMC3158050 | biostudies-literature | 2011 Aug

REPOSITORIES: biostudies-literature