Mutation dynamics and fitness effects followed in single cells

Abstract

Mutation rates and effects in single cells Understanding the dynamics of mutations and the distribution of fitness effects is critical for most evolutionary models. Robert et al. used a single-cell technology to visualize the accumulation of new mutations. The method identifies DNA sequences with mispaired bases and small insertions or deletions caused by DNA replication errors in living Escherichia coli cells. Following the fates of cells after mutation allowed for a precise quantification of the effects of new mutations. A smaller fraction of mutations were found to be deleterious than predicted previously from indirect observations. Science , this issue p. 1283