New data on excisions of Mu from E. coli MCS2 cast doubt on directed mutation hypothesis.

Abstract excerpt

According to the directed mutation hypothesis, certain mutations in bacteria occur more frequently in environments in which the resulting phenotype is selectively favoured than in non-selective environments. This hypothesis therefore challenges the fundamental tenet that mutations occur spontaneously, irrespective of effects on the organism's fitness. One purported case of directed mutation is the excision of a...

Topics

• Arabinose
• Chromosome Deletion
• Escherichia coli
• Lactose
• Mutation