Stress‐induced Mutagenesis in Bacteria

Abstract

Abstract Bacteria spend their lives experiencing repeated rounds of feast and famine. In addition, they are buffeted by a variety of environmental insults such as fluctuations in temperature, pH, osmotic pressure, as well as exposure to DNA damaging agents and antibiotics. To cope with these changing conditions, bacteria have a variety of stress‐responses that result in profound but temporary cell‐wide changes in gene expression and protein activities. Keyed into these responses are a variety of ways in which the potential for genetic change is enhanced. Research has provided a number of examples of stress‐induced mutagenesis. Such transient mutator states may be important for adaptive evolution. Key Concepts: Bacteria respond to stress by inducing temporary cell‐wide changes in gene expression and protein activities. Some of these changes can increase the cell's potential for genetic change. Adaptive evolution can be accelerated when mutation rates are high, but persistent high mutation rates are also deleterious. Thus, transient increases in mutation rates are potentially of greater evolutionary advantage than permanent increases. Stress‐induced mutagenesis appears to be widespread among bacteria. There are many mechanisms that contribute to stress‐induced mutagenesis.