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Adaptive mutation: the uses of adversity
1Department of Environmental Health, Boston University School of Public Health, Massachusetts 02118.
Annual Review of Microbiology
|January 1, 1993
Summary
Adaptive mutation allows useful genetic changes in nongrowing cells under stress, challenging random mutation theories. This directed mutation process favors beneficial mutations, suggesting a mechanism for their selection.
Area of Science:
- Microbiology
- Genetics
- Molecular Biology
Background:
- Traditional mutation theory posits random genetic changes.
- Adaptive mutation suggests non-random, useful mutations arise under stress.
- This phenomenon is observed in bacteria and yeast populations.
Purpose of the Study:
- To investigate the phenomenon of adaptive mutation.
- To challenge the paradigm of random, undirected mutation.
- To explore the mechanisms behind selection-induced mutations.
Main Methods:
- Subjecting microbial populations to nonlethal selective pressures.
- Observing mutation occurrence in nongrowing cells.
- Analyzing genetic variants for utility and replication absence.
Main Results:
- Useful mutants arise in nongrowing cells under selection, while useless mutants do not.
- Evidence indicates adaptive mutation occurs without genomic replication.
- The process appears to favor or select for beneficial mutations.
Conclusions:
- Adaptive mutation challenges the concept of purely random genetic change.
- Cells may possess mechanisms to prevent or eliminate useless mutations under stress.
- A model suggests genetic variants are "immortalized" as mutations only if they confer a growth advantage.