Mutacion en e.coli

Adaptive Reversion of a Frameshift Mutation in Escherichia coli by Simple Base Deletions in Homopolymeric Runs Author(s): Patricia L. Foster and Jeffrey M. Trimarchi Reviewed work(s): Source: Science, New Series, Vol. 265, No. 5170 (Jul. 15, 1994), pp. 407-409 Published by: American Association for the Advancement of Science Stable URL: http://www.jstor.org/stable/2884473 . Accessed: 28/11/201121:13
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W:.N REPORTS

made differentmistakes more frequently. However, a second, perhaps additional, explanation appearslikely in view ofthe prevalence of the adaptive mutations in simple repeats. Template-slippagemutaof tions in simplerepeatsare characteristic yeast cells (22) and of hereditarycolon cancer cells (23-25) that are deficient for mismatchrepair.Thus, the post-synthesis caused by apparentpolyhypermutability merase errorsin E. coli cells exposed to misselectioncould also indicatedecreased of matchrepair(26). Downregulation mismatch repairduringadaptivemutationhas been suggested (6, 9, 27) but not in a noncontext of recombination-dependent, templatedadaptivemutations.In both the cancercells and in the bacteriaexposedto nonlethal selection, the ability to mutate adaptivelyconfers the ability to grow and divide. Mechanisticas well as formalsimimayexist (28), laritiesin the two processes which raises thepossibility of bacterial in model systemsfor mutagenesis cancer.
REFERENCESAND NOTES
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