It has been proposed that transcription introduces a bias into the random process of mutation. Although this hypothesis is supported by experimental data for mutations arising during active bacterial growth, the role of transcription in mutagenesis in non-dividing bacteria is entirely hypothetical. In the present study, we tested the hypothesis of a possible role of transcription in a non-dividing E. coli K12 strain. In this strain (BD010), a mutated trpB allele (trpB9578), placed under stringent transcriptional control, was tested for the appearance of prototrophic revertants on synthetic medium lacking tryptophan. The number of phenotypic revertants which appeared in the absence of trp transcription was compared to that observed when the mutated gene was continuously transcribed. Our results showed that transcription of trpB is not mutagenic under conditions of tryptophan starvation, and that the frequency of TrpB+ reversion is solely a function of the duration of starvation.

Barionovi, D., Ghelardini, P., DI LALLO, G., & Paolozzi, L. (2003). Mutations arise independently of transcription in non-dividing bacteria. MOLECULAR GENETICS AND GENOMICS, 269(4), 517-525 [10.1007/s00438-003-0857-8].

Mutations arise independently of transcription in non-dividing bacteria

DI LALLO, GUSTAVO;
2003

Abstract

It has been proposed that transcription introduces a bias into the random process of mutation. Although this hypothesis is supported by experimental data for mutations arising during active bacterial growth, the role of transcription in mutagenesis in non-dividing bacteria is entirely hypothetical. In the present study, we tested the hypothesis of a possible role of transcription in a non-dividing E. coli K12 strain. In this strain (BD010), a mutated trpB allele (trpB9578), placed under stringent transcriptional control, was tested for the appearance of prototrophic revertants on synthetic medium lacking tryptophan. The number of phenotypic revertants which appeared in the absence of trp transcription was compared to that observed when the mutated gene was continuously transcribed. Our results showed that transcription of trpB is not mutagenic under conditions of tryptophan starvation, and that the frequency of TrpB+ reversion is solely a function of the duration of starvation.
Pubblicato
Rilevanza internazionale
Articolo
Esperti anonimi
Settore BIO/19 - Microbiologia Generale
English
Escherichia coli; Origin of mutations; trpB gene
Barionovi, D., Ghelardini, P., DI LALLO, G., & Paolozzi, L. (2003). Mutations arise independently of transcription in non-dividing bacteria. MOLECULAR GENETICS AND GENOMICS, 269(4), 517-525 [10.1007/s00438-003-0857-8].
Barionovi, D; Ghelardini, P; DI LALLO, G; Paolozzi, L
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Utilizza questo identificativo per citare o creare un link a questo documento: http://hdl.handle.net/2108/131036
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