• Modulation of allele leakiness and adaptive mutability in Escherichia coli

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    • Keywords


      Escherichia coli; phenotypic suppression; adaptive mutagenesis; allele leakiness; streptomycin.

    • Abstract


      It is shown that partial phenotypic suppression of two ochre mutations (argE3 and lacZU118) and an amber mutation (in argE) by sublethal concentrations of streptomycin in an rpsL+ (streptomycin-sensitive) derivative of the Escherichia coli strain AB1157 greatly enhances their adaptive mutability under selection. Streptomycin also increases adaptive mutability brought about by the ppm mutation described earlier. Inactivation of recA affects neither phenotypic suppression by streptomycin nor replication-associated mutagenesis but abolishes adaptive mutagenesis. These results indicate a causal relationship between allele leakiness and adaptive mutability.

    • Author Affiliations


      R. Jayaraman1

      1. School of Biological Sciences, Madurai Kamaraj University, Madurai 625 021, India
    • Dates


© 2017 Indian Academy of Sciences, Bengaluru.