TABLE 1

IS-mediated mutations that arose and were fixed in two evolving populations of E. coli

Mutational eventMutation described inMutation first detected at (generations)aMutation became fixed by (generations)a
Population Ara – 1
    Deletion of 6934 bp from IS 150 located upstream of rbs operon into yieOCooper (2000)500500
    Insertion of IS 150 into pykFFigure 1 (this study)20005000
    Inversion involving existing IS 1 elements located in gatZ and between citC and dpiBFigure 2 (this study)50005000
    Deletion from IS 1 located in nmpC to E. coli B-specific sequence (within 0.7 min)Figure 3 (this study)50005000
Population Ara + 1
    Deletion of 6138 bp from IS 150 located upstream of rbs operon into yieOCooper (2000)500500
    Insertion of IS 150 into nadRFigure 4 (this study)10002000b
    Insertion of IS 150 into hokB-sokBFigure 5 (this study)10002000b
    Inversion involving new IS 150 element in nadR and existing IS 150 in hokX-sokXFigure 4 (this study)20002000b
    Insertion of IS 150 upstream of pbpA-rodA operonFigure 5 (this study)20002000b
    Insertion of IS 150 into yfcUresults (this study)50008000
    Insertion of IS 150 into intergenic region between glcB and yghKresults (this study)50008000
  • a Time in generations. At least seven clones from each population were analyzed at generations 500, 1000, 1500, 2000, 5000, 8000, and 10,000.

  • b These mutations were absent from 1 of 10 clones sampled at generation 2000, but were present in all 31 later clones.