Insertion, excision, and inversion of Tn5.

Abstract

The defining characteristic of bacterial transposons is their ability to move to new loci in the absence of extensive DNA sequence homology or the recA protein (for review, see Calos and Miller 1980; Starlinger 1980). Transposons increase the fitness of bacterial populations by facilitating gene flow among different species and by changing the arrangement and the control of expression of genes within a single species. Transposons that contain genes for antibiotic resistance appear to be responsible for the recurrence of the same resistance genes in otherwise unrelated R-factor plasmids (see Falkow 1975). In the laboratory, such resistance transposons can be used to mutate host genes, to probe and alter the control of gene expression, and to move genes to new locations.