Genesis and Natural History of IS-mediated Transposons
This extract was created in the absence of an abstract.
Excerpt
Transposable elements unable to replicate autonomously have been classified as either transposons (Tn) or insertion sequences (IS), depending on whether or not they carry detectable genes. Transposons are generally flanked by repeated DNA sequences, and some of these repeats are known to be IS elements. In the case of IS1-flanked transposons, the terminal repeats can be in either direct (MacHattie and Jackowski 1977; Iida and Arber 1980) or inverted (So et al. 1979) orientation. This, together with considerations based on the knowledge of the nucleotide sequence of IS1-flanked chloramphenicol (Cm) transposons (Alton and Vapnek 1979; Marcoli et al. 1980) and on the fact that inverse IS1-mediated transposition occurs (Reif 1980; Rosner and Guyer 1980), poses the questions of whether and how any DNA segment can evolve to become a component of an IS1-flanked transposon.
Here we will present evidence that, in fact, a determinant for chloramphenicol resistance (Cmr) located on...
