Transposition Moving a DNA segment from one position of the genome to another or to a different genome. This change in genome structure happens in many organisms from bacteria to higher plants and animals.
Requirements: (1) intact inverted repeats at the ends of the IS-elements or transposons and (2) active transposase
Mechanisms
  • conservative or cut and paste: the transposable element is cut from the donor DNA and paste to the new location in the receptor DNA.
  • replicative: the transposable element is replicated, one copy stays at the original position, the second is intergrated at a new location.
Consequences: restructuring of the genome
The cut and paste mechanism leaves 'scars' in the donor molecule. Thus genes can be damaged or destroyed. Mutations may be induced via insertions into structure genes. Deletions or inversions may also be the result of a transposition.

History: Transposition was discovered by Barbara McClintock in the late 1940ies during her studies on maize genetics ('jumping genes'). 1983 she won the Nobel Prize for her transposon research.

See retrotransposon.