(also known as a transposon)
A DNA sequence that can move from one section of the genome to another, affecting chromosome shape and structure as well as gene expression.
- Cut-and-paste transposons move by excision from their original location and insertion into a new location, catalyzed by a transposase enzyme encoded by the transposon itself.
- Replicative transposons are replicated and the copy is inserted at a new location without loss of the transposon at the original location; this is also catalyzed by a transposase enzyme encoded by the transposon.
- Retrotransposons move via RNA transcription of the transposon followed by reverse transcription of the RNA molecule and insertion of the newly synthesized DNA.