noun, plural: transposons
Transposons are DNA segments that are mobile. They can replicate and insert copies at sites within the same or a different chromosome. They can therefore alter the genetic constitution of an organism.
Transposons have two types according to the genes they code for: (1) simple transposons and (2) complex transposons. The simple transposons consist of genes needed for insertion, particularly the gene coding for transposases, which are enzymes that catalyze their insertion. The complex transposons are those consisting of other genes apart from those needed for insertion. Transposons are the genetic elements associated with antibiotic resistance in certain bacteria. For instance, the Tn5 that codes for transposase Tn5 as well as those for antibiotic resistance to kanamycin.1
In eukaryotes, there are two classes of transposons. The first class is a group of transposons that are bacterial-like in a way that the DNA sequences move directly. The second class, called retrotransposons, move by producing RNA that is transcribed by reverse transcriptase into DNA that is then inserted at a new site.
- transposable element
- jumping gene
1 Reznikoff, William S. (2003). "Tn5 as a model for understanding DNA transposition". Molecular Microbiology 47 (5): 1199–1206.