DNAtransposoner

DNA transposons, or DNAtransposoner, are transposable elements that move within genomes through a DNA intermediate. They typically encode or rely on a transposase enzyme that recognizes terminal inverted repeats and catalyzes excision from a donor site and integration at a new site. Most DNA transposons move by a cut-and-paste mechanism, where the element is excised and inserted elsewhere, usually generating a short target site duplication at the insertion site.

Structure and classification: DNA transposons usually consist of a transposase gene flanked by terminal inverted repeats, which are the signals recognized by the transposase. They are grouped into several superfamilies, including Tc1/mariner, hAT, Mutator-like elements (MULEs), and PIF/IS4. In bacteria, many families are called insertion sequences (IS elements) and represent simpler, autonomous units often carrying only the transposase gene and the flanking repeats.

Autonomous versus non-autonomous: Autonomous DNA transposons carry functional transposase genes and can move on their own. Non-autonomous elements lack a functional transposase and rely on transposase supplied in trans by another element to mobilize.

Biology and evolution: DNA transposons are common across bacteria, fungi, plants, and animals and have significantly influenced genome structure and evolution through insertions, excisions, and rearrangements. They can disrupt genes, alter regulation, or create genetic diversity. Some transposon fragments become co-opted by host genomes for new functions.

Applications: DNA transposons have been repurposed as tools for genome engineering and mutagenesis. Notable systems include Sleeping Beauty and piggyBac for mammalian genome modification, as well as Tol2 for vertebrate genetics.