Transposons are sequences of DNA that are capable of moving around and incorporating into the genome of an individual cell. Often when transposons incorporate into a cell genome, they cause genome sequence changes which can either result in detrimental or beneficial mutations. As a result, the cell may have transposon-silencers which control/suppress transposon activity, or the cells may domesticate transposons; only activating them when required. In fact, the use of select transposable elements in a controlled manner has shown potential for success in gene therapy, although in the past there have been problems associated with the use of transposon-mediated gene transfer in human cells.Currently, the transposon Sleeping Beauty is widely used for preclinical gene therapy studies. However, recent studies have revealed a considerably more precise, predictable, and efficient transposon named piggyBac. Unlike Sleeping Beauty, the piggyBac transposon causes less footprint mutations, is more active, has predictable integration sites, and is capable of inserting large sequences of DNA without reducing efficiency. Although it is believed that the piggyBac system could potentially improve the success of transposon-mediated gene transfer in human cells, the piggyBac system still requires more investigation before it can be safely used for human gene therapy.
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