Transposable Elements and their Use for Target Site Specific Gene Delivery

Transposable elements (TEs), which occupy nearly 40% of eukaryotic DNA, are selfish repetitive sequences, able to proliferate in the host genomes via either their DNA copies or RNA intermediates utilizing the mechanism termed 'reverse transcription' and the RNA-dependant DNA polymerase enzyme, called reverse transcriptase. The newly formed DNA copy of the element then integrates into the genome, using a combination of host and self-encoded proteins, depending on the transposable element origin. Being important model objects for the study of many fundamental molecular biology processes and by actively participating in the gene regulation network, TEs are of great interest for basic researches in molecular genetics and genomics. Their practical use, however, is limited now to some fields of forensic sciences, phylogenetic studies and population genetics. In this mini-review I have tried to put together both theoretical, experimental and speculative data on the use of the transposable elements as tools for the gene delivery into the host eukaryotic genomes, producing stable transgene transformants. The strength of the TE-based constructions as compared with popular viral vectors would be the predictable, genomic target sequence-specific transgene integration, mediated by the enzymatic machinery of some TEs. These and other implications of transposable elements in biomedical sciences will be discussed.