"This paper could be a very important advance," said Allan Spradling, an HHMI investigator at Carnegie Institution in Baltimore. "It really comes down to its application in practice -- how well it works, day in and day out. It's fairly rare to get a transposon that works on a large scale in an effective way. This looks very promising."
Transposons have been used in mice before. But one such active transposon, Sleeping Beauty, does not appear to travel widely among the chromosomes and cannot carry larger fragments of DNA. As a result, scientists have been searching for stable, versatile transposons that can insert randomly in many different mammalian chromosomes and also carry genes into mice and other organisms that are more closely related to people.
PiggyBac was originally identified in the cabbage looper moth. Unlike many mobile genetic units that work only in their native hosts, piggyBac can flit around the genomes of other insects. For that reason, it has been used experimentally as a tool to control pest insects from moths to flies and mosquitoes. The transposon has also seen heavy use in the genetic workhorse, Drosophila, where it is perhaps second only to the P element, whose talent to engineer changes in the fly's genome was co-discovered by Spradling 23 years ago. The P element has since become a backbone of modern fruit fly genetics.
Researchers in Xu's group first tried to adapt the P element for use in mice and to improve the efficiency of the Sleeping Beauty transposon system. When those efforts failed, they chose piggyBac because its enzyme looked and acted differently and it had a good track record in a range of insects.
In their experiments, piggyBac incorporated itself into many chromosomes in human and mouse cells. It also carried
Source:Howard Hughes Medical Institute