Submitted to: Journal of Insect Biochemistry and Molecular Biology
Publication Type: Peer reviewed journal
Publication Acceptance Date: 2/25/2002
Publication Date: 5/1/2002
Citation: Handler, A.M. 2002. Use of the piggyBac transposon for germ-line transformation of insects. Journal of Insect Biochemistry and Molecular Biology. 32:1211-1220. Interpretive Summary: The ability to achieve gene transfer in economically important insects is a major goal of our laboratory at the Center for Medical, Agricultural and Veterinary Entomology (CMAVE), USDA, ARS, Gainesville, FL. Development of this methodology and strategies to effectively and safely utilize transgenic insects for biological control has and will depend upon collaborative interactions and communication among a wide variety of scientists. This article will educate many researchers in the current state of knowledge of one of the most widely used vector systems for insect germ-line transformation. This is the piggyBac system which was developed in large part by scientists at CMAVE. A discussion is given on the original discovery and analysis of the piggyBac transposable element, its eventual development into a gene transfer vector, and transformation experiments in particular insects among dipterans, lepidopterans, and a coleopteran. Data is also provided and discussed showing movement of the piggyBac element among diverese species that has important implications for the effective and safe use of piggyBac in transgenic strains used in biocontrol programs.
Technical Abstract: Germ-line transformation of insects is now possible with four independent transposable element vector systems. Among these, the TTAA-insertion site specific transposon, piggyBac, discovered in Trichoplusia ni, is one of the most widely used. Transformations have been achieved in a wide variety of dipterans, several lepidopterans, and a coleopteran, and for many species, piggyBac transposition was first tested by plasmid-based mobility assays i cell lines and embryos. All plasmid and genomic insertions are consistent with the duplication of a TTAA insertion site, and most germ-line integrations appear to be stable, though this is largely based on stable marker phenotypes. Of the vector systems presently in use for nondrosophilids, piggyBac is the only one not currently associated with a superfamily of transposable elements, though other elements exist that share its TTAA insertion site specificity. While functional piggyBac elements have only been isolated from T. ni, nearly identical elements hav been discovered in a dipteran species, Bactrocera dorsalis, and closely related elements exist in another moth species, Spodoptera frugiperda. It appears that piggyBac has recently traversed insect orders by horizontal transmission, possibly mediated by a baculovirus or other viral system. This interspecies movement has important implications for the practical use of piggyBac to create transgenic insect strains for field release.