|O'Brochta, D - UNIV OF MD BIOTECH INST|
Submitted to: Book Chapter
Publication Type: Book / Chapter
Publication Acceptance Date: December 10, 2003
Publication Date: January 1, 2005
Citation: Handler, A.M., O'Brochta, D.A. 2005. Transposable elements for insect transformation. In: Gilbert, L.I., Iatrou, K., Gill, S.S., editors. Comprenehsive Molecular Insect Science, Volume 4. Oxford, UK: Elsevier. p. 437-474. Technical Abstract: After concerted efforts for more than thirty years to achieve gene-transfer in non-drosophilid insects, only in the last eight years have these efforts been fruitful. Since 1995 the germ-line of nearly 20 species in four orders of insects have been transformed, and this number may be only limited by the insects of current experimental and applied interest. Unlike plant and vertebrate animal systems that allow relatively efficient genomic integration of introduced DNA, insect systems have generally relied on vector-mediated integrations, and the only vectors found reliable for germ-line transformation are those based on transposable elements. Thus far four transposons from non-melanogaster or non-drosophilid species have been found to be widely functional in insects, and for some, other organisms. Their discovery has been of enormous importance to the wider use of transformation technology, since little progress would have been made if most vector systems were specific to a particular host. Equal in importance to the advancements in vector development, have been concurrent progress in genetic marker discovery and development. This began with the finding that cloned eye color genes from Drosophila could complement existing mutations in other insects, and has continued with the more recent use of several fluorescent protein genes that are widely applicable as markers for transformation and reporters for gene expression. The advancement of these techniques comes at a fortuitous time when genomics is providing a wealth of genetic information and resources that might be used to create transgenic strains of pest and beneficial insects to control their population size and behavior. As part of these efforts, genetic transformation is also critical to functional genomics studies that will provide information essential to understanding the biological function of genetic material, and relating specific genomic elements to those functions. Techniques such as enhancer traps and transposon tagging, that rely on remobilizable insertional mutagenesis, are only possible with transposon-based vector systems, and other techniques such a RNAi are greatly facilitated by these systems. Together, routine methods for transposon-mediated germ-line transformation and genomics analysis will provide the tools for dramatic progress in our understanding and control of insect species.