Submitted to: Genetica
Publication Type: Peer reviewed journal
Publication Acceptance Date: 8/2/2002
Publication Date: 11/1/2002
Citation: Handler, A.M. 2002. Prospects for using genetic transformation for improved SIT and new biocontrol methods. Genetica. 116:137-149. Interpretive Summary: The ability to achieve gene transfer in economically important insects is a major goal of our laboratory at the CMAVE. 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 review article will help to educate many of the researchers who wish to use molecular methods to improve insect strains for the sterile insect technique (SIT). The review discusses available systems for insect gene transfer, and existing and prospective model systems for genetic marking of released insects, female lethality for genetic sexing, and male sterility. These systems are discussed in the perspective of the availability of the genetic reagents to create them, and the feasibility of their function in particular species.
Technical Abstract: The genetic manipulation of non-drosophilid insect species is possible by the creation of recombinant DNA constructs that can be integrated into host genomes by several transposon based vector systems. This technology will allow the development and testing of a variety of systems that can improve existing biological control methods, and the development of new highly efficient methods. For programs such as SIT, transgenic strains may include fluorescent protein marker genes for detection of released insects, and conditional gene expression systems that will result in sterile males and female lethality for genetic sexing. Conditional expression systems include the yeast GAL4 system, and the bacterial Tet-off and Tet-on systems that can, respectively, negatively or positively regulate expression of genes for lethality or sterility depending on a dietary source of tetracycline. Importantly, strains for male sterility must also incorporate an effective system for genetic sexing, since typically, surviving females would remain fertile. Models for the use of these expression systems and associated genetic material comes from studies in Drosophila, and while many of these systems should be transferable to other insects, continued research will be necessary in insects of interest to clone genes, optimize germ-line transformation, and perform vector stability studies and risk assessment for their release as transgenic strains.