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ARS Home » Southeast Area » Gainesville, Florida » Center for Medical, Agricultural and Veterinary Entomology » Insect Behavior and Biocontrol Research » Research » Research Project #430461

Research Project: Improvement of Genetically Modified Fruit Fly Strains for Use in the Sterile Insect Technique (SIT)

Location: Insect Behavior and Biocontrol Research

Project Number: 6036-22000-030-11-S
Project Type: Non-Assistance Cooperative Agreement

Start Date: Mar 1, 2016
End Date: Jun 30, 2018

The objective of this cooperative research project is to develop transgenic strains in the Caribbean fruit fly (Anastrepha suspensa) and spotted-winged drosophilid (Drosophila (D.) suzukii) for improved biological control of these important pests of fruit crops. Specific aim-1 of this project is to develop and test caribfly strains genetically transformed with antioxidant genes for superoxide dismutase I, superoxide dismutase II, and catalase in order to improve the viability, fitness, and reproductive competitiveness in males sterilized by irradiation for use in the sterile insect technique (SIT). Specific aim-2 of this project is to test the genetic stability of transgenic strains created for improved SIT in D. suzukii by assessing the frequency of genetic breakdown of conditional lethality strains under mass rearing, resulting in their survival under non-permissive conditions. A determination of the genetic and physiological basis for lethal reversion will provide knowledge necessary to create more highly stable transgenic strains for SIT.

Anastrepha suspensa strains will be genetically transformed with newly isolated antioxidant genes, both individually and in combination. Transformant strains will be tested, by comparison to non-transformed wild type flies, for ectopic gene expression and enzymatic activity, viability and life fitness parameters, and male mating competitiveness before and after sterilization by gamma-irradiation. Drosophila suzukii strains will be genetically transformed with tetracycline-suppressible conditional lethality systems that will be mass-reared and screened for pupal and adult survivors under non-permissive conditions (Tet-free diet). Lethal revertant survivors will be inbred to create lines that will be assessed for mutations in the transgene cassettes and tested for viability and life fitness parameters on Tet- and Tet-free diet. Physiological parameters will be tested in comparison to non-transformed wild flies.