|Handler, Alfred - Al|
Submitted to: Insect Molecular Biology
Publication Type: Peer reviewed journal
Publication Acceptance Date: 12/6/2008
Publication Date: 6/10/2009
Citation: Nirmala, X., Zimowska, G., Handler, A.M. 2009. Characterization of the proteasome ß2 subunit gene and its mutant allele in the tephritid fruit fly pest, Anastrepha suspensa. Insect Molecular Biology. 18(3):333-340. Interpretive Summary: The creation of genetically transformed strains of economically important insects will result in more effective biological control programs, such as the sterile insect technique. Scientists at the ARS Center for Medical, Agricultural and Veterinary Entomology, Gainesville, Florida, have studied the use of mutations that cause lethal effects at elevated temperatures of 29°C or above, yet allow survival at temperatures of 25°C or below. The normal gene for one of these mutations, was isolated from the Caribbean fruit fly, and then mutated. The mutated gene was then genetically transformed in to a wild A. suspensa host strain, and after inbreeding, flies were tested for survival at 25°C and 29°C. The results suggest that a temperature-dependent conditional lethal system has the potential to act as an environmentally benign insect management program, particularly for insects in tropical and sub-tropical regions.
Technical Abstract: Conditional lethal release (CLR) is a proposed variation of the sterile insect technique (SIT) for the biological control of pest insects that would result from the release of transgenic insects carrying dominant conditional lethal genes. After mating with pest insects in the field, lethal gene expression in their progeny under non-permissive conditions is expected to result in suppression of the pest population (Krafsur 1998). Conditional lethal systems using a tetracycline-repressible transcription factor, known as RIDL, depend on the use of dietary antibiotics in mass-rearing (Thomas D.D. et al, 2000). An alternate approach is the use of a temperature-dependent lethal systems, one of which is based on a dominant temperature-sensitive (DTS) mutation of the 20S proteasome subunit gene, Prosß2, originally discovered in Drosophila melanogaster (Holden and Suzuki, Smyth and Belote). The Prosß21 mutation has a dominant lethal effect in pupae reared at 29°C or above, but which survive at 25°C. We have isolated and mutated the AsProsß2 cognate of this gene from a tephritid fruit fly pest, Anastrepha suspensa, and have demonstrated effective pupal lethality at 29°C in flies transformed with the mutant allele. This temperature-dependent conditional lethal system has the potential to act as an environmentally benign insect management program, particularly in tropical and sub-tropical regions.