Ph.D. - University of California, Irvine, 1985
Associate Professor
Center for Agricultural Biotechnology
Plant Sciences Building
College Park, MD 20742
Phone: (301)-405-7681
E-mail: do14@umail.umd.edu
Research: Insect molecular genetics; genetics, molecular genetics, and biochemistry of transposable elements; insect gene vector research and development.
Genetic transformation is a molecular genetic technology that has done much to promote genetic and molecular genetic analysis of model and nonmodel organisms. Applications of this technology for use in human gene therapy and crop modification are revolutionizing these fields of biology. Unfortunately, the biotechnological revolution occurring over the past 15 years and fueled by transgenic technology has failed to reach entomologists beyond those interested in the fruitfly, Drosophila melanogaster. In this insect, we have witnessed that seemingly intractable problems of early development, neurobiology, and even behavior yield to molecular biological approaches as a direct result of available transgenic technology. The wealth of knowledge about this insect has proven to be broadly relevant, and the potential impact of transgenic technology on the rest of insect science can not be underestimated.
The research in my laboratory focuses on insect transposable elements--agents that are likely to be useful in the development of genetic transformation technology. Using a variety of insect model systems, we study a number of related transposable elements within the hAT family of elements. The founding members of this family are the transposable elements hobo from Drosophila melanogaster, Ac from corn, and Tam3 from snapdragons. As part of our efforts to develop tools for manipulating insect genotypes and phenotype, we are investigating the mechanism of hAT element transposition and its regulation using genetic and biochemical approaches. We are using trans-specific differences among the elements within this family as a tool for dissecting mechanistic questions. We have shown that members of this family of transposable elements are capable of undergoing transpositional recombination when placed into a foreign cellular environment. This suggests that these elements are simple recombination systems requiring little for movement other than the single protein (called transposase) that they encode and are excellent starting points for developing genetic transformation systems.
Analysis of the mechanism of hAT element movement has not only aided in developing insect gene vectors, but has also revealed parallels between these widespread recombination systems and the highly specialized recombination system employed by the vertebrate immune systems. Consequently, the investigation of hAT transposable elements in insects may help to clarify the mechanism of V(D)J recombination and its regulation.
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