Dawn Gundersen-Rindal
Parasitoids wasps are very small Hymenopteran insects such as the one pictured here. Except for adult stages, they spend their entire life cycle inside other insects, generally Lepidoptera (caterpillars), as parasites. Because they almost always kill the host lepidopteran before it reaches the adult stage and can reproduce, parasitoids can be effective for the biocontrol of pest insects. Since the host perceives the parasitoid as foreign, its immune system responds by attempting to encapsulate and kill the immature wasp. Many parasitoid wasps contain unique, double stranded, polydisperse DNA viruses, known as polydnaviruses, to help defend against the host immune response. The parasitoid wasp has incorporated the polydnavirus' DNA into its own chromosomes, where it is present as a provirus. When the adult female wasp oviposits in its lepidopteran host, calyx fluid containing the polydnavirus, ovarian proteins, and venom is injected along with eggs. Certain polydnavirus genes are transcribed and translated which exert effects on the host lepidopteran, including disruption of host immune systems and protein synthesis in ways favoring parasitoid survival.
Since one particular polydnavirus from the Braconid parasitoid wasp, Glyptapanteles indiensis, appears to be able to partially insert its own DNA into host insect cell DNA in the laboratory, we are attempting to use this virus to carry other pieces of DNA into insect cells. This is a type of genetic engineering. If this technique is successful, we may be able to change the genes of pest insects so they are rendered inefficient as disease vectors or so that the life cycle of the lepidopteran host is disrupted prior to stages causing crop damage. We are also studying the effects of polydnavirus gene expression at the molecular level on host and non-host lepidopterans.
Recent Publications:
- Chen, Y.-P, Taylor, P., Shapiro, M. and Gundersen-Rindal, D. Quantitative expression analysis of a Glyptapanteles indiensis polydnavirus gene in its natural lepidopteran host, Lymantria dispar. Insect Molecular Biology (submitted)
- Gundersen-Rindal, D., Slack, J.M., and Lynn D.E. 2001. Transfection of Lymantria dispar insect cells. Methods in Cell Science 22:257-263.
- Dougherty, E.M., Lynn, D.E., Stoltz, D.B., McKelvey, T.A., and Gundersen-Rindal, D. 2000. "Stable insect virus-cell expression system". U.S. Patent and Trademark Office, Patent No. 6,143,565.
- Gundersen-Rindal, D. and Dougherty, E.M. 2000. "Evidence for integration of Glyptapanteles indiensis polydnavirus DNA into the chromosome of Lymantria dispar in vitro". Virus Research 66(1):27-37.
- Lee, I.-M., Davis, R.E. and Gundersen-Rindal, D.E. 2000. Phytoplasma: Phytopathogenic Mollicutes. Annual Reviews of Microbiology 54:221-255.
- Gundersen-Rindal, D., Lynn, D.E., and Dougherty, E.M. 1999. "Transformation of lepidopteran and coleopteran insect cell lines by Glyptapanteles indiensis polydnavirus DNA". In Vitro Cellular and Developmental Biology 35:111-114.
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