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United States Department of Agriculture

Agricultural Research Service

Related Topics


Location: Biological Control of Insects Research

2013 Annual Report

1a. Objectives (from AD-416):
Objective 1. Use established procedures to obtain basic understanding of eicosanoid-mediated immune signaling in pest (squash bug, Anasa tristis) and beneficial (spined soldier bug, Podisus maculiventris) insect species. Objective 2. Generate new knowledge for future deployment of dsRNA to silence genes involved in immune signaling, particularly eicosanoid-mediated signaling, in a pest insect (squash bug, Anasa tristis) and test for species specificity using a beneficial insect (spined soldier bug, Podisus maculiventris).

1b. Approach (from AD-416):
1) Determine the influence of infection on PLA2 activity in immune tissues from squash bugs and spined soldier bugs; 2) Characterize and determine the influence of infection on prostaglandin production in immune tissues from squash bugs and spined soldier bugs; 3) Test the idea that prostaglandins and other eicosanoids mediate cellular reactions to infection; 4) Design dsRNA to silence genes involved in immune signaling; and 5) Determine the influence of dsRNA on immune signaling in intact squash bugs.

3. Progress Report:
For objective 1a we continued characterization of an enzyme (phospholipase A2) responsible for signaling infections in a lepidopteran pest, the tobacco budworm and moved far beyond the progress reported for FY12. We identified the gene and characterized the enzyme. This work is the basis for identifying and characterizing a similar gene in squash bugs. For objective 2B we formed a partnership with a biotechnology start-up firm in St. Louis, Missouri to jointly design, synthesize and evaluate their innovative gene silencing tool. The design and synthesis are complete and we will begin evaluation, blocking expression of a midgut enzyme that is known to be lethal in other insect species.

4. Accomplishments

Review Publications
Sun, B., Jiang, X., Zhang, L., Stanley, D.W., Luo, L., Long, W. 2012. Methoprene influences reproduction and flight capacity in adults of the rice leaf roller, Cnaphalocrocis medinalis (Guenee) (Lepidoptera: Pyralidae). Archives of Insect Biochemistry and Physiology. 82(1):1-13.

Zhang, X., Chen, M., Ma, X., Zhao, X., Wang, J., Song, Q., Stanley, D.W., Shao, H. 2013. Suppression of AcMNPV replication by adf and thymosin protein up-regulation in a new testis cell line, Ha-shl-t. Archives of Insect Biochemistry and Physiology. 82(3):158-171.

Park, J., Stanley, D.W., Kim, Y. 2013. Rac1 mediates cytokine-stimulated hemocyte spreading via prostaglandin biosynthesis in the beet armyworm, Spodoptera exigua. Journal of Insect Physiology. 59:682-689.

Last Modified: 10/20/2017
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