Progress 11/15/00 to 11/14/03
Outputs
This project focused on acyl-CoA desaturases that function in the formation of diverse unsaturated fatty acid intermediates used in sex pheromone biosynthetic pathways of moths and the fly Drosophila melanogaster. We isolated desaturase gene sequences expressed in pheromone glands of several agriculturally important moth species and functionally expressed many of them in cells of the yeast Saccharomyces cereviseae. We characterized the unsaturated fatty acids produced in this functional expression system in order to deduce the biochemical properties of the encoded desaturases. We used computational methods to elucidate the evolutionary relationships of the major sequence lineages of this large and enzymatically diverse gene family in moths and flies and to deduce structural determinants of discrete biochemical properties, such as regioselectivity and substrate chain length preferences, of specific functional categories.
Impacts
Sex pheromones have been shown to provide the basis of a highly specific, nontoxic strategy for the control of insect pests that complements other integrated pest management techniques. A practical goal of this research is to characterize the enzymatic properties of insect desaturases and to identify those that might be used to develop low cost, biologically-based procedures for synthesizing pheromones or other commercial applications requiring unsaturated fatty acid intermediates.
Publications
- Jeong, S., You, K. M., Rosenfield, C.-L. and Knipple, D. C. 2003. Structural and functional characterization of acyl-CoA desaturases of Helicoverpa assulta. Insect Biochem. Molec. Biol. 33:609-622.
- You, K. M., Rosenfield, C.-L. and Knipple, D. C. 2003. Ethanol tolerance in the yeast Saccharomyces cerevisiae is dependent on cellular oleic acid content. Applied Envir. Microb. 69:1299-1503.
- Knipple, D. C. and Roelofs, W. L. 2003. Molecular Biological Investigations of Pheromone Desaturases. In "Insect Pheromone Biochemistry and Molecular Biology" (Blomquist, G. J. and R. Vogt, Eds.), Elsevier, Oxford, UK, pp.81-106.
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Progress 01/01/02 to 12/31/02
Outputs
Sex pheromones have been shown to provide the basis of a highly specific, nontoxic strategy for the control of insect pests that complements other integrated pest management techniques. This project focuses on acyl-CoA desaturases that function in the formation of diverse unsaturated fatty acid intermediates in sex pheromone biosynthetic pathways of moths and other insects. The pheromone desaturase gene family arose from ancient duplications of acyl-CoA desaturase genes that provided a primary adaptative response to cold. We have elucidated the evolutionary relationships of the members of this family by analyzing desaturase gene sequences expressed in pheromone glands of eight agriculturally important species of moths. In our ongoing investigations, we characterize the expression and functional properties of pheromone desaturases and use computational approaches to identify structural features of acyl-CoA desaturases that influence discrete enzymatic properties.
Impacts
A practical goal of this research is to characterize the enzymatic properties of insect desaturases and to identify those that might be used to develop low cost, biologically-based procedures for synthesizing pheromones or other commercial applications requiring unsaturated fatty acid intermediates.
Publications
- Knipple, D. C., C.-L. Rosenfield, K. M. You and S. E. Jeong. 2002. Evolution of the integral membrane desaturase gene family in moths and flies. Genetics 162: 1737-1752.
- You, K. M., C.-L. Rosenfield and D. C. Knipple. 2003. Ethanol tolerance in the yeast Saccharomyces cerevisiae is dependent on cellular oleic acid content. Applied Envir. Microb. (In Press).
- Jeong, S., K. M. You, C.-L. Rosenfield and D. C. Knipple. 2003. Structural and functional characterization of acyl-CoA desaturases of Helicoverpa assulta. Insect Biochem. Molec. Biol. (In Press).
- Knipple, D. C. and W. L. Roelofs. 2003. Molecular Biological Investigations of Pheromone Desaturases. In "Insect Pheromone Biochemistry and Molecular Biology" (Blomquist, G. J. and R. Vogt, Eds.), Acaedmic Press, New York (In Press).
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Progress 01/01/01 to 12/31/01
Outputs
This project focuses on acyl-CoA desaturases that function in the formation of diverse unsaturated fatty acid intermediates in sex pheromone biosynthetic pathways of moths and other insects. The pheromone desaturase gene family arose from ancient gene duplications of acyl-CoA desaturase genes that function in a primary adaptative response to cold. We continue to isolate and sequence cDNAs encoding unique desaturases from agriculturally important species of moths. We express these cDNAs in a desaturase-deficient strain of yeast and determine the unique enzymatic properties of the encoded desaturases by characterizing the unsaturated fatty acids present in the lipid extracts of the transformed yeast strains. Computational approaches assist in our ongoing investigations of acyl-CoA desaturase structure and function. Synthetic pheromones have been shown to provide the basis of a highly specific, nontoxic pest control strategy that complements other integrated pest
management techniques.
Impacts
A practical goal of this research is aimed at identifying desaturases with enzymatic properties that can be used to develop low cost, biologically-based procedures for synthesizing pheromones or other commercial applications requiring unsaturated fatty acid intermediates.
Publications
- Rosenfield, C.-L., K. M. You, P. Marsella-Herrick, W. L. Roelofs, and D. C. Knipple. 2001. Structural and functional conservation and divergence among acyl-CoA desaturase-encoding genes of two noctuid species, the corn earworm, Helicoverpa zea, and the cabbage looper, Trichoplusia ni. Insect Biochem. Molec. Biol. 31: 949-964.
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