West Coast Worm Meeting Abstracts - Caenorhabditis elegans ...

POLYUNSATURATED FATTY ACIDS REQUIREMENTS FOR
PROPER FUNCTIONING OF THE NERVOUS SYSTEM
Jenny Watts, John Browse
West Coast Worm Meeting 2000
Institute of Biological Chemistry, Washington State University, Pullman, WA 99164-6340
Polyunsaturated phospholipids are critical for the function of excitable membranes. Membrane-mediated
information transfers are intimately related to the biochemical events that occur within the neuronal
plasma membrane. Polyunsaturated fatty acid components of phospholipids are necessary to create a
fluid environment as well as to provide precursors of second messenger signaling molecules. C. elegans
can synthesize a wide range of polyunsaturated fatty acids using only saturated and monounsaturated
fatty acids from E. coli as precursors. In order to study the role of polyunsaturated fatty acids in the
nervous system, we designed a unique biochemical screen which enabled us to isolate a number of
mutant lines exhibiting a range of altered fatty acid compositions. We discovered that many of the
mutations are in known desaturase genes that encode enzymes responsible for inserting double bonds
into a fatty acid chain. The phenotypes of these strains range from no apparent defects in strains lacking
specific classes of 20-carbon polyunsaturated fatty acids to severe locomotion defects and impaired
defecation in strains with more extreme alterations in fatty acid composition. These more extreme strains
also grow slowly and display temperature sensitive embryonic lethality. Providing the worms with dietary
polyunsaturated fatty acids rescues these defects. We are currently performing assays of neurological
function on the whole range of mutants, both unsupplemented and supplemented with various fatty acids.
Comparison of the worm fatty acid composition with the severity of neurological defects will allow us to
determine the polyunsaturated fatty acid requirements for proper movement and behavior.
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