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EFFECTS OF LOW TEMPERATURE ON THE SURVIVABILITY AND MOTILITY OF LIQIUD CULTURES OF C. ELEGANS.  C. Butts1, J. Jamison3, J. Cohen5, L. Dali2, J. Tillman2, P. Dumars2 and B. Girten4.  Dept of Biology, Paine College, Augusta, Georgia1, Lockheed Martin2, NAFEO3, NASA Ames Research Center4 and STC5. Moffett Field, CA.

   Caenorhabditis elegans has been selected as a model specimen for a variety of scientific disciplines including space flight research.  Our tests on the effects of temperature on C. elegans survivability will enable optimization of experimental design and subsequent data analysis for planned space flight experiments utilizing C. elegans as a model system.  The determination of thermotolerance is a fundamental area that must be further characterized. In this study we assessed the effects of 5°C and 15°C and a thermal cycle ranging from 5°C to 35°C on C. elegans survivability and motility.  C. elegans cultured in liquid media were placed in either Fluoroseal bags or T25 tissue culture flasks.  They were then exposed to the various temperatures stated and daily observations were made.  Thermotolerance was assessed by measuring survivability and motility. The results indicate that C. elegans exposed to a thermal cycle ranging from 5°C to 35°C are not significantly different in terms of survivability (p=0.5303, day 9).  The thermal cycle, however, was deleterious to behavior, as witnessed by abnormal morphology and motility.  The data also show that exposure to 5°C and 15°C results in a significant decrease in survivability (5°C, day 5, p=0.0769; day 6, p=0.4315; day 9, p=0.0375) (15°C, day 1, p=0.2463; day 2, p=0.0008; day 3, p=0.0037; day 5, p=0.0040).  In summary this study demonstrates that low temperatures (5°C and 15°C) decreases survivability and increases abnormal motility and shows that thermal cycling (5°C to 35°C) has a significant deleterious effect on behavior.