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Show SPONTANEOUS MUTATIONAL VARIATION FOR BODY SIZE IN CAENORHABDITIS ELEGANS Tracy Carter Senior Biology TracyCarter® mai I .weber.edu Faculty Sponsor: Larissa L. Vassilieva Dept. of Biology Vassilieva@biology.utah.edu In our previous study with 80 lines of C. elegans, 152 generations of accumulation of spontaneous deleterious mutations (SDM) were performed under relaxed selection. It was shown that SDM decreased body volume by 0.1 % of its original value. Giving a mutation rate of -0.0025 per generation. These numbers are somewhat lower than one would expect, based on theoretical understanding of the role of SDM in numerous biological phenomena. However, as it was shown in our lab, estimates of mutational parameters (their statistical significance and values) crucially depend on the duration of a mutation accumulation experiment. Therefore, we repeated the study of SDM properties for body volume for an additional 300 generations of mutation accumulation, ending at genera- tion 450. Similarly to the previous study, individual worms were photographed using a Leica dissecting microscope with a JVCKY-F50 video camera. The images were then recorded to DVD-disk. The worms were measured using 'Image \" which is a program available through the NIH. Measurements obtained are: length (I), perimeter (p) and surface area (a) of the worm image. Body volume was calculated through those three measurements as: body volume(s)= (? (p+O(p2-16a))(p-O(p2-16a)))/256. Results from this study have theoretical significance with understanding better the properties of SDM, which are currently scarce and contradictory. It also is useful on its own for predicting rates of response to artificial selection in long-term agricultural practice. 18 |