Characterization of new Caenorhabditis elegans lines with a high thermotolerance

The lines of Caenorhabditis elegans displaying low (LT) and high (HT1, HT2, and HT3) thermotolerance were obtained from the wild line N2 by artificial selection for thermostability of locomotion and by natural selection in laboratory for thermotolerance of fertility under tolerable environmental temperature elevation. All these lines are new genetic variants that emerged during the experiment. The worms of lines HT2 and HT3 displayed an elevated upper temperature limit for reproduction (from 26 to 27.5 degrees C), thermostability of locomotion at 36 degrees C, and survival at 37 degrees C as compared with the line N2. The results have demonstrated that adaptation of C. elegans to high temperatures is an appropriate laboratory model for studying the mechanisms involved in the evolution of thermotolerance of poikilothermic Metazoa.