Methodologies for Inducing Cryptobiosis in Tardigrades
Nora C Gardner
Committee: Bob Eckstein, Langdon Martin, JJ Apodaca
Traditionally Drosophila melanogaster and Caenorhabditis elegans have been used as model organisms for researching genetics. Both are members of the superphylum Ecdysozoa. Another member of Ecdysozoa is the phylum tardigrada. The focal species of this experiment, Hypsibius dujardini, is part of the class Eutardigrada and lives primarily in fresh water and mosses. Like some other species of tardigrades H. dujardini can enter cryptobiosis, but because they are water dwelling entering cryptobiosis must be a gradual process, taking up to several days for individuals to desiccate completely. Hypsibius dujardini is renowned for having the smallest known genome in their phylum at 75 Mb. With all of these factors in mind using H. dujardini as a model for genetic studies could yield interesting results. This study was conducted to determine whether or not cryptobiosis could be successfully induced in H. dujardini on Warren Wilson College campus.
The specimens were ordered from Sciento labs at the advice of the Goldstein Lab and University of North Carolina at Chapel Hill. Three treatments were used with 50 individuals per treatment for a total of one hundred fifty individuals. Some were kept at high humidity for a few days while others were placed in sealed containers. After the individuals were completely desiccated they were rehydrated. The number of those that came out of cryptobiosis was found and survival rates were calculated. Two of the three treatments had very similar survival rates, whereas the third treatment had no survivors. While survivor rates were low, this experiment yielded useful results.