Discipline: Biological Sciences
Subcategory: Ecology
Session: 2
Room: Virginia B
Adedamola Olatoregun - Texas Southern University
Tardigrades are invertebrate aquatic organisms that belong to the phylum Tardigradia. They are microscopic varying in size from 0.1 to 2mm and are members of the Ecdysozoa superphylum. They are found in both freshwater and moist terrestrial areas with a widespread distribution that makes them potential bio indicators. Their transparent bodies, ease of cultivation and the ability to reproduce both sexually and asexually are advantages that make tardigrades ideal for use as a model in toxicology screening. Studies have shown some shared biochemical pathways with humans, however not much research has been done looking into the potential use of tardigrades as biological model for environmental risk assessment. Using cadmium, a heavy metal that occurs in nature which is also an environmental toxicant that causes damage to cells via depletion of antioxidants leading to accumulation of reactive oxygen species. Several endpoints including survival, protein expression, gene expression and DNA damage will be used to assess the viability of tardigrades as bio indicators. The findings of this study would further contribute to the current literature on tardigrade and its evolving role in ecotoxicology. Tardigrades (H. dujardini) were cultured with distilled water, and incubated at 21 °C. They were fed Clorococcum hypnosporum twice a week and subsequently divided into two groups, a control and exposure group. The exposure group were exposed to varying concentrations of cadmium to determine EC50 over 24 hrs. Singh’s single cell gel electrophoresis protocol was also modified and used to evaluate DNA damage in both groups. Western immunoblot analysis was also used to analyze protein degradation In the exposure group both 0.1mg/ml and 0.2mg/ml had dropped down to 0% survival after 12hrs, the 0.05mg/ml concentration was at 60% survival and stayed at that rate over 24hrs. The results of the comet seemed to be inconclusive as no significant comet trails were observed in the first set of assays run. Protein degradation was seen in the cells that were exposed to cadmium with no notable degradation in the control. To conclude, Tardigrade seem to carry a huge potential as screening models for toxicity based on the lethality and increased protein expression following exposure to a toxicant. Future studies will focus on Metallothionein and Heat shock protein 70 assays.
Funder Acknowledgement(s): Award Number P031B090216;Title III, Part B, Historically Black Graduate Institutions (HBGI) (CFDA No. 84.031B
Faculty Advisor: Dr Sodipe, ayodotun.sodipe@tsu.edu
Role: I did all parts of the research