Meeting Abstract
Many sea urchins play important ecological roles in their environments, and it is important to study the impacts of environmental stressors on their physiology. Ultraviolet radiation (UVR) exposure has significant negative impacts on marine organisms including an increase in reactive oxygen species (ROS). Oxidative damage by ROS at the cellular level can cause lipid peroxidation, DNA fragmentation, and even cell death which may result in inflammation or disease. To prevent this cellular damage, organisms generate enzymes, such as superoxide dismutase (SOD) and catalase, that breakdown ROS into harmless substances. Elevated SOD and catalase activities under UVB exposure have been detected for many aquatic organisms, yet it is unknown whether UVB exposure affects the activity of these antioxidant enzymes in many sea urchin species. Lytechinus variegatus is well known for its covering behavior in response to UVR exposure whereas Arbacia punctulata does not cover with any materials and remains fully exposed. Whether these behavioral differences result in differences in antioxidant enzyme activity in response to UVR exposure is not known. In this study, coelomocytes of L. variegatus and A. punctulata were exposed to UVB (302 nm) for two hours and catalase activity was measured using colorimetric assays. Results suggest UVB exposure significantly decreased catalase activity in the coelomocytes of both species (t-test, p < 0.0001, L.variegatus, p = 0.0097, A. punctulata). Whether these observed differences in antioxidant activity are associated with covering behavior is yet to be determined.
