Rapid Plasticity In Zooplankton Enzymatic Response To UV Threat

SOUZA, MS, MODENUTTI, B, ESTEBAN BALSEIRO

Puerto Rico -USA

Congreso; ASLO Aquatic Science Meeting; 2011

ASLO

Sunlight’s deleterious effects have been recognized in a variety of zooplankton through direct damage or increase of oxidative stress. However its role as pro-apoptotic stimuli has not been yet studied. This work shows, for the first time, how short-term UVR exposure at natural and sub-lethal levels, simultaneously trigger responses in three different enzyme systems of key cellular processes: Glutathione S-transferase (GST, antioxidant defense), Caspase-3 (CASP-3, apoptosis) and Acetylcholinesterase (AChE, neurotransmitter control) on calanoid copepod Eudiaptomus gracilis. These biomarkers represent early damage (AChE) or physiological responses (GST and CASP-3) acting at hours scalesand helping to handle fluctuations in UVR to keep the organism’s performance. We obtained distinctive effects on enzyme activities with different UVR doses. While the activity of AChE decreased under UVR exposure, the general trend of GST and CASP-3, was an increase in their activities. Changes or dysfunctions in those systems have strong ecological relevance associated with stress response capability (GST), ontogenetic development (CASP-3) and normal neuromuscular function (AChE).