TY - JOUR UR - https://doi.org/10.7287/peerj.preprints.26765v1 DO - 10.7287/peerj.preprints.26765v1 TI - Antioxidant enzyme cycling over reproductive lunar cycles in Pocillopora damicornis AU - Murphy,James WA AU - Collier,Abby C AU - Richmond,Robert H DA - 2018/03/23 PY - 2018 KW - enzymes KW - glutathione peroxidase KW - superoxide dismutase KW - lunar cycling KW - coral KW - glutathione reductase KW - antioxidant defense KW - catalase AB - The impacts of continued degradation of watersheds on coastal coral reefs world-wide is alarming. Action addressing anthropogenic stressors and subsequent rehabilitation of watersheds and adjacent reefs is an urgent priority. The aim of this study is to develop and improve the use of antioxidant enzymes as biomarkers in coral species. In order to fully develop such tools, it is necessary to perform sampling of coral tissues over reproductive cycles to determine variations from baseline. By developing a greater understanding of biochemical markers of stress in corals, specifically antioxidant defense enzymes: superoxide dismutase (SOD), catalase (CAT), glutathione peroxidase (GPx), and glutathione reductase (GR), we have provided molecular tools that identify thresholds of stress on coral reefs. Our results suggest that the coral reproductive state is a significant factor affecting the activity of antioxidant enzymes. Specifically, CAT (65.92 mmol/min/mg protein, p = 0.0177) and GR (12.64 nmol/min/mg protein, p < 0.0001) display maximum activity during peak reproductive state. Whereas significant maximal SOD (154.92 nmol/min/mg protein, p < 0.0454) and Se-independent GPx (5.35 nmol/min/mg protein, p = 0.0001) activity was measured during off-peak reproductive cycles. Such insight into the cyclical variation of the activity of these enzymes should be applied towards differentiating the influence of natural biological activity cycling in diagnostic tests identifying the effects of different physical environmental factors and chemical pollutants on coral health. Through the development and application of these molecular biomarkers of stress, we look to improve our ability to identify problems at the sub-lethal level, when action can be taken to mitigate a/biotic impacts. VL - 6 SP - e26765v1 T2 - PeerJ Preprints JO - PeerJ Preprints J2 - PeerJ Preprints SN - 2167-9843 ER -