Algal Symbionts Increase DNA Damage in Coral Planulae Exposed to Sunlight

Badrun Nesa, Andrew H Baird, Saki Harii, Irina Yakovleva, and Michio Hidaka (2012) Algal symbionts increase DNA damage in coral planulae exposed to sunlight. Zoological Studies 51(1): 12-17. To test the hypothesis that algal symbionts make coral larvae more susceptible to high photosynthetically active radiation (PAR) and ultraviolet radiation (UVR), symbiotic and non-symbiotic planulae of Acropora tenuis were exposed to natural sunlight (high PAR and UVR) at an ambient temperature of approximately 27 degrees C for 4 d. DNA damage to host cells was detected using a comet assay (single-cell gel electrophoresis). Coral cells from symbiotic planulae had longer comet tails than those from non-symbiotic planulae, indicating that cells in symbiotic larvae had more DNA damage than those in non-symbiotic larvae. This result suggests that symbiotic algae are a source of oxidative stress in larvae under conditions at the ocean surface. http://zoolstud.sinica.edu.tw/Journals/51.1/12.pdf