Photoreactivation is the main repair pathway for UV-induced DNA damage in coral planulae
Author:
Reef Ruth1, Dunn Simon1, Levy Oren12, Dove Sophie1, Shemesh Eli2, Brickner Itzchak3, Leggat William14, Hoegh-Guldberg Ove1
Affiliation:
1. Centre for Marine Studies and the ARC Centre of Excellence for Coral Reef Studies, The University of Queensland, St Lucia, QLD 4072 Australia 2. The Mina and Everard Goodman Faculty of Life Sciences, Bar Ilan University,Ramat-Gan 52900, Israel 3. Department of Zoology, George S. Wise Faculty of Life Sciences, Tel Aviv University, Tel Aviv 69978, Israel 4. Comparative Genomics Centre, School of Pharmacy and Molecular Sciences and the ARC Centre of Excellence for Coral Reef Studies, James Cook University,Townsville, QLD 4811, Australia
Abstract
SUMMARY
The larvae of most coral species spend some time in the plankton, floating just below the surface and hence exposed to high levels of ultraviolet radiation (UVR). The high levels of UVR are potentially stressful and damaging to DNA and other cellular components, such as proteins, reducing survivorship. Consequently, mechanisms to either shade (prevent) or repair damage potentially play an important role. In this study, the role of photoreactivation in the survival of coral planulae was examined. Photoreactivation is a light-stimulated response to UV-damaged DNA in which photolyase proteins repair damaged DNA. Photoreactivation rates, as well as the localization of photolyase, were explored in planulae under conditions where photoreactivation was or was not inhibited. The results indicate that photoreactivation is the main DNA repair pathway in coral planulae, repairing UV-induced DNA damage swiftly (K=1.75 h–1 and a half-life of repair of 23 min), with no evidence of any light-independent DNA repair mechanisms, such as nucleotide excision repair (NER), at work. Photolyase mRNA was localized to both the ectoderm and endoderm of the larvae. The amount of cell death in the coral planulae increased significantly when photoreactivation was inhibited, by blocking photoreactivating light. We found that photoreactivation, along with additional UV shielding in the form of five mycosporine-like amino acids, are sufficient for survival in surface tropical waters and that planulae do not accumulate DNA damage despite being exposed to high UVR.
Publisher
The Company of Biologists
Subject
Insect Science,Molecular Biology,Animal Science and Zoology,Aquatic Science,Physiology,Ecology, Evolution, Behavior and Systematics
Reference52 articles.
1. Arai, I., Kato, M., Heyward, A., Ikeda, Y., Iizuka, T. and Maruyama, T. (1993). Lipid composition of positively buoyant eggs of reef building corals. Coral Reefs12, 71-75. 2. Babcock, R. C., Bull, G. D., Harrison, P. L., Heyward, A. J.,Oliver, J. K., Wallace, C. C. and Willis, B. L. (1986). Synchronous spawnings of 105 scleractinian coral species on the Great Barrier Reef. Mar. Biol.90,379-394. 3. Baker, K. S., Smith, R. C. and Green, A. E. S.(1980). Middle ultraviolet radiation reaching the ocean surface. J. Photochem. Photobiol. B.32,367-374. 4. Ball, E. E., Hayward, D. C., Saint, R. and Miller, D. J.(2004). A simple plan-cnidarians and the origins of developmental mechanisms. Nat. Rev. Genet.5, 567-577. 5. Banaszak, A., LaJeunesse, T. C. and Trench, R. K.(2000). The synthesis of mycosporine-like amino acids (MAAs) by cultured, symbiotic dinoflagellates. J. Exp. Mar. Biol. Ecol.249,219-233.
Cited by
35 articles.
订阅此论文施引文献
订阅此论文施引文献,注册后可以免费订阅5篇论文的施引文献,订阅后可以查看论文全部施引文献
|
|