title: Gamma radiation induces growth retardation, impaired egg production, and oxidative stress in the marine copepod Paracyclopina nana.
abstract: Accidental nuclear radioisotope release into the ocean from nuclear power plants is of concern due to ecological and health risks. In this study, we used the marine copepod Paracyclopina nana to examine the effects of radioisotopes on marine organisms upon gamma radiation, and to measure the effects on growth and fecundity, which affect population and community structure. Upon gamma radiation, mortality (LD50 - 96 h=172 Gy) in P. nana was significantly increased in a dose-dependent manner in ovigerous P. nana females. For developmental impairment of gamma-irradiated nauplii, we observed growth retardation; in over 30 Gy-irradiated groups, offspring did not grow to adults. Particularly, over 50 Gy-irradiated ovigerous P. nana females did not have normal bilateral egg sacs, and their offspring did not develop normally to adulthood. Additionally, at over 30 Gy, we found dose-dependent increases in oxidative levels with elevated antioxidant enzyme activities and DNA repair activities. These findings indicate that gamma radiation can induce oxidative stress and DNA damage with growth retardation and impaired reproduction.
authors.affiliation: Department of Biological Sciences, College of Natural Sciences, Sungkyunkwan University, Suwon 440-746, South Korea.
authors.forename: Eun-Ji
authors.initials: EJ
authors.lastname: Won
authors.affiliation: Department of Biological Sciences, College of Natural Sciences, Sungkyunkwan University, Suwon 440-746, South Korea. Electronic address: jslee2@skku.edu.
authors.forename: Jae-Seong
authors.initials: JS
authors.lastname: Lee
mesh_terms: D000818:Animals; D033342:Copepoda / Q000528:radiation effects*; D004249:DNA Damage / Q000528:radiation effects; D005260:Female; D005720:Gamma Rays; D008018:Life Cycle Stages / Q000528:radiation effects; D052287:Oviparity / Q000528:radiation effects; D018384:Oxidative Stress / Q000528:radiation effects*; D010088:Oxidoreductases / Q000378:metabolism; D017382:Reactive Oxygen Species / Q000032:analysis; D014875:Water Pollutants, Radioactive / Q000633:toxicity*
chemical_list: D017382:Reactive Oxygen Species; D014875:Water Pollutants, Radioactive; D010088:Oxidoreductases
keywords: Antioxidant mechanism; DNA repair; Gamma radiation; Growth retardation; Marine copepod; Oxidative stress