title: Crude oil exposure results in oxidative stress-mediated dysfunctional development and reproduction in the copepod Tigriopus japonicus and modulates expression of cytochrome P450 (CYP) genes.
abstract: In this study, we investigated the effects of the water-accommodated fraction (WAF) of crude oil on the development and reproduction of the intertidal copepod Tigriopus japonicus through life-cycle experiments. Furthermore, we investigated the mechanisms underlying the toxic effects of WAF on this benthic organism by studying expression patterns of cytochrome P450 (CYP) genes. Development of T. japonicus was delayed and molting was interrupted in response to WAF exposure. Hatching rate was also significantly reduced in response to WAF exposure. Activities of antioxidant enzymes such as glutathione S-transferase (GST), glutathione reductase (GR), and catalase (CAT) were increased by WAF exposure in a concentration-dependent manner. These results indicated that WAF exposure resulted in oxidative stress, which in turn was associated with dysfunctional development and reproduction. To evaluate the involvement of cytochrome P450 (CYP) genes, we cloned the entire repertoire of CYP genes in T. japonicus (n=52) and found that the CYP genes belonged to five different clans (i.e., Clans 2, 3, 4, mitochondrial, and 20). We then examined expression patterns of these 52 CYP genes in response to WAF exposure. Three TJ-CYP genes (CYP3024A2, CYP3024A3, and CYP3027C2) belonging to CYP clan 3 were significantly induced by WAF exposure in a time- and concentration-dependent manner. We identified aryl hydrocarbon responsive elements (AhRE), xenobiotic responsive elements (XREs), and metal response elements (MRE) in the promoter regions of these three CYP genes, suggesting that these genes are involved in detoxification of toxicants. Overall, our results indicate that WAF can trigger oxidative stress and thus induce dysfunctional development and reproduction in the copepod T. japonicus. Furthermore, we identified three TJ-CYP genes that represent potential biomarkers of oil pollution.
authors.affiliation: Department of Biological Sciences, College of Science, Sungkyunkwan University, Suwon 440-746, South Korea.
authors.forename: Jeonghoon
authors.initials: J
authors.lastname: Han
authors.affiliation: Department of Biological Sciences, College of Science, 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 Science, Sungkyunkwan University, Suwon 440-746, South Korea.
authors.forename: Dae-Sik
authors.initials: DS
authors.lastname: Hwang
authors.affiliation: Department of Environmental Marine Sciences, College of Science and Technology, Hanyang University, Ansan 426-791, South Korea.
authors.forename: Kyung-Hoon
authors.initials: KH
authors.lastname: Shin
authors.affiliation: Graduate School of Biomedical Science and Engineering, Hanyang University, Seoul 133-791, South Korea.
authors.forename: Yong Sung
authors.initials: YS
authors.lastname: Lee
authors.affiliation: School of Biological Sciences and The Swire Institute of Marine Science, The University of Hong Kong, Pokfulam, Hong Kong, China.
authors.forename: Kenneth Mei-Yee
authors.initials: KM
authors.lastname: Leung
authors.affiliation: Department of Life Science, College of Natural Sciences, Hanyang University, Seoul 133-791, South Korea.
authors.forename: Su-Jae
authors.initials: SJ
authors.lastname: Lee
authors.affiliation: Department of Biological Sciences, College of Science, 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 / Q000145:classification / Q000187:drug effects* / Q000201:enzymology / Q000235:genetics; D003577:Cytochrome P-450 Enzyme System / Q000235:genetics*; D005786:Gene Expression Regulation / Q000187:drug effects*; D048788:Growth and Development / Q000187:drug effects; D018384:Oxidative Stress / Q000187:drug effects*; D010088:Oxidoreductases / Q000235:genetics; D010578:Petroleum / Q000633:toxicity*; D010802:Phylogeny; D011401:Promoter Regions, Genetic / Q000235:genetics; D012098:Reproduction / Q000187:drug effects; D014874:Water Pollutants, Chemical / Q000633:toxicity*
chemical_list: D010578:Petroleum; D014874:Water Pollutants, Chemical; D003577:Cytochrome P-450 Enzyme System; D010088:Oxidoreductases
keywords: CYP; Copepod; Cytochrome P450; Oxidative stress; Tigriopus japonicus; Water accommodated fraction