Characterization and expression of superoxide dismutase genes in Chironomus riparius (Diptera, Chironomidae) larvae as a potential biomarker of ecotoxicity.
Superoxide dismutase (SOD, EC 1.15.1.1) is an enzyme involved in the scavenging of reactive oxygen species (ROS) into molecular oxygen and hydrogen peroxide. In this study, a copper-zinc superoxide dismutase (Cu-ZnSOD) gene and a manganese superoxide dismutase (MnSOD) gene in aquatic midge, Chironomus riparius (CrSODs) was identified using an Expressed Sequence Tag (EST) database generated by 454 pyrosequencing. A multiple sequence alignment of C. riparius sequences revealed high homology with other insect sequences in terms of the amino acid level. Phylogenetic analysis of the CrSODs revealed that they were grouped with SODs of other organisms, such as Polypedilum vanderplanki, Drosophila melanogaster, Aedes aegypti, Anopheles gambiae, Culex quinquefasciatus and Bombyx mori. Expression of the corresponding CrSODs was analyzed during different developmental stages and following exposure to various environmental contaminants with different mode of actions i.e., paraquat, cadmium, benzo[a]pyrene, and chloropyrifos. CrSOD gene expression was significantly up or down regulated in response to exposure to the chemicals tested. The overall results suggested that SOD gene expression provided a platform for the understanding of oxidative stress responses caused by exposure to various environmental contaminants, and the SOD genes could be used as biomarkers for environmental disturbances such as oxidative stress initiated by xenobiotics.
School of Environmental Engineering and Graduate School of Energy and Environmental System Engineering, University of Seoul, 90 Jeonnong-dong, Seoul 130-743, Republic of Korea.
Sun-Young
SY
Park
Prakash M Gopalakrishnan
PM
Nair
Jinhee
J
Choi
D000595:Amino Acid Sequence; D000818:Animals; D001564:Benzo(a)pyrene / Q000633:toxicity; D015415:Biomarkers / Q000378:metabolism; D002104:Cadmium / Q000633:toxicity; D002683:Chironomidae / Q000201:enzymology / Q000235:genetics* / Q000254:growth & development; D009033:Culicidae / Q000201:enzymology / Q000235:genetics; D004784:Environmental Monitoring / Q000379:methods; D020224:Expressed Sequence Tags; D005260:Female; D018507:Gene Expression Regulation, Developmental; D015971:Gene Expression Regulation, Enzymologic; D017344:Genes, Insect; D007814:Larva / Q000201:enzymology / Q000235:genetics; D008297:Male; D008969:Molecular Sequence Data; D018384:Oxidative Stress; D010269:Paraquat / Q000633:toxicity; D010802:Phylogeny; D016415:Sequence Alignment; D017386:Sequence Homology, Amino Acid; D013482:Superoxide Dismutase / Q000235:genetics / Q000378:metabolism*; D018675:Toxicity Tests / Q000379:methods
D015415:Biomarkers; D002104:Cadmium; D001564:Benzo(a)pyrene; D013482:Superoxide Dismutase; D010269:Paraquat