title: Identification and mRNA expression of pi-class glutathione S-transferase and selenium-dependent glutathione peroxidase in the gudgeon Gobio gobio exposed to PCB 77.
abstract: In aquatic environments some pollutants are present in water and sediments and organisms possess cellular detoxification systems to face up these xenobiotics. The gudgeon, Gobio gobio, is a freshwater benthopelagic fish that appears particularly adequate for an ecotoxicological assessment of rivers. The aim of this study was the identification of GST and GPx genes in this organism in order to develop new indicators of early exposure to xenobiotics in aquatic environments. Reverse-transcription PCR using degenerate primers and RACE-PCR allowed us to identify a selenium-dependent glutathione peroxidase (Se-GPx), belonging to the class one (GPx-1), and a pi-class glutathione S-transferase (pi-GST) cDNAs. These sequences encoded for 191 and 208 amino acids proteins respectively, they exhibit high identities and similarities with corresponding proteins in other fish and the residues essential to the enzymatic functions are highly conserved. The expression patterns of these two mRNA were established by real-time PCR in five gudgeon tissues: liver, gills, kidney, spleen and muscle. The mRNA levels of these genes were highest in the liver and their expression in the other tissues exhibited some differences. Gudgeons exposed to PCB 77 in the food exhibited an increase in pi-GST mRNA and a decrease in GPx-1 transcripts levels in the liver. However, no modification of the enzymatic activities was observed. The present study provides the first transcriptional data regarding pi-GST and GPx-1 in the gudgeon Gobio gobio.
authors: Department, Environment and Agro-biotechnologies, Centre de Recherche Public-Gabriel Lippmann, rue du Brill, 4422 Belvaux, Luxembourg.
authors: Périne
authors: P
authors: Doyen
authors: François
authors: F
authors: Rodius
authors: Lionel
authors: L
authors: L'hoste
authors: Lucien
authors: L
authors: Hoffmann
authors: Henry-Michel
authors: HM
authors: Cauchie
mesh_terms: D000595:Amino Acid Sequence; D000818:Animals; D003001:Cloning, Molecular; D003530:Cyprinidae / Q000235:genetics* / Q000378:metabolism; D018076:DNA, Complementary / Q000737:chemistry / Q000235:genetics; D029941:Fish Proteins / Q000235:genetics* / Q000378:metabolism; D020869:Gene Expression Profiling; D015971:Gene Expression Regulation, Enzymologic / Q000187:drug effects*; D005979:Glutathione Peroxidase / Q000235:genetics* / Q000378:metabolism; D051549:Glutathione S-Transferase pi / Q000235:genetics* / Q000378:metabolism; D008099:Liver / Q000187:drug effects / Q000201:enzymology / Q000378:metabolism; D008969:Molecular Sequence Data; D011078:Polychlorinated Biphenyls / Q000633:toxicity*; D012333:RNA, Messenger / Q000235:genetics / Q000378:metabolism; D020133:Reverse Transcriptase Polymerase Chain Reaction; D012643:Selenium / Q000378:metabolism; D017422:Sequence Analysis, DNA; D017386:Sequence Homology, Amino Acid; D013997:Time Factors; D014874:Water Pollutants, Chemical / Q000633:toxicity; D000094765:Glutathione Peroxidase GPX1
chemical_list: D018076:DNA, Complementary; D029941:Fish Proteins; D012333:RNA, Messenger; D014874:Water Pollutants, Chemical; D011078:Polychlorinated Biphenyls; D005979:Glutathione Peroxidase; D051549:Glutathione S-Transferase pi; D012643:Selenium; C028451:3,4,3',4'-tetrachlorobiphenyl; D000094765:Glutathione Peroxidase GPX1