title: Molecular cloning and expression study of pi-class glutathione S-transferase (pi-GST) and selenium-dependent glutathione peroxidase (Se-GPx) transcripts in the freshwater bivalve Dreissena polymorpha.
abstract: Glutathione S-transferases (GST) and glutathione peroxidases (GPx) are essential components of cellular detoxification systems. We identified GST and GPx transcripts in the freshwater bivalve Dreissena polymorpha, their full-length coding sequences were obtained by reverse-transcription PCR using degenerated primers followed by 5' and 3' RACE-PCR (rapid amplification of cDNA ends-PCR). The cDNA identified encoded proteins of 205 and 243 amino acids corresponding respectively to a pi-class GST and a selenium-dependent GPx. The comparison of the deduced amino acid sequences with GST and GPx from other species showed that the residues essential to the enzymatic function of these two proteins are highly conserved. We studied their expression pattern in the digestive gland, the gills and the excretory system of D. polymorpha. The results showed that pi-GST mRNA expression is higher in the digestive gland than in the gills or the excretory system. Se-GPx transcripts are expressed at high, medium and very low levels in the digestive gland, the excretory system and the gills, respectively.
authors.affiliation: Lab. IEBE: Interactions Ecotoxicité, Biodiversité, Ecosystèmes - CNRS UMR 7146, Université de Metz, rue Delestraint, 57070 Metz, France.
authors.forename: Périne
authors.initials: P
authors.lastname: Doyen
authors.forename: Aurélie
authors.initials: A
authors.lastname: Bigot
authors.forename: Paule
authors.initials: P
authors.lastname: Vasseur
authors.forename: François
authors.initials: F
authors.lastname: Rodius
mesh_terms: D000595:Amino Acid Sequence; D000818:Animals; D001483:Base Sequence; D003001:Cloning, Molecular; D017124:Conserved Sequence; D004064:Digestive System / Q000201:enzymology; D049875:Dreissena / Q000201:enzymology* / Q000235:genetics; D005618:Fresh Water; D015971:Gene Expression Regulation, Enzymologic; D005880:Gills / Q000201:enzymology; D005979:Glutathione Peroxidase / Q000032:analysis* / Q000235:genetics; D051549:Glutathione S-Transferase pi / Q000032:analysis* / Q000235:genetics; D008969:Molecular Sequence Data; D012333:RNA, Messenger / Q000378:metabolism*; D020133:Reverse Transcriptase Polymerase Chain Reaction; D012643:Selenium / Q000378:metabolism*; D017422:Sequence Analysis, DNA; D020539:Sequence Analysis, Protein; D017386:Sequence Homology, Amino Acid