title: Molecular cloning of four glutathione peroxidase (GPx) homologs and expression analysis during stress exposure of the marine teleost Sparus aurata.
abstract: Glutathione peroxidase (GPx; EC 1.11.1.9) is an important family of enzymes that protects organisms from oxidative damage. Four full-length GPx cDNAs were cloned and characterized by rapid amplification of cDNA ends polymerase chain reaction (RACE-PCR) from the liver of gilthead sea bream (Sparus aurata), an economically important species for Mediterranean aquaculture. Structural and functional annotations were performed for all paralogs, which suggested possible differences in function and subcellular localization. The phylogenetic analysis, based on the amino acid sequences, revealed four groups corresponding to teleostean GPx1a, GPx1b, GPx4a, and GPx4b and three groups for mammalian GPx1, GPx2 and GPx4. The tree topology indicated past duplication events for fish genes, unlike their mammalian homologs. Transcriptional analysis in ten tissues by reverse transcription quantitative polymerase chain reaction (RT-qPCR) evidenced a tissue-specific pattern for each GPx homolog. Fish experimental groups were exposed to stress factors such as fasting and confinement. Relative expression analysis in fish liver demonstrated that GPx1 genes were not regulated by dietary restriction; GPx4b was differentially expressed opposed to regularly fed fish. On the other hand, both GPx1 and GPx4 genes were up-regulated in fish post exposed to confinement, considered as a response to acute stress. The results underline the role of GPx genes as indicators of stress and welfare status in gilthead sea bream aquaculture.
authors.affiliation: Department of Ichthyology and Aquatic Environment, School of Agricultural Sciences, University of Thessaly, Fytokou str. 38445, Volos, Greece. Electronic address: emalandrak@uth.gr.
authors.forename: Emmanouil E
authors.initials: EE
authors.lastname: Malandrakis
authors.affiliation: Department of Ichthyology and Aquatic Environment, School of Agricultural Sciences, University of Thessaly, Fytokou str. 38445, Volos, Greece.
authors.forename: Athanasios
authors.initials: A
authors.lastname: Exadactylos
authors.affiliation: Department of Ichthyology and Aquatic Environment, School of Agricultural Sciences, University of Thessaly, Fytokou str. 38445, Volos, Greece.
authors.forename: Olga
authors.initials: O
authors.lastname: Dadali
authors.affiliation: Department of Ichthyology and Aquatic Environment, School of Agricultural Sciences, University of Thessaly, Fytokou str. 38445, Volos, Greece.
authors.forename: Eleni
authors.initials: E
authors.lastname: Golomazou
authors.affiliation: Department of Ichthyology and Aquatic Environment, School of Agricultural Sciences, University of Thessaly, Fytokou str. 38445, Volos, Greece.
authors.forename: Spiridon
authors.initials: S
authors.lastname: Klaoudatos
authors.affiliation: Department of Ichthyology and Aquatic Environment, School of Agricultural Sciences, University of Thessaly, Fytokou str. 38445, Volos, Greece.
authors.forename: Panagiota
authors.initials: P
authors.lastname: Panagiotaki
mesh_terms: D000595:Amino Acid Sequence; D000818:Animals; D003001:Cloning, Molecular; D005979:Glutathione Peroxidase / Q000235:genetics* / Q000378:metabolism; D008969:Molecular Sequence Data; D009928:Organ Specificity; D010802:Phylogeny; D021541:Sea Bream / Q000378:metabolism*; D013312:Stress, Physiological; D059467:Transcriptome
chemical_list: D005979:Glutathione Peroxidase
keywords: Antioxidants; Confinement; Fasting; Gene expression; Gilthead sea bream