Article ID | Journal | Published Year | Pages | File Type |
---|---|---|---|---|
5848895 | Environmental Toxicology and Pharmacology | 2013 | 9 Pages |
â¢Glutathione biosynthesis genes from Chironomus riparius were characterized.â¢Transcriptional regulation of GSH biosynthesis genes was studied after exposure to Cd and NP.â¢Modulation in the expression of GSH biosynthesis genes was observed after exposure to Cd and NP.â¢Potentially used as biomarkers of Cd and NP stress in aquatic environment.
We characterized Chironomus riparius glutathione (GSH) biosynthesis genes, γ-glutamyl-cysteine ligase catalytic subunit (cr-gcl) and glutathione synthetase (cr-gs) and studied their expression after cadmium (Cd) and nonylphenol (NP) exposure. The full length cDNA of the Cr-GCL catalytic subunit was 2185 base pair (bp) in length containing an open reading frame of 1905 bp, a 13 bp 5Ⲡand 267 bp 3Ⲡuntranslated regions. The theoretical molecular mass of the deduced amino acid sequence (633) was 72.65 kDa with an estimated pI of 5.42. The partial cDNA of Cr-GS was 739 bp in length consisting 221 amino acids. The deduced amino acid sequence of Cr-GCL and Cr-GS cDNAs showed high conservation with homologs from other species. In phylogenetic analysis Cr-GCL and Cr-GS were grouped with equivalent genes from insects belonging to the dipteran order. The expression of cr-gcl and cr-gs was measured using quantitative real-time PCR after exposure to sub lethal concentrations of Cd (2, 10 and 20 mg/L) and NP (10, 50 and 100 μg/L) for 12, 24, 48 and 72 h using real-time PCR methods. The mRNA expression of Cr-GCL and Cr-GS was significantly modulated after exposure to different concentrations of Cd and NP for different time periods. Total GSH levels showed a non-significant decrease after exposure to Cd for 24 h. However, no change in GSH levels was observed after exposure to NP for 24 h. These results suggest that Cr-GS and Cr-GCL expression is modulated by Cd and NP stress and may play an important role in detoxification of xenobiotics and antioxidant defense. We conclude that Cr-GS and Cr-GCL could be used as biomarkers of Cd and NP stress in aquatic environment for the studied species.