Identification and expression of multiple CYP1-like and CYP3-like genes in the bivalve mollusk Mytilus edulis

• Published in: Aquatic toxicology Vol. 128-129; pp. 101 - 112
• Main Authors: Zanette, Juliano, Jenny, Matthew J., Goldstone, Jared V., Parente, Thiago, Woodin, Bruce R., Bainy, Afonso C.D., Stegeman, John J.
• Format: Journal Article
• Language: English
• Published: Amsterdam Elsevier B.V 15.03.2013; Elsevier
• Subjects: agonists; AHR; Animal, plant and microbial ecology; Animals; Applied ecology; Biological and medical sciences; biomarkers; biotransformation; biphenyl; Bivalvia; Blue mussel; CYP; cytochrome P-450; Cytochrome P-450 Enzyme System - genetics; Cytochrome P-450 Enzyme System - metabolism; Cytochrome P450; Ecotoxicology, biological effects of pollution; Fish Proteins - genetics; Fish Proteins - metabolism; Fundamental and applied biological sciences. Psychology; gene activation; Gene Expression Profiling; Gene Expression Regulation - drug effects; General aspects; genes; Invertebrates; lipids; Marine; Mollusca; mussels; Mytilus edulis; Mytilus edulis - drug effects; Mytilus edulis - genetics; Mytilus edulis - metabolism; palps; Pollution; polychlorinated biphenyls; Polychlorinated Biphenyls - toxicity; quantitative polymerase chain reaction; Receptors, Aryl Hydrocarbon - agonists; vertebrates; Water Pollutants, Chemical - toxicity; Blue mussel; Pollution; CYP; AHR; Mytilus edulis; Cytochrome P450; Ecotoxicology; Toxicity; Biological marker; Aquatic environment; Bivalvia; Invertebrata; Mollusca
• ISSN: 0166-445X; 1879-1514
• DOI: 10.1016/j.aquatox.2012.11.017

► Five new CYP genes were characterized in the blue mussel, Mytilus edulis. ► Transcript levels of these CYPs were highest in digestive gland and labial palps. ► Ligands for vertebrate AHR did not elicit increased expression of mussel CYP1-like genes. ► Two CYP3-like genes, but not the CYP1-like genes, were responsive to AHR agonists. ► Mechanisms of CYP gene activation in M. edulis remain unknown. Various sequencing projects over the last several years have aided the discovery of previously uncharacterized invertebrate sequences, including new cytochrome P450 genes (CYPs). Here we present data on the identification and characterization of two CYP1-like and three CYP3-like genes from the bivalve mollusk Mytilus edulis, and assess their potential as biomarkers based on their responses to several known vertebrate aryl hydrocarbon receptor (AHR) agonists. Quantitative real-time PCR was used to measure CYP transcript levels in digestive gland, labial palps, adductor muscle, gill, foot, and different regions of the mantle. Levels of both CYP1-like genes were highest in digestive gland, whereas labial palps had the highest expression levels of the three CYP3-like genes followed by digestive gland and outer margin of the mantle. Mussels were exposed by injection to the AHR agonists, β-naphthoflavone (BNF; 25μgg−1), 3,3′,4,4′,5-polychlorinated biphenyl (PCB126; 2μgg−1), or 6-formylindolo[3,2-b]carbazole (FICZ; 0.1μgg−1), or to Aroclor 1254 (a mixture of PCBs; 50μgg−1) for 24h, followed by CYP expression analysis. There was no statistically significant change in expression of either of the CYP1-like genes after exposure to the various AHR agonists. The CYP3-like-1 gene was significantly up-regulated by BNF in gill tissues and the CYP3-like-2 gene was up-regulated in digestive gland by PCB126 and in gill tissue by BNF. These results suggest that distinct mechanisms of CYP gene activation could be present in M. edulis, although the importance of the CYP1-like and CYP3-like genes for xenobiotic and endogenous lipids biotransformation requires additional investigation.