| Popis: |
Cytochrome P450 are key detoxification enzymes which are potentially induced by xenobiotics such as environmental contaminants. Thus, induction features of some cytochrome P450 are used as biomarkers. Many studies use enzyme activities to detect this induction, but this can also be monitored by protein or mRNA quantitation. There are about 80 different cytochrome P450 genes in vertebrates, but only few sequences are available in fish. Family 1, 2 and 3 are now well studied, but mostly in trout. We isolated CYP1A and CYP4T2 sequences in the sea bass Dicentrarchus labrax, which is considered as an excellent sentinel species in the Mediterranean sea. CYP1A isoform is induced by PAHs, PCBs, and dioxins, and some CYP4 isoforms are known to be induced by phthalate esters plasticizers and chlorinated aryl phenoxy herbicides. We characterize the induction of the genes by these environmental contaminants in several organs. This study gives some knowledge about cytochrome P450 gene regulation in the sea bass, which is essential for further use of these genes as biomarkers. Quantitation of mRNA could be used as additional tools to report CYP1A and CYP4T2 induction, and could lead to the development of efficient biomarkers for these class of marine pollutants. |
