DIFFERENT PRIMARY TOXIC SENSITIVITY ON EMBRYONIC FISH EXPOSED TO IRANIAN HEAVY CRUDE OIL MALFORMATION AND CYP1A EXPRESSIONY

Abstract

In the study, to clarify theeffects of spilled oil on resident fish development, spotted bass(Lateolabrax maculates) and olive flounder (Paralichthys olivaceus)embryos (48 hr post-fertilization) were exposed to oiled gravel effluentof Iranian Heavy crude oil (IHCO) oil for 48 hr. Embryos weremanually dechorionated and observed by a stereomicroscope and acompound microscope. Embryos were fixed in 4% phosphate-bufferedparaformaldehyde and stained for CYP1A and myosin heavy chain.After 24 hr, several complex effects, including the pericardium edemaand tail mutant were observed in both of embryos after the IHCOexposure. The distribution of CYP1A in embryo was assessed byimmunofluorescence. CYP1A immunofluorescence activity was highsignificantly in the endothelium of head, epidermis and cardium and asignificant induction of CYP1A mRNA was observed in both ofembryos after the oil exposure. The extent of tail abnormalities andedema in olive flounder were stronger than those of spotted bass in oilexposed groups. But the levels of CYP1A expression were lower thanthose of spotted bass. Our results confirm that the HSOS causedsignificant damage to resident fish embryos and different toxicsensitivity were investigated in both species at morphological andbiochemical levels. This study was supported by research fund from theKorean Ministry of Land, Transport and Maritime Affairsof Iranian Heavy crude oil (IHCO) oil for 48 hr. Embryos weremanually dechorionated and observed by a stereomicroscope and acompound microscope. Embryos were fixed in 4% phosphate-bufferedparaformaldehyde and stained for CYP1A and myosin heavy chain.After 24 hr, several complex effects, including the pericardium edemaand tail mutant were observed in both of embryos after the IHCOexposure. The distribution of CYP1A in embryo was assessed byimmunofluorescence. CYP1A immunofluorescence activity was highsignificantly in the endothelium of head, epidermis and cardium and asignificant induction of CYP1A mRNA was observed in both ofembryos after the oil exposure. The extent of tail abnormalities andedema in olive flounder were stronger than those of spotted bass in oilexposed groups. But the levels of CYP1A expression were lower thanthose of spotted bass. Our results confirm that the HSOS causedsignificant damage to resident fish embryos and different toxicsensitivity were investigated in both species at morphological andbiochemical levels. This study was supported by research fund from theKorean Ministry of Land, Transport and Maritime Affairs