0~#柴油和东海平湖原油对黑鲷血细胞DNA损伤的研究

Effects of the No.0 diesel oil and Pinghu crude oil on the DNA damage of hemolymph cell in Sparus microcephalus

采用单细胞凝胶电泳技术(SCGE),以砂滤过的清洁海水为对照组,研究0~#柴油(0.015 mg·L^(-1)、0.03 mg·L^(-1)、0.06mg·L^(-1))和东海平湖原油(0.03 mg·L^(-1)、0.06 mg·L^(-1)、0.12 mg·L^(-1))在不同暴露时间(3 d、7 d、15 d和21 d)对黑鲷血细胞核DNA损伤作用。结果显示,黑鲷血细胞DNA损伤程度与两种石油有显著的剂量-效应和时间-效应关系。实验第3天,0~#柴油和东海平湖原油试验组就检测到DNA损伤,主要以1级损伤为主。随0~#柴油和平湖原油浓度的增高和胁迫时间的延长,彗尾DNA相对含量(Tail DNA%)和彗尾长度/核直径(TL/D)值均呈上升趋势,DNA损伤级别逐渐升高。恢复实验结束后,中、高浓度组0~#柴油(0.03 mg·L^(-1)、0.06 mg·L^(-1))和平湖原油(0.06 mg·L^(-1)、0.12 mg·L^(-1))的彗尾DNA相对含量(Tail DNA%)和彗尾长度/核直径(TL/D)值无法恢复至对照组水平(P<0.05)。从DNA损伤程度来推测,0~#柴油的生物毒性大于平湖原油。研究表明,鱼类血细胞DNA损伤可作为监测海洋石油污染的生物标志物。

Individuals of Sparus microcephalus were exposed to various concentrations of water-soluble fraction of the diesel NO. 0（ 0. 015 mg·L（-1）,0. 03 mg·L（-1）,0. 06mg·L（-1）） and the crude oil from Pinghu sea area（ 0. 03 mg·L（-1）,0. 06 mg·L（-1）,0. 12 mg·L（-1）） to evaluate the DNA damage made by the diesel NO.0 and the crude oil from Pinghu sea area on the marine fish. Hemolymph cells were collected from Sparus microcephalus under different exposure time（ 3 d,7 d,15 d and 21 d）,and comet assay was used to detect the DNA damage of hemolymph cells. The results showed that there was dose-effect relationship between the DNA damage and the oil concentration. The DNA damage degree increased with increasing of the concentration of diesel NO. 0 or crude oil from Pinghu sea area. Only in the 3rd day after exposed to the two oil pollutants,slight damage to hemolymph cells was detected,but mainly on the 1 level. However,with increasing of the oil concentration and prolonging of the stress time,the relative content of tail DNA and the ratio of tail length to nucleus diameter tended to increase,which indicated that DNA damage level was increasing gradually. When recovery period was over,tail DNA percentage（ DNA%） and TL/D of the diesel NO. 0 exposure groups under the concentration of 0. 03 mg·L（-1）and 0. 06 mg·L（-1）were still significantly different from the control group（ P〈0. 05）,so were those induced by the crude oil from Pinghu sea area exposure groups of0. 06 mg·L（-1）and 0. 12 mg·L（-1）. Based on the DNA damage degrees made by different groups,it could be concluded that the toxic effects made by the diesel NO. 0 was more serious than those made by the crude oil from Pinghu sea area. The comet assay is proven to be a useful tool to evaluate the genotoxicity of environmental contamination like oil,and the DNA damage of fish hemolymph cell could be a biomarker to monitor the marine oil pollution.