近海沉积物DlPCBs对斑马鱼胚胎EROD和cyp1a mRNA的影响

为探究湛江近海域海洋沉积物中类二噁英多氯联苯(dioxin-like polychlorinated biphenyls,Dl PCBs)的生物学毒性效应,选取湛江近海域2个地点(近工业区TS和近生活区JSW)采集沉积物样品,制备近海域沉积物Dl PCBs提取物,将斑马鱼胚胎暴露于不同浓度的Dl PCBs提取物,测定斑马鱼胚胎7-乙氧基异吩恶唑脱乙基酶(ethoxyresorufin-O-deethylase,EROD)活性和cyp1a m RNA相对表达量。结果发现,JSW采样点Dl PCBs提取物染毒组EROD酶活性变化与TS采样点Dl PCBs提取物一致,在各染毒浓度下,斑马鱼仔鱼EROD酶活性为对照组的1.1~1.8倍。TS和JSW采样点不同浓度Dl PCBs提取物暴露斑马鱼胚胎96 h后,使斑马鱼仔鱼cyp1a m RNA相对表达量是对照组的3.36~19.45倍。说明一定浓度的近海沉积物Dl PCBs能诱导斑马鱼仔鱼EROD酶活性和cyp1a m RNA表达量升高,且呈现浓度-效应关系。

EROD Activity and cyp1a mRNA Expression in Zebrafish Embryo Exposed to Marine Sediment DlPCBs Extract

To study the bio-toxicity of dioxin-like polychlorinated biphenyls (DlPCBs) in marine sediment, the sediments from Zhanjiang industrial and living area (TS and JSW) were collected and extracted focusing on DlPCBs, respectively. Then a range of zebrafish embryos were exposed to different concentrations of the sediment DlPCBs extracts to examine the ethoxyresorufin-O-deethylase (EROD) activity and the expression of cyp1a mRNA. The results showed that the DlPCBs extract from TS and JSW sediments had similarity to cause marked induction of EROD in the zebrafish embryos.The EROD activities in zebrafish embryos induced by different concentrations of the DlPCBs extract were 1.1 to 1.8 times higher than that in the control embryos, respectively, and after the zebrafish embryos were exposed to different concentrations of the DlPCBs for 96h, the juvenile cyp1a mRNA relative expressions were significantly enhanced 3.36 to 19.45 times of that in the control group, respectively. It is indicated that certain concentrations of the DlPCBs extract increased EROD activity and cyp1a mRNA in zebrafish larvae, with a concentration-effect relationship.