四溴联苯醚对菲律宾蛤仔组织解毒代谢基因表达的影响

菲律宾蛤仔(Ruditapes philippinarum)样本壳高(2.76±0.18)cm,壳长(4.11±0.22)cm;四溴联苯醚(BDE-47)梯度设置为0.25、6.25μg/L,以海水组为对照,取样测定时间为0、1、3、6、10、15和21 d。结果表明:BDE-47对菲律宾蛤仔鳃丝和消化盲囊AhR、CYP4、GST-pi和Pgp mRNA表达影响显著(P<0.05),而对照组无明显变化。在实验时间内,各处理组鳃丝和消化盲囊AhR基因表达呈峰值变化,分别于第6天、第1天时达到最大值和最小值,然后恢复至对照组水平;各处理组组织CYP4和GST-pi基因表达均呈峰值变化,分别于第3天、第1天达到最小值和最大值,其中消化盲囊CYP4基因表达在3 d后保持稳定,且被显著抑制,而组织GST-pi基因表达则在6d后趋于稳定,0.25、6.25μg/L处理组表现为高于和低于对照组水平;各处理组鳃Pgp基因表达在实验时间内呈峰值变化,分别于第1天、第10天达到最大值,均显著高于对照组水平,而0.25、6.25μg/L处理组消化盲囊Pgp基因表达在21d内分别呈逐渐升高和峰值变化,6 d后表现为被诱导和抑制。由此可见,菲律宾蛤仔在BDE-47胁迫下组织解毒代谢基因表达均被显著诱导或抑制,其中GST-pi基因在低浓度处理组被诱导,高浓度组被抑制,表现出明显的时间效应性,可作为BDE-47污染评价的生物效应指标。

Effects of tetrabromodiphenyl ether(BDE-47)on the metabolic gene expression in the gills and digestive glands of Ruditapes philippinarum

Effects of BDE-47 on gene expression levels of AhR,CYP4,GST-pi and Pgp of the gills and digestive glands of clam Ruditapes philippinarum were studied in a 21-day exposure test.The results showed that the ex-pression levels of all the 4 genes showed no significant change in the control clams during the exposure.AhR mRNA expression levels reached maximum and minimum at day 6 and day 1.CYP4 and GST-pi mRNA gene ex-pression reached the peak value at day 3 and day 1.CYP4 mRNA gene expression levels in digestive gland were inhibited and kept stable after day 3.GST-pi mRNA expression levels in 0.25 μg/L BDE-47 group are significantly higher than control levels,while in 6.25μg/L BDE-47 treatments are significantly lower than control level.Pgp mRNA expression levels in all BDE-47 treatment groups are significantly higher than control level.Significant dose and time-dependent relationship between the expression levels of GST-pi mRNA and BDE-47 exposure doses were found in the results,indicating that GST-pi mRNA expression in the gills and digestive glands of Ruditapes philippinarum can be considered as a potential biomarker which can be used to evaluate BDE-47 pollution in seawater.