镉铅对泥鳅DNA甲基化水平的影响

目的研究镉(Cd2 )、铅(Pb2 )以及二者联合(Cd2 Pb2 )作用对泥鳅(Misgurnus anguillicaudatus)肝胰脏、肾脏及鳃DNA甲基化水平的影响。方法0.05和5.00 mg/L Cd2 、Pb2 及Cd2 Pb2 对泥鳅染毒,染毒2、7、14、212、8和35 d时取样,用高效液相色谱(HPLC)分析DNA甲基化水平。结果5.00 mg/L Cd2 、Pb2 及Cd2 Pb2 染毒2 d导致DNA异常高水平甲基化;Cd2 及Cd2 Pb2 的毒性影响大于Pb2 (P<0.05)。0.05 mg/L Cd2 与Pb2 作用下,鳃DNA甲基化水平在第7天时明显升高,而肝胰脏和肾脏则在第14天时升高(P<0.05);染毒21 d后,3种组织甲基化水平均下降,并维持异常低度甲基化。结论Cd2 、Pb2 及Cd2 Pb2 对泥鳅DNA甲基化水平的影响与离子种类、浓度及其作用的时间、靶器官等均具有相关性。

Influence of cadmium and lead on the DNA methylation level of loach Misgurnus anguillicaudatus

Objective To study the influence of Cadmium(Cd~(2 )),lead(Pb~(2 )) or Cd~(2 ) Pb~(2 ) on the total DNA methylation level of hepatopancreas,kidney and gill of the loach Misgurnus anguillicaudatus.Methods Loaches were exposed to Cd~(2 ),Pb~(2 ) or Cd~(2 ) Pb~(2 ) which were divided into low-concentration(0.05 mg/L) and high-concentration(5.00 mg/L) treatment groups.The DNA methylation level was analyzed with high performance liquid chromatography(HPLC) after 2,7,14,21,28 or 35 d exposure.Results The extremely high DNA methylation was detected after 2 days exposure at high concentration in Cd~(2 ),Pb~(2 ) or Cd~(2 ) Pb~(2 ) treatment group;the toxicity effects of Cd~(2 ) and Cd~(2 ) Pb~(2 ) were more significant than Pb~(2 )(P<0.05).Under the exposure to low concentration Cd~(2 ) or Pb~(2 ),the increase of DNA methylation was found in gill at 7 days,while in hepatopancreas or kidney at 14 days.After 21 days treatment,DNA methylation level of hepatopancreas,kidney and gill decreased,and finally stabilized at a lower level than that in control group.Conclusion The influence of heavy metal ions on the DNA total methylation was correlative with the kind,concentration,treatment time and target organ of metal ions.