CdSe/ZnS量子点对雄性尼罗罗非鱼红细胞微核率及核异常率的影响

Effect of CdSe/ZnS QDs on Micronucleus and Nuclear Abnormality of Erythrocytes in Male Oreochromis niloticus

[目的]探究CdSe/ZnS量子点对尼罗罗非鱼(Oreochromis niloticus)的遗传毒性。[方法]分别设空白对照组、NaCl对照组和Cd2+对照组以及浓度分别为20、200、2 000和4 000 nmol/L 4个量子点处理组,以腹腔注射方式对雄性尼罗罗非鱼体进行暴露,暴露后1、4、7、14及28 d进行静脉取血制作血涂片,通过微核率、核异常率及总核异常率检测其遗传毒性。[结果]各NaCl对照组与空白对照组均无显著差异。暴露1 d后各量子点处理组产生的微核率达到峰值后总体呈下降趋势。Cd2+对照组的微核率在整个试验期间均与NaCl对照组有显著差异,其微核率14 d达到峰值。核质外凸和核质内凹是核异常的主要类型,核固缩及不均等缢裂细胞类型在前期易被诱导。[结论]量子点外壳及表面修饰基团的综合作用对鱼体有诱导微核率及核异常率增加的效应,但随着时间的推移,罗非鱼能逐步解除该负面效应,由此推测鱼体最终能解除由QDs诱导的遗传毒性。

[Objective] The aim was to assess the potential genotoxicity of CdSe/ZnS QDs on male Oreochromis niloticus.[Method] Seven treatments of blank CK,NaCl CK,Cd2+ CK and four QDs concentrations of 20,200,2 000 and 4 000 nmol/L were set,and male O.niloticus were exposed to active substance by intraperitoneal infection.The fishes were analyzed on 1,4,7,14 and 28 d post treatments by making blood smears and testing the frequency of micronucleus,frequency of nuclear abnormality and total frequency of nuclear abnormality.[Result] There was no significant difference between each blank CK group and NaCl CK group during the whole experiment.The frequencies of micronucleus of QDs treatments reached the maximum after one day and then declined.The micronucleus of Cd2+ CK group reached the maximum on 14 d post treatment,furthermore there was significant difference between each Cd2+ CK group and NaCl CK group from one day to 28 days.Convex and concave nucleoplasm were the dominant types of abnormality.Pyknotis nucleus and unequal karyomitosis were induced by QDs in the treatment prophase.[Conclusion] The shell of QDs and the surface modification group have negative effect on micronucleus and nuclear abnormality,but the fish can remove the negative effect step by step as the time goes.Therefore,it is guessed that the fish can eliminate the toxicity reduced by QDs.