【摘要】 运用RAPD技术和外周血嗜多染红细胞微核试验来分析和评价低浓度溴氰菊酯连续暴露对罗非鱼DNA的影响。RAPD试验结果表明,在12个能扩增出罗非鱼基因组DNA的引物中,引物S326能检测出3μg/L以上浓度溴氰菊酯暴露前后罗非鱼基因组DNA的差异,而小于2.0μg/L的低浓度溴氰菊酯对罗非鱼基因组DNA没有影响。外周血嗜多染红细胞微核试验结果表明,在一定浓度的溴氰菊酯连续暴露后,2.0μg/L以下浓度组罗非鱼外周血红细胞微核率与对照组相比没有显著差异(P>0.05),而3μg/L以上浓度组可诱导罗非鱼外周血红细胞产生微核。微核率与对照组相比差异显著(P<0.05),且表现出明显的剂量—效应和时间—效应关系。研究表明,溴氰菊酯在一定条件下可对鱼类DNA产生影响。更多还原

【Abstract】 The present article intends to report the authors’ research on the harmful effect of continuous exposure of low-concentration deltamethrin on the DNA of tilapia.In our experiments,a random amplified polymorphic DNA(RAPD)technique and periphermal blood polychromatia red-cell micronucleus test were adopted for analyzing the influences of continuous exposure of deltamethrin in 1.0 μg/L,2.0 μg/L,3.0 μg/L,5.0 μg/L and 10.0 μg/L of DM to the DAN of tilapia,trying to set our experimental group and standard control group of concentration as of 0.0 μg/L of DM with each group being paralleled.The whole experiments lasted 15 days.During the period,blood-sample collecting,blood-smear preparation for micronucleus rate observation,and DNA sample taking for RAPD analysis were individually conducted on the 3rd,10th,15th day.The results show that the primer S326 among 12 primers used have produced different amplified fragments in tilapia genomic DNA between before and after the exposure,just above 3.0 μg/L,which has no influences on tilapia’s DNA,that is,on the condition that the concentration of deltamethrin remains below 2.0 μg/L.No differences in RAPD amplifications and experimental results were found until the continuous exposure to deltamethrin lasted for 3 days,10 days,and 15 days,respectively.Peripheral blood polychromatia red cell test indicated that,when the concentration was below 2.0 μg/L,no significant differences were found with the peripheral blood red cell rate between the experimental group and the control continuous exposure group.However,micronuclei were found to give out as a result of deltamethrin induction,which took place at above 3.0 μg/L.And,then,the micronucleus rate turned to be obviously different from the control group(P<0.05).But,if the difference of micronucleus rate was insignificant at the concentration of 3.0 μg/L as compared with the control group on the 3rd day of exposure(P>0.05),the exposure rate would rise obviously for a longer time(10 days,15 days),which proves to be significantly different from the control group(P<0.05).The rate was going up to 1.4×10-33.6×10-3 and 2.2×10-34.0×10-3 during 315 days respectively after being exposed at the concentration of 5.0 μg/L,10.0 μg/L with the difference being highly significant between the two groups(P<0.01).Thus,a clear correlation proves to exist between the dose-response and the time-response in the above experiments,which actually demonstrate that deltamethrin could have obvious effects on the tilapia genomic DNA under specific conditions.更多还原