摘要
鲤鱼(建鲤品种)幼鱼暴露于4个浓度组(0.005、0.05、0.5、5mg/L)的镉离子(Cd^(2+))2d,期间各组的个体均无死亡.用10个RAPD引物对处理后鲤鱼基因组进行扩增,亦未发现有明显的差异扩增条带.但在用甲基化敏感扩增多态性方法研究暴露后鲤鱼肌肉组织的基因组DNA甲基化的变化时发现,5mg/L的Cd^(2+)在d2会使鲤鱼基因组DNA中CCGG区域甲基化发生明显的变化.该组个体1mol后出现大量死亡.另外,0.05mg/L和0.5mg/L Cd^(2+)组个体基因组DNA中CCGG区域甲基化比例2d内略有下降,甲基化位点没有太大改变.说明鲤鱼幼鱼基因组CCGG区域的胞嘧啶甲基化比例在不同浓度Cd^(2+)处理中都比较稳定.低浓度Cd^(2+)条件下鲤鱼主要通过甲基化区域的微调减少Cd^(2+)的生理毒性.高浓度Cd^(2+)处理下,利于基因组DNA甲基化区域发生相当的变化,可能导致一些沉默基因的异常表达.
The 3-month-old Jian common carps（Cyprinus carpio var.Jian） were exposed to various concentrations of Cd^（2＋）（0.005,0.05,0.5,5 mg/L） for two days,and no individuals died within the two-day exposure.Also,no significantly amplified loci were found in both treatment and control fishes when ten RAPD primers were detected for the difference in genome DNA.However,when methylation sensitive amplified polymorphism（MSAP） was applied to analyze methylation changes in genome DNA of muscle,significant changes of methylation in CCGG sites occurred in the fish after 2 days of 5 mg/L Cd^（2＋） exposure.Furthermore,most fish in this group died within one month.In the groups exposed to 0.05 mg/L and 0.5 mg/L for two days,a slight decline in the proportion of methylation loci were observed,but no obvious change in methylation pattern in comparison with the controls.This study shows that the methyltion of Jian carp in CCGG sites of genome DNA was relatively stable during exposure to various concentrations of Cd^（2＋）.At low Cd^（2＋） concentration the Cd^（2＋） physiological toxicity might be reduced by Jian common carp with fine-tuning in methylated sites,while at high Cd^（2＋） concentration,significant changes would occur in methylation sites of genome DNA,possibly leading to an abnormal expression of some silent genes.Fig 2,Tab 2,Ref 31
出处
《应用与环境生物学报》
CAS
CSCD
北大核心
2010年第4期457-461,共5页
Chinese Journal of Applied and Environmental Biology
基金
中央级公益性科研院所基本科研业务费专项资金(No.2009JBFB02)
人事部高层次留学人才回国工作项目(No.2-115084)资助~~
关键词
镉
鲤鱼
DNA甲基化
重金属污染
cadmium
Jian common carp（Cyprinus carpio var.Jian）
DNA methylation
heavy metal pollution
