铅(Pb)胁迫对泥蚶血液MT及Vg基因表达的诱导效应研究

摘要

为了解泥蚶金属硫蛋白基因(MT)和卵黄蛋白原基因(Vg)在重金属Pb胁迫下的表达响应模式,本文设置了1、3、6及9 μg/L 4个浓度梯度的重金属Pb攻毒实验.在此基础上, 利用qRT-PCR技术检测了0、7、14、21、28 d泥蚶血液MT、Vg的相对表达量.结果显示泥蚶MT基因在Pb2+暴毒14 d时开始被显著诱导, 在整个实验过程中基本呈现先增后降的态势.且在14 d和28 d时, 6μg/L及9μg/L浓度组泥蚶 MT 相对表达量均高于1、3 μg/L浓度组.由此可见,在Pb2+胁迫下泥蚶血液MT基因的表达具有一定的时间依赖性和浓度依赖性.相比之下, 泥蚶血液Vg基因的诱导表达情况较MT基因而言不明显.3 μg/L浓度组泥蚶Vg mRNA较对照组在14、21 d时被显著诱导;9 μg/L浓度组其在28 d时才开始被显著诱导.综上可见, 泥蚶MT和Vg在应激重金属Pb过程中起到了一定的抗氧化及重金属解毒作用.%To understand the expression pattern of Tegillarca granosa metallothionein gene (MT) and vitellogenin gene(Vg)under Pb stress,we detected their relative expression levels in the blood of T.granosa after exposure to 1, 3, 6, and 9 μg/L of Cd for 28 days using qRT-PCR technique. The results showed that MT gene was significantly induced by Pb2+on the 14th day, and the expression level first increased and then decreased during the entire ex-perimental period. The expression levels of MT gene under 6 and 9 μg/L concentrations of Pb were higher than those under 1 and 3 μg/L concentrations at 14 and 28 days.These results indicate that the expression of MT gene in the blood of T.granosa under Pb2+stress is dependent on both time and concentration.In contrast,the expression of Vg gene was not as obvious as that of MT gene.The expression of Vg in the 3 μg/L group was significantly higher than that in the control group at 14 and 21 days, while its expression in the 9 μg/L group began to be significantly induced on day 28. This study showed that MT and Vg have an important role in the antioxidant and heavy metal detoxification activities during Pb stress.