铅(Pb)胁迫对泥蚶血液MT及Vg基因表达的诱导效应研究

Effects of lead(Pb) stress on MT and Vg gene expression in the blood of Tegillarca granosa

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9μg/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Pb^(2+)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、3μg/L浓度组。由此可见,在Pb^(2+)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。3μg/L浓度组泥蚶Vg mRNA较对照组在14、21 d时被显著诱导;9μg/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 9μg/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 experimental period.The expression levels of MT gene under 6 and 9μg/L concentrations of Pb were higher than those under 1 and 3μg/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 3μg/L group was significantly higher than that in the control group at 14 and 21 days,while its expression in the 9μg/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.