Zn2+胁迫对花斑裸鲤抗氧化关键基因表达和抗氧化酶活性的影响  

Effects of Zn2+stress on expression of key antioxidant genes and antioxidant enzyme activities in eckloni naked carp Gymnocypris eckloni

作　　者：冉凤霞 金文杰 端智卓玛 黄屾 刘艳慧 李梓瑄 王振吉[2] 吴明辉 简生龙[2] 王国杰[2] 李长忠 RAN Fengxia;JIN Wenjie;DUANZHI Zhuoma;HUANG Shen;LIU Yanhui;LI Zixuan;WANG Zhenji;WU Minghui;JIAN Shenglong;WANG Guojie;LI Changzhong(College of Eco-Environmental Engineering, Qinghai University, Xining 810016, China;Qinghai Fishery Environment Monitoring Station, Xining 810012, China)

机构地区：[1]青海大学生态环境工程学院,青海西宁810016 [2]青海省渔业环境监测站,青海西宁810012

出　　处：《大连海洋大学学报》2021年第3期406-413,共8页Journal of Dalian Ocean University

基　　金：青海省2019年度鱼平台产业项目(ck1979402)。

摘　　要：为探讨水体Zn2+对鱼类的影响,并筛选出有效的生物标记物,以花斑裸鲤Gymnocypris eckloni幼鱼(体质量为10 g±3 g)为试验对象,分别以1、2、5、10、20 mg/L Zn2+为胁迫浓度,计算24、48、72、96 h时的半致死浓度(LD50),经1 mg/L Zn2+胁迫12、24、48、72、96 h后,采用qPCR技术检测鳃、肾脏和肝脏组织中抗氧化防御系统相关的核因子E2相关因子2(Nrf2)、铜锌超氧化物歧化酶(Cu/Zn-SOD)、锰超氧化物歧化酶(Mn-SOD)、过氧化氢酶(CAT)和谷胱甘肽过氧化物酶(GPx)基因表达量变化,以热图分析各基因在3种组织中的应答层次,以及用吸光度法测定SOD、CAT和GPx抗氧化酶活性的变化。结果表明:Zn2+对花斑裸鲤幼鱼胁迫24、48、72、96 h时的半致死浓度(LD50)分别为5.0、3.2、2.5、2.0 mg/L,安全浓度为0.2 mg/L;在Zn2+胁迫96 h内,花斑裸鲤Nrf2、Cu/Zn-SOD、Mn-SOD、CAT和GPx基因表达量及SOD、CAT和GPx酶活性均有不同程度的升高,但升高幅度各异;基因表达量热图分析显示,与鳃、肾脏和肝脏组织中Nrf2的4个下游基因表达量相比,Nrf2表达量相对较低,尤其在肾脏和肝脏组织中表现更为明显。研究表明,花斑裸鲤Nrf2、Cu/Zn-SOD、Mn-SOD、CAT和GPx基因表达量及相关酶活性与Zn2+胁迫存在一定的时间相关性和组织特异性,其可作为预警水体Zn2+污染的备选生物标记物。To evaluate the influence of Zn2+on eckloni naked carp Gymnocypris eckloni and screen the effective biomarkers,juvenile eckloni naked carp with body mass of(10±3)g was exposed to Zn2+prepared by ZnSO4·7H2O at concentration of 1,2,5,10 and 20 mg/L for determination of the LD50 of Zn2+,and the expression of nuclear factor E2 related factor 2(Nrf2),and genes of copper zinc superoxide dismutase(Cu/Zn-SOD),manganese superoxide dismutase(Mn-SOD),catalase(CAT)and glutathione peroxidase(GPx)in gill,kidney and liver tissues were detected by qPCR,the response levels of each gene heat map was analyzed in the three tissues by heat map,and change in the enzyme activities of SOD,CAT and GPx were measured by absorbance method.It was found that the median lethal dose(LD50)of Zn2+was 5.0 mg/L in 24 h,3.2 mg/L in 48 h,2.5 mg/L in 72 h and 2.0 mg/L in 96 h with safe concentration of 0.2 mg/L.The mRNA expression levels of Nrf2,Cu/Zn-SOD,Mn-SOD,CAT and GPx and the activities of SOD,CAT and GPx were shown to be increased in gill,kidney and liver of eckloni naked carp within 96 h of Zn2+stress,with the different extent of increase.The heatmap analysis of gene expression showed that there was lower relative expression of Nrf2 than that in four downstream genes in the three tissues,especially in kidney and liver tissues.The findings indicated that the gene expression levels of Nrf2,Cu/Zn-SOD,Mn-SOD,CAT and GPx and the activities of related enzymes were correlated with the time of Zn2+stress and tissue specificity,and thus were used as potential biomarkers for early warning of water Zn2+pollution.

关 键 词：花斑裸鲤 锌离子 重金属离子胁迫 抗氧化酶基因表达 生物标记物 

分 类 号：S917.4[农业科学—水产科学] X503.225[环境科学与工程—环境工程]