白斑狗鱼早期发育阶段的高温耐受性分析

Analysis of High Temperature Tolerance in Early Development of Esox lucius

对白斑狗鱼早期发育阶段的高温耐受性进行分析,旨为白斑狗鱼的养殖和生态适应性研究奠定理论基础。采用高温胁迫法研究白斑狗鱼受精卵及仔鱼的高温耐受性,用24hUILT_(50)和CT_(max)进行评估;采用实时荧光定量PCR(qRT-PCR)技术和相对定量2^(-ΔΔCt)法,分别比较了不同温度和不同时间高温胁迫下HSP70基因在白斑狗鱼幼鱼脑、鳃、心和肝各组织中的表达情况。结果显示,白斑狗鱼受精卵破膜时间随着孵化温度的上升逐渐缩短,鱼苗上浮率呈现先缓慢上升后急剧下降的趋势。随着驯化水温的提高,白斑狗鱼仔鱼在高温胁迫下的24hUILT_(50)值升高,且CT_(max)出现的时间推迟。在不同温度高温胁迫下,白斑狗鱼幼鱼脑、鳃和心脏组织HSP70基因的表达量呈现先上升后下降的趋势,肝脏组织呈现持续上升的趋势。白斑狗鱼幼鱼脑、鳃和心脏组织在30℃高温胁迫0-24 h时,HSP70基因的表达量呈现先上升后下降的趋势,肝脏组织呈现先下降后上升再下降的趋势。白斑狗鱼幼鱼的脑、鳃、心和肝4种组织在不同温度和不同时间的高温胁迫下,HSP70基因的表达量发生不同程度的变化,其变化具有时间和组织特异性,但应答幅度不尽相同。经过高温驯化后,白斑狗鱼提高了温度耐受性,可能是通过HSP70参与重要调控作用。

Analyzing the high temperature tolerance in early development stage of Esox lucius is aimed to lay a theoretical foundation for the breeding and ecological adaptation of E.lucius.High temperature stress method was used to study the high temperature tolerance of the fertilized eggs and juvenile E.lucius,which was evaluated by 24hUILT_(50) and CT_(max).Real-time fluorescence quantitative PCR(qRT-PCR)and relative quantitative 2^(-ΔΔCt) method were used to compare the expressions of HSP70 gene in the brain,gill,heart and liver of juvenile E.lucius under different temperatures and high temperature stressed times.The results showed that the breaking time of the membranes of the fertilized eggs in E.lucius was shortened gradually as the incubation temperature increased.However,the floating rate of the fry showed the tendency of rising slowly then falling sharply.With the increase of domestication temperature,the 24hUILT_(50) value of the juveniles increased and the occurrence time of CT_(max) delayed under high temperature stress.Under the stress of different high temperature,the expressions of HSP70 gene in the brain,gill and heart tissues of juvenile E.lucius increased first and then decreased,while that in the liver tissue continued to increase.When juvenile E.lucius were subjected to 30℃high temperature stress for 0-24 h,the HSP70 gene expressions in their brains gill and heart tissues increased first and then decreased,while that in the liver tissue tended to be decreasing first and then increasing and then decreasing.The expressions of HSP70 gene in the brain,gill,heart and liver of juvenile E.lucius varied at different degrees under different temperatures and different high temperature stressed times,but the variations were time-specific and tissue-specific,with different response ranges.After high temp-erature domestication,the temperature tolerance of E.lucius increased,which may be involved in important regulation through HSP70.