热应激对虹鳟CRT基因和PDIA4基因mRNA表达的影响

Effects of Heat Stress on m RNA Expression of CRT and PDIA4 in Rainbow Trout(Oncorhynchus mykiss)

在转录组测序研究中,筛选出了与虹鳟热应激相关的钙网蛋白基因CRT和蛋白二硫键异构酶基因PDIA4。为研究其在热应激过程的表达变化规律及应答机制,本试验以全同胞虹鳟为研究对象,通过持续升温,分别在18℃(对照组)、21℃、23℃、24℃、25℃和26℃下随机挑选3尾虹鳟,采用实时荧光定量(Real-timeFQ-PCR)方法测定并分析了肝脏和头肾CRT和PDIA4mRNA的表达变化特征。结果显示,与18℃相比,肝脏、头肾CRT表达量分别在24℃、26℃时显著上调且达到最高(19.16倍和2.76倍,p<0.05);PDIA4mRNA表达量分别在25℃、26℃显著上调且达到最高(57.45倍和188.68倍,p<0.05)。肝脏CRT的表达量在24℃和25℃时显著高于头肾(10.89倍和8.46倍,p<0.05),而PDIA4表达量在24℃、25℃和26℃时显著低于头肾(p<0.05)。因此认为,热应激诱导虹鳟肝脏、头肾中CRT和PDIA4mRNA的表达上调,25℃以上时,虹鳟热应激反应强烈,且对基因表达水平的影响存在组织特异性,肝脏对热刺激的反应比头肾更敏感。本研究为阐述鱼类在热应激下适应性保护机制提供指导。

In the study of transcriptome RNA-seq sequencing, we screened calreticulin gene (CRT) and protein disulfide isomerase A4 gene (PDIA4), which are related to the heat stress of rainbow trout. In order to study the changes of expression from these genes and explain their response mechanisms during heat stress. Individuals of full siblings of rainbow trout were used in this study, and they were heated under heat stress 18℃(control) and 21℃, 23℃, 24℃, 25℃ and 26℃(Heat stress groups). Three rainbow trout were randomly selected randomly to detect the expression changes of CRT and PDIA4 mRNA in rainbow trout liver and head kidney. The results show that compared with 18℃, expression levels of CRT in liver and head kidneys were significantly up-regulated at 24℃ and 26℃(19.16 fold and 2.76 fold, p<0.05);The expression levels of PDIA4 were significantly up-regulated at 25℃, 26℃ and reached the highest (57.45 fold and 188.68 fold, p<0.05). The expression level of CRT in liver was significantly higher than head kidney at the 24 and 25℃(10.89 fold and 8.46 fold, p<0.05), while PDIA4 expression was Significantly lower than kidney at 24℃, 25℃, and 26℃(p<0.05). Therefore, it is considered that heat stress induced the up-regulation of CRT and PDIA4 mRNA expression in rainbow trout liver and head kidneys. 25℃ may be a critical temperature point for rainbow trout response to heat stress. The gene responded to heat stress in a tissue-specific manner, and liver is more sensitive to heat stress than head kidney. The study provides guidance for explaining the adaptive protection mechanism of fish under heat stress.