虹鳟是我国主要的淡水冷水性养殖鱼类，但对高温耐受性差严重制约着其养殖业发展。目前，对应答虹鳟热应激的基因及其调控机理仍不清楚。项目以全雌虹鳟全同胞家系为材料，首先研究不同水温下虹鳟肝损伤、血细胞凋亡、血清免疫和代谢指标变化情况，评判不同水温下虹鳟的热应激反应（HSR）程度，确定HSR变化显著的"关键高温点"。然后基于高通量测序平台HiSeq 2500，进行RNA-Seq，构建虹鳟肝脏和肾脏"关键高温点"和最适水温（18℃）两组间差异基因表达谱，筛选出高温应激前后表达差异显著的蛋白编码基因，对其进行GO分析和KEGG通路分析，并对差异大于200倍的基因通过Real-time PCR进行验证，进而选择HSR关键信号通路上的核心基因3-5个，研究其在HSR过程中，在虹鳟6个组织（血液、肝、肾、脑、鳃和脾）中的时空表达差异，最终揭示虹鳟HSR分子调控机理，为虹鳟耐高温品种选育和抗热应激技术奠定基础。

Rainbow trout (Oncorhynchus mykiss.) is a cold-water species of salmonid, which is cultivated as the main varieties in our country, but its poor resistance to heat seriously restricts the development of aquaculture. So far, the genes involved in heat-shock and their molecular regulation mechanisms still remain unclear in rainbow trout. This project will firstly launch studies on status of liver damage, blood cell apoptosis, serum immune and changes of metabolism parameters under varied temperatures by utilization of all-female full-sib fishes, and the "key high-temperature point" (HTP) indicates the significant changes of heat stress response (HSR) will be defined. Then the differential gene expression profiles of liver and kidney between 18℃ and HTP will be set up respectively through RNA-Seq base on the next-generation sequencing system of HiSeq 2500, and the protein-coding genes differentially expressed will be screened and will be entered into Gene Ontology (GO) and KEGG pathway analysis. Furthermore, the genes of expression differences more than 200 times between 18℃ and HTP will be verified through the Real-time quantitative PCR, and three to five important genes in key HSR pathway will further functionally analyzed by investigating their temporal and spatial expression patterns in six different tissues (blood，liver, kidney, brain, spleen and gills). These results will uncover the molecular mechanisms of HSR，and will contribute to the development of heat resistant breeding programs and heat resistant technology in rainbow trout.