show Abstracthide AbstractA high-temperature selected (HT) strain of rainbow trout was established from the Donaldson (DS) strain by traditional selective breeding in Japan. The aim of this study is to investigate genes related to upper temperature tolerance in this strain utilizing NGS, and to establish comprehensive and comparable datasets in brain, liver, muscle, heart and gill tissues between the HT and DS strains. After assembling, clustering and filtering, 242,530 contigs were obtained. Among them, 7,624 transcripts had at least 10 count in expression analysis in all tissues and used as references. BLASTX homology search showed that 7,329 transcripts matched with known genes. Compared to the DS strains, the HT strain expressed 90, 775, 349, 188 and 194 genes 2 folds or more in brain, liver, muscle, heart, and gill, respectively in the case of fish before heat-exposure treatment. Meanwhile, the HT strain expressed 292, 363, 433, 322 and 211 genes 2 folds or more in brain, liver, muscle, heart, and gill, respectively in case of fish after heat-exposure treatment. Many of heat shock protein family genes and transcription factor AP-1 related genes were highly expressed in all tissues of the HT strain compared with the DS strain. These results suggest that these genes play key roles in upper temperature tolerance. These comprehensive and comparable datasets will offer broad visions for upper temperature tolerance in fish species.