Gene expression profile of the taimen Hucho taimen in response to acute temperature changes.

The endangered cold-water fish species taimen (Hucho taimen) suffer acute temperature changes in culture and wild conditions. Understanding the effects of acute temperature changes on physiological processes of this species is essential for aquaculture practices and conservation. Liver transcriptomic profiles of the taimen (n = 24) exposed to acute temperature decrease (from 20 °C to 10 °C) and acute temperature increase (from 10 °C to 20 °C) was evaluated using high-throughput RNA-Sequencing. Samples were collected at day 0, 1, 7 and 35 in both treatments. Compared to day 0, the total numbers of differentially expressed genes (DEGs) in the taimen after acute temperature decrease were 173, 226 and 42 at day 1, 7 and 35, respectively, and the total numbers of DEGs following acute temperature increase were 260, 253 and 282 at day 1, 7 and 35, respectively. Particularly, 14 key regulatory genes were commonly found between both acute temperature treatments. Functional analysis based on the commonly identified DEGs revealed important metabolic pathways related to metabolism and immune function, suggesting a specific response mechanism of taimen against cold and heat shock. The results may assist in developing management strategies for stress mediation caused by acute temperature changes in the taimen and other cold water fish.