Investigation of cold adaptation mechanisms by transcriptome analysis in the liver of yellowtail kingfish (Seriola aureovittata).

Cold stress is an extreme environmental stressor that constrains the economic development of aquaculture. Yellowtail kingfish (Seriola aureovittata) is a commercially important fish species, but its molecular mechanisms in response to cold stress remain unknown. In this study, we investigated the transcriptional response of yellowtail kingfish liver to cold stress (10 °C) using RNA-sequencing analysis. We obtained 83.21 Gb of clean data from fish in the control group (0 h) and at 6, 12, and 24 h post-stimulation. A total of 2900 differentially expressed genes were identified from the comparison of the bioinformatic data from cold-stressed and control groups. Enrichment analysis suggested that protein processing, energy and lipid metabolism, signal transduction, and stress-induced cell cycle changes were highly involved during cold adaptation. Transport and utilization of fatty acids and cell cycle arrest were enhanced, whereas the rate of glycogen metabolism and protein biosynthesis were inhibited to maintain energy balance and normal fluidity of the cell membrane, thereby enhancing the tolerance of yellowtail kingfish to cold stress. Our study uncovered molecular pathways and key regulatory genes that are crucial for cold adaptation in yellowtail kingfish. These results provide new insights that could inform selective breeding programs aimed at enhancing cold resistance in aquaculture.