Effects of temperature to the liver transcriptome in the hybrid puffer fish (Takifugu rubripes ♀ × Takifugu obscurus ♂).

Water temperature exerts a crucial impact on the growth and development of fish. Hybrids may integrate the superior traits of their parents, thereby leading to higher economic benefits. Takifugu rubripes and T. obscurus are two important economic species in Asia. Here, to investigated the effect of temperature on the hybrid puffer larvae (T. rubripes ♀ × T. obscurus ♂), the larvae (0.79 ± 0.02 cm in body length) were treated to three temperatures: 15 °C (T15), 20 °C (T20), and 25 °C (T25) for 45 days. At the end of the study, the body length and weight were measured, the survival rate was calculated, and liver transcriptome analysis was performed on liver tissues. The hybrid puffer larvae in the T25 group showed a significant increase in average body length and body weight compared to the T15 and T20 groups (P < 0.05). 1292, 329, and 1927 differentially expressed genes (DEGs) were identified in T15 vs. T20, T20 vs. T25, and T15 vs. T25 groups, respectively. KEGG enrichment analyses showed that DEGs were primarily involved in the citrate cycle (TCA cycle), PPAR signaling, glycine, serine and threonine metabolism, and protein digestion and absorption pathways. These results indicated that temperature affects metabolism, signal transduction and protein digestion and absorption in hybrid puffer fish. In addition, twelve DEGs were randomly selected for RNA-seq validation, and the transcriptome results were consistent with the qPCR validation results, illustrating the accuracy of transcriptome sequencing. These findings deepen our understanding of the complex molecular mechanism of the response of hybrid puffer fish to temperature changes and contribute to the development of hybrid puffer fish breeding.