Comparative transcriptome analyses reveal the dynamic responses of avian myotubes to acute heat stress.

The detrimental effects of acute heat stress (AHS) on poultry production have been widely reported. Unraveling the physiological and metabolic responses to AHS could help to provide theoretical basis for developing strategies to mitigate hyperthermia-induced muscle damage. Here, we investigated the effects of different durations of AHS (45 °C for 0.5, 1, 2 and 4 h) on differentiated avian myotubes. Results indicated that AHS destroyed the morphology of differentiated myotubes, and the degree of damage increased with the prolongation of AHS. Dynamic transcriptomic profiling identified 67, 467, 1355 and 2627 differentially expressed genes (DEGs) after 0.5, 1, 2, and 4 h of heat stress, respectively. Only 50 DEGs were regulated across all time points. In addition, genes involved in cell cycle, metabolic process and immune response were upregulated upon short-term heat stress (0.5 and 1 h). However, these thermal-tolerance responses were suppressed upon prolonged heat stress (2 and 4 h). Furthermore, the quick response of molecular chaperone genes might be major targets for acclimation to hyperthermia. Overall, the current transcriptome analyses reveal the dynamic changes of avian myotubes to AHS and promote an understanding of the molecular mechanisms involved in the heat stress response in poultry.