HIF signaling and gene expression change differently during low oxygen and long exercise

HIF-3α mRNA expression increased three times in zebrafish larvae after 9-15 days of training.

• Gene expression analysis revealed different mRNA levels of HIF-1α, HIF-2α, and HIF-3α in zebrafish larvae under various conditions.
• Changes in HIF expression were significantly greater in trained larvae compared to hypoxic animals.
• Hif-2α expression significantly increased after the first day of exercise but later decreased below control levels.
• HIF-1α protein levels transiently increased in hypoxic larvae, while they decreased below control levels in the exercise group.
• The transcriptome was more significantly affected in hypoxic zebrafish, with minimal overlap in gene alterations between hypoxia and exercise.

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