GEOapplication/xmlftp://ftp.ncbi.nlm.nih.gov/geo/series/GSE319nnn/GSE319817/primaryOK200TranscriptomicsDanio rerioExpression profiling by high throughput sequencinghttps://www.ncbi.nlm.nih.gov/geo/query/acc.cgi?acc=GSE319817GEOGSEfalseAcute Hypoxia Alters Electrocardiology and Transcriptomics in Adult Zebrafish (Danio rerio)We combined electrocardiography and transcriptomic profiling to investigate the short- and long-term effects of acute hypoxia on adult zebrafish hearts, testing the hypothesis that rapid recovery of cardiac function does not necessarily indicate concurrent recovery at the molecular level. Continuous ECG recordings revealed pronounced bradycardia during hypoxic exposure, characterized by reduced heart rate (f_H) and prolonged RR intervals. Upon reoxygenation, f_Hincreased and RR intervals shortened within 2–5 minutes as oxygen levels normalized, anesthesia was discontinued, and β-adrenergic stimulation (isoproterenol) restored cardiac excitability. Despite this swift physiological recovery, transcriptomic analyses conducted seven days post-hypoxic exposure demonstrated persistent differential gene expression in previously hypoxia-affected fish compared with sham controls. Upregulated genes were associated with stress response and structural stabilization, whereas downregulated genes suggested a metabolic shift toward energy conservation. Together, these findings indicate a subdued transcriptional landscape consistent with cellular stabilization rather than ongoing injury. In summary, while ECG data alone might imply that acute hypoxic effects are transient, transcriptomic evidence reveals a sustained molecular imprint of hypoxic stress in the zebrafish heart that persists well beyond apparent functional recovery.2026/09/15GSE319817GSM9527049GSM9527048GSM9527047GSM9527046GSM9527045GSM9527044GSM9527051GSM952705020828319817Danio rerio[42466388]