Meeting Abstract
Knowledge of the effects of environmental exposure to hypoxia on critical physiological functions is essential for accurate predictions of its chronic impacts on aquatic organism. Marked disruption of reproductive and endocrine functions was observed in Atlantic croaker collected from the hypoxic region in the northern Gulf of Mexico. Recent research has shown that growth and its physiological upregulation is also impaired in hypoxia-exposed marine fish. Expression of IGFBP, a growth inhibitory protein, and HIF-1alpha, an oxygen-sensitive transcription factor, were upregulated in croaker tissues collected from hypoxic environments. Preliminary field and laboratory studies indicate that hypoxia exposure also causes epigenetic modifications, including increases in global DNA methylation in croaker. Epigenetic modifications can be passed to offspring and persist in future generations no longer exposed to the environmental stressor. Collectively, the results indicate that environmental hypoxia exposure disrupts major physiological functions in a marine teleost species critical for maintenance of fish populations.
