Ocean warming drives tissue-wide metabolic reprogramming in a fish.

Area of Science:

• Marine Biology
• Molecular Biology
• Climate Change Biology

Background:

• Ocean warming and marine heatwaves pose significant threats to marine organisms.
• Understanding the molecular basis of thermal acclimation in marine species is crucial but incomplete.

Purpose of the Study:

• To investigate the metabolic and transcriptional responses of early-life stage clownfish (Amphiprion ocellaris) to different thermal regimes.
• To elucidate the molecular mechanisms underlying acclimation to increased temperatures in fish.

Main Methods:

• An aquaria-based study exposing clownfish to six thermal regimes.
• Measurement of metabolic rates and multi-tissue transcriptional analysis (seven tissues) of Amphiprion ocellaris.
• Analysis focused on the liver-pancreas axis and key energetic pathways.

Main Results:

• Acute exposure to 31°C increased metabolic rates in fish reared at 28°C, with effects diminishing upon chronic exposure.
• Transcriptomic analysis revealed significant metabolic reprogramming across multiple tissues at +3°C.
• Chronic exposure to +3°C led to acclimated metabolic rates, with liver oxidative phosphorylation upregulated and pancreatic insulin secretion downregulated.

Conclusions:

• Temperature increases drive tissue-wide metabolic reprogramming in fish.
• Changes in key energetic pathways, such as oxidative phosphorylation and insulin secretion, are critical for fish acclimation to ocean warming.
• Early-life stage exposure influences the acclimation capacity of clownfish to thermal stress.