Carotenoid dynamics in Atlantic salmon.

Area of Science:

• Biochemistry
• Physiology
• Mathematical Modeling

Background:

• Carotenoids are vital pigments in food chains, but their vertebrate absorption and metabolism are poorly understood.
• Astaxanthin, a key carotenoid, is crucial for Atlantic salmon, impacting their flesh coloration and life history.
• Understanding carotenoid dynamics is vital for aquaculture and ecological studies.

Purpose of the Study:

• To develop a dynamic ordinary differential equation (ODE) model for carotenoid uptake, deposition, and utilization.
• To analyze astaxanthin dynamics in Atlantic salmon at the whole-organism level.
• To provide a framework for understanding carotenoid metabolism and its genetic underpinnings.

Main Methods:

• Developed a dynamic ODE model to simulate carotenoid dynamics.
• Employed sensitivity analysis to identify factors influencing carotenoid retention.
• Utilized the model to predict regulatory mechanisms of pigment release.

Main Results:

• The model accurately mimics astaxanthin uptake and retention over various timescales (hours to years).
• Sensitivity analysis highlighted potential genetic factors affecting muscle carotenoid retention.
• Predicted that astaxanthin release is driven by muscle degradation, not a specific regulatory system.

Conclusions:

• Dynamic models are valuable tools for investigating complex traits and identifying underlying determinants.
• The developed model serves as a foundation for experimental research on carotenoid metabolism.
• The framework can be adapted for modeling carotenoid dynamics in other species, including mammals.