Bone dynamics in zebrafish on low- and high-frequency diets.

Area of Science:

• Comparative physiology
• Zebrafish (Danio rerio) as a model organism
• Bone biology

Background:

• Dietary intake significantly influences physiological parameters.
• Understanding the impact of feeding frequency on bone metabolism is crucial.
• Zebrafish are a valuable model for studying bone health due to skeletal homology with mammals.

Purpose of the Study:

• To investigate the effects of different feeding frequencies on bone parameters in zebrafish.
• To explore the relationship between diet, body composition, and bone density.
• To hypothesize the role of leptin in diet-induced bone changes.

Main Methods:

• Zebrafish were divided into two groups: High-frequency (3 meals/day) and Low-frequency (2 meals/week) diets.
• Fish were fed for 40 days, and total weight and length were measured.
• Vertebral bone density and volume were assessed.
• Scale analysis was performed to quantify resorption lacunae.

Main Results:

• The High-frequency group exhibited significantly greater total weight and length compared to the Low-frequency group (p < 0.01).
• Vertebral bone density was significantly higher in the High-frequency group (p = 0.0009), while bone volume was significantly lower (p = 0.04).
• Scales from the Low-frequency group showed a higher density of resorption lacunae (p = 0.02).

Conclusions:

• Higher feeding frequency in zebrafish leads to increased body size but altered bone characteristics, including higher density and lower volume.
• Increased bone resorption markers in scales of low-frequency fed fish suggest a catabolic bone state.
• The findings support a hypothesis that reduced calorie intake, potentially via higher leptin levels, is catabolic to zebrafish bone.