Lipid Metabolism in Aquatic Species

Lipid metabolism in aquatic species encompasses the synthesis, storage, mobilisation and catabolism of fats, which serve as indispensable sources of energy, structural components of cell membranes and precursors for signalling molecules. Central organs include the liver, the primary site of de novo lipogenesis and β-oxidation, adipose depots or lipid-storing tissues, and the intestine, where dietary lipids are emulsified, absorbed and packaged into lipoproteins. Key regulatory nodes involve transcription factors and nuclear receptors such as sterol regulatory element-binding proteins and peroxisome proliferator-activated receptors, which respond to dietary inputs, hormonal cues and environmental stressors. Variations in temperature, salinity and nutrient availability drive adaptive shifts in fatty acid composition and metabolic flux, underpinning resilience to changing habitats. Understanding these pathways is crucial for optimising feed formulations in aquaculture, improving fish health and addressing global demands for sustainable protein sources.

Research from Nature Portfolio

Studies in model and farmed species have elucidated the interplay between dietary factors and molecular regulators of lipid turnover. In zebrafish, dietary L-carnitine supplementation has been shown to enhance mitochondrial β-oxidation, upregulating carnitine palmitoyltransferase 1 expression, lowering hepatic and muscular lipid deposition, and modulating glucose–lipid cross-talk via effects on glycolytic and gluconeogenic genes. In Nile tilapia, the lipid-lowering efficacy of the PPARα agonist fenofibrate was demonstrated to depend on prior nutritional background, with high-fat pre-feeding enhancing PPARα activation, hepatic fatty acid catabolism and reductions in plasma triglyceride concentrations. Complementary work in adult zebrafish reveals that high-fat diets remodel the gut microbiome, while probiotic Lactobacillus rhamnosus attenuates weight gain and shifts the expression of key genes governing cholesterol and triglyceride metabolism through anorexigenic and orexigenic pathways.

Lipid Metabolism in Aquatic Species publication trend

The graph below shows the total number of articles in lipid metabolism in aquatic species across all publications each year (not limited to Nature Index journals).

Technical terms

Lipogenesis: Biosynthetic pathway that converts acetyl-CoA into fatty acids, primarily in the liver and adipose tissue.

β-Oxidation: Mitochondrial process of fatty acid breakdown to generate acetyl-CoA and ATP.

Carnitine Palmitoyltransferase 1 (CPT1): Rate-limiting mitochondrial enzyme that facilitates long-chain fatty acid import for β-oxidation.

Peroxisome Proliferator-Activated Receptor α (PPARα): Nuclear receptor that regulates genes involved in fatty acid transport and catabolism.

Adenosine Monophosphate-Activated Protein Kinase (AMPK): Cellular energy sensor that promotes catabolic pathways and inhibits anabolic processes when activated.

Microbiome: Community of microorganisms inhabiting the gut, influencing nutrient metabolism, immune function and host energy balance.

References

1. Systemic regulation of L-carnitine in nutritional metabolism in zebrafish, Danio rerio. Scientific Reports (2017).
2. Nutritional background changes the hypolipidemic effects of fenofibrate in Nile tilapia (Oreochromis niloticus). Scientific Reports (2017).
3. Dietary lipid content reorganizes gut microbiota and probiotic L. rhamnosus attenuates obesity and enhances catabolic hormonal milieu in zebrafish. Scientific Reports (2017).
4. Sanguinarine Improves Intestinal Health in Grass Carp Fed High-Fat Diets: Involvement of Antioxidant, Physical and Immune Barrier, and Intestinal Microbiota. Antioxidants (2023).
5. Protective Effects of Bile Acids Against Hepatic Lipid Accumulation in Hybrid Grouper Fed a High-Lipid Diet. Frontiers in Nutrition (2022).
6. Dietary Betaine Mitigates Hepatic Steatosis and Inflammation Induced by a High-Fat-Diet by Modulating the Sirt1/Srebp-1/Pparɑ Pathway in Juvenile Black Seabream (Acanthopagrus schlegelii). Frontiers in Immunology (2021).