Maternal dietary fish oil developmentally programs adipogenic development in the broiler chick embryo

Area of Science:

• Poultry Science
• Developmental Biology
• Nutritional Biochemistry

Background:

• Adipose development in broiler chickens is crucial for meat production.
• Maternal diet composition significantly influences embryonic development and offspring metabolism.
• Omega-3 polyunsaturated fatty acids (n-3 PUFA) are known for their health benefits, but their role in embryonic adipose programming requires further elucidation.

Purpose of the Study:

• To investigate the molecular mechanisms by which fish oil, a source of n-3 PUFA, influences adipose tissue development in chick embryos.
• To determine the effects of maternal fish oil (MFO) versus soybean oil (MSO) on adipocyte morphology, lipid accumulation, and mitochondrial activity in developing chick embryos.
• To analyze the transcriptomic and epigenetic changes induced by MFO in embryonic adipose tissue.

Main Methods:

• Broiler breeder hens were fed diets containing fish oil or soybean oil for four weeks.
• Fertilized eggs were collected and incubated to specific embryonic ages (E14, E16, E20).
• Fatty acid profiling, histological analysis, preadipocyte culture, mitochondrial activity assays, RNA-sequencing (RNA-seq), and DNA methylation analysis were performed.

Main Results:

• Maternal fish oil (MFO) enriched embryonic adipose tissue with EPA and DHA, reduced adipocyte size, and increased the frequency of small adipocytes.
• MFO preadipocytes showed reduced lipid accumulation and enhanced mitochondrial activity compared to MSO controls.
• RNA-seq revealed significant alterations in gene expression in MFO embryos, particularly in lipid metabolism, fatty acid metabolism, and PPAR signaling pathways, including upregulation of Iroquois homeobox genes.
• Differential DNA methylation patterns were observed in response to MFO, with 17 differentially methylated regions identified.

Conclusions:

• Dietary fish oil, rich in n-3 PUFA, programs chick embryos to reduce fat accretion through molecular mechanisms originating during embryonic development.
• Transcriptomic and epigenetic modifications, including changes in lipid metabolism gene expression and DNA methylation, are key mediators of this effect.
• Maternal n-3 PUFA supplementation offers a potential strategy for managing adipose tissue development and potentially reducing fat deposition in broiler chickens post-hatch.