Phenotypic divergence between broiler and layer chicken lines is regulated at the molecular level during development

Area of Science:

• Genomics and transcriptomics
• Comparative developmental biology
• Poultry science

Background:

• Phenotypic variation in poultry is crucial for breeding programs.
• Brazilian broiler (TT) and layer (CC) lines have distinct growth and muscle mass.
• Early embryonic development differences are key to understanding these traits.

Purpose of the Study:

• Compare global transcriptomes of wing and pectoral tissues in TT and CC lines.
• Identify gene expression and regulation disparities during early development (days 2.5-3.5).
• Uncover molecular basis for divergent growth potentials.

Main Methods:

• Transcriptome sequencing of wing and pectoral tissues from broiler and layer embryos.
• Differential gene expression analysis to identify DEGs (differentially expressed genes).
• Gene Ontology (GO) enrichment analysis and regulatory network construction.

Main Results:

• Distinct transcriptomic profiles were observed between broiler and layer lines.
• Upregulated DEGs in broilers were enriched for protease genes, linked to hormone response and cell cycle.
• Downregulated DEGs were associated with receptors, ligands, cell signaling, and differentiation.

Conclusions:

• Significant transcriptomic differences exist between broiler and layer lines during early development.
• Broiler embryos exhibit gene expression favoring increased cell proliferation and delayed differentiation.
• These findings offer insights for improving targeted poultry traits and breeding strategies.