Integrative Transcriptome Analysis Across Follicles Highlights Key Regulatory Pathways in Low and High-Egg-Laying...

Area of Science:

• Reproductive Biology
• Molecular Endocrinology
• Genomics

Background:

• Egg-laying performance is crucial for poultry production and is regulated by complex molecular mechanisms.
• The hypothalamic-pituitary-gonadal (HPG) axis and ovarian follicles play key roles in reproductive outcomes.

Purpose of the Study:

• To investigate the molecular mechanisms underlying differences in egg-laying capacity between low- and high-laying hens.
• To identify key gene expression patterns and signaling pathways that regulate follicular development and steroidogenesis.

Main Methods:

• Integrative transcriptome profiling of ovarian follicles (primordial, primary, small white, small yellow) from low- and high-laying hens.
• Bioinformatic analyses including heatmap clustering and principal component analysis to identify transcriptional divergence.
• Analysis of key signaling pathway components and gene expression related to folliculogenesis and steroidogenesis.

Main Results:

• Transcriptional divergence was observed between low- and high-laying hens, correlating with reproductive performance.
• High-laying hens showed upregulation of PI3K-AKT-FOXO3, TGF-β, and Wnt/β-catenin pathways, promoting follicular growth and granulosa cell proliferation.
• Key genes involved in FSH signaling and steroidogenesis (FSHR, CYP19A1, 17β-HSD, CYP1A1, CYP1B1) were upregulated in high-laying hens' small yellow follicles.

Conclusions:

• Coordinated changes in signaling pathways significantly influence egg-laying performance in hens.
• Specific molecular markers and regulatory networks associated with enhanced follicular development and steroidogenesis have been identified.
• These findings offer potential targets for genetic selection and interventions to improve egg production efficiency.