Hypothalamic and pituitary transcriptome profiling using RNA-sequencing in high-yielding and low-yielding laying hens

Area of Science:

• Animal Science
• Genomics
• Reproductive Biology

Background:

• Reproductive physiology and egg-laying performance in hens are influenced by the hypothalamus and pituitary.
• Understanding gene expression in these brain regions is crucial for improving poultry production.

Purpose of the Study:

• To investigate the hypothalamus and pituitary transcriptomes of high- and low-yielding Chinese Dagu Chickens (CDC).
• To identify differentially expressed genes (DEGs) and associated pathways related to egg production efficiency.

Main Methods:

• RNA sequencing (RNA-seq) was performed on hypothalamus and pituitary tissues from high- and low-yielding CDC hens.
• Transcriptome data was analyzed to identify DEGs and perform functional and pathway enrichment analyses.
• Gallus gallus genome was used as a reference for gene identification.

Main Results:

• Over 46 million clean reads and 24,873 tentative genes were identified.
• Seven and 39 DEGs were found in the hypothalamus and pituitary, respectively.
• Hypothalamus DEGs were enriched in glycosaminoglycan biosynthesis; pituitary DEGs were enriched in extracellular matrix functions and amino acid metabolism pathways.
• Increased expression of genes involved in amino acid metabolism, glycosaminoglycan biosynthesis, and estrogen negative feedback was observed in low-yielding hens.

Conclusions:

• This is the first study to compare hypothalamus and pituitary transcriptomes between high- and low-yielding laying hens.
• Identified DEGs and pathways provide a basis for understanding egg production regulation.
• Genes related to amino acid metabolism and glycosaminoglycan biosynthesis may serve as potential biomarkers for egg production in chickens.