Comparative proteomic analysis of hypothalamus tissue from Huoyan geese between pre-laying period and laying period using an iTRAQ-based approach.

The hypothalamus plays a central role in controlling poultry endocrine and reproductive activities. So far there is limited information focused on the proteome profiles of the hypothalamus from geese during different stages of the egg-laying cycle. In order to identify proteins regulating the egg-laying process of Huoyan geese, we investigated the proteome profiles of the hypothalamus from Huoyan geese during the laying period and pre-laying period by applying an isobaric tags for relative and absolute quantitation (iTRAQ)-based proteomic technology. A total number of 3,337 were identified and quantified, of which 18 were significantly up-regulated and 16 were significantly down-regulated. These differentially expressed proteins were subjected to bioinformatics analyses based on the Gene Ontology annotation and Kyoto Encyclopedia of Genes and Genomes pathway. Some of these were revealed to be involved in hormone and neurotransmitter secretion, exocytosis, calcium ion transport and synaptic transmission. Subsequently, excitatory amino acid transporter 2, complexin-1 and inositol 1,4,5-trisphosphate receptor, type 3 were confirmed at the messenger RNA level using quantitative real-time RT-PCR. Then, the abundance change of these proteins was verified further using Western blotting analysis. These data may aid in elucidating the molecular mechanism of higher laying performance in Huoyan geese.