Identification of differentially expressed genes in hypothalamus of chicken during cold stress.

In order to discover the mechanism of cold stress and identify differentially expressed genes in hypothalamus during cold stress, 4 weeks of age Huainan partridge chickens, Chinese indigenous breed, were chosen for 24 h cold stress and then hypothalamus were isolated and labeled by reverse transcription reaction for cDNA. Labeled cDNA were hybridized with cDNA microarray. After scanning and image processing, the different gene expression profiling of hypothalamus and normal control was investigated. The differentially expressed genes included 334 down-regulated genes and 543 up-regulated genes. In these differentially regulated genes, myosin heavy chain polypeptide 11 (MYH11), light chain polypeptide 9 (MYL9) and tenascin-Y (TNXB), etc., which involved in muscle activity were significantly down-regulated. Genes like cholecystokinin (CCK), neuropeptide Y (NPY), neuropeptide Y receptor 5 (NPY5R), hypocretin receptor 2 (HCRTR2) and hypocretin neuropeptide precursor (HCRT) which responsible for regulation of feeding behavior were significantly up-regulated. In addition, genes responsible for lipid synthesis, like apolipoprotein (APOB) and agouti related protein homolog (AGRP), were also up-regulated. Through pathway analysis using the Kyoto Encyclopedia of Gene and Genomics, during 24 h cold stress, the neuroactive ligand-receptor interaction was firstly initiated in chickens for stimulation of central nervus for feed intake. Adipocytokine signaling pathway was in high activation for supplementation of body energy. Jak-STAT, Ca(2+) signaling pathway and other biological reactions were also initiated in response to cold stress. The biological pathways participated in cold stress would provide important information for clarify the mechanism of cold stress and the differentially expressed genes would give much help for screening of candidate genes in breeding of cold stress resistant lines.