Transcriptome responses to heat stress in hypothalamus of a meat-type chicken

Background: Heat stress has resulted in great losses in poultry production. To address this issue, we systematically analyzed chicken hypothalamus transcriptome responses to thermal stress using a 44 k chicken Agilent microarray, Methods: Hypothalamus samples were collected from a control group reared at 25 degrees C, a heat-stress group treated at 34 degrees C for 24 h, and a temperature-recovery group reared at 25 degrees C for 24 h following a heat-stress treatment. We compared the expression profiles between each pair of the three groups using microarray data. Results: A total of 1,967 probe sets were found to be differentially expressed in the three comparisons with P < 0.05 and a fold change (FC) higher than 1.5, and the genes were mainly involved in self-regulation and compensation required to maintain homeostasis. Consistent expression results were found for 11 selected genes by quantitative real-time PCR. Thirty-eight interesting differential expression genes were found from GO term annotation and those genes were related to meat quality, growth, and crucial enzymes. Using these genes for genetic network analysis, we obtained three genetic networks. Moreover, the transcripts of heat-shock protein, including Hsp 40 and Hsp 90, were significantly altered in response to thermal stress. Conclusions: This study provides a broader understanding of molecular mechanisms underlying stress response in chickens and discovery of novel genes that are regulated in a specific thermal-stress manner.