Objective: Uncoupling protein one (UCP1) is involved in thermogenesis, especially in non-shivering heat production. In chickens, a single nucleotide polymorphism (SNP) of the av-UCP (avian UCP) gene has been reported to be associated with body weight gain and increased abdominal fat. The purpose of this study was to examine the relationship between the av-UCP gene SNP and heat production in chicks. Methods: C/C and T/T male chicks (Rhode Island Red) of av-UCP gene SNP (g. 1270, C > T) were exposed to a low temperature environment (16 °C for 15 min) and their physiological responses were compared. Results: After cold exposure, mean rectal temperatures of C/C chicks were higher than those of T/T chicks. In pectoral muscle, genes expression of av-UCP and carnitine palmitoyltransferase-1 were higher in C/C chicks than T/T chicks. Hypothalamic expression levels of thyrotropin-releasing hormone and proopiomelanocortin genes were higher in C/C chicks than T/T chicks. Expression of hypothalamic corticotropin-releasing hormone, arginine vasotocin, brain-derived neurotrophic factor and neuropeptide Y genes did not differ between C/C and T/T chicks. In addition, plasma free fatty acid levels in C/C chicks were lower than those of T/T chicks. Conclusion: These results suggest that the av-UCP gene SNP affects non-shivering heat production via the hypothalamo-pituitary-thyroid axis and fatty acid metabolism in the chicken.
