Temperature affects liver and muscle metabolism in photostimulated migratory redheaded buntings ( Emberiza bruniceps )

AbstractWe investigated the transcriptional effects of temperature on metabolism in the liver and flight muscle prior to the onset of spring migration in redheaded buntings. We measured changes in body mass, cellular lipid accumulation, and transcription of metabolic genes in the liver and flight muscle, during a week of exposure to 8-h short photoperiod (SP; 8L: 16D) and 13-h-long photoperiod (LP; 13L: 11D) at 22  °C to ascertain the responsiveness to LP, and during 2.5 weeks of LP at 22 and 38 °C to examine the effect of temperature on LP-induced metabolic response. Particularly, we measured mRNA expression of genes involved in the fatty acids and triglycerides biosynthesis (srebf1,elovl6,scd,fads2, anddgat2), glucose and lipid metabolism (sirt1,foxo1,ppara,pparg,hdac3, andhmgcr) in the liver, and fatty acid transport (cd36 andfabp3) and metabolism (myod1) in the flight muscle. Birds gained weight and had elevated lipid accumulation at 22  °C but not at 38 °C in the liver and muscle tissues. We also found significant differences in gene expression patterns during 2.5 weeks of LP exposure. For instance, as compared to week 1, there were decreasedelovl6,dgat2, andsrebf1 and increasedfoxo1 mRNA levels in the liver, and decreasedcd36 andfabp3 mRNA levels in the muscle at 38  °C after 2.5 weeks of LP. It is suggested that a drastic change in temperature could alter the molecular metabolism in the liver and skeletal muscle with photoperiod-induced transition in the s...
Source: Journal of Comparative Physiology B: Biochemical, Systemic, and Environmental Physiology - Category: Physiology Source Type: research