Further studies on short-term adaptations in the expression of lipogenic genes in broilers.
This experiment was conducted to determine possible relationships between certain indices of lipid metabolism and specific gene expression in chickens fed graded levels of dietary crude protein. Male, broiler chickens (Gallus gallus) growing from 7 to 28days of age were fed diets containing 12 or 30% protein ad libitum. Both groups were then switched to the diets containing the opposite level of protein. Birds were sampled at 0, 6, 9, 12, 18 and 24h following the switch in protein levels. Measurements taken included in vitro lipogenesis (IVL), malic enzyme (ME), aspartate aminotransferase (AAT) and isocitrate dehydrogenase (NADP) (ICD) activities. In addition, ME, AAT, ICD, fatty acid synthase (FAS), and acetyl coenzyme carboxylase (ACC) gene expression rates were determined. IVL and ME activities were inversely related to dietary protein levels (12 to 30%) and to acute changes from 12 to 30%. In contrast, expression of ME, FAS and ACC genes was decreased by feeding a 30% protein diet (acute or chronic feeding). Results of the present study demonstrate a continued role for protein in the regulation of broiler metabolism. It should be pointed out; however, that metabolic regulation at the gene level only occurs when feeding very high or very low levels of dietary protein.
Animal Biosciences and Biotechnology Laboratory, Animal and Natural Resources Institute, United States Department of Agriculture-Agricultural Research Service, Beltsville Agricultural Research Center, Beltsville, MD 20705, USA. bob.rosebrough@ars.usda.gov
R W
RW
Rosebrough
B A
BA
Russell
M P
MP
Richards
D000103:Acetyl-CoA Carboxylase / Q000235:genetics / Q000378:metabolism; D000222:Adaptation, Physiological / Q000187:drug effects / Q000235:genetics; D000818:Animals; D001219:Aspartate Aminotransferases / Q000235:genetics / Q000378:metabolism; D002645:Chickens / Q000235:genetics* / Q000378:metabolism*; D004044:Dietary Proteins / Q000008:administration & dosage / Q000494:pharmacology; D064429:Fatty Acid Synthases / Q000235:genetics / Q000378:metabolism; D005786:Gene Expression Regulation / Q000187:drug effects; D007521:Isocitrate Dehydrogenase / Q000235:genetics / Q000378:metabolism; D050356:Lipid Metabolism / Q000235:genetics*; D050155:Lipogenesis / Q000235:genetics*; D008099:Liver / Q000187:drug effects / Q000201:enzymology / Q000378:metabolism; D008291:Malate Dehydrogenase / Q000235:genetics / Q000378:metabolism; D008297:Male; D020133:Reverse Transcriptase Polymerase Chain Reaction; D013997:Time Factors
D004044:Dietary Proteins; D008291:Malate Dehydrogenase; D007521:Isocitrate Dehydrogenase; D064429:Fatty Acid Synthases; D001219:Aspartate Aminotransferases; D000103:Acetyl-CoA Carboxylase