title: Expression of carnitine palmitoyl-CoA transferase-1B is influenced by a cis-acting eQTL in two chicken lines selected for high and low body weight.
abstract: Carnitine palmitoyl-CoA transferase-1B is a mitochondrial enzyme in the fatty acid oxidation pathway. In a previous study, CPT1B was identified as differentially expressed in the hypothalamus of two lines of chickens established by long-term selection for high (HWS) or low (LWS) body weight. Mammals have three paralogs (CPT1a, b and c) while nonmammalian vertebrates only have two (CPT1A, B). CPT1A is expressed in liver and CPT1B in muscle. CPT1c is expressed in hypothalamus, where it regulates feeding and energy expenditure. We identified an intronic length polymorphism, fixed for different alleles in the two populations, and mapped the hitherto missing CPT1B locus in the chicken genome assembly, to the distal tip of chromosome 1p. Based on molecular phylogeny and gene synteny we suggest that chicken CPT1B is pro-orthologous of the mammalian CPT1c. Chicken CPT1B was differentially expressed in both muscle and hypothalamus but in opposite directions: higher levels in hypothalamus but lower levels in muscle in the HWS than in the LWS line. Using an advanced intercross population of the lines, we found CPT1B expression to be influenced by a cis-acting expression quantitative trait locus in muscle. The increased expression in hypothalamus and reduced expression in muscle is consistent with an increased food intake in the HWS line and at the same time reduced fatty acid oxidation in muscle yielding a net accumulation of energy intake and storage. The altered expression of CPT1B in hypothalamus and peripheral tissue is likely to be a mechanism contributing to the remarkable difference between lines.
authors.affiliation: Department of Neuroscience, Uppsala University, Uppsala, Sweden.
authors.forename: Sojeong
authors.initials: S
authors.lastname: Ka
authors.forename: Ellen
authors.initials: E
authors.lastname: Markljung
authors.forename: Henrik
authors.initials: H
authors.lastname: Ring
authors.forename: Frank W
authors.initials: FW
authors.lastname: Albert
authors.forename: Mohammad
authors.initials: M
authors.lastname: Harun-Or-Rashid
authors.forename: Per
authors.initials: P
authors.lastname: Wahlberg
authors.forename: Pablo M
authors.initials: PM
authors.lastname: Garcia-Roves
authors.forename: Juleen R
authors.initials: JR
authors.lastname: Zierath
authors.forename: D Michael
authors.initials: DM
authors.lastname: Denbow
authors.forename: Svante
authors.initials: S
authors.lastname: Pääbo
authors.forename: Paul B
authors.initials: PB
authors.lastname: Siegel
authors.forename: Leif
authors.initials: L
authors.lastname: Andersson
authors.forename: Finn
authors.initials: F
authors.lastname: Hallböök
mesh_terms: D000818:Animals; D001483:Base Sequence; D001835:Body Weight / Q000235:genetics*; D002334:Carnitine O-Palmitoyltransferase / Q000235:genetics* / Q000378:metabolism; D002645:Chickens / Q000235:genetics*; D002874:Chromosome Mapping; D002875:Chromosomes / Q000235:genetics; D003433:Crosses, Genetic; D019143:Evolution, Molecular; D005260:Female; D015971:Gene Expression Regulation, Enzymologic; D005838:Genotype; D006801:Humans; D007031:Hypothalamus / Q000201:enzymology; D008297:Male; D024101:Mitochondrial Proteins / Q000378:metabolism; D005810:Multigene Family / Q000235:genetics; D009132:Muscles / Q000201:enzymology; D009928:Organ Specificity / Q000235:genetics; D010802:Phylogeny; D011110:Polymorphism, Genetic; D040641:Quantitative Trait Loci / Q000235:genetics*; D012333:RNA, Messenger / Q000235:genetics / Q000378:metabolism; D026801:Synteny / Q000235:genetics
chemical_list: D024101:Mitochondrial Proteins; D012333:RNA, Messenger; D002334:Carnitine O-Palmitoyltransferase
keywords: body weight; chromosomal mapping; fatty acid; genotyping; hypothalamus; lipid metabolism; mRNA expression; malonyl-CoA; mitochondria; pectoral muscle; skeletal muscle