title: Thermal manipulation during embryogenesis has long-term effects on muscle and liver metabolism in fast-growing chickens.
abstract: Fast-growing chickens have a limited ability to tolerate high temperatures. Thermal manipulation during embryogenesis (TM) has previously been shown to lower chicken body temperature (Tb) at hatching and to improve thermotolerance until market age, possibly resulting from changes in metabolic regulation. The aim of this study was to evaluate the long-term effects of TM (12 h/d, 39.5°C, 65% RH from d 7 to 16 of embryogenesis vs. 37.8°C, 56% RH continuously) and of a subsequent heat challenge (32°C for 5 h at 34 d) on the mRNA expression of metabolic genes and cell signaling in the Pectoralis major muscle and the liver. Gene expression was analyzed by RT-qPCR in 8 chickens per treatment, characterized by low Tb in the TM groups and high Tb in the control groups. Data were analyzed using the general linear model of SAS considering TM and heat challenge within TM as main effects. TM had significant long-term effects on thyroid hormone metabolism by decreasing the muscle mRNA expression of deiodinase DIO3. Under standard rearing conditions, the expression of several genes involved in the regulation of energy metabolism, such as transcription factor PGC-1α, was affected by TM in the muscle, whereas for other genes regulating mitochondrial function and muscle growth, TM seemed to mitigate the decrease induced by the heat challenge. TM increased DIO2 mRNA expression in the liver (only at 21°C) and reduced the citrate synthase activity involved in the Krebs cycle. The phosphorylation level of p38 Mitogen-activated-protein kinase regulating the cell stress response was higher in the muscle of TM groups compared to controls. In conclusion, markers of energy utilization and growth were either changed by TM in the Pectoralis major muscle and the liver by thermal manipulation during incubation as a possible long-term adaptation limiting energy metabolism, or mitigated during heat challenge.
authors.affiliation: INRA, UR83 Recherches Avicoles, Nouzilly, France.
authors.forename: Thomas
authors.initials: T
authors.lastname: Loyau
authors.affiliation: INRA, UR83 Recherches Avicoles, Nouzilly, France.
authors.forename: Sonia
authors.initials: S
authors.lastname: Métayer-Coustard
authors.affiliation: INRA, UR83 Recherches Avicoles, Nouzilly, France.
authors.forename: Cécile
authors.initials: C
authors.lastname: Berri
authors.affiliation: INRA, UR83 Recherches Avicoles, Nouzilly, France.
authors.forename: Sabine
authors.initials: S
authors.lastname: Crochet
authors.affiliation: INRA, UR83 Recherches Avicoles, Nouzilly, France.
authors.forename: Estelle
authors.initials: E
authors.lastname: Cailleau-Audouin
authors.affiliation: INRA, UR83 Recherches Avicoles, Nouzilly, France.
authors.forename: Mélanie
authors.initials: M
authors.lastname: Sannier
authors.affiliation: INRA, UR83 Recherches Avicoles, Nouzilly, France.
authors.forename: Pascal
authors.initials: P
authors.lastname: Chartrin
authors.affiliation: INRA, UR83 Recherches Avicoles, Nouzilly, France.
authors.forename: Christophe
authors.initials: C
authors.lastname: Praud
authors.affiliation: INRA, UR83 Recherches Avicoles, Nouzilly, France.
authors.forename: Christelle
authors.initials: C
authors.lastname: Hennequet-Antier
authors.affiliation: INRA, UR83 Recherches Avicoles, Nouzilly, France.
authors.forename: Nicole
authors.initials: N
authors.lastname: Rideau
authors.affiliation: INRA, UR83 Recherches Avicoles, Nouzilly, France.
authors.forename: Nathalie
authors.initials: N
authors.lastname: Couroussé
authors.affiliation: INRA, UR83 Recherches Avicoles, Nouzilly, France.
authors.forename: Sandrine
authors.initials: S
authors.lastname: Mignon-Grasteau
authors.affiliation: KU Leuven, Department of Biosystems, Leuven, Belgium; University of Liège, Gembloux Agro-Bio Tech, Animal Science Unit, Gembloux, Belgium.
authors.forename: Nadia
authors.initials: N
authors.lastname: Everaert
authors.affiliation: INRA, UR83 Recherches Avicoles, Nouzilly, France.
authors.forename: Michel Jacques
authors.initials: MJ
authors.lastname: Duclos
authors.affiliation: Institute of Animal Science, The Volcani Center, Bet Dagan, Israel.
authors.forename: Shlomo
authors.initials: S
authors.lastname: Yahav
authors.affiliation: INRA, UR83 Recherches Avicoles, Nouzilly, France.
authors.forename: Sophie
authors.initials: S
authors.lastname: Tesseraud
authors.affiliation: INRA, UR83 Recherches Avicoles, Nouzilly, France.
authors.forename: Anne
authors.initials: A
authors.lastname: Collin
mesh_terms: D000818:Animals; D001831:Body Temperature; D002642:Chick Embryo; D002645:Chickens / Q000235:genetics / Q000254:growth & development*; D047108:Embryonic Development / Q000235:genetics; D020869:Gene Expression Profiling; D018507:Gene Expression Regulation, Developmental; D007328:Insulin / Q000378:metabolism; D008099:Liver / Q000201:enzymology / Q000378:metabolism*; D009132:Muscles / Q000201:enzymology / Q000378:metabolism*; D010766:Phosphorylation; D011494:Protein Kinases / Q000378:metabolism; D012333:RNA, Messenger / Q000235:genetics / Q000378:metabolism; D015398:Signal Transduction; D013312:Stress, Physiological; D013997:Time Factors
chemical_list: D007328:Insulin; D012333:RNA, Messenger; D011494:Protein Kinases