title: Breed-dependent transcriptional regulation of phosphoenolpyruvate carboxylase, cytosolic form, expression in the liver of broiler chickens.
abstract: Hepatic gluconeogenesis is the main source of glucose during chicken embryonic development, and it plays a major role in glucose homeostasis for developing embryos. Phosphoenolpyruvate carboxylase (PEPCK) catalyzes the rate-limiting step of gluconeogenesis, yet how hepatic PEPCK expression is differentially regulated between chicken breeds remains elusive. In this study, fertile eggs from a slow-growing Chinese Yellow Feathered Chicken and a fast-growing White Recessive Rock Chicken were incubated under the same standard conditions, and serum and liver samples were collected on embryonic d 18 (18E). The fast-growing breed had a significantly higher fetal weight (P < 0.01) and serum glucose concentration (P < 0.05) compared with the slow-growing breed. The fast-growing breed also had significantly higher hepatic mRNA expression levels of the cystolic form of PEPCK (PEPCK-c; P < 0.05) and significantly higher hepatic mRNA and protein expression levels of cAMP response element binding protein 1 (CREB-1; P < 0.05). Moreover, the binding of phosphorylated CREB-1 to the PEPCK-c promoter tended to be higher in the fast-growing breed (P = 0.08). Breed-specific epigenetic modifications of the PEPCK-c promoter were also observed; the fast-growing breed demonstrated lower CpG methylation (P < 0.05) and histone H3 (P < 0.05) levels but more histone H3 acetylation (H3ac) and histone H3 lysine 27 trimethylation (H3K27me3; P < 0.05) compared with the slow-growing breed. Our results suggest that hepatic PEPCK-c expression is transcriptionally regulated in a breed-specific manner and that fast- and slow-growing broiler chicken fetuses exhibit different epigenetic modifications on their PEPCK-c promoter regions.
authors.affiliation: Key Laboratory of Animal Physiology and Biochemistry, Nanjing Agricultural University, Nanjing 210095, P.R. China.
authors.forename: Feng
authors.initials: F
authors.lastname: Guo
authors.forename: Yanhong
authors.initials: Y
authors.lastname: Zhang
authors.forename: Lanli
authors.initials: L
authors.lastname: Su
authors.forename: Abdelkareem A
authors.initials: AA
authors.lastname: Ahmed
authors.forename: Yingdong
authors.initials: Y
authors.lastname: Ni
authors.forename: Ruqian
authors.initials: R
authors.lastname: Zhao
mesh_terms: D000818:Animals; D030161:Avian Proteins / Q000235:genetics* / Q000378:metabolism; D015153:Blotting, Western / Q000662:veterinary; D002642:Chick Embryo; D002645:Chickens / Q000235:genetics* / Q000378:metabolism; D017362:Cyclic AMP Response Element-Binding Protein / Q000235:genetics* / Q000378:metabolism; D044127:Epigenesis, Genetic; D018507:Gene Expression Regulation, Developmental; D047468:Immunoprecipitation / Q000662:veterinary; D007527:Isoenzymes / Q000235:genetics / Q000378:metabolism; D008099:Liver / Q000378:metabolism*; D010730:Phosphoenolpyruvate Carboxylase / Q000235:genetics* / Q000378:metabolism; D011401:Promoter Regions, Genetic; D012333:RNA, Messenger / Q000235:genetics / Q000378:metabolism; D060888:Real-Time Polymerase Chain Reaction / Q000662:veterinary; D014158:Transcription, Genetic
chemical_list: D030161:Avian Proteins; D017362:Cyclic AMP Response Element-Binding Protein; D007527:Isoenzymes; D012333:RNA, Messenger; D010730:Phosphoenolpyruvate Carboxylase