title: Differential expression of lipid metabolism-related genes and myosin heavy chain isoform genes in pig muscle tissue leading to different meat quality.
abstract: The aim of this study was to investigate the variations in meat quality, lipid metabolism-related genes, myosin heavy chain (MyHC) isoform genes and peroxisome proliferator-activated receptor gamma coactivator-1α (PGC-1α) gene mRNA expressions in longissimus dorsi muscle (LM) of two different pig breeds. Six Rongchang and six Landrace barrows were slaughtered at 161 days of age. Subsequently, meat quality traits and gene expression levels in LM were observed. Results showed that Rongchang pigs not only exhibited greater pH, CIE a*24 h and intramuscular fat content but also exhibited lower body weight, carcass weight, dressing percentage, LM area and CIE b*24 h compared with Landrace pigs (P<0.05). Meanwhile, the mRNA expression levels of the lipogenesis (peroxisome proliferator-activated receptor gamma, acetyl-CoA carboxylase and fatty acid synthase) and fatty acid uptake (lipoprotein lipase)-related genes were greater in the Rongchang (P<0.05), whereas the lipolysis (adipose triglyceride lipase and hormone sensitive lipase) and fatty acid oxidation (carnitine palmitoyltransferase-1B)-related genes were better expressed in the Landrace. Moreover, compared with the Landrace, the mRNA expression levels of MyHCI, MyHCIIa and MyHCIIx were greater, whereas the mRNA expression levels of MyHCIIb were lower in the Rongchang pigs (P<0.05). In addition, the mRNA expression levels of PGC-1α were greater in Rongchang pigs than in the Landrace (P<0.05), which can partly explain the differences in MyHC isoform gene expressions between Rongchang and Landrace pigs. Although the small number of samples does not allow to obtain a definitive conclusion, we can suggest that Rongchang pigs possess better meat quality, and the underlying molecular mechanisms responsible for the better meat quality in fatty pigs may be partly due to the higher mRNA expression levels of lipogenesis and fatty acid uptake-related genes, as well as the oxidative and intermediate muscle fibers, and due to the lower mRNA expression levels of lipolysis and fatty acid oxidation-related genes, as well as the glycolytic muscle fibers.
authors.affiliation: Institute of Animal Nutrition,Sichuan Agricultural University,Ya'an 625014,Sichuan,China.
authors.forename: C
authors.initials: C
authors.lastname: Zhang
authors.affiliation: Institute of Animal Nutrition,Sichuan Agricultural University,Ya'an 625014,Sichuan,China.
authors.forename: J Q
authors.initials: JQ
authors.lastname: Luo
authors.affiliation: Institute of Animal Nutrition,Sichuan Agricultural University,Ya'an 625014,Sichuan,China.
authors.forename: P
authors.initials: P
authors.lastname: Zheng
authors.affiliation: Institute of Animal Nutrition,Sichuan Agricultural University,Ya'an 625014,Sichuan,China.
authors.forename: B
authors.initials: B
authors.lastname: Yu
authors.affiliation: Institute of Animal Nutrition,Sichuan Agricultural University,Ya'an 625014,Sichuan,China.
authors.forename: Z Q
authors.initials: ZQ
authors.lastname: Huang
authors.affiliation: Institute of Animal Nutrition,Sichuan Agricultural University,Ya'an 625014,Sichuan,China.
authors.forename: X B
authors.initials: XB
authors.lastname: Mao
authors.affiliation: Institute of Animal Nutrition,Sichuan Agricultural University,Ya'an 625014,Sichuan,China.
authors.forename: J
authors.initials: J
authors.lastname: He
authors.affiliation: Institute of Animal Nutrition,Sichuan Agricultural University,Ya'an 625014,Sichuan,China.
authors.forename: J
authors.initials: J
authors.lastname: Yu
authors.affiliation: Institute of Animal Nutrition,Sichuan Agricultural University,Ya'an 625014,Sichuan,China.
authors.forename: J L
authors.initials: JL
authors.lastname: Chen
authors.affiliation: Institute of Animal Nutrition,Sichuan Agricultural University,Ya'an 625014,Sichuan,China.
authors.forename: D W
authors.initials: DW
authors.lastname: Chen
mesh_terms: D000818:Animals; D005786:Gene Expression Regulation; D050356:Lipid Metabolism / Q000235:genetics*; D008297:Male; D008460:Meat / Q000032:analysis / Q000592:standards*; D018482:Muscle, Skeletal / Q000378:metabolism*; D018995:Myosin Heavy Chains / Q000235:genetics* / Q000378:metabolism; D047495:PPAR gamma / Q000235:genetics* / Q000378:metabolism; D020033:Protein Isoforms / Q000378:metabolism; D012333:RNA, Messenger / Q000235:genetics / Q000378:metabolism; D034421:Sus scrofa / Q000235:genetics* / Q000378:metabolism
chemical_list: D047495:PPAR gamma; D020033:Protein Isoforms; D012333:RNA, Messenger; D018995:Myosin Heavy Chains
keywords: PGC-1α; Rongchang pigs; lipid metabolism; meat quality; myosin heavy chain