Age-Dependent Expression of MyHC Isoforms and Lipid Metabolism-Related Genes in the Longissimus Dorsi Muscle of Wild and Domestic Pigs

• Main Authors: Milka Vrecl, Marko Cotman, Matjaž Uršič, Marjeta Čandek-Potokar, Gregor Fazarinc
• Format: Article
• Language: English
• Published: MDPI AG 2018-12-01
• Series: Animals
• Subjects: skeletal myofibers; postnatal transformation; quantitative PCR; histochemistry; MyHC isoforms; lipid metabolism-related genes
• Online Access: http://www.mdpi.com/2076-2615/9/1/10

This study aimed to compare age-dependent changes in the relative expression of genes encoding myosin heavy chain (MyHC) isoforms and selected lipid metabolism-related genes in the longissimus dorsi muscle of wild pigs (WPs) and domestic pigs (DPs). Muscles sampled from postnatal day one as well as three-week-old and two-year-old animals were used in quantitative polymerase chain reaction (qPCR) assays, histological evaluations of succinate dehydrogenase (SDH) activity, and intra-myofiber lipid (IMFL) assessment. Expression of the MyHC isoforms displayed the most extensive age- and breed-dependent changes within the first three postnatal weeks. The MyHCembry level decreased significantly faster in the WPs than in the DPs. The relative MyHC-I and -IIa expression was significantly higher in the WPs, and MyHC-IIb was substantially higher in the DPs. The differences in MyHC expression corroborated the number of SDH-positive myofibers and IMFLs. Expression of the peroxisome proliferator-activated receptor gamma coactivator 1 alpha (PGC-1α), peroxisome proliferator-activated receptor gamma (PPARγ) and lipoprotein lipase (LPL) genes displayed only age-related variations. In summary, the evidence is provided for accelerated postnatal myofiber transformation directed towards oxidative myofibers in WPs. The SDH activity/staining intensity largely reflected the expression of MyHCs, and not genes involved in lipid uptake and utilization.