Vrecl Milka, Cotman Marko, Uršič Matjaž, Čandek-Potokar Marjeta, Fazarinc Gregor
Veterinary Faculty, Institute of Preclinical Sciences, University of Ljubljana, Gerbičeva 60, 1000 Ljubljana, Slovenia.
Agricultural Institute of Slovenia, Hacquetova ulica 17, 1000 Ljubljana, Slovenia.
Animals (Basel). 2018 Dec 28;9(1):10. doi: 10.3390/ani9010010.
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 level decreased significantly faster in the WPs than in the DPs. The relative and expression was significantly higher in the WPs, and was substantially higher in the DPs. The differences in 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.
本研究旨在比较野猪（WPs）和家猪（DPs）背最长肌中编码肌球蛋白重链（MyHC）亚型的基因以及选定的脂质代谢相关基因的相对表达随年龄的变化。从出生后第1天以及3周龄和2岁的动物身上采集肌肉，用于定量聚合酶链反应（qPCR）分析、琥珀酸脱氢酶（SDH）活性的组织学评估以及肌内脂质（IMFL）评估。MyHC亚型的表达在出生后的前三周内显示出最广泛的年龄和品种依赖性变化。WPs中该水平的下降明显快于DPs。WPs中MyHCⅡa和Ⅱx的相对表达显著更高，而MyHCⅠ在DPs中显著更高。MyHC表达的差异与SDH阳性肌纤维和IMFL的数量相符。过氧化物酶体增殖物激活受体γ共激活因子1α（PGC-1α）、过氧化物酶体增殖物激活受体γ（PPARγ）和脂蛋白脂肪酶（LPL）基因的表达仅显示出与年龄相关的变化。总之，本研究为WPs出生后向氧化型肌纤维的肌纤维转化加速提供了证据。SDH活性/染色强度在很大程度上反映了MyHCs的表达，而不是参与脂质摄取和利用的基因的表达。
