Kalbe Claudia, Zebunke Manuela, Lösel Dorothea, Brendle Julia, Hoy Steffen, Puppe Birger
Institute of Muscle Biology and Growth, Leibniz Institute for Farm Animal Biology (FBN), D-18196, Dummerstorf, Germany.
Institute of Behavioural Physiology, Leibniz Institute for Farm Animal Biology (FBN), D-18196, Dummerstorf, Germany.
Sci Rep. 2018 Feb 7;8(1):2533. doi: 10.1038/s41598-018-20652-2.
Self-determined physical activity is an essential behavioural need and can vary considerably between individuals of a given species. Although locomotion is suggested as a prerequisite for adequate function of skeletal muscle, domestic pigs are usually reared under limited space allowance. The aim of our study was to investigate if a different voluntary locomotor activity leads to altered properties in the muscle structure, biochemistry and mRNA expression of selected genes involved in myogenesis and skeletal muscle metabolism. Based on a video tracking method, we assigned pigs to three categories according to their total distances walked over five observed time points: long distance, medium distance, and short distance. The microstructure and biochemistry parameters of the M. semitendinosus were unaffected by the distance categories. However, we found distance-dependent differences in the mRNA expression of the genes encoding growth (IGF2, EGF, MSTN) and transcription factors (MRF4, MYOD). In particular, the IGF2/MSTN ratio appears to be a sensitive indicator, at the molecular level, for the locomotor activity of individuals. Our results indicate that the myogenic growth potential of pigs under standard rearing conditions is triggered by their displayed voluntary locomotor activity, but the covered distances are insufficient to induce adaptive changes at the tissue level.
自主的身体活动是一种基本的行为需求，在给定物种的个体之间可能存在很大差异。尽管运动被认为是骨骼肌正常功能的先决条件，但家猪通常在有限的空间内饲养。我们研究的目的是调查不同的自主运动活动是否会导致参与肌生成和骨骼肌代谢的选定基因的肌肉结构、生物化学和mRNA表达特性发生改变。基于视频跟踪方法，我们根据猪在五个观察时间点行走的总距离将其分为三类：长距离、中距离和短距离。半腱肌的微观结构和生物化学参数不受距离类别的影响。然而，我们发现编码生长（IGF2、EGF、MSTN）和转录因子（MRF4、MYOD）的基因的mRNA表达存在距离依赖性差异。特别是，IGF2/MSTN比值似乎在分子水平上是个体运动活动的敏感指标。我们的结果表明，在标准饲养条件下，猪的肌生成生长潜力是由其表现出的自主运动活动触发的，但所覆盖的距离不足以在组织水平上诱导适应性变化。
