Department of Biology, New Mexico State University, Las Cruces, New Mexico; and.
Systemix Institute, Redmond, Washington.
Physiol Genomics. 2016 Sep 1;48(9):699-710. doi: 10.1152/physiolgenomics.00068.2016. Epub 2016 Jul 22.
Skeletal muscle is distinguished from other tissues on the basis of its shape, biochemistry, and physiological function. Based on mammalian studies, fiber size, fiber types, and gene expression profiles are regulated, in part, by the electrical activity exerted by the nervous system. To address whether similar adaptations to changes in electrical activity in skeletal muscle occur in teleosts, we studied these phenotypic properties of ventral muscle in the electric fish Sternopygus macrurus following 2 and 5 days of electrical inactivation by spinal transection. Our data show that morphological and biochemical properties of skeletal muscle remained largely unchanged after these treatments. Specifically, the distribution of type I and type II muscle fibers and the cross-sectional areas of these fiber types observed in control fish remained unaltered after each spinal transection survival period. This response to electrical inactivation was generally reflected at the transcript level in real-time PCR and RNA-seq data by showing little effect on the transcript levels of genes associated with muscle fiber type differentiation and plasticity, the sarcomere complex, and pathways implicated in the regulation of muscle fiber size. Data from this first study characterizing the acute influence of neural activity on muscle mass and sarcomere gene expression in a teleost are discussed in the context of comparative studies in mammalian model systems and vertebrate species from different lineages.
骨骼肌在形态、生物化学和生理功能上有别于其他组织。基于哺乳动物的研究，纤维大小、纤维类型和基因表达谱部分受到神经系统电活动的调节。为了研究电鱼 Sternopygus macrurus 中的骨骼肌是否会发生类似的电活动适应性变化，我们在脊髓横切后 2 天和 5 天对其腹侧肌肉进行了电失活处理，研究了这些表型特性。我们的数据表明，形态和生化特性在这些处理后基本保持不变。具体来说，在对照组鱼中观察到的 I 型和 II 型肌纤维的分布以及这些纤维类型的横截面积在每次脊髓横切存活期后均未改变。这一电失活反应在实时 PCR 和 RNA-seq 数据的转录水平上得到了普遍反映，与肌纤维类型分化和可塑性、肌节复合体以及与肌纤维大小调节相关的途径相关的基因的转录水平几乎没有受到影响。本文首次研究了神经活动对硬骨鱼肌肉质量和肌节基因表达的急性影响，该研究在哺乳动物模型系统和不同进化枝的脊椎动物物种的比较研究背景下进行了讨论。
