Smith D S, Kathirithamby J
Tissue Cell. 1984;16(6):929-40. doi: 10.1016/0040-8166(84)90072-7.
The fine structure of the principal and ancillary metathoracic flight muscle fibres in the adult male of a strepsipteran, Elenchus tenuicornis, is described. Power-producing dorsal longitudinal and dorso-ventral flight muscles show features consistent with myoneural asynchrony: myofibrils are large and discrete and are separated by large closely packed mitochondria; the sarcoplasmic reticulum is very reduced but engages with T-system membranes in dyads at the mid-sarcomere H-band level. With respect to other asynchronous insect flight muscles, the fibres of Elenchus are anomalous (i) in the small fibre diameter, (ii) in the variable contour of the myofibrils and (iii) in the absence of tracheolar invagination. The functional significance of these structural features is discussed. Ancillary metathoracic muscles are structurally comparable with other synchronous fibres in possessing an extensive SR compartment. Structural evidence for asynchrony in the flight mechanism of Strepsiptera is considered in the context of the evolution of this mechanism throughout the insect Orders.
本文描述了捻翅目昆虫细角栉角蛉成年雄性个体中，中胸飞行主肌和辅助肌纤维的精细结构。产生动力的背纵肌和背腹飞行肌呈现出与肌神经异步性相符的特征：肌原纤维大且离散，被大量紧密排列的线粒体分隔；肌浆网非常不发达，但在肌节H带水平的二联体中与T系统膜相连。相较于其他异步昆虫飞行肌，栉角蛉的纤维在以下方面存在异常：（i）纤维直径小；（ii）肌原纤维轮廓多变；（iii）没有气管内陷。文中讨论了这些结构特征的功能意义。辅助中胸肌在结构上与其他同步纤维相当，具有广泛的肌浆网区室。在捻翅目飞行机制在整个昆虫目中的进化背景下，考虑了捻翅目飞行机制中异步性的结构证据。
