Valvassori R, De Eguileor M, Lanzavecchia G
Tissue Cell. 1978;10(1):167-78. doi: 10.1016/0040-8166(78)90015-0.
Flight muscle fibers of Anax imperator nymphs, in different developmental stages are analyzed for several morphological features, such as the arragnement and numerical ratio of actin and myosin filaments, the pattern of the T system and sarcoplasmic reticulum, the number of microtubules and the fractional volume of mitochondria in each fiber. The T system is initially represented by longitudinal grooves on the cell surface, joined with vesicles of the sarcoplasmic reticulum; this pattern rapidly changes and the grooves start to break up into longitudinal segments. The thin to thick filament ratio is at first quite high (about 4-4.5:1) but rapidly falls to the final (3:1) when the myofibrils are well developed at the fiber periphery. Statistical analyses show that the measured values are significantly different in the various stages of development, also indicating a progressive reduction of the ratio variability. The reduction of thin to thick filament ratio and the variance decrease fit quite well with the hypothesis that the synthesis of actin and myosin depends on independently regulated messenger RNA molecules.
对不同发育阶段的帝王蟌若虫飞行肌纤维的几种形态特征进行了分析，如肌动蛋白丝和肌球蛋白丝的排列及数量比、T系统和肌浆网的模式、微管数量以及每根纤维中线粒体的分数体积。T系统最初表现为细胞表面的纵向凹槽，与肌浆网的小泡相连；这种模式迅速改变，凹槽开始分裂成纵向片段。细肌丝与粗肌丝的比例起初相当高（约4 - 4.5:1），但当肌原纤维在纤维周边充分发育时，迅速降至最终的（3:1）。统计分析表明，在不同发育阶段测量值存在显著差异，这也表明比例变异性在逐渐降低。细肌丝与粗肌丝比例的降低和方差的减小与肌动蛋白和肌球蛋白的合成依赖于独立调节的信使RNA分子这一假设相当吻合。
