Daczewska M, Kiełbówna L
Laboratory of Evolutionary and Developmental Biology of Vertebrates, University of Wrocław, Poland.
Folia Biol (Krakow). 2000;48(1-2):37-42.
Two stages can be distinguished in the differentiation of myotomal muscle fibres in Triturus vulgaris. In the first stage only synchronously differentiating myotomal cells are engaged; in the second stage mesenchymal cells also take part in the process. Myotomal cells (primary myoblasts) fuse to form 2-3 nucleate myotubes. Only in the caudal part of the embryo mononucleate myotubes persist. The mononucleate myotubes, like polynucleate ones, occupy the whole length of the myotome. The differentiation of myotubes is accompanied by vitellolysis. At further development stages mesenchymal cells enter the intermyotomal fissure, after which they migrate to the myotomes, between the myotubes. The cells that remain in the intermyotomal fissures retain their fibroblastic potential (they synthesise collagen). Their daughter cells adjoining the myotubes acquire myogenic abilities. Their myoblastic potential is evidenced by their ability to fuse with the myotube. Fusion of secondary myoblasts (of mesenchymal origin) with the myotube results in further growth of the myotubes. In T. vulgaris myotomal myotubes and muscle fibres developing from them are of myotomal-mesenchymal origin.
在普通蝾螈的肌节肌纤维分化过程中可区分出两个阶段。在第一阶段，只有同步分化的肌节细胞参与其中；在第二阶段，间充质细胞也参与该过程。肌节细胞（原代成肌细胞）融合形成含2 - 3个核的肌管。只有在胚胎的尾部，单核肌管会持续存在。单核肌管与多核肌管一样，占据肌节的全长。肌管的分化伴随着卵黄溶解。在进一步发育阶段，间充质细胞进入肌节间裂，之后它们迁移到肌节，位于肌管之间。留在肌节间裂中的细胞保留其成纤维细胞潜能（它们合成胶原蛋白）。与肌管相邻的它们的子代细胞获得成肌能力。它们的成肌细胞潜能通过其与肌管融合的能力得以证明。次级成肌细胞（间充质起源）与肌管的融合导致肌管进一步生长。在普通蝾螈中，肌节肌管以及由它们发育而来的肌纤维是肌节 - 间充质起源的。
