Huang R, Christ B
Institute of Anatomy, University of Freiburg, Germany.
Anat Embryol (Berl). 2000 Nov;202(5):369-74. doi: 10.1007/s004290000130.
The myotome originates from the dermomyotome. Controversy surrounds the location of myotome precursor cells within the dermomyotome and their segregation from the dermomyotome. Here we addressed the problem of myotome formation by labeling dermomyotome cells using the quail-chick marking technique. We carried out five series of transplantation and replaced: (1) the medial third, (2) the intermediate third, (3) the lateral third, (4) the cranial half, (5) the caudal half of a thoracic dermomyotome. The grafting procedures were performed in HH-stages 15-17 of quail and chick embryos. The chimeras were reincubated for 2 days up to HH-stages 24-25. All of the grafted parts contributed to the myotome. The epaxial myotome is derived from the medial third of the dermomyotome, while the hypaxial myotome is formed by both the intermediate and lateral third of the dermomyotome. Ep- and hypaxial myotome domains meet in the thickest part of the myotome that is situated in the middle of its ventrolateral axis. Myotome growth in the epaxial domain begins earlier than in the hypaxial domain. Cranial and caudal edges of the dermomyotome contribute equally to both the epaxial and hypaxial myotomes. The first born myotome cells are located in the lateral part of the epaxial myotome and development then proceedes in medial and lateral directions.
肌节起源于皮肌节。关于肌节前体细胞在皮肌节中的位置以及它们与皮肌节的分离存在争议。在这里，我们通过使用鹌鹑 - 鸡标记技术标记皮肌节细胞来解决肌节形成的问题。我们进行了五组移植替换实验：（1）胸段皮肌节的内侧三分之一，（2）中间三分之一，（3）外侧三分之一，（4）头侧半，（5）尾侧半。移植操作在鹌鹑和鸡胚胎的HH分期15 - 17期进行。嵌合体再孵育2天直至HH分期24 - 25期。所有移植部分都对肌节有贡献。轴上肌节源自皮肌节的内侧三分之一，而轴下肌节由皮肌节的中间三分之一和外侧三分之一形成。轴上和轴下肌节区域在肌节最厚的部分交汇，该部分位于其腹外侧轴的中部。轴上区域的肌节生长比轴下区域开始得更早。皮肌节的头侧和尾侧边缘对轴上和轴下肌节的贡献相同。最早形成的肌节细胞位于轴上肌节的外侧部分，然后向内侧和外侧方向发展。
