The developmental fate of the cephalic mesoderm in quail-chick chimeras.
The developmental fate of the cephalic mesoderm in quail-chick chimeras.
复制标题
DOI：
--
复制
发表时间：
1992
期刊：
影响因子：
4.6
通讯作者：
G. Couly;P. Coltey;N. L. Le Douarin
中科院分区：
文献类型：
--
作者：
G. Couly;P. Coltey;N. L. Le Douarin
利用同位素等时替代技术研究了鹌鹑和鸡胚胎神经胚晚期（3体节）头状近轴和索前中胚层的发育命运。参与手术的领土特别小，移植的大小约为150乘50至60微米。在这个阶段，神经嵴细胞还没有开始迁移，中胚层细胞的命运完全受到审查。发现前索中胚层产生以下眼肌：腹直肌和内侧肌以及腹直肌。近轴中胚层分为两个纵向带：一个中位数，躺在头囊泡（中位数近轴中胚层-MPM）;一个侧面，躺在前肠（侧面近轴中胚层-LPM）。前者产生其他三个眼肌，有助于中脑脑膜，并具有基本的骨骼生成能力。它构成了蝶骨体、眶蝶骨和耳囊;面部骨骼的其余部分起源于神经嵴。在3体节期，MPM仅由少数细胞代表。LPM在该阶段更丰富，基本上具有生肌潜能，对结缔组织也有一定的贡献。然而，大多数与面肌和下鳃肌相关的结缔细胞是神经嵴起源的。这项工作更重要的结果是表明，头部中胚层不形成真皮。这一功能由神经嵴细胞接管，神经嵴细胞形成面部的骨骼和真皮。如果我们将头部的所谓“体节”与躯干体节进行比较，就会发现前者的骨骼生成能力降低了，而后者却保持了它们的肌生成能力，而在脊椎动物头部的进化过程中，骨骼和真皮的形成基本上由神经嵴接管。
The developmental fate of the cephalic paraxial and prechordal mesoderm at the late neurula stage (3-somite) in the avian embryo has been investigated by using the isotopic, isochronic substitution technique between quail and chick embryos. The territories involved in the operation were especially tiny and the size of the transplants was of about 150 by 50 to 60 microns. At that stage, the neural crest cells have not yet started migrating and the fate of mesodermal cells exclusively was under scrutiny. The prechordal mesoderm was found to give rise to the following ocular muscles: musculus rectus ventralis and medialis and musculus oblicus ventralis. The paraxial mesoderm was separated in two longitudinal bands: one median, lying upon the cephalic vesicles (median paraxial mesoderm--MPM); one lateral, lying upon the foregut (lateral paraxial mesoderm--LPM). The former yields the three other ocular muscles, contributes to mesencephalic meninges and has essentially skeletogenic potencies. It contributes to the corpus sphenoid bone, the orbitosphenoid bone and the otic capsules; the rest of the facial skeleton is of neural crest origin. At 3-somite stage, MPM is represented by a few cells only. The LPM is more abundant at that stage and has essentially myogenic potencies with also some contribution to connective tissue. However, most of the connective cells associated with the facial and hypobranchial muscles are of neural crest origin. The more important result of this work was to show that the cephalic mesoderm does not form dermis. This function is taken over by neural crest cells, which form both the skeleton and dermis of the face. If one draws a parallel between the so-called "somitomeres" of the head and the trunk somites, it appears that skeletogenic potencies are reduced in the former, which in contrast have kept their myogenic capacities, whilst the formation of skeleton and dermis has been essentially taken over by the neural crest in the course of evolution of the vertebrate head.