Suzuki A S, Yamamoto Y, Imoh H
Department of Biology, Faculty of General Education, Kumamoto University, Kumamoto City, Japan.
Dev Growth Differ. 1997 Apr;39(2):135-41. doi: 10.1046/j.1440-169x.1997.t01-1-00002.x.
It has been indicated that specification of the dorsal marginal mesoderm of the Cynops gastrula is established by vertical interactions with other layers, which occur during its extended involution. In the present study, when the prospective notochordal area of the early gastrula was almost completely removed together with the dorsal mesoderm-inducing endoderm and most of the bottle cells, the D-less gastrulas still formed the dorsal axis with a well-differentiated notochord; in half of them, where the involution occurred bi-laterally, twin axes were observed. On the other hand, when the wound of a D-less gastrula was repaired by transplanting the ventral marginal zone and ectoderm, the formation of the dorsal axis was inhibited if the involution of the lateral marginal zone was prevented by the transplanted piece. The present study suggests that: (i) cells having dorsal mesoderm-forming potency distribute farther laterally than the fate map; and (ii) the extended involution plays an essential role in the specification of the dorsal marginal mesoderm, especially in notochordal differentiation in normal Cynops embryogenesis.
有研究表明，东方蝾螈原肠胚背侧边缘中胚层的特化是通过与其他层的垂直相互作用建立的，这种相互作用发生在其延长内卷期间。在本研究中，当早期原肠胚的预期脊索区与诱导背侧中胚层的内胚层以及大部分瓶状细胞几乎完全被去除时，缺失这些结构的原肠胚仍能形成具有分化良好脊索的背轴；其中一半在双侧发生内卷的情况下，观察到了双轴。另一方面，当通过移植腹侧边缘区和外胚层修复缺失这些结构的原肠胚的伤口时，如果移植块阻止了侧边缘区的内卷，背轴的形成就会受到抑制。本研究表明：（i）具有形成背侧中胚层能力的细胞分布比命运图谱所显示的更靠外侧；（ii）延长内卷在正常东方蝾螈胚胎发育中背侧边缘中胚层的特化，尤其是脊索分化中起重要作用。
