Jacobson M
Dev Biol. 1984 Mar;102(1):122-9. doi: 10.1016/0012-1606(84)90180-5.
Horseradish peroxidase (HRP) was used as an intracellular lineage tracer in two experiments designed to reveal the sites of origin of cells that formed the duplicate embryo which developed in relation to an organizer grafted in the ventral marginal zone (VMZ) of Xenopus laevis embryos. In the first experiment a dorsal blastoporal lip fully labeled with HRP was grafted in the VMZ of an unlabeled embryo at the beginning of gastrulation. This resulted in development of a second embryo in which labeled cells, of graft origin, formed the notochord, and parts of the somites, endoderm, and neural tube. The second experiment was designed to show the sites of origin of the host's cells that formed parts of the induced embryo. HRP was injected into individual blastomeres in a series of Xenopus embryos at the 32-cell stage and each embryo received an unlabeled organizer graft in the VMZ at the beginning of gastrulation. In these embryos the lineages that contributed to the host's primary neural tube did not contribute any cells to the induced neural tube. All the cells in the induced neural tube which originated from the host were descendants of ventral blastomeres that did not contribute to the neural tube normally. This shows that the second neural tube is formed as a result of the action of the organizer on cells in its immediate vicinity which would not normally have entered neural pathways of differentiation.
在两项实验中，辣根过氧化物酶（HRP）被用作细胞内谱系示踪剂，以揭示形成与移植到非洲爪蟾胚胎腹侧边缘区（VMZ）的组织者相关的重复胚胎的细胞起源部位。在第一个实验中，在原肠胚形成开始时，将一个完全用HRP标记的背侧胚孔唇移植到一个未标记胚胎的VMZ中。这导致了第二个胚胎的发育，其中来自移植组织的标记细胞形成了脊索以及部分体节、内胚层和神经管。第二个实验旨在展示形成诱导胚胎部分的宿主细胞的起源部位。在32细胞期，将HRP注射到一系列非洲爪蟾胚胎的单个卵裂球中，并且在原肠胚形成开始时，每个胚胎在VMZ接受一个未标记的组织者移植。在这些胚胎中，对宿主初级神经管有贡献的谱系没有向诱导神经管贡献任何细胞。诱导神经管中所有源自宿主的细胞都是腹侧卵裂球的后代，这些腹侧卵裂球通常不会参与神经管的形成。这表明第二个神经管是组织者对其紧邻区域中通常不会进入神经分化途径的细胞起作用的结果。
