Dale L, Slack J M
Imperial Cancer Research Fund, University of Oxford, UK.
Development. 1987 Apr;99(4):527-51. doi: 10.1242/dev.99.4.527.
A complete fate map has been produced for the 32-cell stage of Xenopus laevis. Embryos with a regular cleavage pattern were selected and individual blastomeres were injected with the lineage label fluorescein-dextran-amine (FDA). The spatial location of the clones was deduced from three-dimensional (3D) reconstructions of later stages and the volume of each tissue colonized by labelled cells in each tissue was measured. The results from 107 cases were pooled to give a fate map which shows the fate of each blastomere in terms of tissue types, the composition of each tissue by blastomere, the location of each prospective region on the embryo and the fate of each blastomere in terms of spatial localization. Morphogenetic movements up to stage 10 (early gastrula) were assessed by carrying out a number of orthotopic grafts at blastula and gastrula stages using donor embryos uniformly labelled with FDA. Although there is a regular topographic projection from the 32-cell stage this varies a little between individuals because of variability of positions of cleavage planes and because of short-range cell mixing during gastrulation. The cell mixing means that the topographic projection fails for anteroposterior segments of the dorsal axial structures and it is not possible to include short segments of notochord or neural tube or individual somites on the pregastrulation fate map.
非洲爪蟾32细胞期的完整命运图谱已经绘制完成。选择具有规则卵裂模式的胚胎，将谱系标记物荧光素-葡聚糖-胺（FDA）注射到单个卵裂球中。通过后期的三维（3D）重建推断克隆的空间位置，并测量每个组织中被标记细胞定殖的每个组织的体积。汇总107个案例的结果，得出一个命运图谱，该图谱显示了每个卵裂球在组织类型方面的命运、每个组织按卵裂球划分的组成、胚胎上每个预期区域的位置以及每个卵裂球在空间定位方面的命运。通过在囊胚期和原肠胚期使用均匀标记有FDA的供体胚胎进行一些原位移植，评估了直到10期（早期原肠胚）的形态发生运动。尽管从32细胞期开始有规则的地形投影，但由于卵裂平面位置的变异性以及原肠胚形成过程中的短程细胞混合，个体之间略有差异。细胞混合意味着背轴结构前后节段的地形投影失败，并且在前原肠胚命运图谱上不可能包括脊索或神经管的短节段或单个体节。
