Germ-layer surface tensions and "tissue affinities" in Rana pipiens gastrulae:: Quantitative measurements
Germ-layer surface tensions and "tissue affinities" in Rana pipiens gastrulae:: Quantitative measurements
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DOI：
10.1006/dbio.1997.8741
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发表时间：
1997-12-15
影响因子：
2.7
通讯作者：
Steinberg, MS
中科院分区：
文献类型：
--
作者：
Davis, GS;Phillips, HM;Steinberg, MS
两栖类原肠胚形成过程中引起胚层扩散和分层的形态发生特性被 Holtfreter 称为“组织亲和力”。差异粘附假说（DAH）将这种液体状组织重排归因于迁移细胞群内部和之间的细胞间粘附产生的力。该理论预测，在初级胚层中，深层外胚层的内聚性应最大，深层中胚层的内聚性应居中，而深层内胚层的内聚性应最小。此外，诱导后分化的神经外胚层的内聚性应该增加，导致其内化并与表皮分离。 DAH 还解释了为什么“液体”组织的内聚力（其细胞可以自由重新排列）应该可以作为组织表面张力来测量。使用专门设计的组织表面张力计，我们证明（i）淡色林蛙深层胚层的聚集体确实具有类似液体的表面张力，（ii）它们的表面张力值恰好符合解释体外和体内胚层分层所需的顺序，以及（iii）位于弓肠顶部下方的深层外胚层的表面张力是尚未深层外胚层的表面张力的两倍 外胚层。这些测量提供了直接的定量证据，表明在脊椎动物形态发生的早期阶段控制胚层的“组织亲和力”反映在组织表面张力中。 (C) 1997 年学术出版社。
The morphogenetic properties causing germ-layer spreading and stratification in amphibian gastrulation were called "tissue affinities" by Holtfreter. The differential adhesion hypothesis (DAH) attributes such liquidlike tissue rearrangements to forces generated by intercellular adhesions within and between the migrating cell populations. This theory predicts that, among the primary germ layers, the cohesiveness of deep ectoderm should be the greatest, that of deep mesoderm should be intermediate, and that of deep endoderm should be the least. Also, the cohesiveness of differentiating neural ectoderm should increase after induction, causing it to internalize and segregate from epidermis. The DAH also explains why the cohesiveness of "liquid" tissues, whose cells are free to rearrange, should be measurable as tissue surface tensions. Using a specially designed tissue surface tensiometer, we demonstrate that (i) aggregates of Rana pipiens deep germ layers do possess liquid-like surface tensions, (ii) their surface tension values lie in precisely the sequence necessary to account for germ-layer stratification in vitro and in vivo, and (iii) the surface tension of deep ectoderm just underlain by the archenteron roof is twice that of not-yet-underlain deep ectoderm. These measurements provide direct, quantitative evidence that the "tissue affinities" governing germ-layer now during early stages of vertebrate morphogenesis are reflected in tissue surface tensions. (C) 1997 Academic Press.