Gastrulation in the sea urchin embryo requires the deposition of crosslinked collagen within the extracellular matrix.
Gastrulation in the sea urchin embryo requires the deposition of crosslinked collagen within the extracellular matrix.
复制标题
海胆胚胎中的原肠胚形成需要交联胶原蛋白在细胞外基质内的沉积。
DOI：
10.1016/0012-1606(87)90148-5
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发表时间：
1987
影响因子：
2.7
通讯作者：
McClay,DR
中科院分区：
文献类型：
--
作者：
Wessel,GM;McClay,DR
这项研究表明，胶原细胞外基质（ECM）是必需的原肠形成的海胆胚胎。所采取的方法是用两种类型的试剂（蹄铁酸试剂、β-氨基丙腈（BAPN）和三种类型的脯氨酸类似物：脱氢脯氨酸、顺式-OH-脯氨酸和氮杂环丁烷羧酸）破坏胶原蛋白加工，并通过形态学、免疫学和生化标准评估对胚胎发生的影响。长期暴露于受精后的任何一种药物的胚胎在间充质囊胚阶段之前没有表现出可检测到的发育异常。然而，这些胚胎，没有原肠胚，也没有进一步分化，并保持在间充质囊胚阶段至少36小时。在删除的代理，胚胎恢复正常的发育时间表，并形成pluteus幼虫是无法区分的控制胚胎。通过用I型和IV型胶原的单特异性抗体的免疫荧光研究，可以看出，溶血剂BAPN减少了ECM内胶原的积累。通过使用ELISA和通过OH-脯氨酸的生物化学测定来确认和定量这种作用。当药物从受抑制的胚胎中去除时，胶原蛋白沉积恢复正常，与原肠胚形成一致。蛋白质印迹分析，使用单特异性抗体的胶原蛋白，证明的作用，lastictic剂是通过抑制胶原蛋白分子的分子内和分子间交联，以减少细胞外胶原蛋白的稳定性。BAPN对形态发生表现出剂量依赖性影响，但对整个发育过程中胚胎的呼吸作用和蛋白质合成没有影响。虽然乳酸脱氢酶试剂影响胶原沉积，但显示其不影响ECM的其它分子的表达，也不影响几种细胞表面分子的表达。然而，在内胚层中特异性表达的细胞表面分子，称为Endo 1，在受抑制的胚胎中不表达。在去除乳酸脱氢酶剂后，Endo 1表达，其外观与回收胚胎中的原肠胚形成一致。这些结果表明，胶原ECM是重要的原肠形成和随后的分化在海胆，但不是早期的发育过程。此外，Endo 1表达对胶原ECM的依赖性提高了这种细胞表面分子以某种方式受推定的内胚层细胞与ECM的相互作用调节的可能性。
This study demonstrates that a collagenous extracellular matrix (ECM) is necessary for gastrulation in the sea urchin embryo. The approach taken was to disrupt collagen processing with two types of agents (a lathyritic agent, β-aminopropionitrile (BAPN), and three types of proline analogs: dehydroproline,cis-OH-proline, and azetidine carboxylic acid) and to assess the effect on embryogenesis by morphological, immunological, and biochemical criteria. Embryos chronically exposed to either of the agents following fertilization displayed no detectable developmental abnormalities before the mesenchyme blastula stage. These embryos, however, did not gastrulate nor differentiate any further and remained at the mesenchyme blastula stage for at least 36 hr. Upon removal of the agents, the embryos resumed a normal developmental schedule and formed pluteus larvae that were indistinguishable from control embryos. By immunofluorescence studies with monospecific antibodies to type I and type IV collagens it is seen that the lathyritic agent BAPN reduces the accumulation of collagens within the ECM. This effect is confirmed and quantitated by use of an ELISA and by a biochemical determination of OH-proline. When the agents are removed from the inhibited embryos, collagen deposition returns to normal, coincident with gastrulation. Western-blot analysis, using monospecific antibodies to collagen, demonstrates that the effect of the lathyritic agent is to reduce the stability of the extracellular collagen by inhibiting the intra- and intermolecular crosslinking of collagen molecules. BAPN exhibits a dose-dependent effect on morphogenesis, but has no effect on respiration nor on protein synthesis of the embryos throughout development. Although the lathyritic agent affects collagen deposition, it is shown to not affect the expression of other molecules of the ECM, nor that of several cell surface molecules. However, a cell surface molecule that is expressed specifically in the endoderm, termed Endo 1, is not expressed in the inhibited embryos. Endo 1 is expressed after removal of the lathyritic agent and its appearance is coincident with gastrulation in the recovered embryos. These results suggest that a collagenous ECM is important for gastrulation and subsequent differentiation in the sea urchin, but not for earlier developmental processes. In addition, the dependence of Endo 1 expression on the collagenous ECM raises the possibility that this cell surface molecule is in some way regulated by interactions of the presumptive endodermal cells with the ECM.