Regional requirements for Dishevelled signaling during Xenopus gastrulation:: separable effects on blastopore closure, mesendoderm internalization and archenteron formation
Regional requirements for Dishevelled signaling during Xenopus gastrulation:: separable effects on blastopore closure, mesendoderm internalization and archenteron formation
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DOI：
10.1242/dev.01542
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发表时间：
2004-12-01
期刊：
影响因子：
4.6
通讯作者：
Wallingford, JB
中科院分区：
文献类型：
--
作者：
Ewald, AJ;Peyrot, SM;Wallingford, JB
在两栖动物原肠胚形成期间，胚胎通过几种不同组织的联合作用而转化。有趣的是，许多这些形态发生过程可以在组织外植体中自主发生，但完整胚胎中的组织必须相互作用并相互协调，以实现原肠胚形成的主要目标：关闭囊胚孔，使内胚层和中胚层完全进入外胚层，并产生原肠。在这里，我们提出了青蛙原肠胚的高分辨率3D数字数据集和形态测量学，允许同时评估单个胚胎中会聚延伸，囊胚孔闭合和原肠形成的进展。为了研究不同的形态发生引擎如何一起工作来完成原肠胚形成，我们将这些工具与原肠胚形成的延时分析相结合，并检查了野生型胚胎和原肠胚形成被Dishevelled（Xdsh）信号操纵破坏的胚胎。值得注意的是，虽然抑制Xdsh信号中断收敛延伸和囊胚孔关闭，中内胚层内化进行非常有效的在这些胚胎。此外，许多原肠延长被发现是独立的Xdsh信号，特别是在原肠胚形成的后半期。最后，即使在正常胚胎中，我们也发现原肠胚形成期间发生的各种形态发生过程之间存在令人惊讶的分离程度。总之，这些数据突出了PCP信号在非洲爪蟾原肠胚形成的不同事件中的核心作用，并表明形态发生过程之间的松散关系可能促进了不同两栖动物物种中各种原肠胚形成机制的进化。
During amphibian gastrulation, the embryo is transformed by the combined actions of several different tissues. Paradoxically, many of these morphogenetic processes can occur autonomously in tissue explants, yet the tissues in intact embryos must interact and be coordinated with one another in order to accomplish the major goals of gastrulation: closure of the blastopore to bring the endoderm and mesoderm fully inside the ectoderm, and generation of the archenteron. Here, we present high-resolution 3D digital datasets of frog gastrulae, and morphometrics that allow simultaneous assessment of the progress of convergent extension, blastopore closure and archenteron formation in a single embryo. To examine how the diverse morphogenetic engines work together to accomplish gastrulation, we combined these tools with time-lapse analysis of gastrulation, and examined both wild-type embryos and embryos in which gastrulation was disrupted by the manipulation of Dishevelled (Xdsh) signaling. Remarkably, although inhibition of Xdsh signaling disrupted both convergent extension and blastopore closure, mesendoderm internalization proceeded very effectively in these embryos. In addition, much of archenteron elongation was found to be independent of Xdsh signaling, especially during the second half of gastrulation. Finally, even in normal embryos, we found a surprising degree of dissociability between the various morphogenetic processes that occur during gastrulation. Together, these data highlight the central role of PCP signaling in governing distinct events of Xenopus gastrulation, and suggest that the loose relationship between morphogenetic processes may have facilitated the evolution of the wide variety of gastrulation mechanisms seen in different amphibian species.