The function and mechanism of convergent extension during gastrulation of Xenopus laevis.
The function and mechanism of convergent extension during gastrulation of Xenopus laevis.
复制标题
非洲爪蟾原肠胚形成过程中会聚伸展的功能和机制。
DOI：
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发表时间：
1985
期刊：
影响因子：
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通讯作者：
J. Shih
中科院分区：
文献类型：
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作者：
R. Keller;M. Danilchik;R. Gimlich;J. Shih
被认为在异武肠胃肠道中起作用的过程包括瓶细胞的形成，细胞在胚泡屋顶上的迁移以及圆周托管区域的自主收敛延伸。对最近和经典结果的综述表明，只有最后一个解释了胃胃的大部分组织位移，包括将边缘区域扩散到胚孔孔，边缘区域的涉及和胚泡的闭合。通过延时视频和Cine显微镜分析的显微外科操作和膨胀研究表明，背侧管区域包含两个区域，这些区域显示出自主或半自主收敛扩展。涉及边缘区域（IMZ）的背侧经历了融合（缩小）和延伸（延长），从中间阶段开始，并通过神经性继续进行，因此它同时向后延伸到山羊角塞，并狭窄地延伸到胚胎圆周。同时，上覆的非涉及边缘区（NIMZ）的相应区域开始了互补的收敛延伸，但速率更高，植物散布到占IMZ空缺的表面积。组织重组实验表明，背面IMZ的深细胞带来了收敛的延伸。用细胞谱系示踪剂对这些细胞的少量种群的标记表明，收敛延伸涉及深细胞的插入，以形成更长，较窄的阵列。培养外植体中深细胞的直接延时视频和Cine显微照片表明，收敛延伸涉及径向和圆周插入。清除早期胃的整个胚层屋顶，包括NIMZ的全部或部分，表明仅IMZ的收敛延伸可以带来其互动和胚芽封闭。讨论了融合扩展在其他两栖动物和其他后生动物的胃肠道中的作用及其对早期发展中相关问题的意义。
The processes thought to function in Xenopus gastrulation include bottle cell formation, migration of cells on the roof of the blastocoel, and autonomous convergent extension of the circumblastoporal region. A review of recent and classical results shows that only the last accounts for the bulk of the tissue displacement of gastrulation, including spreading of the marginal zone toward the blastopore, involution of the marginal zone, and closure of the blastopore. Microsurgical manipulation and explantation studies, analysed by time-lapse video and cine microscopy, shows that the dorsal circumblastoporal region contains two regions which show either autonomous or semiautonomous convergent extension. The dorsal involuting marginal zone (IMZ) undergoes convergence (narrowing) and extension (lengthening) after its involution, beginning at the midgastrula stage and continuing through neurulation, such that it simultaneously extends posteriorly across the yolk plug and narrows the blastoporal circumference. Concurrently, the corresponding region of the overlying non-involuting marginal zone (NIMZ) begins a complementary convergent extension, but at a greater rate, which spreads vegetally to occupy surface area vacated by the IMZ. Tissue recombination experiments show that the deep cells of the dorsal IMZ bring about convergent extension. Labelling of small populations of these cells with a cell lineage tracer shows that convergent extension involves intercalation of deep cells to form a longer, narrower array. Direct time-lapse video and cine micrography of deep cells in cultured explants show that convergent extension involves radial and circumferential intercalation. Removal of the entire blastocoel roof of the early gastrula, including all or part of the NIMZ, shows that convergent extension of the IMZ alone can bring about its involution and blastopore closure. The role of convergent extension in gastrulation of other amphibians and other metazoans and its significance to related problems in early development are discussed.