Assessing normal embryogenesis in Caenorhabditis elegans using a 4D microscope: Variability of development and regional specification
Assessing normal embryogenesis in Caenorhabditis elegans using a 4D microscope: Variability of development and regional specification
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DOI：
10.1006/dbio.1997.8509
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发表时间：
1997-04-15
影响因子：
2.7
通讯作者：
Schnabel, H
中科院分区：
文献类型：
--
作者：
Schnabel, R;Hutter, H;Schnabel, H
秀丽隐杆线虫以其不变性胚胎发生而闻名。这种发育模式与从果蝇到高等脊椎动物的其他生物形成了明显的对比。借助4D显微镜系统（多焦点，延时视频记录系统），我们分析了秀丽隐杆线虫的正常胚胎发生，该系统允许对单个胚胎的细胞分裂，细胞位置和迁移进行广泛的记录和分析。该仪器揭示了细胞分裂时间、细胞定位和细胞-细胞接触等自然发生的变化，这是早期直接观察无法检测到的（Sulston et al., 1983, Dev. Biol. 100, 64-119）。胚胎非常灵活，从不同的早期阶段产生基本不变的前形态发生阶段。对早期创始卵裂球在前形态发生阶段的后代分布的分析表明，这些卵裂球在胚胎中建立了离散的区域，这一过程涉及相当数量的细胞运动，这在不同的胚胎中也是不同的。只有单元格命运分配保持不变。然而，如前所述，这不是由于细胞命运的自主不变规范，而是由于细胞-细胞相互作用发生的很早，当胚胎中卵裂球的拓扑结构仍然足够精确，以确保诱导模式的可重复性。奠基卵裂球在胚胎中产生胚胎区域的新概念可以解释谱系本身的惊人复杂性，也可以解释胚胎双边对称性建立的复杂的不对称谱系模式。许多细胞，包括双侧同源细胞，显然仅仅因为它们在胚胎中的位置而被选择了特定的命运，而与细胞产生的谱系血统无关。我们假设，细胞间相互作用产生区域是线虫胚胎发生的关键原则，线虫的胚胎发生遵循与其他生物胚胎发生相同的基本原则。(C) 1997学术出版社。
Caenorhabditis elegans is renowned for its invariant embryogenesis. This pattern of development is in apparent contrast to other organisms from Drosophila to higher vertebrates. With the aid of a 4D microscope system (multifocal, time-lapse video recording system) which permits the extensive documentation and analysis of cell divisions, cell positions, and migrations in single embryos we have analyzed normal embryogenesis of C. elegans. The instrumentation reveals a naturally occurring variability in cell division timing, cell positioning, and cell-cell contacts which could not have been detected by the direct observation used earlier (Sulston et al., 1983, Dev. Biol. 100, 64-119). Embryos are very flexible and produce an essentially invariant premorphogenetic stage from variable earlier stages. An analysis of the distribution of the descendants of the early founder blastomeres at the premorphogenetic stage shows that these establish discrete regions in the embryo, a process involving a considerable amount of cell movement, which again varies in different embryos. Only cell fate assignment remains invariant. However, as shown earlier, this is not due to an autonomous invariant specification of cell fates but due to the fact that cell-cell interactions occur very early when the topology of blastomeres in the embryo is still sufficiently precise to ensure reproducible patterns of inductions. A new concept that founder blastomeres produce embryonic regions in the embryo can explain the striking complexity of the lineage per se and also the complicated asymmetric lineage patterns by which the bilateral symmetry of the embryo is established. Many cells, including bilateral homologs, were apparently chosen for a specific fate solely by their position in the embryo, irrespectively of the lineage descent by which the cells are created. We postulate that the production of regions by cell-cell interactions is the pivotal principle guiding the embryogenesis of C. elegans and that the embryogenesis of the worm follows the same basic principles as embryogenesis in other organisms. (C) 1997 Academic Press.