Teddy Jessica M, Kulesa Paul M
Stowers Institute for Medical Research, 1000 East 50th Street, Kansas City, MO 64110, USA.
Development. 2004 Dec;131(24):6141-51. doi: 10.1242/dev.01534. Epub 2004 Nov 17.
The proper assembly of craniofacial structures and the peripheral nervous system requires neural crest cells to emerge from the neural tube and navigate over long distances to the branchial arches. Cell and molecular studies have shed light on potential intrinsic and extrinsic cues, which, in combination, are thought to ensure the induction and specification of cranial neural crest cells. However, much less is known about how migrating neural crest cells interpret and integrate signals from the microenvironment and other neural crest cells to sort into and maintain the stereotypical pattern of three spatially segregated streams. Here, we explore the extent to which cranial neural crest cells use cell-to-cell and cell-environment interactions to pathfind. The cell membrane and cytoskeletal elements in chick premigratory neural crest cells were labeled in vivo. Three-dimensional reconstructions of migrating neural crest cells were then obtained using confocal static and time-lapse imaging. It was found that neural crest cells maintained nearly constant contact with other migrating neural crest cells, in addition to the microenvironment. Cells used lamellipodia or short, thin filopodia (1-2 microm wide) for local contacts (<20 microm). Non-local, long distance contact (up to 100 microm) was initiated by filopodia that extended and retracted, extended and tracked, or tethered two non-neighboring cells. Intriguingly, the cell-to-cell contacts often stimulated a cell to change direction in favor of a neighboring cell's trajectory. In summary, our results present in vivo evidence for local and long-range neural crest cell interactions, suggesting a possible role for these contacts in directional guidance.
颅面结构和周围神经系统的正常组装需要神经嵴细胞从神经管中产生，并长距离迁移至鳃弓。细胞和分子研究揭示了潜在的内在和外在信号，这些信号被认为共同确保颅神经嵴细胞的诱导和特化。然而，对于迁移中的神经嵴细胞如何解读和整合来自微环境及其他神经嵴细胞的信号，从而分选并维持三个空间上分离的流的刻板模式，我们所知甚少。在这里，我们探究颅神经嵴细胞在多大程度上利用细胞间和细胞与环境的相互作用来寻找路径。我们在体内标记了鸡胚迁移前神经嵴细胞的细胞膜和细胞骨架成分。然后使用共聚焦静态和延时成像获得迁移中神经嵴细胞的三维重建图像。结果发现，除了微环境外，神经嵴细胞与其他迁移中的神经嵴细胞保持着近乎恒定的接触。细胞使用片状伪足或短而细的丝状伪足（宽1 - 2微米）进行局部接触（<20微米）。非局部的长距离接触（长达100微米）由丝状伪足发起，这些丝状伪足伸展和缩回、伸展并追踪，或连接两个非相邻细胞。有趣的是，细胞间接触常常刺激一个细胞改变方向，转向相邻细胞的轨迹。总之，我们的结果提供了体内证据，证明了神经嵴细胞存在局部和远距离相互作用，表明这些接触在定向引导中可能发挥作用。
