Goldstein B
MRC Laboratory of Molecular Biology, Cambridge, United Kingdom.
J Cell Biol. 1995 May;129(4):1071-80. doi: 10.1083/jcb.129.4.1071.
Cells of the early Caenorhabditis elegans embryo divide in an invariant pattern. Here I show that the division axes of some early cells (EMS and E) are controlled by specific cell-cell contacts (EMS-P2 or E-P3 contact). Altering the orientation of contact between these cells alters the axis along which the mitotic spindle is established, and hence the orientation of cell division. Contact-dependent mitotic spindle orientation appears to work by establishing a site of the type described by Hyman and White (1987. J. Cell Biol. 105:2123-2135) in the cortex of the responding cell: one centrosome moves toward the site of cell-cell contact during centrosome rotation in both intact embryos and reoriented cell pairs. The effect is especially apparent when two donor cells are placed on one side of the responding cell: both centrosomes are "captured," pulling the nucleus to one side of the cell. No centrosome rotation occurs in the absence of cell-cell contact, nor in nocodazole-treated cell pairs. The results suggest that some of the cortical sites described by Hyman and White are established cell autonomously (in P1, P2, and P3), and some are established by cell-cell contact (in EMS and E). Additional evidence presented here suggests that in the EMS cell, contact-dependent spindle orientation ensures a cleavage plane that will partition developmental information, received by induction, to one of EMS's daughter cells.
秀丽隐杆线虫早期胚胎的细胞以一种不变的模式进行分裂。在此我表明，一些早期细胞（EMS和E）的分裂轴受特定的细胞间接触（EMS-P2或E-P3接触）控制。改变这些细胞间接触的方向会改变有丝分裂纺锤体形成的轴，从而改变细胞分裂的方向。接触依赖性有丝分裂纺锤体定向似乎是通过在反应细胞的皮层中建立一个由海曼和怀特（1987年。《细胞生物学杂志》105:2123 - 2135）所描述类型的位点来起作用的：在完整胚胎和重新定向的细胞对中，在中心体旋转过程中，一个中心体朝着细胞间接触的位点移动。当两个供体细胞置于反应细胞的一侧时，这种效应尤为明显：两个中心体都被“捕获”，将细胞核拉向细胞的一侧。在没有细胞间接触时，以及在诺考达唑处理的细胞对中，不会发生中心体旋转。结果表明，海曼和怀特所描述的一些皮层位点是细胞自主建立的（在P1、P2和P3中），而一些是通过细胞间接触建立的（在EMS和E中）。此处提供的额外证据表明，在EMS细胞中，接触依赖性纺锤体定向确保了一个分裂平面，该平面将通过诱导接收的发育信息分配给EMS的一个子细胞。
