Differential proliferation rates generate patterns of mechanical tension that orient tissue growth
Differential proliferation rates generate patterns of mechanical tension that orient tissue growth
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DOI：
10.1038/emboj.2013.197
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发表时间：
2013-10-30
期刊：
影响因子：
11.4
通讯作者：
Tapon, Nicolas
中科院分区：
文献类型：
--
作者：
Mao, Yanlan;Tournier, Alexander L.;Tapon, Nicolas
细胞分裂的方向是组织形态发生的关键机制。在正在生长的果蝇翼成虫盘上皮中，中央翼袋中的大多数细胞分裂通过 Dachsous-Fat-Dachs 平面极性路径沿近端-远端 (P-D) 轴定向。然而，尽管达赫斯极化很强，但翼袋外围的细胞却倾向于将其分裂方向垂直于 P-D 轴。在这里，我们表明这些圆周分裂是由影响细胞形状的圆周机械力定向的，从而定向有丝分裂纺锤体。我们认为这种圆周力模式不是由单个上皮细胞的极化收缩局部产生的。相反，这些力表现为一种全局张力模式，似乎源于翼袋内细胞增殖率的差异。因此，我们表明局部过度生长足以诱导邻近细胞拉伸和细胞分裂的重新定向。我们的结果表明，细胞增殖的模式速率可以影响组织力学，从而决定细胞分裂的方向和组织形状。
Orientation of cell divisions is a key mechanism of tissue morphogenesis. In the growing Drosophila wing imaginal disc epithelium, most of the cell divisions in the central wing pouch are oriented along the proximal-distal (P-D) axis by the Dachsous-Fat-Dachs planar polarity pathway. However, cells at the periphery of the wing pouch instead tend to orient their divisions perpendicular to the P-D axis despite strong Dachs polarization. Here, we show that these circumferential divisions are oriented by circumferential mechanical forces that influence cell shapes and thus orient the mitotic spindle. We propose that this circumferential pattern of force is not generated locally by polarized constriction of individual epithelial cells. Instead, these forces emerge as a global tension pattern that appears to originate from differential rates of cell proliferation within the wing pouch. Accordingly, we show that localized overgrowth is sufficient to induce neighbouring cell stretching and reorientation of cell division. Our results suggest that patterned rates of cell proliferation can influence tissue mechanics and thus determine the orientation of cell divisions and tissue shape.