Department of Biology, Massachusetts Institute of Technology, Cambridge, Massachusetts 02142, USA.
Department of Bioengineering, University of Pittsburgh, Pittsburgh, Pennsylvania 15260, USA.
Nat Commun. 2017 May 15;8:15014. doi: 10.1038/ncomms15014.
Sculpting organism shape requires that cells produce forces with proper directionality. Thus, it is critical to understand how cells orient the cytoskeleton to produce forces that deform tissues. During Drosophila gastrulation, actomyosin contraction in ventral cells generates a long, narrow epithelial furrow, termed the ventral furrow, in which actomyosin fibres and tension are directed along the length of the furrow. Using a combination of genetic and mechanical perturbations that alter tissue shape, we demonstrate that geometrical and mechanical constraints act as cues to orient the cytoskeleton and tension during ventral furrow formation. We developed an in silico model of two-dimensional actomyosin meshwork contraction, demonstrating that actomyosin meshworks exhibit an inherent force orienting mechanism in response to mechanical constraints. Together, our in vivo and in silico data provide a framework for understanding how cells orient force generation, establishing a role for geometrical and mechanical patterning of force production in tissues.
塑造生物体形状需要细胞产生具有适当方向性的力。因此，了解细胞如何使细胞骨架定向产生能够改变组织形状的力是至关重要的。在果蝇胚胎发生过程中，腹侧细胞中的肌动球蛋白收缩会在腹侧产生一个狭长的上皮皱襞，称为腹侧皱襞，其中肌动球蛋白纤维和张力沿着皱襞的长度定向。通过结合改变组织形状的遗传和机械扰动，我们证明了几何和力学约束作为在腹侧皱襞形成过程中定向细胞骨架和张力的线索。我们开发了一个二维肌动球蛋白网格收缩的计算模型，证明肌动球蛋白网格在响应力学约束时表现出一种固有的力定向机制。总之，我们的体内和体外数据为理解细胞如何定向力的产生提供了一个框架，为在组织中产生力的几何和力学模式的作用奠定了基础。
