推動細(xì)胞形狀發(fā)生變化的力在發(fā)育中起根本性作用,。在有絲分裂過程中，粘附細(xì)胞從扁平形變成圓形,，這種變化被認(rèn)為是細(xì)胞分裂的幾何要求所必需的,。Stewart等人研究了推動這種形狀變化的力,。他們發(fā)現(xiàn),，有絲分裂中讓細(xì)胞形狀變成圓形的力既取決于肌動球蛋白的細(xì)胞骨架,，又取決于細(xì)胞調(diào)控“克分子滲透壓濃度”的能力。讓細(xì)胞形狀變成圓形的力是由滲透壓產(chǎn)生的,，肌動球蛋白皮質(zhì)通過抵抗外力來維持這種變圓的力,。這些結(jié)果支持以下觀點(diǎn)：在動物細(xì)胞中，肌動球蛋白皮質(zhì)起細(xì)胞內(nèi)壁的作用,，引導(dǎo)滲透擴(kuò)張來控制細(xì)胞形狀。（生物谷 Bioon.com）
生物谷推薦原文出處：
Nature doi:10.1038/nature09642
Hydrostatic pressure and the actomyosin cortex drive mitotic cell rounding
Martin P. Stewart,Jonne Helenius,Yusuke Toyoda,Subramanian P. Ramanathan,Daniel J. Muller& Anthony A. Hyman
During mitosis, adherent animal cells undergo a drastic shape change, from essentially flat to round1, 2, 3. Mitotic cell rounding is thought to facilitate organization within the mitotic cell and be necessary for the geometric requirements of division4, 5, 6, 7. However, the forces that drive this shape change remain poorly understood in the presence of external impediments, such as a tissue environment2. Here we use cantilevers to track cell rounding force and volume. We show that cells have an outward rounding force, which increases as cells enter mitosis. We find that this mitotic rounding force depends both on the actomyosin cytoskeleton and the cells’ ability to regulate osmolarity. The rounding force itself is generated by an osmotic pressure. However, the actomyosin cortex is required to maintain this rounding force against external impediments. Instantaneous disruption of the actomyosin cortex leads to volume increase, and stimulation of actomyosin contraction leads to volume decrease. These results show that in cells, osmotic pressure is balanced by inwardly directed actomyosin cortex contraction. Thus, by locally modulating actomyosin-cortex-dependent surface tension and globally regulating osmotic pressure, cells can control their volume, shape and mechanical properties.
