Actomyosin-dependent cortical dynamics contributes to the prophase force-balance in the early Drosophila embryo.
Actomyosin-dependent cortical dynamics contributes to the prophase force-balance in the early Drosophila embryo.
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肌动蛋白依赖性皮质动力学有助于早期果蝇胚胎的预言。
DOI：
10.1371/journal.pone.0018366
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发表时间：
2011-03-31
期刊：
影响因子：
3.7
通讯作者：
Mogilner A
中科院分区：
文献类型：
--
作者：
Sommi P;Cheerambathur D;Brust-Mascher I;Mogilner A
果蝇胚胎有丝分裂纺锤体在前期的组装依赖于皮质动力蛋白产生的向外力和动力蛋白-14和核弹性产生的内向力的平衡。已知肌球蛋白II有助于细胞皮层的动力学，但这如何影响前期力平衡尚不清楚。在这里，我们通过向早期果蝇胚胎注射肌球蛋白II抑制剂Y27632来研究这个问题。我们观察到密集皮质肌动蛋白帽的面积和纺锤极的间距都有显著的增加。对EB1-GFP标记的微管+端和皮层肌动蛋白的跟踪显示，星状微管可以与这些扩大的帽的所有区域相互作用，可能是通过它们与皮质动力蛋白的相互作用。在肌动蛋白帽异常小但前期纺锤体长度正常的打乱突变体中，肌球蛋白II抑制产生非常短的纺锤体。这些结果表明，两种互补的向外力是由上覆的皮层施加在前期纺锤体上。具体来说，定位在机械坚硬的肌动蛋白帽上的动力蛋白和肌动球蛋白驱动的肌动蛋白皮层可变形软块的收缩，共同将星状微管向外拉。因此，肌凝蛋白II控制肌动蛋白皮质的大小和动态特性，从而影响前期基础纺锤体的两极间距。
The assembly of the Drosophila embryo mitotic spindle during prophase depends upon a balance of outward forces generated by cortical dynein and inward forces generated by kinesin-14 and nuclear elasticity. Myosin II is known to contribute to the dynamics of the cell cortex but how this influences the prophase force-balance is unclear. Here we investigated this question by injecting the myosin II inhibitor, Y27632, into early Drosophila embryos. We observed a significant increase in both the area of the dense cortical actin caps and in the spacing of the spindle poles. Tracking of microtubule plus ends marked by EB1-GFP and of actin at the cortex revealed that astral microtubules can interact with all regions of these expanded caps, presumably via their interaction with cortical dynein. In Scrambled mutants displaying abnormally small actin caps but normal prophase spindle length in late prophase, myosin II inhibition produced very short spindles. These results suggest that two complementary outward forces are exerted on the prophase spindle by the overlying cortex. Specifically, dynein localized on the mechanically firm actin caps and the actomyosin-driven contraction of the deformable soft patches of the actin cortex, cooperate to pull astral microtubules outward. Thus, myosin II controls the size and dynamic properties of the actin-based cortex to influence the spacing of the poles of the underlying spindle during prophase.
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影响因子：
7.8
作者：
KIEHART, DP;MABUCHI, I;INOUE, S
通讯作者：
INOUE, S
影响因子：
2.9
作者：
Fabian, Lacramioara;Forer, Arthur
通讯作者：
Forer, Arthur
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2
作者：
Backouche, F.;Haviv, L.;Bernheim-Groswasser, A.
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Bernheim-Groswasser, A.
影响因子：
64.5
作者：
Rosenblatt, J;Cramer, LP;McGee, KM
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McGee, KM
影响因子：
3.3
作者：
Sharp, DJ;Brown, HM;Scholey, JM
通讯作者：
Scholey, JM