The Par complex directs fate determinant segregation from the apical membrane of asymmetrically dividing Drosophila neuroblasts. While the physical interactions that recruit the Par complex have been extensively studied, little is known about how the membrane itself behaves during polarization. We examined the membrane dynamics of neuroblasts and surrounding cells using a combination of super-resolution and time lapse imaging, revealing cellular-scale movements of diverse membrane features during asymmetric division cycles. Membrane domains that are distributed across the neuroblast membrane in interphase become polarized in early mitosis, where they mediate formation of cortical patches of the Par protein aPKC. Membrane and protein polarity cycles are precisely synchronized and are generated by extensive actin dependent forces that deform the surrounding tissue. In addition to suggesting a role for the membrane in asymmetric division, our results reveal the mechanical nature of the neuroblast polarity cycle.

中文翻译：

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肌动蛋白依赖性膜极化揭示了神经母细胞极性循环的机械性质

Par复合物指导命运决定因素从果蝇神经母细胞不对称分裂的根尖膜分离。虽然已经广泛研究了募集Par配合物的物理相互作用，但对于膜本身在极化过程中的行为知之甚少。我们使用超分辨率和延时成像相结合的方法检查了成神经细胞和周围细胞的膜动力学，揭示了不对称分裂周期中各种膜特征的细胞尺度运动。在相间跨整个神经母细胞膜分布的膜结构域在早期有丝分裂中被极化，在那里它们介导Par蛋白aPKC的皮质斑块的形成。膜和蛋白质的极性循环精确同步，并由广泛的肌动蛋白依赖性力产生，这些力使周围组织变形。除了暗示膜在不对称分裂中的作用外，我们的研究结果还揭示了成神经细胞极性循环的机械性质。