Randall Division of Cell and Molecular Biophysics, King's College London, London SE1 1UL, England, UK.
J Cell Biol. 2010 May 17;189(4):681-9. doi: 10.1083/jcb.200912134. Epub 2010 May 10.
Drosophila melanogaster macrophages are highly migratory cells that lend themselves beautifully to high resolution in vivo imaging experiments. By expressing fluorescent probes to reveal actin and microtubules, we can observe the dynamic interplay of these two cytoskeletal networks as macrophages migrate and interact with one another within a living organism. We show that before an episode of persistent motility, whether responding to developmental guidance or wound cues, macrophages assemble a polarized array of microtubules that bundle into a compass-like arm that appears to anticipate the direction of migration. Whenever cells collide with one another, their microtubule arms transiently align just before cell-cell repulsion, and we show that forcing depolymerization of microtubules by expression of Spastin leads to their defective polarity and failure to contact inhibit from one another. The same is true in orbit/clasp mutants, indicating a pivotal role for this microtubule-binding protein in the assembly and/or functioning of the microtubule arm during polarized migration and contact repulsion.
果蝇黑色素体巨噬细胞是高度迁移的细胞，非常适合用于高分辨率的活体成像实验。通过表达荧光探针来揭示肌动蛋白和微管，我们可以观察到这两种细胞骨架网络在巨噬细胞迁移和相互作用时的动态相互作用。我们表明，在持续运动的发作之前，无论是对发育指导还是创伤线索的反应，巨噬细胞都会组装一个极化的微管阵列，这些微管捆绑成一个类似指南针的臂，似乎可以预测迁移的方向。每当细胞彼此碰撞时，它们的微管臂在细胞排斥之前短暂对齐，我们表明通过表达 Spastin 迫使微管解聚会导致它们的极性缺陷，并导致它们无法彼此接触抑制。在轨道/扣合突变体中也是如此，这表明这种微管结合蛋白在极化迁移和接触排斥过程中微管臂的组装和/或功能中起着关键作用。
