Department of Molecular and Cell Biology, University of California, Berkeley, Berkeley, CA 94720, USA.
Department of Molecular and Cell Biology, University of California, Berkeley, Berkeley, CA 94720, USA.
Cell Rep. 2017 Oct 17;21(3):559-569. doi: 10.1016/j.celrep.2017.09.083.
Cell migration is indispensable to morphogenesis and homeostasis. Live imaging allows mechanistic insights, but long-term observation can alter normal biology, and tools to track movements in vivo without perturbation are lacking. We develop here a tool called M-TRAIL (matrix-labeling technique for real-time and inferred location), which reveals migration histories in fixed tissues. Using clones that overexpress GFP-tagged extracellular matrix (ECM) components, motility trajectories are mapped based on durable traces deposited onto basement membrane. We applied M-TRAIL to Drosophila follicle rotation, comparing in vivo and ex vivo migratory dynamics. The rate, trajectory, and cessation of rotation in wild-type (WT) follicles measured in vivo and ex vivo were identical, as was rotation failure in fat2 mutants. However, follicles carrying intracellularly truncated Fat2, previously reported to lack rotation ex vivo, in fact rotate in vivo at a reduced speed, thus revalidating the hypothesis that rotation is required for tissue elongation. The M-TRAIL approach could be applied to track and quantitate in vivo cell motility in other tissues and organisms.
细胞迁移对于形态发生和动态平衡是必不可少的。实时成像可以提供机械洞察力，但长期观察会改变正常的生物学，并且缺乏在不干扰的情况下跟踪体内运动的工具。我们在这里开发了一种称为 M-TRAIL（用于实时和推断位置的基质标记技术）的工具，它可以揭示固定组织中的迁移历史。使用过表达 GFP 标记细胞外基质（ECM）成分的克隆，基于基底膜上沉积的持久痕迹来绘制运动轨迹。我们将 M-TRAIL 应用于果蝇滤泡旋转，比较体内和体外的迁移动态。体内和体外测量的野生型（WT）滤泡的旋转速度、轨迹和停止都是相同的，fat2 突变体的旋转失败也是如此。然而，携带细胞内截断 Fat2 的滤泡，先前报道在体外缺乏旋转，实际上在体内以降低的速度旋转，从而再次验证了旋转是组织伸长所必需的假设。M-TRAIL 方法可用于跟踪和定量其他组织和生物体中的体内细胞迁移。
