Quantitative and unbiased analysis of directional persistence in cell migration
Quantitative and unbiased analysis of directional persistence in cell migration
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DOI：
10.1038/nprot.2014.131
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发表时间：
2014-08-01
期刊：
影响因子：
14.8
通讯作者：
Gautreau, Alexis
中科院分区：
文献类型：
--
作者：
Gorelik, Roman;Gautreau, Alexis
细胞在迁移过程中控制方向持久性的机制是一个主要问题。然而，测量方向持久性的共同指标，即位移与轨迹长度的比率，是有偏差的，特别是细胞速度。无偏方法是计算作为时间的函数的方向自相关。该函数仅取决于与轨迹相切的矢量的角度。这种方法由于计算比较困难，一直没有得到广泛的应用。在这里，我们讨论了经典指数的偏差，并介绍了一个定制的开源计算机程序，DiPer，它计算方向自相关。此外，DiPer还绘制和计算其他基本参数，以在两个维度上分析细胞迁移：它单独和集体显示细胞轨迹，并计算平均速度和均方位移（MSD），以评估细胞随时间推移探索的区域。这个用户友好的程序可以通过Microsoft Excel执行，它可以生成出版物级质量的图。该方案需要大约15分钟才能完成。我们最近使用DiPer分析了三种不同哺乳动物细胞类型在二维培养中的细胞迁移：乳腺癌细胞系MDA-MB-231，能动阿米巴Dictyosteelium discoideum和鱼鳞角膜细胞。DiPer不仅可以用于2D中的随机迁移，还可以用于定向迁移和3D中的迁移（仅方向自相关）。此外，它可以用于任何类型的跟踪颗粒：细胞器，细菌和整个生物体。
The mechanism by which cells control directional persistence during migration is a major question. However, the common index measuring directional persistence, namely the ratio of displacement to trajectory length, is biased, particularly by cell speed. An unbiased method is to calculate direction autocorrelation as a function of time. This function depends only on the angles of the vectors tangent to the trajectory. This method has not been widely used, because it is more difficult to compute. Here we discuss biases of the classical index and introduce a custom-made open-source computer program, DiPer, which calculates direction autocorrelation. In addition, DiPer also plots and calculates other essential parameters to analyze cell migration in two dimensions: it displays cell trajectories individually and collectively, and it calculates average speed and mean square displacements (MSDs) to assess the area explored by cells over time. This user-friendly program is executable through Microsoft Excel, and it generates plots of publication-level quality. The protocol takes similar to 15 min to complete. We have recently used DiPer to analyze cell migration of three different mammalian cell types in 2D cultures: the mammary carcinoma cell line MDA-MB-231, the motile amoeba Dictyostelium discoideum and fish-scale keratocytes. DiPer can potentially be used not only for random migration in 2D but also for directed migration and for migration in 3D (direction autocorrelation only). Moreover, it can be used for any types of tracked particles: cellular organelles, bacteria and whole organisms.