Figure 4.

Classification of FAs on the basis of k-mean clustering. (a) The relationship among duration, maximum area, and relocation distance of 21 FAs extracted from the cell in Figure 3. Duration versus maximum area of the FAs and duration versus relocation distance of the FAs are also depicted in (b) and (c), respectively. On the basis of k-mean clustering, these FAs were classified into three groups: green, blue, and red circles. (d) Spatial distribution of these FAs at t = 0, 21, 39, and 60 minutes is shown. The FAs indicated by the green circles were located at the front protrusive region (region F), whereas the FAs indicated by the red circles were in the cell rear (region R). The FAs indicated by the blue circles were approximately in the lateral region between the cell front and the cell rear regions (region L). Scale bar: 20 μm. (e, f, g) Average and standard deviations of the maximum area, duration, and relocation distance of FAs are shown in (e), (f), and (g), respectively. For statistical analysis, a total of 70 FAs were extracted from 10 cells. One-way analysis of variance demonstrated significant difference between FAs in region F, region L, and region R.