Fig. 1.

Fragment shape and movement resembles that of whole keratocytes. (A) Phase-contrast images of live fragments (Top) and whole keratocytes (Bottom) are shown. Fragments exhibit a similar spectrum of lamellipodial shape variation as cells. (B) The first two principal modes of shape variation, as determined by principal components analysis of aligned outlines of 122 live fragments (Top) and 148 cells (Bottom), are shown. Essentially the same modes—cell area (Mode 1) and front-to-rear lamellipodial length (Mode 2)—are found for both fragments and cells. These two modes capture approximately 90% of the shape variation in the populations. For each mode, the mean cell shape is shown together with reconstructions of shapes one and two standard deviations away from the mean in each direction along the given mode. The variation accounted for by each mode is indicated.