Modeling the Excess Cell Surface Stored in a Complex Morphology of Bleb-Like Protrusions
Fig 1
Transition from spread to rounded states and localization of F-actin and myosin in the cortex of a typical rounded cell and cortical structure.
A. Merged DIC and fluorescence image of spread Swiss 3T3 fibroblasts stably transfected with Lifeact-RFP (green) cells with clearly visible signal from stress fibers. Cell outlines traced from image. Bar = 20μm. B. Image of the same cell after trypsin-induced detachment. The white outline shows the former spread shape. Yellow arrow points to the rounded cell. C. Cartoon compares the radius of a sphere required to accommodate the cell volume from the spread state (R = 50μm) versus the rounded state (R = 13 μm) for the cell on the left. D. Distribution of spread and rounded cell areas. E. Distribution of rounded cell radii. F. DIC and confocal fluorescence images of rounded CHO cell stably expressing GFP-Lifeact (green) and RFP-MLC (red) Bar = 5 μm. G. Transmission electron microscopy image of GFP immunogold staining of rounded CHO cells with stable expression of Lifeact-GFP. Black dots which represent gold particles show the position of actin filaments. Bar = 1 μm. H. Inset shows outlined region in G at higher magnification. Arrow points to F-actin immediately underlying the plasma membrane in BLiPs: arrowhead points to the F-actin in the cortex closer toward center of the cell. Bar = 0.5 μm.