Fig. 3: Division of GUVs (red) by increasing the GFP concentration.

a Asymmetric division of a single GUV into one large and one small daughter vesicle. b Symmetric division of a  single GUV into two daughter vesicles of equal size. The division process starts, in the absence of GFP, from a certain vesicle shape as displayed in I. Addition of GFP then transforms each GUV into two spherical membrane segments that are connected by a closed membrane neck as in II. A further increase in the GFP concentration leads to the cleavage of the neck and to the division of the GUV as shown in III. The GUVs in (a,III) and (b,III) are denoted by D^† and E^†, respectively. The key parameter that controls the relative size of the two daughter vesicles is the volume-to-area ratio v (see the “Methods” section, Eq. (6)). c Profile of lipid fluorescence along the white dashed line in (b,II) indicates a closed neck but neck fission along the white dashed line in (b,III). d Two snapshots from Supplementary Movie 2: The GUV had the dumbbell shape F^† when it underwent neck fission after about 7:27 min:s, resulting in two daughter vesicles that diffused freely away from each other and were completely separated at 7:41 min:s. The parameters for the shapes D^†, E^†, and F^† are included in Table 1. The membranes in a and b contained 0.1 mol%, the one in d 1 mol% anchor-lipids. All scale bars: 5 μm. Source data for panel c are provided in the Source Data file.