Top: Shown here is a typical simulation trajectory of GP-directed budding, at simulation times 600, 1800, 2700, and 4200 τ0, from left to right, with GP-GP interaction strength εgg = 2.3. Bottom: Given here is a simulation trajectory of NC-directed budding, at 600, 1800, 2700, and 5600 τ0, with εgg = 2.5 and NC-GP interaction strength εng = 3.5. The second time point in each row corresponds to an example of the intermediate with a constricted neck described in the text. Except where noted otherwise, the membrane bending modulus κmem ≈ 14.5 kBT throughout the article. To see this figure in color, go online.