Dissipative Particle Dynamics Simulations for Shape Change of Growing Lipid Bilayer Vesicles

The characteristic shape changes observed in the growth and division of L-form cells have been explained by several theoretical studies and simulations using a vesicle model in which the membrane area increases with time. In those theoretical studies, characteristic shapes such as tubulation and budding were reproduced in a non-equilibrium state, but it was not possible to incorporate deformations that would change the topology of the membrane. We constructed a vesicle model in which the area of the membrane increases using coarse-grained particles and analyzed the changes in the shape of growing membrane by the dissipative particle dynamics (DPD) method. In the simulation, lipid molecules were added to the lipid membrane at regular time intervals to increase the surface area of the lipid membrane. As a result, it was found that the vesicle deformed into a tubular shape or a budding shape depending on the conditions for adding lipid molecules. This suggests that the difference in the place where new lipid molecules are incorporated into the cell membrane during the growth of L-form cells causes the difference in the transformation pathway of L-form cells.