Construction of nuclear envelope shape by a high-genus vesicle with pore-size constraint

TL;DR

This study uses simulations to explore how high-genus vesicles with pore-size constraints shape the nuclear envelope, revealing conditions for various morphologies relevant to cell biology.

Contribution

It introduces a computational model for high-genus vesicle morphology under pore constraints, elucidating factors influencing nuclear envelope shape.

Findings

Circular-cage stomatocyte formation under bending-energy minimization.

Reduced pore radius stabilizes circular pore alignment.

Conditions for spherical stomatocyte include small perinuclear volume and osmotic pressure.

Abstract

Nuclear pores have an approximately uniform distribution in the nuclear envelope of most living cells. Hence, the morphology of the nuclear envelope is a spherical stomatocyte with a high genus. We have investigated the morphology of high-genus vesicles under pore-size constraint using dynamically triangulated membrane simulations. Bending-energy minimization without volume or other constraints produces a circular-cage stomatocyte, where the pores are aligned in a circular line on an oblate bud. As the pore radius is reduced, the circular-pore alignment is more stabilized than a random pore distribution on a spherical bud. However, we have clarified the conditions for the formation of a spherical stomatocyte: a small perinuclear volume, osmotic pressure within nucleoplasm, and repulsion between the pores. When area-difference elasticity is taken into account, the formation of cylindrical or budded tubules from the stomatocyte and discoidal stomatocyte is found.