Generation of stable overlaps between antiparallel filaments

TL;DR

This paper presents a particle-based stochastic model demonstrating how motors and passive cross linkers work together to generate and regulate stable overlaps between antiparallel microtubules during cell division.

Contribution

It introduces a novel model showing the distinct roles of motors and passive cross linkers in stabilizing microtubule overlaps, advancing understanding of spindle assembly.

Findings

Motors decrease overlap length in a length-dependent manner.

Passive cross linkers increase overlap independently of length.

Passive cross linkers contribute to size regulation and structural stability.

Abstract

During cell division, sister chromatids are segregated by the mitotic spindle, a bipolar assembly of interdigitating antiparallel polar filaments called microtubules. Establishing a stable overlap region is essential for maintenance of bipolarity, but the underlying mechanisms are poorly understood. Using a particle-based stochastic model, we find that the interplay of motors and passive cross linkers can robustly generate partial overlaps between antiparallel filaments. Our analysis shows that motors reduce the overlap in a length-dependent manner, whereas passive cross linkers increase it independently of the length. In addition to maintaining structural integrity, passive cross linkers can thus also have a dynamic role for size regulation.