Oblique circle method for measuring the curvature and twist of mitotic spindle microtubule bundles

Scientific paper - Original scientific paper

• Author: Arian Ivec
• Author: Monika Trupinić
• Author: Iva M. Tolić
• Author: Nenad Pavin
• Author's institution: University of Zagreb; Faculty of Science; (Department of Physics)
• Scientific / art field, discipline and subdiscipline: NATURAL SCIENCES; Physics

Abstract (english)

The highly ordered spatial organization of microtubule bundles in the mitotic spindle is crucial for its proper functioning. The recent discovery of twisted shapes of microtubule bundles and spindle chirality suggests that the bundles extend along curved paths in three dimensions, rather than being confined to a plane. This, in turn, implies that rotational forces, i.e., torques, exist in the spindle in addition to the widely studied linear forces. However, studies of spindle architecture and forces are impeded by a lack of a robust method for the geometric quantification of microtubule bundles in the spindle. In this work, we describe a simple method for measuring and evaluating the shapes of microtubule bundles by characterizing them in terms of their curvature and twist. By using confocal microscopy, we obtain three-dimensional images of spindles, which allows us to trace the entire microtubule bundle. For each traced bundle, we first fit a plane and then fit a circle lying in that plane. With this robust method, we extract the curvature and twist, which represent the geometric information characteristic for each bundle. As the bundle shapes reflect the forces within them, this method is valuable for the understanding of forces that act on chromosomes during mitosis.

• Keywords (english): mitotic spindle; chirality; twist; helicity; methods
• Language: english
• Publication type: Scientific paper - Original scientific paper
• Publication status: Published
• Peer review: Peer review - international
• Publication version: Published version
• Journal title: Biophysical Journal
• Numbering: vol. 120, no. 17, pp. 3641-3648
• p-ISSN: 0006-3495
• DOI: https://doi.org/10.1016/j.bpj.2021.07.024
• URN:NBN: urn:nbn:hr:217:021477
• Publication: 2021-09
• Project: Number: 855158; Title (english): Molecular origins of aneuploidies in healthy and diseased human tissues; Acronym: ANEUPLOIDY; Jurisdiction: eu; Funding stream: Europska komisija
• Project: Number: 647077; Title (english): A new class of microtubules in the spindle exerting forces on kinetochores; Acronym: NewSpindleForce; Jurisdiction: eu; Funding stream: H2020
• Project: Number: IP-2019-04-5967; Title (croatian): Ravnoteža sila i momenta sila u diobenom vretenu; Title (english): Balance of forces and torques in the mitotic spindle; Acronym: SpindleForceBalance; Leader: Nenad Pavin; Jurisdiction: Croatia; Funding stream: IP
• Project: Number: PZS-2019-02-7653; Title (croatian): Mehanizmi nastajanja snopova mikrotubula potrebni za sazrijevanje diobenog vretena; Title (english): Mechanisms of microtubule bundle formation required for spindle maturation; Acronym: SpindleForm; Leader: Iva Tolić; Jurisdiction: Croatia; Funding stream: PZS
• Document URL: https://linkinghub.elsevier.com/retrieve/pii/S0006349521006329
• Type of resource: Text
• Access conditions: Open access
• Public note: Copyright 2021 Biophysical Society. This is an open access article under the CC BY-NC-ND license (http://creativecommons.org/licenses/by-nc-nd/4.0/). Submitted March 1, 2021, and accepted for publication July 27, 2021.
• Created on: 2023-07-28 20:45:39