# Reconstituting Early Mitotic Chromosome Movement In Vitro

> **NIH NIH F31** · PRINCETON UNIVERSITY · 2020 · $44,895

## Abstract

Project Summary/Abstract
 The goal of mitosis is to accurately transfer replicated chromosomes from parent cell to each daughter
cell. The cell accomplishes this using the mitotic spindle, a dense network of ~105 microtubules and ~200
microtubule associated proteins. Microtubules are dynamic polymers that can switch between states of
growing and shrinking. Some of spindle's proteins are molecular motors, which consume energy to move,
assemble, or disassemble microtubules. Together, microtubule dynamics and motor activity generate
mechanical forces, by which the spindle first aligns and then segregates chromosomes during the course of
mitosis. This process facilitates the transfer of genetic information from old to new cells, which is an essential
feature of life. That being said, aberrant chromosome movements can lead to daughter cells that have the
wrong numbers of chromosomes, an unhealthy condition known as aneuploidy that arises in nearly every
cancer type. As such, understanding how the spindle moves chromosomes has medical relevance. However,
the density of the spindle and the presence of the cell cortex make it difficult to measure forces on
chromosomes and resolve single microtubules in vivo. Therefore, many crucial molecular and mechanical
details about how the spindle produces forces to move chromosomes remain unknown, and without this
knowledge, our understanding of how cells become aneuploid will be lacking. To overcome the obstacles in
vivo, the proposed research uses a novel, cell-free assay to reconstitute in vitro the movements of single
chromosomes. Experiments will combine single molecule fluorescence imaging, force microscopy, and
biochemical methods to study the molecular mechanisms and mechanics of chromosome movement during
early mitosis. First, the mechanisms that drive chromosome movement will be investigated by inhibiting or
depleting molecular players and measuring microtubule dynamics. Then, force microscopy will be used to
measure forces on chromosomes before and after molecular players are inhibited or depleted, to study how
different motor proteins contribute to the forces that move chromosomes. Completion of these experiments will
improve our understanding of how the spindle applies forces to move chromosomes during mitosis. In the long
term, this knowledge will help us improve our understanding of how cells develop aneuploidy.

## Key facts

- **NIH application ID:** 9838664
- **Project number:** 5F31CA236160-02
- **Recipient organization:** PRINCETON UNIVERSITY
- **Principal Investigator:** Sagar Udayashankar Setru
- **Activity code:** F31 (R01, R21, SBIR, etc.)
- **Funding institute:** NIH
- **Fiscal year:** 2020
- **Award amount:** $44,895
- **Award type:** 5
- **Project period:** 2018-12-15 → 2020-12-14

## Primary source

NIH RePORTER: https://reporter.nih.gov/project-details/9838664

## Citation

> US National Institutes of Health, RePORTER application 9838664, Reconstituting Early Mitotic Chromosome Movement In Vitro (5F31CA236160-02). Retrieved via AI Analytics 2026-05-23 from https://api.ai-analytics.org/grant/nih/9838664. Licensed CC0.

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