# Equipment Supplement for Centromere Interactions and Meiotic Chromosome Segregation in Yeast

> **NIH NIH R01** · OKLAHOMA MEDICAL RESEARCH FOUNDATION · 2021 · $30,960

## Abstract

Summary of parent project (R01GM138889)
In prophase of meiosis I, homologous chromosomes pair and become connected by
crossovers. The connection provided by crossovers helps the partners attach to
microtubules that radiate from opposite sides of the spindle. This bipolar attachment is
stabilized by tension as the partner kinetochores are tugged towards opposite poles by the
connected microtubules. This allows the chromosome pair to remain poised at the spindle
mid-zone while other pairs become correctly attached to microtubules. Our parent grant is
focused on centromere-pairing. This occurs when the centromeres of the partner
chromosomes come together and then become attached in a poorly understood way that,
like crossovers, allows the homologous partners to correctly form bipolar attachments,
even if they have failed to become attached by a crossover. We have proposed
experiments in the parent project to monitor the behavior of centromeres as the
chromosome partners become attached to the spindle in meiosis I. Nearly half of the
experiments in the proposal involve sustained imaging of living meiotic yeast cells. We
have proposed to image fluorescently-tagged centromeres, in cells that are sustained in
microfluidics chambers mounted on the microscope stage. In these experiments genes of
interest can be interrogated for their roles in the biorientation process by flowing over the
cells compounds that trigger the expression of specific genes or the degradation of
specific proteins. In addition, we propose to measure the ability of crossovers and
centromere connections between homologous partner chromosomes to transmit tension
between the homologous kinetochores. This will allow us to ask questions about the
biophysical properties of connections that do, or do not, stabilize bioriented microtubule
attachments. These experiments measure the Brownian vibration of the kinetochores as
a means to determine the spring-stiffness of the connection between them (provided by a
crossover or centromere connection) (Fig. 1). Together the experiments will define to0.5 s
Soft Spring
Stiff Spring
Figure 1.
Kymograph
of GFP-
tagged bi-
oriented
centromeres.
\Image
analysis tracks
the centroid of
each GFP
focus and
changes in
distance
between
centroids.
Image from M.
Gardner.
molecular basis of the bridge formed between partner centromeres by the centromere pairing process and the
biophysical characteristics of connections formed by centromere pairing and crossing-over.

## Key facts

- **NIH application ID:** 10387848
- **Project number:** 3R01GM138889-01A1S1
- **Recipient organization:** OKLAHOMA MEDICAL RESEARCH FOUNDATION
- **Principal Investigator:** DEAN S DAWSON
- **Activity code:** R01 (R01, R21, SBIR, etc.)
- **Funding institute:** NIH
- **Fiscal year:** 2021
- **Award amount:** $30,960
- **Award type:** 3
- **Project period:** 2021-07-01 → 2022-03-31

## Primary source

NIH RePORTER: https://reporter.nih.gov/project-details/10387848

## Citation

> US National Institutes of Health, RePORTER application 10387848, Equipment Supplement for Centromere Interactions and Meiotic Chromosome Segregation in Yeast (3R01GM138889-01A1S1). Retrieved via AI Analytics 2026-05-26 from https://api.ai-analytics.org/grant/nih/10387848. Licensed CC0.

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