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

> **NIH NIH R01** · OKLAHOMA MEDICAL RESEARCH FOUNDATION · 2022 · $49,017

## 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 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. These experiments will allow us to
measure the ability of crossovers and centromere connections between homologous
partner chromosomes to transmit tension between the homologous kinetochores when
they are attached to microtubules. Further, we will be able to ask questions about the
biophysical properties of connections (e.g. their stiffness) that do, or do not, stabilize
bioriented microtubule attachments. The method measures the Brownian vibration of
the kinetochores. Kinetochore pairs with stiff connections vibrate less then pairs with
soft connections. Thus, vibration rates can be converted into measurements pulling
forces on the kinetochores (Fig. 1). The experiments will define the molecular basis of0.5 s
Soft Spring
Stiff Spring
Figure 1.
Kymograph of
GFP-tagged bi-
oriented
centromeres.
Images are
acquired at 50
frames per
second. Image
analysis tracks
the centroid of
each GFP focus
distance between
centroids. Image
from M. Gardner
and colleagues).
and changes in
the bridge that is formed between partner centromeres during the centromere pairing process and the
biophysical characteristics of the connections between centromeres provided by both centromere pairing and
crossing-over.

## Key facts

- **NIH application ID:** 10580231
- **Project number:** 3R01GM138889-02S1
- **Recipient organization:** OKLAHOMA MEDICAL RESEARCH FOUNDATION
- **Principal Investigator:** DEAN S DAWSON
- **Activity code:** R01 (R01, R21, SBIR, etc.)
- **Funding institute:** NIH
- **Fiscal year:** 2022
- **Award amount:** $49,017
- **Award type:** 3
- **Project period:** 2022-04-01 → 2022-12-31

## Primary source

NIH RePORTER: https://reporter.nih.gov/project-details/10580231

## Citation

> US National Institutes of Health, RePORTER application 10580231, Equipment Supplement for Centromere Interactions and Meiotic Chromosome Segregation in Yeast (3R01GM138889-02S1). Retrieved via AI Analytics 2026-05-24 from https://api.ai-analytics.org/grant/nih/10580231. Licensed CC0.

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