# Form and function of the bacterial nucleoid: structural studies using cryo-ET

> **NIH NIH F32** · UNIVERSITY OF WISCONSIN-MADISON · 2021 · $66,390

## Abstract

Project Summary/Abstract:
 All organisms share a common genetic code. From the nucleus of mammalian cells to the nucleoid of
the smallest bacterium, we all use DNA to encode the traits and cellular processes that drive the diversity of life
on earth. Passing along one’s genome is the most fundamental form of heritability and errors in this process
can have dire consequences. It is therefore of great importance that all organisms carry out reliable replication
and segregation of DNA during cell division, and that organisms maintain methods to protect nuclear material
in the event of cellular stress. To study the form and function of DNA structures, I propose taking advantage of
the recent advancements in cryoelectron tomography (cryo-ET) methodology to visualize the bacterial
nucleoid, as a model for understanding in vivo chromosome structure and to develop the tools and best
practices for the study of the cells most important molecule. Using the resources of the Cryoelectron
Microscopy Research Center at UW-Madison, cryo-ET of the model organism Rhodobacter sphaeroides will
allow the study of in vivo nuclear structures. Rhodobacter sphaeroides is an ideal organism for studying the
nucleoid, not only because its size is amenable to cryo-ET, but also because its two chromosomes require
unique replication dynamics. This work seeks to observe the structure and interactions of the nucleoid during
the cell cycle of R. sphaeroides. The results of which have a strong potential to provide translational break
throughs and will build up molecular tools and methods that will have relevance beyond bacteriology.
Additionally, this work will study the compaction of the bacterial nucleoid during physiological stress and
antibiotic treatments, preliminary data have been shown. Importantly, studying the compaction of nuclear
material following antibiotic stress is expected to generate new knowledge leading to a better understanding of
the mechanisms bacteria use to survive and persist during antibiotic treatment. Potentially impacting the study
on antibiotic resistance.

## Key facts

- **NIH application ID:** 10311636
- **Project number:** 1F32GM143854-01
- **Recipient organization:** UNIVERSITY OF WISCONSIN-MADISON
- **Principal Investigator:** Daniel Parrell
- **Activity code:** F32 (R01, R21, SBIR, etc.)
- **Funding institute:** NIH
- **Fiscal year:** 2021
- **Award amount:** $66,390
- **Award type:** 1
- **Project period:** 2021-09-01 → 2023-08-31

## Primary source

NIH RePORTER: https://reporter.nih.gov/project-details/10311636

## Citation

> US National Institutes of Health, RePORTER application 10311636, Form and function of the bacterial nucleoid: structural studies using cryo-ET (1F32GM143854-01). Retrieved via AI Analytics 2026-05-25 from https://api.ai-analytics.org/grant/nih/10311636. Licensed CC0.

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