# Mechanisms Driving Meiotic Chromosome Morphogenesis

> **NIH NIH F32** · NEW YORK UNIVERSITY · 2020 · $64,926

## Abstract

Project Summary
The overall goal of this proposal is to facilitate my aspiration to become a primary investigator of chromosome
biology at a research-intensive university. This project will build on my graduate background in mammalian
meiosis while expanding my technical abilities to facilitate my investigation of chromosome biology in other
contexts, such as human disease. The proposed research utilizes S. cerevisiae to investigate the chromosome
dynamics that occur prior to the first meiotic division. During this time, the nucleus is reorganized to allow for
the alignment of homologous chromosomes. The proper alignment of homologous chromosomes depends on
a series of molecular pathways, including endogenous DNA damage and repair, checkpoint signaling, and the
construction of a structural scaffold known as the synaptonemal complex (SC). The SC is made of two lateral
elements that form along the lengths of each chromosome and one central element that connect the lateral
elements of homologous chromosomes. The conserved axis proteins Hop1 (HORMAD1/2 proteins in mice and
humans) are an essential component of the lateral element and a central regulator of SC assembly.
 Despite extensive research, how the axis proteins localize to chromatin and then recruit the central
element to build the SC remains unclear. Indeed, a large fraction of Hop1 dissociate from the lateral elements
as the central element is deposited, raising the question whether Hop1 is a structural component of the SC or
only needed to mediate deposition of the central element. Aim 1 utilizes conditional protein induction and
depletion experiments to test the requirements of Hop1 in SC formation. It will also determine the role of Hop1
dissociation in this process. Aim 2 investigates the interface between DNA and the lateral element by using a
novel hop1 separation-of-function allele that exhibits normal DSB induction and repair kinetics but altered DNA
breakage patterns, which likely reflect altered Hop1 chromatin association. This allele of HOP1 removes an
uncharacterized region in the center of Hop1 that shares features with PHD domains, which are canonically
important for reading and responding to histone marks. Aim 2-1 uses this hop1 mutant to determine the effects
the axis patterning by ChIP-seq of axis proteins and to correlate these effects with altered break patterning
observed by whole-chromosome Southern blot analysis. Aim 2-2 utilizes targeted biotinylation and mass
spectrometry to define the chromatin environment surrounding Hop1 binding sites. This experiment will be
used to identify candidate proteins that will be tested for a role in axis protein positioning using the yeast
deletion library. The results of this proposal will provide important new insight into the mechanism of meiotic
chromosome morphogenesis and will serve as a framework for understanding infertility and birth defects in
humans. This proposal has a strong training component and will expand my knowledge ...

## Key facts

- **NIH application ID:** 10068593
- **Project number:** 1F32GM139386-01
- **Recipient organization:** NEW YORK UNIVERSITY
- **Principal Investigator:** Carolyn Rose Milano
- **Activity code:** F32 (R01, R21, SBIR, etc.)
- **Funding institute:** NIH
- **Fiscal year:** 2020
- **Award amount:** $64,926
- **Award type:** 1
- **Project period:** 2020-08-01 → 2022-07-31

## Primary source

NIH RePORTER: https://reporter.nih.gov/project-details/10068593

## Citation

> US National Institutes of Health, RePORTER application 10068593, Mechanisms Driving Meiotic Chromosome Morphogenesis (1F32GM139386-01). Retrieved via AI Analytics 2026-05-23 from https://api.ai-analytics.org/grant/nih/10068593. Licensed CC0.

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