# The genetic control of neuronal number and behavior

> **NIH NIH K99** · HARVARD UNIVERSITY · 2022 · $100,000

## Abstract

Project Summary/Abstract
The genetic control of neuron number is an important mechanism by which genes can encode for behavior.
Expansions of specific neuronal populations have been associated with behavioral innovations such as
increased olfactory abilities, while deficiencies of particular neuronal types in humans have been associated
with disorders including autism spectrum disorder. However, the genes and molecular pathways that specify
neuron number to govern behavior are largely unknown. The proposed research investigates two ways in
which innate behaviors are controlled by population sizes of specific neurons in the hypothalamus of
Peromyscus deer mice. In the first aim, I will investigate how variation in parental nesting behavior is controlled
by numbers of neuron expressing vasopressin, a neuropeptide with important roles in sociosexual behavior. In
the second aim, I will investigate how variation in sex-specific parental behaviors are controlled by sex-specific
neuronal numbers.
This research takes advantage of two closely-related species of Peromyscus deer mice which have evolved
large, heritable differences in parental care, but have minimal genetic differences between them. First, I will
use comparative genomic sequencing and neurogenetics approaches, such as the detection of immediate-
early genes, to implicate candidate cell types whose neuron numbers are co-evolving with and responsible for
behavioral differences across Peromyscus species. Then, by combining genetic mapping with single-nuclei
sequencing, I will determine the causal genetic loci controlling neuronal population sizes and test candidate
genes for their effect on neuron number and downstream behavior. This research will implicate important
neurodevelopmental pathways regulating innate behavior and contribute to our ability to diagnose and treat
neurodevelopmental diseases.
The proposed research will be conducted under the mentorship of Dr. Hopi Hoekstra, an expert in Peromyscus
behavioral genetics, and Dr. Sean Eddy, an expert in comparative genomic data analysis. Additionally, I will be
mentored by an advisory committee composed of Dr. Catherine Dulac, an expert in neurogenetics of social
behaviors, Dr. Steve McCarroll, an expert in neuronal single-cell genomics, and Drs. Francesca Dominici and
David Parkes, co-directors of the Harvard Data Science Initiative. Under this mentorship, I will develop
research skills in molecular biology, mouse behavioral experiments, and neuronal single-cell data analysis. I
will also use my training and participation in the MOSAIC program to develop leadership skills including lab
management, inclusive mentoring, and scientific presentation skills. Together, my research training and career
development activities will launch my successful transition to an independent research scientist.

## Key facts

- **NIH application ID:** 10428112
- **Project number:** 1K99GM146243-01
- **Recipient organization:** HARVARD UNIVERSITY
- **Principal Investigator:** Jennifer Chen
- **Activity code:** K99 (R01, R21, SBIR, etc.)
- **Funding institute:** NIH
- **Fiscal year:** 2022
- **Award amount:** $100,000
- **Award type:** 1
- **Project period:** 2022-07-01 → 2024-06-30

## Primary source

NIH RePORTER: https://reporter.nih.gov/project-details/10428112

## Citation

> US National Institutes of Health, RePORTER application 10428112, The genetic control of neuronal number and behavior (1K99GM146243-01). Retrieved via AI Analytics 2026-05-24 from https://api.ai-analytics.org/grant/nih/10428112. Licensed CC0.

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