# Dissecting sex hormone effects on genes, neurons, and behavior using cichlid fish

> **NIH NIH R35** · UNIV OF MARYLAND, COLLEGE PARK · 2021 · $378,282

## Abstract

Juntti | Project Summary
The overarching goal of my research program is to understand how hormones shape the neural
pathways that control social behavior. Gonadal hormones are key regulators of development
and adult neural function, and their signaling leads to profound differences in vertebrate animal
reproductive and aggressive behaviors across sexes. Differences in hormone signaling across
men and women could contribute to discrepancies in incidence of neuropsychiatric conditions,
but the neuronal and transcriptional basis for their actions are not clear. These hormones may
determine the connectivity of cells, their activity patterns, or both. Reproductive behaviors in
cichlid fish are an ideal model system to understand how hormones impact gene transcription
and neural circuit function. Cichlid social behaviors have been studied for nearly a century, and
are complex yet stereotyped and quantifiable. Dozens of cichlid species have sequenced
genomes, and we have pioneered CRISPR gene editing and transgenesis in these species. We
have identified a population of neurons sensitive to the hormones progestin and prostaglandin
F2α (PGF) that is essential for spawning behavior. Progestin receptor (PR) signaling regulates
gene expression in these cells, while PGF and its receptor, Ptgfr, are sufficient and necessary to
initiate spawning. We seek to determine the contribution of Ptgfr+ cells to a variety of social
behaviors through genetically directed manipulation of these cells. The implementation of the
QF-QUAS system for the first time in cichlids will permit studies of these and other cells. Like
other steroid hormone receptors, PR acts as a ligand-activated transcription factor. However, its
genomic targets are not known in brain, and so it is not clear how it regulates behavior. We will
identify how PR regulates cichlid behavior routines and determine the genomic targets of PR
that underlie its actions. The production of progestin (and other steroids) is regulated by the
hypothalamic-pituitary-gonadal axis. Sensory inputs regulate the production of progestin in
cichlids: male odorants promote its synthesis. We will identify cell groups that mediate this
signaling from olfaction to the endocrine system. These approaches will build upon our previous
findings and leverage technologies that we have developed, together yielding insights into how
the vertebrate brain regulates and responds to sex hormones. These experiments will lay a
foundation for understanding the gene networks coordinated by hormones and delineating the
neurons that regulate social behaviors.

## Key facts

- **NIH application ID:** 10275847
- **Project number:** 1R35GM142872-01
- **Recipient organization:** UNIV OF MARYLAND, COLLEGE PARK
- **Principal Investigator:** Scott Alan Juntti
- **Activity code:** R35 (R01, R21, SBIR, etc.)
- **Funding institute:** NIH
- **Fiscal year:** 2021
- **Award amount:** $378,282
- **Award type:** 1
- **Project period:** 2021-09-01 → 2026-07-31

## Primary source

NIH RePORTER: https://reporter.nih.gov/project-details/10275847

## Citation

> US National Institutes of Health, RePORTER application 10275847, Dissecting sex hormone effects on genes, neurons, and behavior using cichlid fish (1R35GM142872-01). Retrieved via AI Analytics 2026-05-23 from https://api.ai-analytics.org/grant/nih/10275847. Licensed CC0.

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