# Translational control of sensory identity

> **NIH NIH R21** · COLUMBIA UNIVERSITY HEALTH SCIENCES · 2021 · $162,000

## Abstract

Abstract
Sensory epithelia provide the link between the surrounding environment and its neuronal representation in the
brain. The main olfactory epithelium (MOE) permits detection of volatile chemicals by selective activation of
olfactory sensory neurons (OSNs), whose identity is defined by singular expression of an olfactory receptor
gene (OR). Singular OR choice enables OSN maturation, defines the receptive field of the cell, and determines
its axonal targeting to glomeruli in the olfactory bulb. Patterns of glomeruli activity are believed to represent the
functional topographic map of odorant cues in the environment. Thus, expression of a singular OR is required
for proper neuronal identity, axonal wiring, and odorant perception. Surprisingly, recent single cell RNA-Seq
data suggest that individual immature neurons may express multiple OR mRNA transcripts, which is in direct
conflict with the longstanding “one-receptor one-neuron” hypothesis.
Our work has identified the RNA binding protein Mex3a in immature OSNs as a post-transcriptional regulator
that may repress OR transcripts from being translated before one OR is selected for singular expression.
Genetic gain of function experiments assign Mex3a as a guardian of the immature neuron state, potentially by
binding OR mRNAs directly to prevent their translation, or by targeting an entire class of transcripts such as
cilia directed proteins. We propose to identify the direct RNA targets of Mex3a in the MOE, and determine how
neuronal differentiation and OR choice are affected in genetic loss of function animals. These studies are
poised to unveil a novel post-transcriptional mechanism for regulation of stochastic choice, and will also
uncover gene regulatory networks responsible for maintaining progenitor states in sensory cells.

## Key facts

- **NIH application ID:** 10129339
- **Project number:** 5R21DC017823-03
- **Recipient organization:** COLUMBIA UNIVERSITY HEALTH SCIENCES
- **Principal Investigator:** Rachel Duffie
- **Activity code:** R21 (R01, R21, SBIR, etc.)
- **Funding institute:** NIH
- **Fiscal year:** 2021
- **Award amount:** $162,000
- **Award type:** 5
- **Project period:** 2019-04-01 → 2022-03-31

## Primary source

NIH RePORTER: https://reporter.nih.gov/project-details/10129339

## Citation

> US National Institutes of Health, RePORTER application 10129339, Translational control of sensory identity (5R21DC017823-03). Retrieved via AI Analytics 2026-05-23 from https://api.ai-analytics.org/grant/nih/10129339. Licensed CC0.

---

*[NIH grants dataset](/datasets/nih-grants) · CC0 1.0*