# Roles of T-box transcriptional regulators in the development of RGC subtypes

> **NIH NIH R01** · UNIVERSITY OF TEXAS HLTH SCI CTR HOUSTON · 2024 · $489,515

## Abstract

Project Summary
Light is an important regulator in circadian biology, behavior, and gene expression. Light-
triggered visual functions are orchestrated through multiple channels and conveyed by specific
retinal ganglion cell (RGC) types. Despite significant progress in our understanding of the
morphologies and functions of the 40+ RGC types, the cellular and molecular basis underlying the
formation and survival of the diverse RGC types remains poorly understood. This grant proposal
focuses on the roles of T-box transcription factors Tbr1 and Tbr2 in regulating specific types of
retinal ganglion cells (RGCs). We have previously found that Tbr1 expression marks two distinct
subsets of OFF RGCs, and that Tbr1 plays a critical role in regulating the dendritic morphogenesis
in these RGCs. We have shown that Tbr2 is essential for the formation and maintaining the
survival of ipRGCs. Most recently, we further discovered that Tbr2-expressing neurons are
comprised of two populations. The goals of this project are to understand the genetic regulatory
networks mediated by Tbr1 and Tbr2 in order to gain a comprehensive understanding of how
these distinct RGCs are formed during development. We will accomplish this goal by determining
the role and function of Tbr1 and its transcriptional network in regulating development and
dendritic morphogenesis in developing RGCs. We will analyze the retinofugal projections of
ipRGC subtype, investigate the role of Tbr2 downstream regulator Irx1 in the development of
ipRGC subtype, elucidate the identity of Tbr2+ displaced amacrine cells and the role of Tbr2 in
these dACs, and establish Tbr2-mediated RGC-to-RGC/dAC networks during development.
The objective of this application is to understand the design principle underlying RGC subtype
formation and the structure and function of retinal circuits. Completion of the proposed project
will build deeper understanding regarding how two closely related transcription factors function
so differently in regulating the development of distinct RGC subtypes.

## Key facts

- **NIH application ID:** 10828751
- **Project number:** 5R01EY024376-09
- **Recipient organization:** UNIVERSITY OF TEXAS HLTH SCI CTR HOUSTON
- **Principal Investigator:** Chai-An Mao
- **Activity code:** R01 (R01, R21, SBIR, etc.)
- **Funding institute:** NIH
- **Fiscal year:** 2024
- **Award amount:** $489,515
- **Award type:** 5
- **Project period:** 2015-07-01 → 2026-04-30

## Primary source

NIH RePORTER: https://reporter.nih.gov/project-details/10828751

## Citation

> US National Institutes of Health, RePORTER application 10828751, Roles of T-box transcriptional regulators in the development of RGC subtypes (5R01EY024376-09). Retrieved via AI Analytics 2026-05-23 from https://api.ai-analytics.org/grant/nih/10828751. Licensed CC0.

---

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