# Transgenic Pigs with Red-Shifted Channelrhodopsin-Citrine Fusion Proteins

> **NIH NIH OT2** · UNIVERSITY OF FLORIDA · 2020 · $462,155

## Abstract

PROJECT SUMMARY
Large animals are increasingly utilized in biomedical research and offer an advantage in that their
anatomy and physiology closely parallel humans. Yet despite these advantages, rodent models
dominate many areas of research, including neuroscience. This might be due in part to the greater
number of technologies available to rodent researchers. In the current application, the investigator
proposes to create a new technology to facilitate large animal researchers and bridge this gap.
Specifically, she proposes to create transgenic pigs with red-shifted channelrhodopsin-citrine fusion
proteins or green fluorescent protein/calmodulin protein sensors expressed in neurons. This will allow
for simultaneous visualization of neurons (and their innervation), and the ability to precisely control or
monitor neural activity. An important advantage of the red-shifted channelrhodopsin variant is that it
can be activated by near far red light (~630 nm), thus decreasing phototoxic events and opening the
door to less-invasive methods of neural activation (i.e. through the skin). Moreover, the fusion of the
green fluorescent protein derivative, citrine, will allow for identification of specific neural elements
expressing channelrhodpsin, as well as enable visualization of organ innervation. To create the
transgenic pigs, the investigator proposes to target porcine fetal fibroblasts using piggyBac
transposon technology. The piggyBac transposon system allows for “cut and paste” integration of the
targeting construct into the porcine genome. An advantage of this approach is that it promotes stable
transgene expression. Transgenic pigs will be derived from the targeted fetal fibroblasts at the
University of Missouri where Dr. Randall Prather and his team will perform somatic cell nuclear
transfer. Embryos containing the targeted nuclear material will be transferred to a surrogate gilt and
allowed to develop until term. Transgenic pigs will then be studied and characterized in the
investigator's lab at the University of Florida. The proposed work is completely aligned with the
priorities of SPARC and will facilitate the imaging and targeting of peripheral nerves with end organs
in a large animal model. Moreover, its utility is not limited to peripheral nervous system researchers,
as central nervous system neurons will also express channelrhodopsin-citrine fusion proteins or green
fluorescent protein/calmodulin protein sensors. Thus, the work proposed in this application has the
potential to greatly accelerate the neuroscience field and propel the bench-to-bedside process.

## Key facts

- **NIH application ID:** 10065184
- **Project number:** 3OT2OD026582-01S1
- **Recipient organization:** UNIVERSITY OF FLORIDA
- **Principal Investigator:** Leah R Reznikov
- **Activity code:** OT2 (R01, R21, SBIR, etc.)
- **Funding institute:** NIH
- **Fiscal year:** 2020
- **Award amount:** $462,155
- **Award type:** 3
- **Project period:** 2019-07-01 → 2022-06-30

## Primary source

NIH RePORTER: https://reporter.nih.gov/project-details/10065184

## Citation

> US National Institutes of Health, RePORTER application 10065184, Transgenic Pigs with Red-Shifted Channelrhodopsin-Citrine Fusion Proteins (3OT2OD026582-01S1). Retrieved via AI Analytics 2026-05-26 from https://api.ai-analytics.org/grant/nih/10065184. Licensed CC0.

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