# Genetic co-regulation by master transcription factors in Drosophila intestinal stem cells

> **NIH NIH SC2** · CALIFORNIA STATE UNIVERSITY NORTHRIDGE · 2020 · $145,000

## Abstract

Project Summary
Many of our organs remain healthy and functional because they replace cells that are lost to injury or disease
with new ones, through divisions of adult stem cells contained within them. Adult stem cells divide
asymmetrically, generating a new copy of themselves (self-renew) and another cell that will eventually
“differentiate” into a cell with specialized function (e.g. absorb nutrients, fight infections, produce a hormone,
etc). While there has been great progress in identifying some of the so-called “master regulator genes” that
control a stem cell’s decision between self-renewal or differentiation, we know comparatively much less about
the specific genetic programs triggered by master regulators in the process. This is in spite of the many efforts
to identify targets of master regulators through genome-wide screening technologies, which frequently fall in
disuse due to a lack of further validation. Here I propose a research project that simultaneously addresses both
problems, by asking… “Can we more efficiently identify critical stem cell genes by integrating public lists of
putative master regulator targets obtained in complementary but unrelated studies?” To address the above
question, I propose to use the Drosophila melanogaster (fruit fly) midgut as an in vivo experimental model.
Previous studies have generated independent lists of putative targets for three known master regulators of
stem cells in the Drosophila intestine (Escargot, Capicua and Stat92E). We used bioinformatics to compare
these lists, and identified genes that are putatively targeted by only one or all three master regulators, which
we refer to as “mono-“ or “co-regulated”, respectively. In Aim 1 of this proposal, we will inhibit each of the
master regulators using RNAi-mediated protein knockdown in intestinal progenitors, and validate mono- and
co-regulated candidates based on changes to their expression as determined by reverse transcription
quantitative PCR (RT-qPCR). In Aim 2, we will compare the effects on the maintenance, proliferation rate and
differentiation potential of intestinal progenitors following the RNAi-mediated knockdown of mono- or co-
regulated candidates validated in Aim 1. This approach will allow us to test the hypothesis that co-regulated
genes are more frequently critical for the biology of the intestinal stem cells than mono-regulated counterparts.
Finally, our preliminary observations have shown that inhibiting Esg function leads to a reduction in Stat92E
activity, and here I propose to test bioinformatic predictions about regulatory connections between Esg and
Stat92E generated by incorporating yet another database of genetic and protein interaction data in. If
successful, this project will: a) exploit Drosophila as a prime genetics model system to generate a host of new
research leads for understanding and treating gastrointestinal diseases; b) provide a proof of concept to
encourage and guide the use of valuable information th...

## Key facts

- **NIH application ID:** 9980960
- **Project number:** 5SC2GM125573-03
- **Recipient organization:** CALIFORNIA STATE UNIVERSITY NORTHRIDGE
- **Principal Investigator:** Mariano A Loza Coll
- **Activity code:** SC2 (R01, R21, SBIR, etc.)
- **Funding institute:** NIH
- **Fiscal year:** 2020
- **Award amount:** $145,000
- **Award type:** 5
- **Project period:** 2018-09-05 → 2022-07-31

## Primary source

NIH RePORTER: https://reporter.nih.gov/project-details/9980960

## Citation

> US National Institutes of Health, RePORTER application 9980960, Genetic co-regulation by master transcription factors in Drosophila intestinal stem cells (5SC2GM125573-03). Retrieved via AI Analytics 2026-05-22 from https://api.ai-analytics.org/grant/nih/9980960. Licensed CC0.

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