# Mechanisms of Cell Competition in Growth and Development

> **NIH NIH R35** · COLUMBIA UNIVERSITY HEALTH SCIENCES · 2021 · $400,362

## Abstract

The central problem this work addresses is how cells communicate their fitness and recognize
aberrant fitness differences that might endanger growing tissues. Much evidence indicates that
the recognition of fitness disparities elicits interactions that prevent the weaker cells from
contributing to the animal, promoting optimal tissue and organismal fitness. Cell competition is a
mechanism that facilitates this homeostatic process, and is initiated upon recognition of cells
perceived as less fit by their more robust neighbors. Examples of competitive behavior between
cells of different fitness are numerous, but the best studied those induced by reduced ribosomal
proteins (Rp), or reduced or enhanced expression of the transcription factor Myc. The developing
Drosophila wing is the critical paradigm for study of cell competition - as a model system it is
unsurpassed for mosaic studies of cell-cell interactions in living animals, and offers unparalleled
genetic and molecular toolkits. We recently discovered that communication between the “winner”
and “loser” cells is mediated by a novel signaling pathway consisting of components co-opted
from the highly conserved innate immune response pathways. Our long-term goal is to explore
both proximate (how does this work) and ultimate (what is it for) questions about cell competition.
In this proposal, we focus on three major quests: 1), to further explore the mechanism by which
signal activation is controlled and restricted to only nearby “loser” cells; 2) to delineate the
endogenous role of cell competition during normal animal physiology; and 3) to investigate the
existence of a general mechanism of cell fitness sensing.
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## Key facts

- **NIH application ID:** 10135119
- **Project number:** 5R35GM131871-03
- **Recipient organization:** COLUMBIA UNIVERSITY HEALTH SCIENCES
- **Principal Investigator:** Laura A Johnston
- **Activity code:** R35 (R01, R21, SBIR, etc.)
- **Funding institute:** NIH
- **Fiscal year:** 2021
- **Award amount:** $400,362
- **Award type:** 5
- **Project period:** 2019-04-01 → 2024-03-31

## Primary source

NIH RePORTER: https://reporter.nih.gov/project-details/10135119

## Citation

> US National Institutes of Health, RePORTER application 10135119, Mechanisms of Cell Competition in Growth and Development (5R35GM131871-03). Retrieved via AI Analytics 2026-05-24 from https://api.ai-analytics.org/grant/nih/10135119. Licensed CC0.

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