# RNA-Based Communication in Heterogeneous Populations of Cell Mimics

## TL;DR

This paper shows how RNA can be used to enable communication between synthetic cell-like structures, creating dynamic signaling gradients.

## Contribution

The study introduces RNA regulators as programmable signaling molecules for communication in synthetic cell populations.

## Key findings

- RNA regulators can activate reporter expression at both transcription and translation levels.
- Spatiotemporal RNA gradients are influenced by sender and receiver configurations.
- Distributed RNA circuits outperform bulk cell-free reactions in specific activation.

## Abstract

RNA regulators offer a promising path for building complex,
orthogonal
circuits due to their low resource demands and design flexibility.
In this study, we explore their potential as signaling molecules in
communication between synthetic cells. Specifically, we engineer populations
of heterogenetic porous polymer cell mimics to produce, emit, and
receive two types of small synthetic RNA regulators. These RNAs are
required to activate reporter expression at both the levels of transcription
and translation. We distribute this AND gate circuit in receiver and
two types of sender cell mimics to compare the distributed logic computation
to the behavior of the circuit in well-mixed, bulk cell-free expression
reactions. Analyzing different densities and spatial arrangements
of senders and receivers, we reveal spatiotemporal gradients in RNA
signals and identify configurations that increase specific activation.
With small regulatory RNAs, the engineering toolbox for communication
between synthetic cells expands to include a programmable class of
signaling molecules. The rapid turnover of RNA suggests applications
in establishing dynamic signaling gradients in communities of synthetic
cells.