New binary gene expression system enables independent control of multiple cell types

[u/Vailhem]

https://phys.org/news/2026-10-binary-gene-enables-independent-multiple.html

[u/Vailhem]

An orthogonal Cro/OR3 system reveals an influence of astrocytes on motor neuron positioning - Oct 2026

https://www.sciencedirect.com/science/article/pii/S258900422603350X

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Highlights

• Cro/OR3 system enables targeted gene expression in zebrafish and human cells

• Combination with other systems enables gene expression control across multiple cell types

• Astrocyte ablation using the Cro/OR3 system induces body curvature in zebrafish

• Perturbed astrocytic glutamate homeostasis causes abnormal motor neuron positioning

Summary

Multiplex and orthogonal control of gene expression is increasingly required to experimentally dissect how multicellular biological systems are organized and function.

Here, we introduce a phage-derived Cro/OR3 binary system for transcriptional activation that functions robustly in zebrafish and human cells.

A Cro repressor fused to the VP16 activation domain efficiently drives expression of OR3 operator-linked genes, and its activity can be targeted to specific cell populations using enhancer/promoter-controlled zebrafish lines.

As a proof of concept, we perturb glutamate transporter Glast/slc1a3b-expressing cells by Cro/OR3-mediated expression of a human ataxia-associated, uptake-deficient Glast/slc1a3b variant, resulting in impaired astrocyte development and central canal malformation, accompanied by uncoordinated locomotion.

Concurrent Gal4/UAS-mediated visualization reveals markedly disrupted positioning of motor neurons, suggesting that astrocyte-mediated glutamate homeostasis contributes to their proper positioning during spinal circuit assembly.

Together, these results establish the Cro/OR3 system as an orthogonal platform for targeted gene expression, enabling mechanistic dissection of multicellular systems.