# ShineGAL4 drivers for tissue and cell-type specific optogenetics in Drosophila

## TL;DR

Researchers developed ShineGAL4, a new optogenetic tool for precise control of gene expression in specific tissues and cells in fruit flies.

## Contribution

The study introduces ShineGAL4 drivers, enabling light-controlled gene expression in diverse Drosophila tissues and cell types.

## Key findings

- ShineGAL4 drivers allow rapid and specific gene induction in tissues like fat body, muscles, and neurons.
- The system uses CRISPR to replace GAL4 with a photoswitchable version for spatiotemporal control.
- An optogenetic cassette was developed for activating GAL4 in previously silent clones.

## Abstract

An optogenetic split-GAL4 system, ShineGAL4, allows genes to be manipulated with unprecedented spatiotemporal precision. Here, we convert a panel of 14 GAL4 drivers widely used in Drosophila research into their ShineGAL4 counterparts. Homology assisted CRISPR knock-in (HACK) is used to replace GAL4 with the GAL4 DNA binding domain fused to a Magnet photoswitch. We show that the resulting ShineGAL4 drivers enable gene expression to be rapidly induced by light specifically in fat body, muscles, enterocytes, oenocytes, Malpighian tubules, neurons, neuroblast lineages, glial subtypes or in all glia. We also develop an optogenetic cassette for photoactivation of GAL4 in ‘silent’ FLP-out clones. This panel of optogenetic tools will enable precise spatiotemporal control of gene expression in a wide range of different Drosophila tissues and cell-types.

Summary: A panel of optogenetic GAL4 drivers has been developed for temporal control of tissue and cell-type specific genetic manipulations in Drosophila.