Multiplex Detection of Gene Expression in the Intact Drosophila Brain Using Expansion-Assisted Iterative Fluorescence...

Area of Science:

• Neuroscience
• Molecular Biology
• Genetics

Background:

• Analyzing gene expression in intact tissues is crucial but faces methodological limitations.
• Current in situ methods struggle with high throughput and resolution for complex tissues like the central nervous system (CNS).

Purpose of the Study:

• To adapt and improve the EASI-FISH protocol for robust, high-throughput gene expression analysis in the adult Drosophila CNS.
• To enable visualization of gene expression in specific neuronal and glial cell types within the intact fly brain.

Main Methods:

• Adaptation of the EASI-FISH protocol using commercially available reagents.
• Development of a new gel formulation for enhanced robustness, enabling multiple hybridization rounds and embedding of multiple samples.
• Integration with expansion microscopy for high-resolution imaging and the GAL4-UAS system for cell-type specific detection (e.g., GFP co-detection).

Main Results:

• The improved EASI-FISH protocol successfully detects dozens of genes in situ within the intact adult Drosophila CNS.
• Enhanced gel formulation increases throughput, reduces costs, and allows for direct comparison of experimental conditions.
• High resolution and sensitivity enable the detection of single RNA transcripts, providing detailed gene expression maps.

Conclusions:

• The EASI-FISH protocol offers a powerful, integrated approach combining high image quality and high throughput for gene expression studies.
• This method is valuable for deciphering cellular functions by providing detailed insights into gene activity within the complex architecture of the fly brain.
• The protocol's robustness and efficiency make it suitable for large-scale analyses and comparative studies in neuroscience research.