Decoding gene regulation in the fly brain.

Area of Science:

• Neuroscience
• Genomics
• Developmental Biology

Background:

• The Drosophila brain is a key model for understanding neuronal diversity and function.
• Gene regulatory networks (GRNs), comprising transcription factors and enhancers, control cell identity.
• Previous studies have identified diverse cell types but lacked detailed GRN characterization at the single-cell level.

Purpose of the Study:

• To characterize cell-type-specific gene regulatory networks in the Drosophila brain.
• To identify regulatory elements and their target genes across different neuronal cell types and developmental stages.

Main Methods:

• Single-cell chromatin accessibility profiling of over 240,000 cells across 9 developmental timepoints.
• Integration of chromatin accessibility data with single-cell transcriptomes.
• Application of motif discovery, network inference, and deep learning to construct enhancer GRNs.

Main Results:

• Identification of over 95,000 cell-type-specific regulatory regions in the fly brain.
• Discovery of 70,000 regulatory regions associated with neurogenesis, reprogramming, and maturation trajectories.
• Construction of enhancer GRNs for 40 cell types, linking accessible regions to transcription factors and target genes.

Conclusions:

• The DeepFlyBrain resource provides unprecedented insight into neuronal regulatory diversity in the Drosophila brain.
• Characterized enhancer architectures enhance understanding of cell-type-specific gene regulation.
• The findings enable the design of genetic tools for precise cell-type targeting and manipulation.