Investigating CNS synaptogenesis at single-synapse resolution by combining reverse genetics with correlative light...

Area of Science:

• Neuroscience
• Cell Biology
• Developmental Biology

Background:

• Determining direct synaptic connections in the central nervous system (CNS) is challenging.
• Understanding molecular pathways controlling synaptogenesis in vivo is difficult.

Purpose of the Study:

• To develop genetic tools for high-resolution neuronal and synaptic labeling in Drosophila.
• To establish a correlative light and 3D electron microscopy (3D CLEM) protocol for ultrastructural analysis.
• To investigate molecular mechanisms of synaptic development in mechanosensory neurons.

Main Methods:

• Genetic tools for single-neuron and single-synapse labeling in Drosophila.
• Correlative light and 3D electron microscopy (3D CLEM) for ultrastructural imaging.
• Cell-specific gene disruption combined with single-neuron labeling.

Main Results:

• Genetically encoded markers reliably indicate active zones in Drosophila mechanosensory neurons.
• 3D CLEM revealed characteristic CNS synapse ultrastructure, including T-bar dense bodies.
• Liprin-α, Lar, and DSyd-1 (RhoGAP100F) show similar requirements for synaptic vesicle recruitment.

Conclusions:

• The developed genetic and 3D CLEM tools enable high-resolution analysis of synaptogenesis.
• Liprin-α and its interactors may have a shared role in presynaptic vesicle recruitment in the CNS.
• The 3D CLEM approach is broadly applicable to studying synapse development across various cell types.