Dpr-DIP matching expression in Drosophila synaptic pairs.

Area of Science:

• Neuroscience
• Molecular Biology
• Genetics

Background:

• Cellular recognition mechanisms for synaptic partner selection remain unclear.
• Cell surface and secreted molecules (CSMs) are crucial for cell-cell interactions in neural development.
• Understanding these mechanisms is vital for deciphering neural circuit formation.

Purpose of the Study:

• To investigate the role of CSMs in synaptic partner selection.
• To identify specific molecules involved in precise neuronal connectivity.
• To elucidate the molecular basis of neural circuit assembly in the fly visual system.

Main Methods:

• Transcriptome profiling of 7 closely related neurons in the fly medulla.
• Analysis of cell surface and secreted molecule (CSM) expression patterns.
• Coexpression analysis and correlation with connectome data.

Main Results:

• Each neuron type expressed a unique combination of hundreds of CSMs at synapse formation onset.
• 21 paralogs of the defective proboscis extension response (Dpr) family showed cell-type-specific expression.
• 9 members of the Dpr interacting protein (DIP) family exhibited complementary layer-specific expression, suggesting Dpr-DIP interactions mediate connectivity.

Conclusions:

• Dpr and DIP families are key regulators of synaptic partner selection.
• Dpr-DIP interactions likely guide the formation of precise neural circuits.
• This study provides a molecular framework for understanding neural connectome development.