Drosophila ankyrin 2 is required for synaptic stability.

Area of Science:

• Neuroscience
• Cell Biology
• Genetics

Background:

• Synaptic connections rely on transsynaptic adhesion complexes anchored to the cytoskeleton for stability.
• The Drosophila neuromuscular junction (NMJ) is a model for studying synaptic structural remodeling.

Purpose of the Study:

• To identify genes regulating synaptic stability using a mutagenesis screen.
• To investigate the role of Drosophila ankyrin 2 (ank2) in synaptic structure and stability.

Main Methods:

• Conducted a mutagenesis screen in Drosophila to identify genes affecting synaptic stability.
• Analyzed ank2 mutant larvae to assess neuromuscular junction (NMJ) structure and stability.
• Examined the presynaptic membrane cytoskeleton and microtubule organization in ank2 mutants.

Main Results:

• Mutations in ank2 were recovered, affecting giant isoforms specific to the nervous system.
• ank2 mutant larvae exhibited severe NMJ instability, including reduced terminal size and bouton withdrawal.
• Lack of Ank2 led to presynaptic active zone disassembly and disintegration of the synaptic microtubule cytoskeleton.
• Ank2 is essential for anchoring synaptic microtubules, functioning downstream of spectrin.

Conclusions:

• Drosophila ankyrin 2 is vital for maintaining synaptic stability by providing a cytoskeletal scaffold for microtubules.
• Ank2's role in microtubule anchorage is critical for the structural integrity of neuromuscular junctions.