pigk Mutation underlies macho behavior and affects Rohon-Beard cell excitability

Area of Science:

• Neuroscience
• Genetics
• Cell Biology

Background:

• Touch-evoked behavior relies on sensory neuron function.
• The zebrafish mutant 'macho' exhibits touch insensitivity and impaired neuronal sodium currents.

Purpose of the Study:

• To identify the genetic basis of the 'macho' zebrafish touch-insensitive phenotype.
• To elucidate the role of the identified gene in sensory neuron function and touch response.

Main Methods:

• Whole-genome sequencing to identify mutations in 'macho' zebrafish.
• Pigk gene knockdown and overexpression experiments in zebrafish embryos.
• Electrophysiological recordings of sensory neuron sodium currents (INa).
• Behavioral assays to assess touch response.

Main Results:

• A mutation in the pigk gene was identified in 'macho' mutants.
• PigK knockdown phenocopied 'macho' touch insensitivity and reduced INa.
• Overexpression of wild-type pigk rescued touch response and neuronal function in mutants.
• Pigk's role extends beyond maintaining INa and action potential firing for behavioral touch response.

Conclusions:

• The pigk gene is essential for touch-evoked behavior in zebrafish.
• PigK function is critical for sensory neuron sodium currents and action potential generation.
• Pigk plays a vital role in touch response independent of its function in neuronal excitability.