Multiple Neuropeptide-Coding Genes Involved in Planarian Pharynx Extension

Area of Science:

• Neuroscience
• Animal Behavior
• Molecular Biology

Background:

• Planarian feeding involves complex behaviors, including pharynx extension.
• The specific neuronal mechanisms regulating pharynx extension remain largely unknown.

Purpose of the Study:

• To identify neuronal cell types and molecular players involved in regulating planarian pharynx extension.
• To elucidate the neural control of feeding behavior in planarians.

Main Methods:

• Quantitative analysis of pharynx extension behavior.
• RNA interference (RNAi) screening of candidate genes, including neurotransmitter and neuropeptide genes.
• In situ hybridization to determine gene expression patterns.

Main Results:

• Pharynx extension is dependent on the head portion of the planarian.
• Knockdown of Prohormone Convertase 2 (PC2) disrupted pharynx extension, implicating neuropeptides.
• RNAi screening identified at least five neuropeptide genes essential for pharynx extension.
• Identified neuropeptides are expressed in various neurons, including those in the brain.

Conclusions:

• Neuropeptides play a critical role in regulating planarian pharynx extension.
• The nervous system, particularly neuropeptidergic signaling, intricately controls planarian feeding behavior.
• This study provides novel insights into the molecular basis of feeding behavior in a model organism.