Gustatory avoidance of fatty acids by Aedes aegypti depends on an arthropod-specific TRP channel

Area of Science:

• Neuroscience
• Entomology
• Molecular Biology

Background:

• Mosquitoes rely on taste for feeding decisions, but the underlying molecular mechanisms are poorly understood.
• Transient Receptor Potential (TRP) channels, specifically Painless1 (Pain1), are expressed in mosquito gustatory receptor neurons (GRNs), suggesting a role in taste perception.

Purpose of the Study:

• To investigate the gustatory roles of Pain homologs in both *Drosophila* and *Aedes aegypti*.
• To determine the function of *Aedes aegypti* Painless1 (Pain1) in fatty acid detection and feeding behavior.

Main Methods:

• Examined gustatory responses to fatty acids in *Drosophila* and *Aedes aegypti* using *pain* and *pain1* mutations.
• Assessed fatty acid-induced action potentials in GRNs.
• Investigated the expression patterns of *pain* and *pain1* in taste organs.

Main Results:

• In *Drosophila*, *pain* mutations abolished attraction to low and repulsion from high fatty acid concentrations, with GRN-specific dependencies.
• *Aedes aegypti* showed gustatory rejection of fatty acids, and *Aedes pain1* was essential for this avoidance and for fatty acid-induced neural responses.
• Pain homologs are insect-specific, absent in vertebrates.

Conclusions:

• Pain homologs, particularly mosquito Pain1, play critical roles in gustatory perception of fatty acids.
• Pain1's function in mosquito taste suggests it as a potential target for novel repellents to control disease vectors.