A gustatory receptor paralogue controls rapid warmth avoidance in Drosophila

Area of Science:

• Neuroscience
• Animal Behavior
• Molecular Biology

Background:

• Behavioral responses to temperature are crucial for survival and maintaining optimal body temperature.
• The molecular and cellular mechanisms underlying thermal preference are not well understood.
• Previous studies on Drosophila melanogaster (fruit flies) presented conflicting evidence regarding the roles of internal versus peripheral temperature sensors.

Purpose of the Study:

• To reconcile conflicting views on thermal preference in Drosophila.
• To identify the molecular basis of rapid thermal preference responses in fruit flies.
• To investigate the role of gustatory receptors in thermosensation.

Main Methods:

• Experimental manipulation of thermal gradients (shallow vs. steep).
• Genetic analysis, including the role of the transient receptor potential channel TRPA1.
• Investigating the function of gustatory receptor GR28B(D) in thermosensation.
• Misexpression experiments to assess GR28B(D) thermosensitivity.

Main Results:

• Drosophila's rapid thermal preference in steep gradients does not require TRPA1.
• The gustatory receptor GR28B(D) drives rapid behavioral responses via peripheral thermosensors.
• GR28B(D) misexpression confers thermosensitivity to various cell types, indicating its role as a warmth sensor.
• Identified a functional distinction between peripheral and internal warmth sensors.

Conclusions:

• Thermal preference is a multi-system response, with different mechanisms for different contexts.
• Gustatory receptors, previously unlinked to temperature sensation, are key peripheral thermosensors.
• This discovery reveals a new class of thermosensory molecules and highlights parallels with endotherm thermoregulation.