Pheromone sensing in Drosophila requires support cell-expressed Osiris 8

Area of Science:

• Olfactory receptor research
• Insect sensory systems
• Molecular biology

Background:

• Animal noses have distinct sensory subsystems defined by olfactory receptor families.
• Drosophila melanogaster antennae possess two subsystems: one expressing odorant receptors (Ors) and another expressing ionotropic receptors (Irs).
• While Ors and Irs are well-studied, the subsystem-specific roles of other genes remain unclear.

Purpose of the Study:

• To identify genes with subsystem-specific expression in Drosophila melanogaster antennae.
• To investigate the roles of these genes, particularly non-neuronal ones, in olfactory function.
• To characterize a novel Or subsystem-specific gene involved in pheromone detection.

Main Methods:

• Generation of subsystem-specific transcriptomic datasets for Or and Ir subsystems.
• Analysis of single-cell antennal transcriptomic data.
• RNA in situ hybridization to determine gene expression patterns.
• Characterization of the Osiris 8 (Osi8) gene and its function.

Main Results:

• Hundreds of genes with selective enrichment in either Or or Ir subsystems were identified.
• Most neuronal genes showed broad expression, while many non-neuronal genes exhibited highly selective expression.
• Osiris 8 (Osi8), a transmembrane protein, is specifically expressed in support cells of pheromone-sensing sensilla.
• Loss of Osi8 function abolished high-sensitivity responses to pheromones without affecting development or basal neuronal activity.

Conclusions:

• A novel protein, Osiris 8, essential for insect pheromone detection, has been identified.
• The study underscores the significant contribution of support cells to neuronal sensory functions.
• The generated data provides a valuable resource for future research on olfactory subsystem-specific genes.