G protein γ subunit Gγ13 is essential for olfactory function and aggressive behavior in mice

Area of Science:

• Neuroscience
• Molecular Biology
• Genetics

Background:

• Olfactory receptors are G protein-coupled receptors initiating signaling cascades.
• Specific alpha subunits (Gαolf, Gαi2, Gαo) are crucial for olfactory and vomeronasal functions.
• The role of G protein gamma subunits in these systems is less understood.

Purpose of the Study:

• To investigate the expression and function of the G protein gamma 13 (Gγ13) subunit in the olfactory and vomeronasal systems.
• To determine the role of Gγ13 in odor-guided behaviors.

Main Methods:

• Spatiotemporal expression analysis of Gγ13 in olfactory and vomeronasal organs.
• Gene knockout of Gng13 (Gγ13 gene) in mature olfactory and vomeronasal sensory neurons using the Cre-loxP system.
• Immunohistochemistry to assess Gγ13 expression in mutant mice.
• Behavioral experiments to evaluate social interactions, specifically male-male aggression.

Main Results:

• Gγ13 exhibits specific spatiotemporal expression in the olfactory and vomeronasal systems, with notable presence in the main olfactory bulb but absence in the accessory olfactory bulb glomeruli.
• Genetic nullification of Gng13 led to reduced Gγ13 expression in the apical vomeronasal epithelium.
• Male mutant mice lacking Gγ13 displayed significantly reduced frequency and duration of aggressive encounters compared to wild-type mice.

Conclusions:

• The Gγ13 subunit is a critical signaling component in both the main olfactory epithelium and the apical vomeronasal epithelium.
• Gγ13 plays an essential role in odor-triggered social behaviors, including male-male aggression.