RT Journal Article
SR Electronic
T1 Hawkmoth Pheromone Transduction Involves G-Protein–Dependent Phospholipase Cβ Signaling
JF eneuro
JO eNeuro
FD Society for Neuroscience
SP ENEURO.0376-24.2024
DO 10.1523/ENEURO.0376-24.2024
VO 12
IS 3
A1 Schneider, Anna C.
A1 Schröder, Katrin
A1 Chang, Yajun
A1 Nolte, Andreas
A1 Gawalek, Petra
A1 Stengl, Monika
YR 2025
UL http://www.eneuro.org/content/12/3/ENEURO.0376-24.2024.abstract
AB Evolutionary pressures adapted insect chemosensation to their respective physiological needs and tasks in their ecological niches. Solitary nocturnal moths rely on their acute olfactory sense to find mates at night. Pheromones are detected with maximized sensitivity and high temporal resolution through mechanisms that are mostly unknown. While the inverse topology of insect olfactory receptors and heteromerization with the olfactory receptor coreceptor suggest ionotropic transduction via odorant-gated receptor–ion channel complexes, contradictory data propose amplifying G-protein–coupled transduction. Here, we used in vivo tip-recordings of pheromone-sensitive sensilla of male Manduca sexta hawkmoths at specific times of day (rest vs activity). Since the olfactory receptor neurons distinguish signal parameters in three consecutive temporal windows of their pheromone response (phasic; tonic; late, long-lasting), respective response parameters were analyzed separately. Disruption of G-protein–coupled transduction and block of phospholipase C decreased and slowed the phasic response component during the activity phase of hawkmoths without affecting any other component of the response during activity and rest. A more targeted disruption of Gα subunits by blocking Gαo or sustained activation of Gαs using bacterial toxins affected the phasic pheromone response, while toxins targeting Gαq and Gα12/13 were ineffective. Consistent with these data, the expression of phospholipase Cβ4 depended on zeitgeber time, which indicates circadian clock-modulated metabotropic pheromone transduction cascades that maximize sensitivity and temporal resolution of pheromone transduction during the hawkmoth's activity phase. Thus, discrepancies in the literature on insect olfaction may be resolved by considering circadian timing and the distinct odor response components.