Table 1.

Signaling systems implicated in insect olfactory transduction

Pathway/Components	Effect/evidence	Reference
Gαq: Ca+2/IP3/DAG/PLC
Gαq	Expressed in olfactory neurons	[15-17-20]
dgαq mutant/knockdown	Decreased response	[19,28]
PKC activators	Activate AC1 channel	[13]
DAG kinase (rdgA) mutant	Decreased response	[19]
PI-TP	Expressed in olfactory neurons	[23]
PI-TP (rdgB) mutant	Decreased response	[23]
IP3 kinase1	Expressed in olfactory neurons	[26]
IP3 kinase1overexpression	Altered response	[26]
IP3	Odor-evoked increase	[10,11]
PLC	Expressed in olfactory neurons	[24]
PLC (norpA) mutant	Decreased response	[24]
PLCβ (plc21C) mutant	Decreased response	[19]
Gαs: Cyclic nucleotides
Gαs	Expressed in olfactory neurons	[17]
Gαs mutant	Decreased response	[25,27]
AC and PDE	Expressed in olfactory neurons	[25]
AC mutant (rut)	Altered response	[25,27]
PDE mutant (dnc)	Altered response	[25,27]
cAMP	Odor-evoked increase	[10,52]
cAMP	No odor-evoked increase	[10,12,51]
cGMP	Odor-evoked increase	[12]
cGMP	Activates AC1 channel	[13]
cAMP/cGMP	Activates Or83b	[52]
cAMP/cGMP	Does not activate Or83b	[51]
CNG channel	Expressed in olfactory neurons	[21]
CNG K+ (eag) mutant	Decreased response	[22]
Or83b co-receptor
Function requires Or83b	Imaging/electrophysiology	[34,40,41,51]
Or83b enhances function	Imaging/electrophysiology	[37,42,43]
Function without Or83b	Imaging/electrophysiology	[47–50]
Function with G-protein	Imaging/electrophysiology	[48,49,52]
Function without G-protein	Imaging/electrophysiology	[37,42,43,50,51]

Abbreviations: PKC, protein kinase C; DAG, diacylglycerol; PI-TP, phosphatidylinositol transfer protein; IP₃, inositol 1,4,5-trisphosphate; PLC, phospholipase C; CNG, cyclic nucleotide-gated; AC, adenylate cyclase; PDE, phosphodiesterase; cAMP, 3′-5′-cyclic adenosine monophosphate; cGMP, 3′-5′-cyclic guanosine monophosphate.