Knockdown of a β-Adrenergic-Like Octopamine Receptor Affects Locomotion and Reproduction of Tribolium castaneum

Abstract

The neurohormone octopamine regulates many crucial physiological processes in insects and exerts its activity via typical G-protein coupled receptors. The roles of octopamine receptors in regulating behavior and physiology in Coleoptera (beetles) need better understanding. We used the red flour beetle, Tribolium castaneum, as a model species to study the contribution of the octopamine receptor to behavior and physiology. We cloned the cDNA of a β-adrenergic-like octopamine receptor (TcOctβ2R). This was heterologously expressed in human embryonic kidney (HEK) 293 cells and was demonstrated to be functional using an in vitro cyclic AMP assay. In an RNAi assay, injection of dsRNA demonstrated that TcOctβ2R modulates beetle locomotion, mating duration, and fertility. These data present some roles of the octopaminergic signaling system in T. castaneum. Our findings will also help to elucidate the potential functions of individual octopamine receptors in other insects.

Pharmacological Properties and Function of the PxOctβ3 Octopamine Receptor in Plutella xylostella (L.)

“…The second phenylalanine after the FxxxWxP motif in TM6 and that after the NPxxY motif in TM7 were also conserved. These conserved cysteine and phenylalanine sites are not only necessary for aminergic GPCRs but are also conserved in all previously reported adrenergic receptors [ 29 ] ( Figure 1 ).…”

“…However, TcOctβ3 has been found to be highly expressed in early larvae, and there may be differences in the level of expression of this gene among different species. In addition, we found that the level of expression of PxOctβ3 differed in females and males, which was also reflected in PxOctβ1 and PxOctβ2 [ 28 , 29 , 30 ]. In addition, this study confirmed that an increase in the nerve impulse responses of male pheromone-sensitive receptor neurons (RNs) after octopamine injection in silkworm ( Bombyx mori ) is either absent or less sensitive in females [ 44 ].…”

Molecular and Pharmacological Characterization of β-Adrenergic-like Octopamine Receptors in the Endoparasitoid Cotesia chilonis (Hymenoptera: Braconidae)

“…CcOctβRs were all expressed in the leg. The transcript levels of NcOctβ2R [ 70 ] and TcOctβ2R [ 50 ] were found to exhibit high expressions in the leg. There are large muscles in insect legs, and the expressions of DmOctβRs were all detected in the adult muscles [ 28 ].…”

“…The β-adrenergic-like OAR family generally has three subtypes, including Octβ1R, Octβ2R, and Octβ3R. Octβ1R regulates feeding and learning behavior [ 23 , 44 ], and Octβ3R plays an essential role in metamorphosis regulation of ecdysone synthesis and pupation [ 45 , 46 ], whereas Octβ2R has multiple functions, including ovulation [ 47 , 48 , 49 ], locomotion [ 50 , 51 , 52 ], and stress resistance [ 53 ].…”

Arylalkalamine N‐acetyltransferase‐1 acts on a secondary amine in the yellow fever mosquito, Aedes aegypti

“…Previous studies showed that octopaminergic/tyraminergic signalling pathways played essential roles for the insect fertility [33,34]. In invertebrates, octopamine and tyramine might play the roles as epinephrine and norepinephrine played in vertebrates [35].…”