Expression of β-adrenergic-like octopamine receptors during Drosophila development

An invertebrate biogenic amine, octopamine, plays diverse roles in multiple physiological processes (e.g. neurotransmitter, neuromodulator, and circulating neurohormone). Octopamine is thought to function by binding to G-protein-coupled receptors. In Drosophila, three β-adrenergic-like octopamine receptors (Octβ1R, Octβ2R, and Octβ3R) have been identified. We investigated the expression of three OctβR genes in embryos, larvae, and adults. These OctβRs showed distinct expression patterns in the central nervous system (CNS) throughout development, and Octβ3R expression was evident in an endocrine organ, the ring gland, in larvae. In larvae, Octβ1R, Octβ2R, and Octβ3R were expressed in salivary glands and imaginal discs, Octβ2R and Octβ3R in midgut, and Octβ3R in gonads. In adult, besides in the CNS, each OctβR was strongly expressed in ovary and testis. Our findings provide a basis for understanding the mechanisms by which OctβRs mediate multiple diverse octopaminergic functions during development.