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 beta-adrenergic-like octopamine receptors (Oct beta 1R, Oct beta 2R, and Oct beta 3R) have been identified. We investigated the expression of three Oct beta R genes in embryos, larvae, and adults. These Oct beta Rs showed distinct expression patterns in the central nervous system (CNS) throughout development, and Oct beta 3R expression was evident in an endocrine organ, the ring gland, in larvae. In larvae, Oct beta 1R, Oct beta 2R, and Oct beta 3R were expressed in salivary glands and imaginal discs, Oct beta 2R and Oct beta 3R in midgut, and Oct beta 3R in gonads. In adult, besides in the CNS, each Oct beta R was strongly expressed in ovary and testis. Our findings provide a basis for understanding the mechanisms by which Oct beta Rs mediate multiple diverse octopaminergic functions during development.