Information regarding the downstream effectors and signaling pathways, however, is largely unknown. Enhanced understanding of the molecules and target sites mediating individual post-mating processes is needed to narrow the knowledge gap and gain insights into an effective strategy to control female fecundity. Oviposition consists of ovulation, transfer of a mature egg from the ovary to the uterus where fertilization occurs, and deposition of eggs to an external location with proper environmental conditions. Octopamine, a major biogenic amine in insects, is vital for oviposition. Females lacking the vesicular monoamine transporter, which is involved in storage and exocytotic release of biogenic amines, are sterile and the sterility is rescued by transgenic VMAT expression in the OA but not in other biogenic amine neurons in the vmat mutant. OA is made from tyrosine by the sequential actions of tyrosine decarboxylase and tyramine beta-hydroxylase, and functions as a neurotransmitter, neuromodulator and neurohormone. Similar to the vmat mutant, the tdc2 or tbh Semaxanib mutant females are sterile, and OA feeding in the mated tdc2 or tbh females is sufficient to induce egg-laying. While OA neurons have broad projection patterns within and outside of the central nervous system, the subset of OA neurons in the abdominal ganglion that innervates the reproductive system plays a key role in oviposition since restored TbH expression in those neurons reinstates fecundity of the tbh females. In the reproductive system OA axon terminals are found in the ovaries, oviducts, sperm storage organs and uterus where OA is likely to exert multiple functions. For instance OA, when applied to the dissected reproductive system, modulates muscle activity in a tissue specific manner: it enhances muscle contractions in the ovary but inhibits them in the oviduct. This suggests that OA receptors present in the ovary, oviduct and other areas regulate distinct elements of the reproductive process.Five G-protein coupled receptors specific for OA are identified in Drosophila and comprise two alpha1 Olaparib adrenergic-like receptors OAMB-K3 and OAMB-AS generated from the oamb locus by alternative splicing and three beta adrenergic-like receptors Octb1R, Octb2R and Octb3R.