title: Molecular characterization and possible biological roles of allatotropin in Rhodnius prolixus.
abstract: Allatotropins (ATs) are a family of neuropeptides that have been shown to stimulate the biosynthesis of juvenile hormone in certain insect species, and to have stimulatory activity on some visceral muscles. Here, we have examined the AT in Rhodnius prolixus. Molecular analysis revealed a cDNA fragment of 973 bp encoding one mature amidated AT (Rhopr-AT) with transcript levels observed in the central nervous system (CNS) and pool of fat body, trachea and associated peripheral nerves. AT-like immunoreactive neurons were found throughout the CNS and AT-like immunoreactive processes were present on some peripheral tissues. Bioassays based upon changes in hindgut and dorsal vessel contractions failed to demonstrate any myotropic effects of Rhopr-AT on these tissues; however Rhopr-AT stimulated contractions of muscles surrounding the salivary glands and secretion of saliva, as judged by the reduction in content of the cherry red saliva from the salivary glands. Serotonin stimulated an increase in peristaltic contractions of the gland though no secretion was observed. Co-application of Rhopr-AT and serotonin resulted in a more rapid secretion than either chemical alone.
authors.affiliation: Department of Biology, University of Toronto Mississauga, Mississauga, ON L5L 1C6, Canada. Electronic address: maryam.masood@mail.utoronto.ca.
authors.forename: Maryam
authors.initials: M
authors.lastname: Masood
authors.affiliation: Department of Biology, University of Toronto Mississauga, Mississauga, ON L5L 1C6, Canada. Electronic address: ian.orchard@utoronto.ca.
authors.forename: Ian
authors.initials: I
authors.lastname: Orchard
mesh_terms: D000595:Amino Acid Sequence; D000818:Animals; D002490:Central Nervous System / Q000187:drug effects; D007301:Insect Hormones / Q000235:genetics / Q000378:metabolism* / Q000494:pharmacology; D009119:Muscle Contraction / Q000187:drug effects; D009479:Neuropeptides / Q000235:genetics / Q000378:metabolism* / Q000494:pharmacology; D010802:Phylogeny; D012239:Rhodnius / Q000378:metabolism*
chemical_list: D007301:Insect Hormones; D009479:Neuropeptides; C050669:allatotropin
keywords: Dorsal vessel; Gene transcript; Hindgut; Immunohistochemistry; Insect; Salivary gland; Serotonin