title: Cloning, localization, and physiological effects of sulfakinin in the kissing bug, Rhodnius prolixus.
abstract: Sulfakinins (SKs) are a family of multifunctional neuropeptides that have been shown to have myotropic activity on muscles of the digestive system and to function as feeding satiety factors. Here, we confirm via cloning the presence of two sulfakinins (Rhopr-SK-1 and Rhopr-SK-2) in Rhodnius prolixus. Reverse transcriptase quantitative PCR demonstrates that the Rhopr-SK transcript is highly expressed in the central nervous system (CNS) of unfed fifth-instar R. prolixus. Fluorescent in situ hybridization shows transcript expression only in neurons in the brain. Immunohistochemical staining of SK-like peptides was observed in the same neurons in the brain and in processes extending throughout the CNS, as well as over the posterior midgut and anterior hindgut. Rhopr-SK-1 (sulfated form) induces contractions of the hindgut in a dose-dependent manner. Injection Rhopr-SK-1 (sulfated form) significantly decreases the overall weight of the blood meal consumed, suggesting SK's role as a satiety factor in R. prolixus.
authors.affiliation: Department of Biology, University of Toronto Mississauga, Mississauga, ON, L5L 1C6, Canada. Electronic address: hussain.al.alkawi@mail.utoronto.ca.
authors.forename: Hussain
authors.initials: H
authors.lastname: Al-Alkawi
authors.affiliation: Department of Biology, University of Toronto Mississauga, Mississauga, ON, L5L 1C6, Canada.
authors.forename: Angela B
authors.initials: AB
authors.lastname: Lange
authors.affiliation: Department of Biology, University of Toronto Mississauga, Mississauga, ON, L5L 1C6, Canada.
authors.forename: Ian
authors.initials: I
authors.lastname: Orchard
mesh_terms: D000595:Amino Acid Sequence; D000818:Animals; D001921:Brain / Q000378:metabolism; D002490:Central Nervous System / Q000378:metabolism; D003198:Computer Simulation; D018076:DNA, Complementary / Q000235:genetics; D004064:Digestive System / Q000378:metabolism; D005260:Female; D017404:In Situ Hybridization, Fluorescence; D008297:Male; D009132:Muscles / Q000378:metabolism; D009474:Neurons / Q000378:metabolism; D009479:Neuropeptides / Q000235:genetics / Q000378:metabolism / Q000502:physiology; D012239:Rhodnius / Q000235:genetics / Q000378:metabolism*; D012528:Satiety Response
chemical_list: D018076:DNA, Complementary; D009479:Neuropeptides
keywords: Hindgut contraction; Immunohistochemistry; In situ hybridization; Insect; Neuropeptide; Satiety