title: Orcokinins contribute to the regulation of vitellogenin transcription in the cockroach Blattella germanica.
abstract: Orcokinins (OKs) are neuropeptides that were first identified in crustacean through their myotropic activity. In insects, the OK gene gives rise to two mRNAs coding for two different families of conserved mature neuropeptides: OKA and OKB. Although OKs are conserved in many insect species, its physiological role in this animal class is not fully understood. Until now prothoracicotropic, regulatory of light entrainment to the circadian clock and "awakening" activities have been reported for these peptides in different insect species. Here we report the identification of OKA and OKB precursors in the cockroach Blattella germanica. OKA mRNA was detected in brain, whereas OKB mRNA was detected both in brain and midgut. In vivo silencing of OK precursors suggests the involvement of OK gene products in the regulation of vitellogenin expression in the fat body, an action that appears to be independent of juvenile hormone. This is the first time that a function of this kind has been reported for OKs.
authors.affiliation: Institute of Evolutionary Biology (CSIC-Universitat Pompeu Fabra), Passeig Marítim de la Barceloneta 37-49, 08003 Barcelona, Spain. Electronic address: sheila.ons@presi.unlp.edu.ar.
authors.forename: Sheila
authors.initials: S
authors.lastname: Ons
authors.affiliation: Institute of Evolutionary Biology (CSIC-Universitat Pompeu Fabra), Passeig Marítim de la Barceloneta 37-49, 08003 Barcelona, Spain. Electronic address: xavier.belles@ibe.upf-csic.es.
authors.forename: Xavier
authors.initials: X
authors.lastname: Bellés
authors.affiliation: Institute of Evolutionary Biology (CSIC-Universitat Pompeu Fabra), Passeig Marítim de la Barceloneta 37-49, 08003 Barcelona, Spain. Electronic address: joseluis.maestro@ibe.upf-csic.es.
authors.forename: José L
authors.initials: JL
authors.lastname: Maestro
mesh_terms: D000595:Amino Acid Sequence; D000818:Animals; D020048:Blattellidae / Q000737:chemistry / Q000235:genetics* / Q000254:growth & development; D001923:Brain Chemistry / Q000235:genetics; D005216:Fat Body / Q000737:chemistry; D005260:Female; D041981:Gastrointestinal Tract / Q000737:chemistry; D005786:Gene Expression Regulation; D007605:Juvenile Hormones / Q000378:metabolism; D008969:Molecular Sequence Data; D009479:Neuropeptides / Q000302:isolation & purification*; D034622:RNA Interference; D014819:Vitellogenins / Q000737:chemistry / Q000235:genetics*
chemical_list: D007605:Juvenile Hormones; D009479:Neuropeptides; D014819:Vitellogenins; C079067:orcokinin
keywords: Brain-gut peptides; Fat body; Insect reproduction; Orcokinin; Vitellogenesis