title: Anopheles gambiae corazonin: gene structure, expression and effect on mosquito heart physiology.
abstract: Haemolymph flow in mosquitoes is primarily driven by the contraction of a dorsal vessel that is subdivided into an abdominal heart and a thoracic aorta. The factors that regulate mosquito heart contractions are not understood, but in other insects heart physiology is partially controlled by several neurohormones. One of these is corazonin, a neuropeptide initially discovered because of its cardioacceleratory activity in the cockroach Periplaneta americana. In the present study, we describe the corazonin gene and transcript structure in the mosquito Anopheles gambiae, characterize its developmental expression, and test its role in modulating heart physiology. We show that the A. gambiae corazonin gene encodes the most common form of the corazonin peptide ([Arg(7) ]-corazonin) and that it is alternatively spliced, with the only difference between the transcripts occurring in the 5' untranslated region. Analysis of the developmental expression of corazonin and the corazonin receptor revealed that transcription of both follows a bimodal distribution, with highest mRNA levels in 2nd instar larvae and during the pupa to adult transition. Finally, experiments where mosquitoes were injected with various doses of corazonin and experiments where the transcription of corazonin and the corazonin receptor were reduced by RNA interference failed to detect a significant role for this neuropeptide in modulating mosquito heart physiology.
authors.affiliation: Department of Biological Sciences, Vanderbilt University, Nashville, TN, USA. julian.hillyer@vanderbilt.edu
authors.forename: J F
authors.initials: JF
authors.lastname: Hillyer
authors.forename: T Y
authors.initials: TY
authors.lastname: Estévez-Lao
authors.forename: L J
authors.initials: LJ
authors.lastname: Funkhouser
authors.forename: V A
authors.initials: VA
authors.lastname: Aluoch
mesh_terms: D000595:Amino Acid Sequence; D000818:Animals; D000852:Anopheles / Q000187:drug effects / Q000235:genetics* / Q000502:physiology*; D005786:Gene Expression Regulation / Q000187:drug effects; D055785:Gene Knockdown Techniques; D006321:Heart / Q000187:drug effects / Q000502:physiology*; D019476:Insect Proteins / Q000737:chemistry / Q000235:genetics* / Q000378:metabolism / Q000494:pharmacology; D008969:Molecular Sequence Data; D009479:Neuropeptides / Q000737:chemistry / Q000235:genetics* / Q000378:metabolism / Q000494:pharmacology; D034622:RNA Interference / Q000187:drug effects; D012333:RNA, Messenger / Q000235:genetics / Q000378:metabolism; D018013:Receptors, Neuropeptide / Q000235:genetics; D014158:Transcription, Genetic / Q000187:drug effects
chemical_list: D019476:Insect Proteins; D009479:Neuropeptides; D012333:RNA, Messenger; D018013:Receptors, Neuropeptide; C468120:corazonin receptor; C060602:corazonin protein, insect