title: Molecular and functional characterization of Anopheles gambiae inward rectifier potassium (Kir1) channels: a novel role in egg production.
abstract: Inward rectifier potassium (Kir) channels play essential roles in regulating diverse physiological processes. Although Kir channels are encoded in mosquito genomes, their functions remain largely unknown. In this study, we identified the members of the Anopheles gambiae Kir gene family and began to investigate their function. Notably, we sequenced the A. gambiae Kir1 (AgKir1) gene and showed that it encodes all the canonical features of a Kir channel: an ion pore that is composed of a pore helix and a selectivity filter, two transmembrane domains that flank the ion pore, and the so-called G-loop. Heterologous expression of AgKir1 in Xenopus oocytes revealed that this gene encodes a functional, barium-sensitive Kir channel. Quantitative RT-PCR experiments then showed that relative AgKir1 mRNA levels are highest in the pupal stage, and that AgKir1 mRNA is enriched in the adult ovaries. Gene silencing of AgKir1 by RNA interference did not affect the survival of female mosquitoes following a blood meal, but decreased their egg output. These data provide evidence for a new role of Kir channels in mosquito fecundity, and further validates them as promising molecular targets for the development of a new class of mosquitocides to be used in vector control.
authors.affiliation: Department of Anesthesiology, Vanderbilt University, Nashville, TN 37232, USA; Department of Pharmacology, Vanderbilt University, Nashville, TN 37232, USA.
authors.forename: Rene
authors.initials: R
authors.lastname: Raphemot
authors.affiliation: Department of Biological Sciences, Vanderbilt University, Nashville, TN 37232, USA.
authors.forename: Tania Y
authors.initials: TY
authors.lastname: Estévez-Lao
authors.affiliation: Department of Entomology, Ohio Agricultural Research and Development Center, The Ohio State University, Wooster, OH 44691, USA.
authors.forename: Matthew F
authors.initials: MF
authors.lastname: Rouhier
authors.affiliation: Department of Entomology, Ohio Agricultural Research and Development Center, The Ohio State University, Wooster, OH 44691, USA.
authors.forename: Peter M
authors.initials: PM
authors.lastname: Piermarini
authors.affiliation: Department of Anesthesiology, Vanderbilt University, Nashville, TN 37232, USA; Department of Pharmacology, Vanderbilt University, Nashville, TN 37232, USA; Institute of Chemical Biology, Vanderbilt University, Nashville, TN 37232, USA; Institute for Global Health, Vanderbilt University, Nashville, TN 37232, USA. Electronic address: jerod.s.denton@vanderbilt.edu.
authors.forename: Jerod S
authors.initials: JS
authors.lastname: Denton
authors.affiliation: Department of Biological Sciences, Vanderbilt University, Nashville, TN 37232, USA; Institute for Global Health, Vanderbilt University, Nashville, TN 37232, USA. Electronic address: julian.hillyer@vanderbilt.edu.
authors.forename: Julián F
authors.initials: JF
authors.lastname: Hillyer
mesh_terms: D000595:Amino Acid Sequence; D000818:Animals; D000852:Anopheles / Q000378:metabolism* / Q000502:physiology*; D001483:Base Sequence; D005260:Female; D008969:Molecular Sequence Data; D009865:Oocytes / Q000378:metabolism / Q000502:physiology; D010053:Ovary / Q000378:metabolism / Q000502:physiology; D010063:Ovum; D024661:Potassium Channels, Inwardly Rectifying; D011679:Pupa / Q000378:metabolism / Q000502:physiology; D034622:RNA Interference; D014982:Xenopus laevis
chemical_list: D024661:Potassium Channels, Inwardly Rectifying
keywords: Anopheles gambiae; Fecundity; Inward rectifier potassium channel; Kir; Mosquito; Ovary; Oviposition