An odorant receptor from the southern house mosquito Culex pipiens quinquefasciatus sensitive to oviposition attractants.
BACKGROUND
Insect odorant receptors (ORs) are heteromers comprised of highly variable odorant-binding subunits associated with one conserved co-receptor. They are potential molecular targets for the development of novel mosquito attractants and repellents. ORs have been identified in the malaria mosquito, Anopheles gambiae, and in the yellow fever mosquito, Aedes aegypti. However, they are still unknown in the Southern house mosquito, Culex quinquefasciatus, which transmits pathogens that cause human diseases throughout the world, including West Nile Virus in the United States.


METHODS
We have employed a combination of bioinformatics, molecular cloning and electrophysiology approaches to identify and characterize the response profile of an OR in Cx. quinquefasciatus. First, we have unveiled a large multigenic family of one-hundred-fifty-eight putative ORs in this species, including a subgroup of conserved ORs in three mosquito species. Using the Xenopus oocytes expression system, we have determined the response profile of CquiOR2, an antennae-specific OR, which shares high identity with putative orthologs in Anopheles gambiae (AgamOR2) and Aedes aegypti (AaegOR2).


CONCLUSIONS
We show that CquiOR2 is highly sensitive to indole, an oviposition attractant for Cx. quinquefasciatus. The response profile of CquiOR2 expressed in Xenopus oocytes resembles that of an olfactory receptor neuron housed in the antennal short blunt-tipped sensilla (A2) of Cx. quinquefasciatus, which are natural detectors for oviposition attractants. This first Culex OR de-orphanized is, therefore, a potential molecular target for screening oviposition attractants.
Pelletier
Julien
J
Department of Entomology, University of California Davis, Davis, California, United States of America.
Hughes
David T
DT
Luetje
Charles W
CW
Leal
Walter S
WS
D000818:Animals; D003001:Cloning, Molecular; D019295:Computational Biology; D003465:Culex / Q000502:physiology*; D004594:Electrophysiology; D007211:Indoles / Q000494:pharmacology; D009865:Oocytes; D010058:Oviposition; D018035:Receptors, Odorant / Q000502:physiology*; D014981:Xenopus
D007211:Indoles; D018035:Receptors, Odorant; C030374:indole
Cell. 1999 Mar 5;96(5):725-36
10089887
J Med Entomol. 1999 Mar;36(2):158-66
10083752
Chem Senses. 2007 Oct;32(8):727-38
17569743
Proc Natl Acad Sci U S A. 2008 Apr 29;105(17):6433-8
18427108
Nature. 2008 Apr 24;452(7190):1007-11
18408711
J Am Mosq Control Assoc. 1992 Mar;8(1):11-7
1583482
Proc Natl Acad Sci U S A. 2010 Mar 2;107(9):4418-23
20160092
J Chem Ecol. 2010 Mar;36(3):245-8
20191395
Proc Natl Acad Sci U S A. 2009 Nov 3;106(44):18803-8
19858490
Nature. 2008 Apr 24;452(7190):1002-6
18408712
Proc Natl Acad Sci U S A. 2006 Oct 31;103(44):16538-43
17060610
Neuron. 1992 Nov;9(5):861-71
1419000
PLoS One. 2009 Jul 16;4(7):e6237
19606229
Chem Senses. 2009 Mar;34(3):231-52
19153252
Nature. 2010 Mar 4;464(7285):66-71
20130575
Can J Zool. 1970 Mar;48(2):293-5
5415448
Proc Natl Acad Sci U S A. 2008 Sep 9;105(36):13598-603
18711137
Nature. 2004 Jan 15;427(6971):212-3
14724626
Neuron. 1999 Feb;22(2):327-38
10069338
Proc Natl Acad Sci U S A. 2001 Dec 4;98(25):14693-7
11724964
J Chem Ecol. 2004 May;30(5):965-76
15274442
Insect Biochem Mol Biol. 2008 Aug;38(8):770-80
18625400
PLoS One. 2008 Aug 22;3(8):e3045
18725946
Nature. 2010 Mar 4;464(7285):37-8
20203594
Insect Mol Biol. 2007 Oct;16(5):525-37
17635615
Neuron. 2004 Sep 2;43(5):703-14
15339651
Science. 2002 Oct 4;298(5591):176-8
12364795
PLoS One. 2009 Sep 15;4(9):e7032
19753115
Int J Biol Sci. 2009 Dec 03;5(7):745-57
20011135
Mol Biol Evol. 2007 Aug;24(8):1596-9
17488738
Nucleic Acids Res. 1997 Sep 1;25(17):3389-402
9254694
Insect Biochem Mol Biol. 2006 Mar;36(3):169-76
16503478