Odor coding in the maxillary palp of the malaria vector mosquito Anopheles gambiae.
BACKGROUND
Many species of mosquitoes, including the major malaria vector Anopheles gambiae, utilize carbon dioxide (CO(2)) and 1-octen-3-ol as olfactory cues in host-seeking behaviors that underlie their vectorial capacity. However, the molecular and cellular basis of such olfactory responses remains largely unknown.


RESULTS
Here, we use molecular and physiological approaches coupled with systematic functional analyses to define the complete olfactory sensory map of the An. gambiae maxillary palp, an olfactory appendage that mediates the detection of these compounds. In doing so, we identify three olfactory receptor neurons (ORNs) that are organized in stereotyped triads within the maxillary-palp capitate-peg-sensillum population. One ORN is CO(2)-responsive and characterized by the coexpression of three receptors that confer CO(2) responses, whereas the other ORNs express characteristic odorant receptors (AgORs) that are responsible for their in vivo olfactory responses.


CONCLUSIONS
Our results describe a complete and highly concordant map of both the molecular and cellular olfactory components on the maxillary palp of the adult female An. gambiae mosquito. These results also facilitate the understanding of how An. gambiae mosquitoes sense olfactory cues that might be exploited to compromise their ability to transmit malaria.
Lu
Tan
T
Department of Biological Sciences, Center for Molecular Neuroscience, Institute of Chemical Biology and Global Health and Program in Developmental Biology, Vanderbilt University, Nashville, Tennessee 37235, USA.
Qiu
Yu Tong
YT
Wang
Guirong
G
Kwon
Jae Young
JY
Rutzler
Michael
M
Kwon
Hyung-Wook
HW
Pitts
R Jason
RJ
van Loon
Joop J A
JJ
Takken
Willem
W
Carlson
John R
JR
Zwiebel
Laurence J
LJ
D000818:Animals; D000852:Anopheles / Q000187:drug effects / Q000502:physiology* / Q000648:ultrastructure; D002245:Carbon Dioxide / Q000494:pharmacology; D004553:Electric Conductivity; D019476:Insect Proteins / Q000235:genetics / Q000378:metabolism; D007303:Insect Vectors / Q000187:drug effects / Q000502:physiology* / Q000648:ultrastructure; D008288:Malaria / Q000635:transmission; D000442:Octanols / Q000494:pharmacology; D009812:Odorants; D018034:Olfactory Receptor Neurons / Q000187:drug effects / Q000502:physiology*; D012903:Smell / Q000235:genetics / Q000502:physiology*
D019476:Insect Proteins; D000442:Octanols; D002245:Carbon Dioxide; C038844:1-octen-3-ol