title: Antennal transcriptome profiles of anopheline mosquitoes reveal human host olfactory specialization in Anopheles gambiae.
abstract: BACKGROUND
  Two sibling members of the Anopheles gambiae species complex display notable differences in female blood meal preferences. An. gambiae s.s. has a well-documented preference for feeding upon human hosts, whereas An. quadriannulatus feeds on vertebrate/mammalian hosts, with only opportunistic feeding upon humans. Because mosquito host-seeking behaviors are largely driven by the sensory modality of olfaction, we hypothesized that hallmarks of these divergent host seeking phenotypes will be in evidence within the transcriptome profiles of the antennae, the mosquito's principal chemosensory appendage.
  
  
  RESULTS
  To test this hypothesis, we have sequenced antennal mRNA of non-bloodfed females from each species and observed a number of distinct quantitative and qualitative differences in their chemosensory gene repertoires. In both species, these gene families show higher rates of sequence polymorphisms than the overall rates in their respective transcriptomes, with potentially important divergences between the two species. Moreover, quantitative differences in odorant receptor transcript abundances have been used to model potential distinctions in volatile odor receptivity between the two sibling species of anophelines.
  
  
  CONCLUSIONS
  This analysis suggests that the anthropophagic behavior of An. gambiae s.s. reflects the differential distribution of olfactory receptors in the antenna, likely resulting from a co-option and refinement of molecular components common to both species. This study improves our understanding of the molecular evolution of chemoreceptors in closely related anophelines and suggests possible mechanisms that underlie the behavioral distinctions in host seeking that, in part, account for the differential vectorial capacity of these mosquitoes.
authors.forename: David C
authors.initials: DC
authors.lastname: Rinker
authors.forename: Xiaofan
authors.initials: X
authors.lastname: Zhou
authors.forename: Ronald Jason
authors.initials: RJ
authors.lastname: Pitts
authors.forename: Antonis
authors.initials: A
authors.lastname: Rokas
authors.affiliation: Center for Human Genetics Research, Vanderbilt University Medical Center, Nashville, Tennessee, USA. l.zwiebel@vanderbilt.edu.
authors.forename: Laurence J
authors.initials: LJ
authors.lastname: Zwiebel
mesh_terms: D000818:Animals; D000852:Anopheles / Q000235:genetics*; D057506:Arthropod Antennae / Q000378:metabolism*; D019143:Evolution, Molecular; D005260:Female; D016678:Genome; D006801:Humans; D058977:Molecular Sequence Annotation; D018035:Receptors, Odorant / Q000235:genetics* / Q000378:metabolism; D017423:Sequence Analysis, RNA; D059467:Transcriptome
chemical_list: D018035:Receptors, Odorant