A spatial map of antennal-expressed ionotropic receptors in the malaria mosquito

Cell Rep. 2023 Feb 28;42(2):112101. doi: 10.1016/j.celrep.2023.112101. Epub 2023 Feb 13.

Abstract

The mosquito's antenna represents its main olfactory appendage for detecting volatile chemical cues from the environment. Whole-mount fluorescence in situ hybridization of ionotropic receptors (IRs) expressed in the antennae reveals that the antenna might be divisible into proximal and distal functional domains. The number of IR-positive cells appear stereotyped within each antennal segment (flagellomere). Highly expressed odor-tuning IRs exhibit distinct co-localization patterns with the IR coreceptors Ir8a, Ir25a, and Ir76b that might predict their functional properties. Genetic knockin and in vivo functional imaging of IR41c-expressing neurons indicate both odor-induced activation and inhibition in response to select amine compounds. Targeted mutagenesis of IR41c does not abolish behavioral responses to the amine compounds. Our study provides a comprehensive map of IR-expressing neurons in the main olfactory appendage of mosquitoes. These findings show organizing principles of Anopheles IR-expressing neurons, which might underlie their functional contribution to the detection of behaviorally relevant odors.

Keywords: CP: Neuroscience; CRISPR/Cas9; HACK; Orco; QF2; calcium imaging; olfaction; olfactory neuron; sensory biology.

Publication types

  • Research Support, U.S. Gov't, Non-P.H.S.
  • Research Support, N.I.H., Extramural
  • Research Support, Non-U.S. Gov't

MeSH terms

  • Animals
  • Anopheles*
  • In Situ Hybridization, Fluorescence
  • Malaria*
  • Odorants
  • Receptors, Odorant* / genetics
  • Smell

Substances

  • Receptors, Odorant