title: Hybrid neurons in a microRNA mutant are putative evolutionary intermediates in insect CO2 sensory systems.
abstract: Carbon dioxide (CO2) elicits different olfactory behaviors across species. In Drosophila, neurons that detect CO2 are located in the antenna, form connections in a ventral glomerulus in the antennal lobe, and mediate avoidance. By contrast, in the mosquito these neurons are in the maxillary palps (MPs), connect to medial sites, and promote attraction. We found in Drosophila that loss of a microRNA, miR-279, leads to formation of CO2 neurons in the MPs. miR-279 acts through down-regulation of the transcription factor Nerfin-1. The ectopic neurons are hybrid cells. They express CO2 receptors and form connections characteristic of CO2 neurons, while exhibiting wiring and receptor characteristics of MP olfactory receptor neurons (ORNs). We propose that this hybrid ORN reveals a cellular intermediate in the evolution of species-specific behaviors elicited by CO2.
authors.affiliation: Department of Biological Chemistry, Howard Hughes Medical Institute, David Geffen School of Medicine, University of California, Los Angeles, CA 90095, USA.
authors.forename: Pelin
authors.initials: P
authors.lastname: Cayirlioglu
authors.forename: Ilona Grunwald
authors.initials: IG
authors.lastname: Kadow
authors.forename: Xiaoli
authors.initials: X
authors.lastname: Zhan
authors.forename: Katsutomo
authors.initials: K
authors.lastname: Okamura
authors.forename: Greg S B
authors.initials: GS
authors.lastname: Suh
authors.forename: Dorian
authors.initials: D
authors.lastname: Gunning
authors.forename: Eric C
authors.initials: EC
authors.lastname: Lai
authors.forename: S Lawrence
authors.initials: SL
authors.lastname: Zipursky
mesh_terms: D020413:3' Untranslated Regions; D000818:Animals; D030801:Animals, Genetically Modified; D002245:Carbon Dioxide / Q000032:analysis* / Q000378:metabolism; D004330:Drosophila / Q000235:genetics / Q000502:physiology*; D029721:Drosophila Proteins / Q000235:genetics* / Q000378:metabolism; D005786:Gene Expression Regulation; D006822:Hybrid Cells / Q000502:physiology; D035683:MicroRNAs / Q000235:genetics / Q000378:metabolism*; D009154:Mutation; D018034:Olfactory Receptor Neurons / Q000166:cytology / Q000502:physiology*; D011956:Receptors, Cell Surface / Q000378:metabolism*; D012679:Sense Organs / Q000502:physiology; D013045:Species Specificity; D014157:Transcription Factors / Q000235:genetics* / Q000378:metabolism
chemical_list: D020413:3' Untranslated Regions; D029721:Drosophila Proteins; D035683:MicroRNAs; D011956:Receptors, Cell Surface; D014157:Transcription Factors; C054079:carbon dioxide receptor; C418490:nerfin-1 protein, Drosophila; D002245:Carbon Dioxide