Gene Symbol: Orco
Description: Odorant receptor co-receptor
Alias: 83A.2, 83b, A45, CG10609, DOR45, DOR83b, DmORCO, DmOrco, DmelOrco, Dmel\CG10609, OR49, OR83B, OR83b, ORCO, Or83b, or83b, orco, vainsA, odorant receptor co-receptor, CG10609-PA, CG10609-PB, Or83b, Orco-PA, Orco-PB, odorant receptor 83b, odorant receptor coreceptor, olfactory co-receptor, olfactory coreceptor, olfactory receptor co-receptor
Species: fruit fly
Products:     Orco

Top Publications

  1. Ignell R, Root C, Birse R, Wang J, Nassel D, Winther A. Presynaptic peptidergic modulation of olfactory receptor neurons in Drosophila. Proc Natl Acad Sci U S A. 2009;106:13070-5 pubmed publisher
    ..We detect opposite behavioral phenotypes after reduction and over expression of DTKR in ORNs. Our findings suggest a presynaptic inhibitory feedback to ORNs from peptidergic LNs in the antennal lobe. ..
  2. Trott A, Donelson N, Griffith L, Ejima A. Song choice is modulated by female movement in Drosophila males. PLoS ONE. 2012;7:e46025 pubmed publisher
  3. Krstic D, Boll W, Noll M. Sensory integration regulating male courtship behavior in Drosophila. PLoS ONE. 2009;4:e4457 pubmed publisher
    ..The model will complement studies on the connectivity and intrinsic properties of the neurons forming the circuitry that regulates male courtship behavior. ..
  4. Ditzen M, Pellegrino M, Vosshall L. Insect odorant receptors are molecular targets of the insect repellent DEET. Science. 2008;319:1838-42 pubmed publisher
    ..attraction to food odors in Drosophila, and this inhibition requires the highly conserved olfactory co-receptor OR83b. DEET inhibits odor-evoked currents mediated by the insect odorant receptor complex, comprising a ligand-binding ..
  5. Sargsyan V, Getahun M, Llanos S, Olsson S, Hansson B, Wicher D. Phosphorylation via PKC Regulates the Function of the Drosophila Odorant Co-Receptor. Front Cell Neurosci. 2011;5:5 pubmed publisher
    ..receptors (ORs) have a unique design of heterodimers formed by an olfactory receptor protein and the ion channel Orco. Heterologously expressed insect ORs are activated via an ionotropic and a metabotropic pathway that leads to cAMP ..
  6. Ai M, Blais S, Park J, Min S, Neubert T, Suh G. Ionotropic glutamate receptors IR64a and IR8a form a functional odorant receptor complex in vivo in Drosophila. J Neurosci. 2013;33:10741-9 pubmed publisher
    ..These findings provide direct evidence that IR8a is a subunit that forms a functional olfactory receptor with IR64a in vivo to mediate odor detection. ..
  7. Nichols A, Luetje C. Transmembrane segment 3 of Drosophila melanogaster odorant receptor subunit 85b contributes to ligand-receptor interactions. J Biol Chem. 2010;285:11854-62 pubmed publisher
    The OR class insect odorant receptors are ligand-gated ion channels comprised of at least one common subunit (OR83b in Drosophila) and at least one putative odorant-binding subunit...
  8. Louis M, Huber T, Benton R, Sakmar T, Vosshall L. Bilateral olfactory sensory input enhances chemotaxis behavior. Nat Neurosci. 2008;11:187-99 pubmed
    ..We found additional evidence that the overall accuracy of navigation is enhanced by the increase in the signal-to-noise ratio conferred by bilateral sensory input. ..
  9. Nakagawa T, Pellegrino M, Sato K, Vosshall L, Touhara K. Amino acid residues contributing to function of the heteromeric insect olfactory receptor complex. PLoS ONE. 2012;7:e32372 pubmed publisher
    ..The functional insect Or comprises an odor- or pheromone-specific Or subunit and the Orco co-receptor, which is highly conserved in all insect species...

More Information


  1. Masuda Nakagawa L, Gendre N, O Kane C, Stocker R. Localized olfactory representation in mushroom bodies of Drosophila larvae. Proc Natl Acad Sci U S A. 2009;106:10314-9 pubmed publisher
    ..Stereotypic representation of single OSN input in calyx glomeruli provides a mechanism for MB neurons to detect and discriminate olfactory cues. ..
  2. Benton R, Vannice K, Vosshall L. An essential role for a CD36-related receptor in pheromone detection in Drosophila. Nature. 2007;450:289-93 pubmed
  3. Ng M, Roorda R, Lima S, Zemelman B, Morcillo P, Miesenbock G. Transmission of olfactory information between three populations of neurons in the antennal lobe of the fly. Neuron. 2002;36:463-74 pubmed
    ..These circuits may serve as dynamic templates that extract higher order features from afferent activity patterns. ..
  4. Lai S, Lee T. Genetic mosaic with dual binary transcriptional systems in Drosophila. Nat Neurosci. 2006;9:703-9 pubmed
    ..In addition, dual-expression-control MARCM with a ubiquitous LexA::GAD driver revealed many unidentified cells in the GAL4-GH146-positive projection neuron lineages. ..
  5. Bhandawat V, Maimon G, Dickinson M, Wilson R. Olfactory modulation of flight in Drosophila is sensitive, selective and rapid. J Exp Biol. 2010;213:3625-35 pubmed publisher
    ..This makes these behaviors a useful paradigm for studying the relationship between sensory neuron activity and behavioral decision-making in a simple and genetically tractable organism...
  6. Olsen S, Bhandawat V, Wilson R. Excitatory interactions between olfactory processing channels in the Drosophila antennal lobe. Neuron. 2007;54:89-103 pubmed
    ..Thus, a dense network of lateral connections distributes odor-evoked excitation between channels in the first brain region of the olfactory processing stream. ..
  7. Hoare D, McCrohan C, Cobb M. Precise and fuzzy coding by olfactory sensory neurons. J Neurosci. 2008;28:9710-22 pubmed publisher
    ..We hypothesize that fuzzy coding occurs in other organisms, is translated into differing degrees of activation of the glomeruli, and forms a key component of response variability in the first stages of olfactory processing. ..
  8. Lone S, Sharma V. Or47b receptor neurons mediate sociosexual interactions in the fruit fly Drosophila melanogaster. J Biol Rhythms. 2012;27:107-16 pubmed publisher
    ..Further, the neuropeptide pigment dispersing factor (PDF) and PDF-positive ventral lateral (LN(v)) clock neurons appear to be dispensable for the regulation of SSI; however, dorsal neurons may be involved. ..
  9. Gaudry Q, Hong E, Kain J, de Bivort B, Wilson R. Asymmetric neurotransmitter release enables rapid odour lateralization in Drosophila. Nature. 2013;493:424-8 pubmed publisher
    ..Our data also show that small differences in spike timing and spike rate can produce reliable differences in olfactory behaviour. ..
  10. Kalidas S, Smith D. Novel genomic cDNA hybrids produce effective RNA interference in adult Drosophila. Neuron. 2002;33:177-84 pubmed
    ..elegans. These results demonstrate a simple strategy to knock out gene function in specific cells in living adult Drosophila that can be applied to define the biological function of hundreds of orphan genes and open reading frames...
  11. Fujii S, Krishnan P, Hardin P, Amrein H. Nocturnal male sex drive in Drosophila. Curr Biol. 2007;17:244-51 pubmed
  12. Libert S, Zwiener J, Chu X, Vanvoorhies W, Roman G, Pletcher S. Regulation of Drosophila life span by olfaction and food-derived odors. Science. 2007;315:1133-7 pubmed
    ..Furthermore, mutation of odorant receptor Or83b resulted in severe olfactory defects, altered adult metabolism, enhanced stress resistance, and extended life span...
  13. Sachse S, Rueckert E, Keller A, Okada R, Tanaka N, Ito K, et al. Activity-dependent plasticity in an olfactory circuit. Neuron. 2007;56:838-50 pubmed
    ..Behavioral responses to CO2 were also reduced after such exposure. We suggest that activity-dependent functional plasticity may be a general feature of the Drosophila olfactory system. ..
  14. Root C, Ko K, Jafari A, Wang J. Presynaptic facilitation by neuropeptide signaling mediates odor-driven food search. Cell. 2011;145:133-44 pubmed publisher
    ..Thus, starvation increases expression of sNPFR1 to change the odor map, resulting in more robust food-search behavior. ..
  15. Elmore T, Ignell R, Carlson J, Smith D. Targeted mutation of a Drosophila odor receptor defines receptor requirement in a novel class of sensillum. J Neurosci. 2003;23:9906-12 pubmed
    ..Therefore, Or43b is required for odor responsiveness in these olfactory neurons in vivo. Or83b, a receptor expressed in a large fraction of olfactory neurons including Or43b neurons, does not confer odor ..
  16. Mathew D, Martelli C, Kelley Swift E, Brusalis C, Gershow M, Samuel A, et al. Functional diversity among sensory receptors in a Drosophila olfactory circuit. Proc Natl Acad Sci U S A. 2013;110:E2134-43 pubmed publisher
    ..Some odorants elicited strong physiological responses but weak behavioral responses or weak physiological responses but strong behavioral responses. ..
  17. Sato K, Pellegrino M, Nakagawa T, Nakagawa T, Vosshall L, Touhara K. Insect olfactory receptors are heteromeric ligand-gated ion channels. Nature. 2008;452:1002-6 pubmed publisher
    ..members of the olfactory receptor (OR) gene family, along with the highly conserved and broadly expressed Or83b co-receptor...
  18. Kain P, Chakraborty T, Sundaram S, Siddiqi O, Rodrigues V, Hasan G. Reduced odor responses from antennal neurons of G(q)alpha, phospholipase Cbeta, and rdgA mutants in Drosophila support a role for a phospholipid intermediate in insect olfactory transduction. J Neurosci. 2008;28:4745-55 pubmed publisher
    ..Our results suggest that G(q)alpha-mediated olfactory transduction in Drosophila requires a phospholipid second messenger the levels of which are regulated by a cycle of phosphatidylinositol 1,4-bisphosphate breakdown and regeneration. ..
  19. Silbering A, Rytz R, Grosjean Y, Abuin L, Ramdya P, Jefferis G, et al. Complementary function and integrated wiring of the evolutionarily distinct Drosophila olfactory subsystems. J Neurosci. 2011;31:13357-75 pubmed publisher
    ..We integrate knowledge on the different phylogenetic and developmental properties of these receptors and circuits to propose models for the functional contributions and evolution of these distinct olfactory subsystems...
  20. Poon P, Kuo T, Linford N, Roman G, Pletcher S. Carbon dioxide sensing modulates lifespan and physiology in Drosophila. PLoS Biol. 2010;8:e1000356 pubmed publisher
    ..Because Gr63a is expressed in a well-defined population of neurons, future work may now be directed at dissecting more complex neurosensory and neuroendocrine circuits that modulate aging in Drosophila. ..
  21. MONTAGUE S, Mathew D, Carlson J. Similar odorants elicit different behavioral and physiological responses, some supersustained. J Neurosci. 2011;31:7891-9 pubmed publisher
    ..Odors that elicit such responses could provide a novel means of controlling insect pests and vectors of human disease by impairing the location of human hosts, food sources, and mates. ..
  22. German P, van der Poel S, Carraher C, Kralicek A, Newcomb R. Insights into subunit interactions within the insect olfactory receptor complex using FRET. Insect Biochem Mol Biol. 2013;43:138-45 pubmed publisher
    ..These receptors form a complex that is currently thought to contain at least two subunit members: the non-canonical Orco ion channel subunit and a ligand-binding receptor subunit...
  23. Chiang A, Priya R, Ramaswami M, Vijayraghavan K, Rodrigues V. Neuronal activity and Wnt signaling act through Gsk3-beta to regulate axonal integrity in mature Drosophila olfactory sensory neurons. Development. 2009;136:1273-82 pubmed publisher
    ..Together, we provide evidence that Gsk-3beta is a key sensor involved in neural circuit integrity, maintaining axon stability through neural activity and the Wnt pathway. ..
  24. Getahun M, Olsson S, Lavista Llanos S, Hansson B, Wicher D. Insect odorant response sensitivity is tuned by metabotropically autoregulated olfactory receptors. PLoS ONE. 2013;8:e58889 pubmed publisher
    ..but ORs possess a unique configuration composed of an odorant-specific protein OrX and a ubiquitous coreceptor (Orco)...
  25. Lundin C, KALL L, Kreher S, Kapp K, Sonnhammer E, Carlson J, et al. Membrane topology of the Drosophila OR83b odorant receptor. FEBS Lett. 2007;581:5601-4 pubmed
    ..Here, we report a detailed topology mapping of the Drosophila OR83b receptor using engineered glycosylation sites as topology markers...
  26. Neuhaus E, Gisselmann G, Zhang W, Dooley R, Störtkuhl K, Hatt H. Odorant receptor heterodimerization in the olfactory system of Drosophila melanogaster. Nat Neurosci. 2005;8:15-7 pubmed
    ..b>DOR83b, an odorant receptor that is ubiquitously expressed in olfactory neurons from Drosophila melanogaster and highly ..
  27. Wicher D, Schäfer R, Bauernfeind R, Stensmyr M, Heller R, Heinemann S, et al. Drosophila odorant receptors are both ligand-gated and cyclic-nucleotide-activated cation channels. Nature. 2008;452:1007-11 pubmed publisher
    ..odorant receptors (for example, Or22a), dimerized with a ubiquitously expressed chaperone protein, such as Or83b in Drosophila. Or83b has a structure akin to GPCRs, but has an inverted orientation in the plasma membrane...
  28. Shang Y, Claridge Chang A, Sjulson L, Pypaert M, Miesenbock G. Excitatory local circuits and their implications for olfactory processing in the fly antennal lobe. Cell. 2007;128:601-12 pubmed
    ..Lateral excitation may boost PN signals and enhance their transmission to third-order neurons in a mechanism akin to stochastic resonance. ..
  29. Jin X, Ha T, Smith D. SNMP is a signaling component required for pheromone sensitivity in Drosophila. Proc Natl Acad Sci U S A. 2008;105:10996-1001 pubmed publisher
    ..Therefore, pheromone perception in Drosophila should serve as an excellent model to elucidate the role of CD36 members in transmembrane signaling. ..
  30. Vosshall L, Hansson B. A unified nomenclature system for the insect olfactory coreceptor. Chem Senses. 2011;36:497-8 pubmed publisher
  31. Steck K, Veit D, Grandy R, Badia S, Badia S, Mathews Z, et al. A high-throughput behavioral paradigm for Drosophila olfaction - The Flywalk. Sci Rep. 2012;2:361 pubmed publisher
    ..Consequently, Flywalk allows automatic screening of individual flies for their olfactory preference and sensitivity. ..
  32. Nichols A, Chen S, Luetje C. Subunit contributions to insect olfactory receptor function: channel block and odorant recognition. Chem Senses. 2011;36:781-90 pubmed publisher
    Insect olfactory receptors are heteromeric ligand-gated ion channels composed of at least one common subunit (Orco) and at least one subunit that confers odorant specificity...
  33. Getahun M, Wicher D, Hansson B, Olsson S. Temporal response dynamics of Drosophila olfactory sensory neurons depends on receptor type and response polarity. Front Cell Neurosci. 2012;6:54 pubmed publisher
    ..This diversity increases the capacity of the insect olfactory system to respond to the diverse spatiotemporal signals in the natural environment. ..
  34. Yao C, Carlson J. Role of G-proteins in odor-sensing and CO2-sensing neurons in Drosophila. J Neurosci. 2010;30:4562-72 pubmed publisher
    ..Ggamma30A is also required for normal CO2 response. The simplest interpretation of these results is that Galpha(q) and Ggamma30A play a role in the response of CO2-sensing neurons, but are not required for Or-mediated odor signaling. ..
  35. Wang J, Wong A, Flores J, Vosshall L, Axel R. Two-photon calcium imaging reveals an odor-evoked map of activity in the fly brain. Cell. 2003;112:271-82 pubmed
    ..The development of this imaging system affords an opportunity to monitor activity in defined neurons throughout the fly brain with high sensitivity and excellent spatial resolution. ..
  36. Schneider J, Dickinson M, Levine J. Social structures depend on innate determinants and chemosensory processing in Drosophila. Proc Natl Acad Sci U S A. 2012;109 Suppl 2:17174-9 pubmed publisher
    ..We have established a paradigm for studying social behaviors at a group level in Drosophila and expect that a genetic dissection of this phenomenon will identify conserved molecular mechanisms of social organization in other species. ..
  37. Jones W, Cayirlioglu P, Kadow I, Vosshall L. Two chemosensory receptors together mediate carbon dioxide detection in Drosophila. Nature. 2007;445:86-90 pubmed
    ..This in turn could bolster the worldwide fight against malaria and other insect-borne diseases. ..
  38. Benton R, Sachse S, Michnick S, Vosshall L. Atypical membrane topology and heteromeric function of Drosophila odorant receptors in vivo. PLoS Biol. 2006;4:e20 pubmed
    ..odorant receptors (ORs): a divergent member of the OR family and the highly conserved, broadly expressed receptor OR83b. OR83b is essential for olfaction in vivo and enhances OR function in vitro, but the molecular mechanism by which ..
  39. Gomez Marin A, Stephens G, Louis M. Active sampling and decision making in Drosophila chemotaxis. Nat Commun. 2011;2:441 pubmed publisher
    ..Our findings suggest that larval chemotaxis represents an intermediate navigation strategy between the biased random walks of Escherichia Coli and the stereo-olfaction observed in rats and humans. ..
  40. Vosshall L, Amrein H, Morozov P, Rzhetsky A, Axel R. A spatial map of olfactory receptor expression in the Drosophila antenna. Cell. 1999;96:725-36 pubmed
    ..The isolation of candidate odorant receptor genes along with a genetic analysis of olfactory-driven behavior in insects may ultimately afford a system to understand the mechanistic link between odor recognition and behavior. ..
  41. Tanoue S, Krishnan P, Krishnan B, Dryer S, Hardin P. Circadian clocks in antennal neurons are necessary and sufficient for olfaction rhythms in Drosophila. Curr Biol. 2004;14:638-49 pubmed
  42. Lee Y, Kim S, Montell C. Avoiding DEET through insect gustatory receptors. Neuron. 2010;67:555-61 pubmed publisher
    ..olfactory receptor neurons (ORNs), DEET is detected through a mechanism employing the olfactory receptor, OR83b. However, it is controversial as to whether ORNs respond directly to DEET or whether DEET blocks the response to ..
  43. Wang L, Anderson D. Identification of an aggression-promoting pheromone and its receptor neurons in Drosophila. Nature. 2010;463:227-31 pubmed publisher
    ..Identification of a pheromone-OSN pair controlling aggression in a genetic organism opens the way to unravelling the neurobiology of this evolutionarily conserved behaviour. ..
  44. Kwon Y, Kim S, Ronderos D, Lee Y, Akitake B, Woodward O, et al. Drosophila TRPA1 channel is required to avoid the naturally occurring insect repellent citronellal. Curr Biol. 2010;20:1672-8 pubmed publisher
    ..Here, we show that Drosophila use two pathways for direct avoidance of citronellal. The olfactory coreceptor OR83b contributes to citronellal repulsion and is essential for citronellal-evoked action potentials...
  45. Kwon J, Dahanukar A, Weiss L, Carlson J. The molecular basis of CO2 reception in Drosophila. Proc Natl Acad Sci U S A. 2007;104:3574-8 pubmed
    ..The identification of these receptors may now allow the identification of agents that block or activate them. Such agents could affect the responses of insect pests to the humans they seek. ..
  46. Smart R, Kiely A, Beale M, Vargas E, Carraher C, Kralicek A, et al. Drosophila odorant receptors are novel seven transmembrane domain proteins that can signal independently of heterotrimeric G proteins. Insect Biochem Mol Biol. 2008;38:770-80 pubmed publisher
    ..Whole cell patching of Or43b/Or83b-transfected HEK293 cells revealed the opening of plasma membrane cation channels on addition of ligand...
  47. Asahina K, Louis M, Piccinotti S, Vosshall L. A circuit supporting concentration-invariant odor perception in Drosophila. J Biol. 2009;8:9 pubmed publisher
    ..We investigated how subsets of larval OSNs with overlapping but distinct response properties cooperate to mediate perception of a given odorant across a range of concentrations...
  48. Larsson M, Domingos A, Jones W, Chiappe M, Amrein H, Vosshall L. Or83b encodes a broadly expressed odorant receptor essential for Drosophila olfaction. Neuron. 2004;43:703-14 pubmed
    ..Most Drosophila olfactory neurons express two types of odorant receptor genes: Or83b, a broadly expressed receptor of unknown function, and one or more members of a family of 61 selectively expressed ..
  49. Grillenzoni N, de Vaux V, Meuwly J, Vuichard S, Jarman A, Holohan E, et al. Role of proneural genes in the formation of the larval olfactory organ of Drosophila. Dev Genes Evol. 2007;217:209-19 pubmed
  50. Asahina K, Pavlenkovich V, Vosshall L. The survival advantage of olfaction in a competitive environment. Curr Biol. 2008;18:1153-5 pubmed publisher
    ..We investigated the extent to which the olfactory system confers a survival advantage on Drosophila larvae foraging for food under conditions of limited resources and competition from other larvae. ..
  51. Kazama H, Yaksi E, Wilson R. Cell death triggers olfactory circuit plasticity via glial signaling in Drosophila. J Neurosci. 2011;31:7619-30 pubmed publisher
    ..By strengthening excitatory interactions between neurons in a deafferented brain region, this mechanism might help boost activity to compensate for lost sensory input. ..
  52. Dobritsa A, Van der Goes van Naters W, Warr C, Steinbrecht R, Carlson J. Integrating the molecular and cellular basis of odor coding in the Drosophila antenna. Neuron. 2003;37:827-41 pubmed
    ..Ectopic expression in a wild-type cell shows that two receptors can function in a single cell. The ab3A neuron does not depend on normal odor receptor gene expression to navigate to its target in the CNS. ..
  53. Olsen S, Wilson R. Lateral presynaptic inhibition mediates gain control in an olfactory circuit. Nature. 2008;452:956-60 pubmed publisher
    ..A substantial portion of this interglomerular inhibition acts at a presynaptic locus, and our results imply that this is mediated by both ionotropic and metabotropic receptors on the same nerve terminal. ..
  54. Bretman A, Westmancoat J, Gage M, Chapman T. Males use multiple, redundant cues to detect mating rivals. Curr Biol. 2011;21:617-22 pubmed publisher
    ..We reveal the robust mechanisms by which males assess their socio-sexual environment to precisely attune responses via the expression of plastic behavior. ..
  55. Deng Y, Zhang W, Farhat K, Oberland S, Gisselmann G, Neuhaus E. The stimulatory G?(s) protein is involved in olfactory signal transduction in Drosophila. PLoS ONE. 2011;6:e18605 pubmed publisher
    ..We found that G?(s) plays a crucial role for odorant induced signal transduction in OR83b expressing olfactory sensory neurons, but not in neurons expressing CO? responsive proteins GR21a/GR63a...
  56. Lone S, Sharma V. Social synchronization of circadian locomotor activity rhythm in the fruit fly Drosophila melanogaster. J Exp Biol. 2011;214:3742-50 pubmed publisher
    ..mediated as group-wise interactions among phase-desynchronized flies possessing compromised olfactory ability (Or83b(0)) did not improve phase synchrony...
  57. Krishnan P, Chatterjee A, Tanoue S, Hardin P. Spike amplitude of single-unit responses in antennal sensillae is controlled by the Drosophila circadian clock. Curr Biol. 2008;18:803-7 pubmed publisher
    ..These results argue that rhythms in GPRK2 levels control OR localization and OR-dependent ion channel activity and/or composition to mediate rhythms in spontaneous spike amplitude. ..
  58. Pellegrino M, Steinbach N, Stensmyr M, Hansson B, Vosshall L. A natural polymorphism alters odour and DEET sensitivity in an insect odorant receptor. Nature. 2011;478:511-4 pubmed publisher
    ..The functional insect odorant receptor complex consists of a common co-receptor, ORCO (ref. 15) (formerly called OR83B; ref. 16), and one or more variable odorant receptor subunits that confer odour selectivity...
  59. Suh G, Wong A, Hergarden A, Wang J, Simon A, Benzer S, et al. A single population of olfactory sensory neurons mediates an innate avoidance behaviour in Drosophila. Nature. 2004;431:854-9 pubmed
    ..These data demonstrate that the activation of a single population of sensory neurons innervating one glomerulus is responsible for an innate avoidance behaviour in Drosophila. ..