FlyBase Allele Report: Dmel\Orco[2]

General Information

Symbol

Dmel\Orco²

Species

D. melanogaster

Name

FlyBase ID

FBal0190982

Feature type

allele

Associated gene

Dmel\Orco

Associated Insertion(s)

TI{TI}Orco²

Carried in Construct

Also Known As

or83b²

Key Links

Allele class

loss of function allele

Mutagen

Nature of the Allele

Allele class

loss of function allele

(Larsson et al., 2004)

Mutagen

recombination

(Larsson et al., 2004)

FLPase

(Larsson et al., 2004)

I-SceI

(Larsson et al., 2004)

gene targeting by homologous recombination

(Larsson et al., 2004)

Progenitor genotype

Associated Insertion(s)

TI{TI}Orco²

Cytology

Description

Genomic sequence encoding the putative transcription start site and the first five transmembrane domains of Orco has been deleted and replaced by a w^+* marker.

(Larsson et al., 2004)

Mutations Mapped to the Genome

Curation Data

Type

Location

Additional Notes

References

Variant Molecular Consequences

Associated Sequence Data

DDBJ / EMBL / GenBank

DNA sequence

Protein sequence

UniProtKB/Swiss-Prot

UniProtKB/TrEMBL

Expression Data

Reporter Expression

Additional Information

Statement

Reference

Marker for

Reflects expression of

Reporter construct used in assay

Human Disease Associations

Disease Ontology (DO) Annotations

Models Based on Experimental Evidence ( 0 )

Disease

Evidence

References

Modifiers Based on Experimental Evidence ( 0 )

Disease

Interaction

References

Comments on Models/Modifiers Based on Experimental Evidence ( 0 )

Disease-implicated variant(s)

Phenotypic Data

Phenotypic Class

abnormal cell number | adult stage | progressive

(Long et al., 2024)

abnormal chemosensory behavior (with Orco¹)

(Gomez-Marin and Louis, 2014)

abnormal chemosensory behavior (with Orco¹), with Orco^UAS.GFP, Scer\GAL4^Or42b.PF

(Gomez-Marin and Louis, 2014)

abnormal chemosensory behavior | adult stage

(Wang et al., 2021)

abnormal chemosensory behavior | adult stage (with Df(3R)ED5156)

(Kwon et al., 2010)

abnormal chemosensory behavior | adult stage (with Orco¹)

(Schneider et al., 2012)

abnormal chemosensory behavior | larval stage

(Tastekin et al., 2015)

abnormal locomotor behavior

(Liu et al., 2007)

abnormal locomotor behavior | larval stage

(Tastekin et al., 2015)

abnormal neuroanatomy | adult stage | progressive

(Long et al., 2024)

abnormal neurophysiology

(Ronderos et al., 2014)

abnormal neurophysiology (with Orco¹)

(Benton et al., 2007)

abnormal neurophysiology | adult stage

(Wang et al., 2021)

abnormal neurophysiology | adult stage, with Orco^S289A.UAS, Scer\GAL4^{Orco.2.642.Hsim\VP22}

(Poudel et al., 2021)

abnormal smell perception

(Ronderos et al., 2014, Larsson et al., 2004)

abnormal smell perception (with Orco¹)

(Louis et al., 2008)

abnormal smell perception (with Orco¹), with Orco^UAS.cLa, Scer\GAL4^Or42a.PF

(Louis et al., 2008)

abnormal smell perception (with Orco¹), with Orco^UAS.GFP, Scer\GAL4^Or42a.PF

(Gomez-Marin et al., 2011)

abnormal smell perception | adult stage

(Fişek and Wilson, 2014)

abnormal smell perception | dominant | female

(Libert et al., 2007)

long lived | female

(Libert et al., 2007)

long lived | male

(Libert et al., 2007)

Phenotype Manifest In

Detailed Description

Statement

Reference

Orco²/Orco² mutants do not exhibit a significant change in the propensity of flies to prefer 1% yeast extract to a 5mM sucrose solution, as compared to wild type.

(Ganguly et al., 2017)

Orco²/Orco² larvae have a significant reduction in the time they spend in the vicinity of an appetitive odor, compared to controls.

(Tastekin et al., 2015)

Lateral horn neurons that normally express Scer\GAL4^NP6099 show disinhibited odor responses in Orco² mutant flies.

(Fişek and Wilson, 2014)

Orco¹/Orco² mutants are anosmic and do not display 'weathervaning' (modulation of direction in response to chemotaxis).

Expression of Orco^{Scer\UAS.T:Avic\GFP} in one olfactory sensory neuron, under the control of Scer\GAL4^Or42b.PF and in an Orco¹/Orco², reduces the strength of 'weathervaning' in chemotaxis, compared to wild-type larvae with bilateral function. These larvae exhibit the reorientation bais observed in wild-type.

(Gomez-Marin and Louis, 2014)

In contrast to wild-type, antennal intermediate 2 (ai2) neurons from Orco² mutants are insensitive to farnesol.

Electroantennographs (EAGs) recordings from wild-type show significant response to farnesol that is completely abolished in Orco² mutants.

(Ronderos et al., 2014)

As in wild type, Orco¹/Orco² mutant males exhibit inhibition of the female contact-induced male-male aggression seen in wild type males that have previously been exposed to females.

(Yuan et al., 2014)

In contrast to wild type, Orco¹/Orco² flies do not show a preference for ethanol-containing food odors (over food odors without ethanol) in an olfactory choice assay.

(Schneider et al., 2012)

The social space index of mutant flies is not significantly different from wild-type controls.

(Simon et al., 2012)

Larvae with olfactory input restricted to a single unilateral Or42a-expressing olfactory receptor neuron (expressing Orco^{Scer\UAS.T:Avic\GFP} under the control of Scer\GAL4^Or42a.PF in a single olfactory receptor neuron in a Orco¹/Orco² background) navigate poorly and show tortuous paths in an assay to study the response to a stable gradient of the odour ethyl butyrate, failing to robustly orient towards the gradient.

(Gomez-Marin et al., 2011)

Orco²/Df(3R)ED5156 flies show a defect in citronellal avoidance in a direct airborne repellent test (DART) assay.

(Kwon et al., 2010)

As in wild type, Orco² mutants exhibit a reduction in lifespan in response to live yeast.

(Poon et al., 2010)

In the dark in the presence of a virgin female, Or83b² males scan for the female by spreading their wings and scanning in a zigzag course, as do wild-type males in this courtship assay. The courtship performance of the mutant males in the dark is normal.

Or83b² males court with the same intensity as wild-type males in daylight.

Or83b² males are clearly able to distinguish between decapitated males and females in daylight in a courtship assay.

(Krstic et al., 2009)

Orco¹/Orco² mutant larvae direct turns towards and away from the peak of the gradient with equal probability in an assay to study the response to an exponential gradient of the odorant isoamyl acetate, in contrast to wild-type larvae, which direct more than 63% of turns towards the gradient.

Larvae with olfactory input restricted to the Or42a-expressing olfactory sensory neurons (expressing Orco^Scer\UAS.cLa under the control of Scer\GAL4^Or42a.PF in a Orco¹/Orco² background) are more sensitive to isoamyl acetate than wild-type animals in an assay to study the response to a radially symmetrical odour gradient, showing significant responses to the odour at source concentrations as low as 0.12M. Mutant and wild-type larvae navigate efficiently along the odorant line (from low to high odorant concentration) in an assay to study the response to an exponential odorant gradient, in response to either isoamyl acetate, isopropyl acetate, 2-hexenal or anisole.

(Louis et al., 2008)

Or83b¹/Or83b² Or67d-expressing olfactory sensory neurons show severely decreased spontaneous activity compared to control neurons.

(Benton et al., 2007)

Fully fed homozygous females show an increase in median life span compared to wild-type controls. Homozygous males also show an increase in life span compared to controls, although the magnitude of life extension is generally smaller than that seen in the homozygous female flies. Heterozygous flies show intermediate longevity compared to homozygous and wild-type controls.

Heterozygous females but not heterozygous males show a deficiency in attraction to live yeast paste.

Lifespan is further increased by dietary restriction in Or83b² flies.

Or83b² females show significantly lower egg production compared to controls from 24 to 48 hours after eclosion and higher levels of egg production compared to controls at 8 days and at 12 days after eclosion.

Or83b² females are more resistant to hyperoxia than control flies.

Homozygous flies are starvation resistant compared to controls.

The average weight of homozygous males and females is similar to that of control flies and metabolic rate (as measured by CO₂ production) is not decreased.

(Libert et al., 2007)

Homozygous flies show a normal level of activity during the first minute in an open field arena, but by the fifth minute, their activity is higher than that in wild-type flies.

(Liu et al., 2007)

Olfactory sensory neuron morphology and membrane organization appear normal in Or83b¹/Or83b² mutants.

(Benton et al., 2006)

Electroantennograms recorded in Or83b² mutant antennae show no response to a range of odours that induce strong negative responses in controls. The odour-responsive neurons of the ab1 sensillum are all affected in Or83b² mutants, as can be seen from electroantennograms in response to specific odours that evoke action potentials in these neurons in controls; Or83b² ab1A fails to show odour-evoked action potentials to ethyl acetate, Or83b² ab1B fails to respond to acetoin and ab1D fails to respond to methyl salicylate. However, Or83b² ab1C responses to carbon dioxide are completely normal. Or83b² adults show severely impaired responses to acetoin and are anosmic to 2-phenylethanol.

(Larsson et al., 2004)

External Data

Linkouts

Interactions

Show genetic interaction network for Enhancers & Suppressors

Phenotypic Class

Suppressed by

Statement

Reference

Orco² has abnormal smell perception phenotype, suppressible by Scer\GAL4^{Orco.2.642.Hsim\VP22}/Or83c^UAS.cRa

(Ronderos et al., 2014)

Orco² has abnormal neurophysiology phenotype, suppressible by Scer\GAL4^{Orco.2.642.Hsim\VP22}/Or83c^UAS.cRa

(Ronderos et al., 2014)

Other

Statement

Reference

Orco², Poxn^ΔM22-B5, Poxn^ΔPBs, Poxn^ΔXBs has abnormal courtship behavior | male phenotype

(Krstic et al., 2009)

Phenotype Manifest In

Suppressed by

Statement

Reference

Orco² has antennal intermediate sensillum ai2 phenotype, suppressible by Scer\GAL4^{Orco.2.642.Hsim\VP22}/Or83c^UAS.cRa

(Ronderos et al., 2014)

Additional Comments

Genetic Interactions

Statement

Reference

Driving Or83c^Scer\UAS.cRa with Scer\GAL4^{Orco.2.642.T:Hsim\VP22} restores farnesol sensitivity to ai2b neurons in Orco² mutants.

(Ronderos et al., 2014)

Poxn^ΔXBs; Poxn^ΔM22-B5/Poxn^ΔM22-B5 Poxn^ΔPBs; Or83b² males show virtually no courtship activities in the dark. Only 10% of these males initiate courtship with a long latency, and their courtship is limited to a few seconds of wing extension.

In daylight, Poxn^ΔXBs; Poxn^ΔM22-B5/Poxn^ΔM22-B5 Poxn^ΔPBs; Or83b² males initiate courtship fairly reliably and rather quickly compared to control males. However, they show a strongly reduced courtship vigor index compared to controls.

A significantly reduced fraction of Or83b² males initiate courtship towards decapitated females in the dark as compared to wild-type males. The latency of these Or83b² males till courtship initiation towards decapitated females is prolonged compared to that of wild-type males, but is still significantly shorter than that towards decapitated males. The Or83b² males court decapitated females and males vigorously, but are able to discriminate between the two sexes as effectively as wild-type control flies.

The fraction of Poxn^ΔXBs; Poxn^ΔM22-B5/Poxn^ΔM22-B5 Poxn^ΔPBs; Or83b² males initiating courtship of decapitated animals in the dark is marginal, but those males that do initiate courtship court decapitated flies vigorously.

(Krstic et al., 2009)

Snmp¹ Or83b²/Snmp² Or83b¹ double mutant Or67d-expressing olfactory sensory neurons show show severely decreased spontaneous activity compared to control neurons, as is seen in Or83b¹/Or83b² single mutant neurons.

(Benton et al., 2007)

Xenogenetic Interactions

Statement

Reference

Complementation and Rescue Data

Rescued by

Orco² is rescued by Scer\GAL4^{Orco.2.642.Hsim\VP22}/Orco^UAS.EGFP

(Libert et al., 2007)

Orco² is rescued by Scer\GAL4^{Orco.2.642.Hsim\VP22}/Orco^UAS.cLa

(Larsson et al., 2004)

Comments

Orco¹/Orco² larvae expressing Orco^{Scer\UAS.T:Avic\GFP} under the control of Scer\GAL4^Or42a.PF unilaterally in single olfactory sensory neuron on one side of the head are able to navigate up an exponential gradient of the odorant isoamyl acetate, although their paths meander more than Orco¹/Orco² larvae expressing Orco^{Scer\UAS.T:Avic\GFP} under the control of Scer\GAL4^Or42a.PF bilaterally in both Or42a-expressing olfactory sensory neurons. Unilaterally rescued animals in which the right olfactory sensory neuron is functional perform better than unilaterally rescued animals in which the left olfactory sensory neuron is functional.

Orco¹/Orco² larvae expressing Orco^{Scer\UAS.T:Avic\GFP} under the control of Scer\GAL4^Or1a.PF bilaterally in both Or1a-expressing olfactory sensory neurons detect an exponential methyl benzoate odorant gradient with sufficient accuracy to reach the peak zone of the gradient field in 60% of cases. Orco¹/Orco² larvae expressing Orco^{Scer\UAS.T:Avic\GFP} under the control of Scer\GAL4^Or1a.PF unilaterally in single olfactory sensory neuron on one side of the head have a low chemotaxis score in this assay and while larvae in which the right olfactory sensory neuron is functional show some rescue of chemotaxis compared to Orco¹/Orco² larvae, larvae in which the left olfactory sensory neuron is functional show no rescue of chemotactic behaviour.

(Louis et al., 2008)

Images (0)

Mutant

Wild-type

Stocks (1)

Bloomington

23130

w^*; TI{TI}Orco²

Notes on Origin

Discoverer

Orco²/Df(3R)ED5156 but not homozygous Orco² flies show a defect in citronellal avoidance, indicating that the Orco² stock contains a suppressor of this phenotype.

(Kwon et al., 2010)

External Crossreferences and Linkouts ( 0 )

Synonyms and Secondary IDs (10)

Reported As

Symbol Synonym

Or83b-2

(Tessier and Broadie, 2008)

Or83b^-

(Benton et al., 2007)

Or83b²

(Zhao et al., 2024, Ha et al., 2023, MacWilliam et al., 2018, Krstic et al., 2013, Simon et al., 2012, Kazama et al., 2011, Kong et al., 2010, Kwon et al., 2010, Krstic et al., 2009, Louis et al., 2008, Benton et al., 2007, Kwon et al., 2007, Libert et al., 2007, Olsen et al., 2007, Benton et al., 2006)

Orco

(Getahun et al., 2013)

Orco<up> 2</up>

(Ronderos et al., 2014)

or83b2

(Suyama et al., 2023)

or83b²

(Deng et al., 2011, Liu et al., 2007)

orco²

(Miller and Broadie, 2024, Golovin et al., 2021, Poudel et al., 2021, Zhang et al., 2020, Utashiro et al., 2018, Dubey et al., 2016, Hueston et al., 2016, Silbering et al., 2016)

ΔOr83b²

(Ganguly et al., 2017)

Name Synonyms

Secondary FlyBase IDs

References (59)

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