FB2026_01 , released March 12, 2026
FB2026_01 , released March 12, 2026
Gene: Dmel\ort
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General Information
Symbol
Dmel\ort
Species
D. melanogaster
Name
ora transientless
Annotation Symbol
CG7411
Feature Type
FlyBase ID
FBgn0003011
Gene Model Status
Stock Availability
Gene Summary
ora transientless (ort) encodes an ionotropic histamine-gated chloride channel required for vision. It is essential in the first-order interneurons to receive histaminergic inputs from the photoreceptors. In the central brain the product of ort modulates preference and tolerance for high and low temperature. [Date last reviewed: 2019-03-14] (FlyBase Gene Snapshot)
Also Known As

ora, hclA, HisCl2, Hist1

Key Links
Genomic Location
Cytogenetic map
Sequence location
Recombination map
3-66
RefSeq locus
NT_033777 REGION:19659748..19663672
Sequence
Genomic Maps
Other Genome Views
The following external sites may use different assemblies or annotations than FlyBase.
Function
Gene Ontology (GO) Annotations (17 terms)
Molecular Function (5 terms)
Terms Based on Experimental Evidence (1 term)
CV Term
Evidence
References
Terms Based on Predictions or Assertions (4 terms)
CV Term
Evidence
References
Biological Process (9 terms)
Terms Based on Experimental Evidence (6 terms)
CV Term
Evidence
References
involved_in adult behavior
inferred from mutant phenotype
inferred from mutant phenotype
involved_in chloride transport
inferred from direct assay
involved_in response to ether
inferred from mutant phenotype
inferred from mutant phenotype
involved_in thermotaxis
inferred from mutant phenotype
Terms Based on Predictions or Assertions (3 terms)
CV Term
Evidence
References
Cellular Component (3 terms)
Terms Based on Experimental Evidence (1 term)
CV Term
Evidence
References
Terms Based on Predictions or Assertions (2 terms)
CV Term
Evidence
References
is_active_in plasma membrane
inferred from biological aspect of ancestor with PANTHER:PTN001054635
Protein Family (UniProt)
-
Summaries
Gene Snapshot
ora transientless (ort) encodes an ionotropic histamine-gated chloride channel required for vision. It is essential in the first-order interneurons to receive histaminergic inputs from the photoreceptors. In the central brain the product of ort modulates preference and tolerance for high and low temperature. [Date last reviewed: 2019-03-14]
Gene Group (FlyBase)
HISTAMINE-GATED CHLORIDE CHANNEL SUBUNITS -
Histamine-gated chloride channels mediate synaptic inhibition and regulate cellular excitability. Histamine serves as a fast neurotransmitter in the visual system and some mechanosensory circuits of arthropods. (Adapted from FBrf0232136, FBrf0141682 and FBrf0205744).
Phenotypic Description (Red Book; Lindsley and Zimm 1992)
ort: ora transientless (J.C. Hall)
Electroretinogram lacks on-transient, and shows either no off-transient or a delayed one, occurring 100-150 milliseconds after the light coincident photoreceptor potential is elicited. Rhodopsin levels, prolonged depolarizing afterpotentials, and rhabdomere structure are normal in R1-6 photoreceptors of ort eyes, unlike the case of ninaE single or double mutants (see allele tables of ort and ninaE).
Summary (Interactive Fly)

histamine-gated chloride channel required for synaptic transmission at the photoreceptor-large monopolar cells synapse and for orientation and motion vision - responsible for synaptic transients in electroretinograms - modulates temperature preference and controls tolerance of low and high temperature

Gene Model and Products
Number of Transcripts
1
Number of Unique Polypeptides
1

Please see the JBrowse view of Dmel\ort for information on other features

To submit a correction to a gene model please use the Contact FlyBase form

Protein Domains (via Pfam)
Isoform displayed:
Pfam protein domains
InterPro name
classification
start
end
Protein Domains (via SMART)
Isoform displayed:
SMART protein domains
InterPro name
classification
start
end
Structure
Protein 3D structure   (Predicted by AlphaFold)   (AlphaFold entry Q9VDU9)

If you don't see a structure in the viewer, refresh your browser.
Model Confidence:
  • Very high (pLDDT > 90)
  • Confident (90 > pLDDT > 70)
  • Low (70 > pLDDT > 50)
  • Very low (pLDDT < 50)

AlphaFold produces a per-residue confidence score (pLDDT) between 0 and 100. Some regions with low pLDDT may be unstructured in isolation.

Experimentally Determined Structures
Crossreferences
Comments on Gene Model

Gene model reviewed during 5.47

Transcript Data
Annotated Transcripts
Name
FlyBase ID
RefSeq ID
Length (nt)
Assoc. CDS (aa)
FBtr0083784
2158
485
Additional Transcript Data and Comments
Reported size (kB)

2.2 (northern blot)

Comments
External Data
Crossreferences
Polypeptide Data
Annotated Polypeptides
Name
FlyBase ID
Predicted MW (kDa)
Length (aa)
Theoretical pI
UniProt
RefSeq ID
GenBank
FBpp0083198
55.5
485
7.89
Polypeptides with Identical Sequences

There is only one protein coding transcript and one polypeptide associated with this gene

Additional Polypeptide Data and Comments
Reported size (kDa)
Comments
External Data
Linkouts
Sequences Consistent with the Gene Model
Mapped Features

Click to get a list of regulatory features (enhancers, TFBS, etc.) and gene disruptions (point mutations, indels, etc.) within or overlapping Dmel\ort using the Feature Mapper tool.

External Data
Crossreferences
Eukaryotic Promoter Database - A collection of databases of experimentally validated promoters for selected model organisms.
Linkouts
Expression Data
Testis-specificity index

The testis specificity index was calculated from modENCODE tissue expression data by Vedelek et al., 2018 to indicate the degree of testis enrichment compared to other tissues. Scores range from -2.52 (underrepresented) to 5.2 (very high testis bias).

-0.70

Transcript Expression
No Assay Recorded
Stage
Tissue/Position (including subcellular localization)
Reference
expression microarray
Stage
Tissue/Position (including subcellular localization)
Reference
in situ
Stage
Tissue/Position (including subcellular localization)
Reference
northern blot
Stage
Tissue/Position (including subcellular localization)
Reference
RT-PCR
Stage
Tissue/Position (including subcellular localization)
Reference
Additional Descriptive Data

ort expression has been analyzed via RT-PCR on isolated Tm5c cell bodies which had been labeled with ScerGAL4ort.C1a.

ort is expressed in ocellar postsynaptic L-type interneurons.

ort transcript is observed mainly in the head and testis. Transcript levels are relatively low in headless female adults, and headless, gonadless male adults.

Eye-enriched transcripts determined by ratio of expression level in wild-type heads. versus expression level in so heads.

ort transcript cannot be detected in eggs or larvae using RT-PCR. Although RT-PCR demonstrates the presence of ort transcript in adult heads, this expression is not detectable by in situ hybridization.

Marker for
 
Subcellular Localization
CV Term
Polypeptide Expression
immunolocalization
Stage
Tissue/Position (including subcellular localization)
Reference
mass spectroscopy
Stage
Tissue/Position (including subcellular localization)
Reference
Additional Descriptive Data

ort is prominently expressed in ocellar postsynaptic L-type interneurons.

Marker for
 
Subcellular Localization
CV Term
Evidence
References
Expression Deduced from Reporters
Reporter: P{ort-GAL4.3126}
Stage
Tissue/Position (including subcellular localization)
Reference
Reporter: P{ort-GAL4.C1-3}
Stage
Tissue/Position (including subcellular localization)
Reference
Reporter: P{ort-GAL4.C1-4}
Stage
Tissue/Position (including subcellular localization)
Reference
Reporter: P{ort-GAL4.C1}
Stage
Tissue/Position (including subcellular localization)
Reference
Stage
Tissue/Position (including subcellular localization)
Reference
Reporter: P{ort-GAL4.C1a}
Stage
Tissue/Position (including subcellular localization)
Reference
Reporter: P{ort-GAL4.C2}
Stage
Tissue/Position (including subcellular localization)
Reference
Reporter: P{ort-GAL4.C2b}
Stage
Tissue/Position (including subcellular localization)
Reference
Reporter: P{ort-GAL4.C3}
Stage
Tissue/Position (including subcellular localization)
Reference
Stage
Tissue/Position (including subcellular localization)
Reference
Reporter: P{ort-GAL4.DBD.C2}
Stage
Tissue/Position (including subcellular localization)
Reference
Stage
Tissue/Position (including subcellular localization)
Reference
Stage
Tissue/Position (including subcellular localization)
Reference
Stage
Tissue/Position (including subcellular localization)
Reference
High-Throughput Expression Data
Associated Tools

JBrowse - Visual display of RNA-Seq signals

View Dmel\ort in JBrowse
RNA-Seq by Region - Search RNA-Seq expression levels by exon or genomic region
Reference
See Gelbart and Emmert, 2013 for analysis details and data files for all genes.
Developmental Proteome: Life Cycle
Developmental Proteome: Embryogenesis
External Data and Images
Linkouts
DRscDB - A single-cell RNA-seq resource for data mining and data comparison across species
EMBL-EBI Single Cell Expression Atlas - Single cell expression across species
FlyAtlas - Adult expression by tissue, using Affymetrix Dros2 array
FlyAtlas2 - A Drosophila melanogaster expression atlas with RNA-Seq, miRNA-Seq and sex-specific data
Flygut - An atlas of the Drosophila adult midgut
Images
Alleles, Insertions, Transgenic Constructs, and Aberrations
Classical and Insertion Alleles ( 21 )
For All Classical and Insertion Alleles Show
 
Other relevant insertions
Transgenic Constructs ( 17 )
For All Alleles Carried on Transgenic Constructs Show
Transgenic constructs containing/affecting coding region of ort
Transgenic constructs containing regulatory region of ort
Aberrations (Deficiencies and Duplications) ( 6 )
Variants
Variant Molecular Consequences
Alleles Representing Disease-Implicated Variants
Phenotypes
For more details about a specific phenotype click on the relevant allele symbol.
Lethality
Allele
Sterility
Allele
Other Phenotypes
Allele
Phenotype manifest in
Allele
Orthologs
Human Orthologs (via DIOPT v9.1)
Species\Gene Symbol
Score
Best Score
Best Reverse Score
Alignment
Complementation?
Transgene?
Homo sapiens (Human) (26)
5 of 14
Yes
No
5 of 14
Yes
No
5  
5 of 14
Yes
No
5 of 14
Yes
No
2 of 14
No
No
1  
2 of 14
No
No
2 of 14
No
No
2 of 14
No
No
3  
2 of 14
No
No
2 of 14
No
No
2 of 14
No
No
2 of 14
No
No
2 of 14
No
No
2 of 14
No
No
2 of 14
No
No
1  
2 of 14
No
No
2 of 14
No
No
2 of 14
No
No
2 of 14
No
No
2 of 14
No
No
2 of 14
No
Yes
1 of 14
No
No
1 of 14
No
Yes
1 of 14
No
No
1 of 14
No
No
1  
1 of 14
No
No
Model Organism Orthologs (via DIOPT v9.1)
Species\Gene Symbol
Score
Best Score
Best Reverse Score
Alignment
Complementation?
Transgene?
Rattus norvegicus (Norway rat) (22)
5 of 14
Yes
No
5 of 14
Yes
No
5 of 14
Yes
No
5 of 14
Yes
No
4 of 14
No
No
2 of 14
No
No
2 of 14
No
No
2 of 14
No
No
2 of 14
No
No
2 of 14
No
No
2 of 14
No
No
2 of 14
No
No
2 of 14
No
No
2 of 14
No
No
2 of 14
No
No
2 of 14
No
No
2 of 14
No
No
2 of 14
No
No
2 of 14
No
No
1 of 14
No
No
1 of 14
No
No
1 of 14
No
No
Mus musculus (laboratory mouse) (24)
5 of 14
Yes
No
5 of 14
Yes
No
5 of 14
Yes
No
5 of 14
Yes
No
4 of 14
No
No
2 of 14
No
No
2 of 14
No
No
2 of 14
No
No
2 of 14
No
No
2 of 14
No
No
2 of 14
No
No
2 of 14
No
No
2 of 14
No
No
2 of 14
No
No
2 of 14
No
No
2 of 14
No
No
2 of 14
No
No
2 of 14
No
No
2 of 14
No
No
2 of 14
No
No
2 of 14
No
No
2 of 14
No
No
1 of 14
No
No
1 of 14
No
No
Xenopus tropicalis (Western clawed frog) (17)
4 of 13
Yes
No
4 of 13
Yes
No
3 of 13
No
No
1 of 13
No
Yes
1 of 13
No
No
1 of 13
No
No
1 of 13
No
No
1 of 13
No
No
1 of 13
No
No
1 of 13
No
No
1 of 13
No
No
1 of 13
No
No
1 of 13
No
Yes
1 of 13
No
No
1 of 13
No
No
1 of 13
No
No
1 of 13
No
No
Danio rerio (Zebrafish) (33)
6 of 14
Yes
No
6 of 14
Yes
No
5 of 14
No
No
5 of 14
No
No
4 of 14
No
No
4 of 14
No
No
4 of 14
No
No
2 of 14
No
No
2 of 14
No
No
2 of 14
No
No
2 of 14
No
No
2 of 14
No
No
2 of 14
No
No
2 of 14
No
No
2 of 14
No
No
2 of 14
No
No
2 of 14
No
No
2 of 14
No
No
2 of 14
No
No
2 of 14
No
No
2 of 14
No
No
1 of 14
No
No
1 of 14
No
No
1 of 14
No
No
1 of 14
No
No
1 of 14
No
No
1 of 14
No
No
1 of 14
No
No
1 of 14
No
No
1 of 14
No
No
1 of 14
No
No
1 of 14
No
No
1 of 14
No
Yes
Caenorhabditis elegans (Nematode, roundworm) (44)
5 of 14
Yes
No
4 of 14
No
No
4 of 14
No
No
4 of 14
No
No
4 of 14
No
Yes
4 of 14
No
Yes
4 of 14
No
Yes
4 of 14
No
Yes
4 of 14
No
Yes
4 of 14
No
No
4 of 14
No
Yes
3 of 14
No
No
3 of 14
No
Yes
3 of 14
No
No
3 of 14
No
Yes
3 of 14
No
No
3 of 14
No
No
3 of 14
No
Yes
2 of 14
No
No
2 of 14
No
No
2 of 14
No
No
2 of 14
No
No
2 of 14
No
No
2 of 14
No
No
2 of 14
No
No
2 of 14
No
No
2 of 14
No
No
2 of 14
No
No
2 of 14
No
No
2 of 14
No
No
2 of 14
No
No
2 of 14
No
No
2 of 14
No
No
2 of 14
No
No
1 of 14
No
No
1 of 14
No
No
1 of 14
No
No
1 of 14
No
No
1 of 14
No
No
1 of 14
No
No
1 of 14
No
No
1 of 14
No
No
1 of 14
No
Yes
1 of 14
No
No
Anopheles gambiae (African malaria mosquito) (13)
12 of 12
Yes
Yes
Arabidopsis thaliana (thale-cress) (0)
Saccharomyces cerevisiae (Brewer's yeast) (0)
Schizosaccharomyces pombe (Fission yeast) (0)
Escherichia coli (enterobacterium) (0)
Other Organism Orthologs (via OrthoDB)
Data provided directly from OrthoDB:ort. Refer to their site for version information.
Paralogs
Paralogs (via DIOPT v9.1)
Drosophila melanogaster (Fruit fly) (23)
6 of 13
3 of 13
3 of 13
3 of 13
3 of 13
3 of 13
3 of 13
3 of 13
3 of 13
3 of 13
3 of 13
2 of 13
1 of 13
1 of 13
1 of 13
1 of 13
1 of 13
1 of 13
1 of 13
1 of 13
1 of 13
1 of 13
1 of 13
Human Disease Associations
FlyBase Human Disease Model Reports
    Disease Ontology (DO) Annotations
    Models Based on Experimental Evidence ( 0 )
    Allele
    Disease
    Evidence
    References
    Potential Models Based on Orthology ( 3 )
    Modifiers Based on Experimental Evidence ( 0 )
    Allele
    Disease
    Interaction
    References
    Disease Associations of Human Orthologs (via DIOPT v9.1 and OMIM)
    Note that ortholog calls supported by only 1 or 2 algorithms (DIOPT score < 3) are not shown.
    Functional Complementation Data
    Functional complementation data is computed by FlyBase using a combination of the orthology data obtained from DIOPT and OrthoDB and the allele-level genetic interaction data curated from the literature.
    Interactions
    Summary of Physical Interactions
    Interaction Browsers
    Summary of Genetic Interactions
    Interaction Browsers
    Starting gene(s)
    Interaction type
    Interacting gene(s)
    Reference
    Starting gene(s)
    Interaction type
    Interacting gene(s)
    Reference
    External Data
    Linkouts
    DroID - A comprehensive database of gene and protein interactions.
    Pathways
    Signaling Pathways (FlyBase)
    Metabolic Pathways
    FlyBase
    External Links
    External Data
    Linkouts
    Reactome - An open-source, open access, manually curated and peer-reviewed pathway database.
    Class of Gene
    Genomic Location and Detailed Mapping Data
    Chromosome (arm)
    3R
    Recombination map
    3-66
    Cytogenetic map
    Sequence location
    FlyBase Computed Cytological Location
    Cytogenetic map
    Evidence for location
    92A13-92A13
    Limits computationally determined from genome sequence between P{EP}EP650 and P{PZ}l(3)1058510585
    Experimentally Determined Cytological Location
    Cytogenetic map
    Notes
    References
    Experimentally Determined Recombination Data
    Location

    3-66.4

    Right of (cM)
    Notes

    Mapping based on ort1.

    Stocks and Reagents
    Stocks (24)
    Genomic Clones (15)
     

    Please Note FlyBase no longer curates genomic clone accessions so this list may not be complete

    cDNA Clones (12)
     

    Please Note This section lists cDNAs and ESTs that fall within the genomic extent of the gene model, which may include cDNAs and ESTs of genes within introns, or of overlapping genes. Please see JBrowse for alignment of the cDNAs and ESTs to the gene model.

    cDNA clones, fully sequenced
    BDGP DGC clones
    Other clones
      Drosophila Genomics Resource Center cDNA clones

      For each fully sequenced cDNA the DGRC maintains various forms of the cDNA (e.g tagged or untagged) in several different host vectors for subsequent cloning and expression in Drosophila and Drosophila cell lines.

      cDNA Clones, End Sequenced (ESTs)
      BDGP DGC clones
        RNAi and Array Information
        Linkouts
        DRSC - Results frm RNAi screens
        Antibody Information
        Laboratory Generated Antibodies
         

        polyclonal

        Commercially Available Antibodies
         
        Cell Line Information
        Publicly Available Cell Lines
         
          Other Stable Cell Lines
           
          Other Comments

          Mutant analysis of ort (unspecified) provides evidence for the participation of a G0-like protein in learning and memory. Sex-dependent enhancement in pertussis toxin catalysed ADP-ribosylation with respect to wild type: attributed in part to an increase in the α subunit of the G0-like protein.

          Mutations at the ninaE locus are sufficient to produce the morphological rhabdomere defects seen in ort1 ninaE1.

          Placed in 92A-92B by deficiency mapping.

          Relationship to Other Genes
          Source for database merge of

          Source for merge of: ort Hist1

          Additional comments

          Source for identity of Hist1 CG7411 was sequence comparison ( date:010922 ).

          Double mutant ort1 ninaE1 described as "oraJK84"; components separable by recombination.

          Nomenclature History
          Source for database identify of

          Source for identity of: Hist1 CG7411

          Nomenclature comments
          Etymology
          Synonyms and Secondary IDs (29)
          Reported As
          Symbol Synonym
          GluCI
          Name Synonyms
          Histamine-gated chloride channel subunit 2
          glycine receptor α2-like
          histamine-gated chloride channel subunit 1
          indefinite
          outer rhabdomere absent
          outer rhabdomeres absent
          outer rhabdomeres transientless
          outer-rhabdomeres-absent
          Secondary FlyBase IDs
          • FBgn0016658
          • FBgn0038726
          Datasets (0)
          Study focus (0)
          Experimental Role
          Project
          Project Type
          Title
          Study result (0)
          Result
          Result Type
          Title
          External Crossreferences and Linkouts ( 56 )
          Sequence Crossreferences
          NCBI Gene - Gene integrates information from a wide range of species. A record may include nomenclature, Reference Sequences (RefSeqs), maps, pathways, variations, phenotypes, and links to genome-, phenotype-, and locus-specific resources worldwide.
          GenBank Nucleotide - A collection of sequences from several sources, including GenBank, RefSeq, TPA, and PDB.
          GenBank Protein - A collection of sequences from several sources, including translations from annotated coding regions in GenBank, RefSeq and TPA, as well as records from SwissProt, PIR, PRF, and PDB.
          RefSeq - A comprehensive, integrated, non-redundant, well-annotated set of reference sequences including genomic, transcript, and protein.
          UniProt/GCRP - The gene-centric reference proteome (GCRP) provides a 1:1 mapping between genes and UniProt accessions in which a single 'canonical' isoform represents the product(s) of each protein-coding gene.
          UniProt/TrEMBL - Automatically annotated and unreviewed records of protein sequence and functional information
          Other crossreferences
          AlphaFold DB - AlphaFold provides open access to protein structure predictions for the human proteome and other key proteins of interest, to accelerate scientific research.
          DRscDB - A single-cell RNA-seq resource for data mining and data comparison across species
          EMBL-EBI Single Cell Expression Atlas - Single cell expression across species
          FlyAtlas2 - A Drosophila melanogaster expression atlas with RNA-Seq, miRNA-Seq and sex-specific data
          FlyMine - An integrated database for Drosophila genomics
          KEGG Genes - Molecular building blocks of life in the genomic space.
          MARRVEL_MODEL - MARRVEL (model organism gene)
          Linkouts
          Drosophila Genomics Resource Center - Drosophila Genomics Resource Center (DGRC) cDNA clones
          DroID - A comprehensive database of gene and protein interactions.
          DRSC - Results frm RNAi screens
          Eukaryotic Promoter Database - A collection of databases of experimentally validated promoters for selected model organisms.
          FlyAtlas - Adult expression by tissue, using Affymetrix Dros2 array
          FlyCyc Genes - Genes from a BioCyc PGDB for Dmel
          Flygut - An atlas of the Drosophila adult midgut
          FlyMet - A comprehensive tissue-specific metabolomics resource for Drosophila.
          iBeetle-Base - RNAi phenotypes in the red flour beetle (Tribolium castaneum)
          Interactive Fly - A cyberspace guide to Drosophila development and metazoan evolution
          Reactome - An open-source, open access, manually curated and peer-reviewed pathway database.
          References (163)