FB2026_01 , released March 12, 2026
FB2026_01 , released March 12, 2026
Gene: Dmel\ogre
Open Close
General Information
Symbol
Dmel\ogre
Species
D. melanogaster
Name
optic ganglion reduced
Annotation Symbol
CG3039
Feature Type
FlyBase ID
FBgn0004646
Gene Model Status
Stock Availability
Gene Summary
optic ganglion reduced (ogre) encodes one of the innexin subunits spanning the membrane 4 times. Together with the products of Inx2 and Inx3, it forms homo or hetero oligomers forming gap junctions, which allow the transfer of small solute between cells. [Date last reviewed: 2019-03-14] (FlyBase Gene Snapshot)
Also Known As

inx1, l(1)ogre, innexin 1

Key Links
Genomic Location
Cytogenetic map
Sequence location
Recombination map
1-18
RefSeq locus
NC_004354 REGION:6973620..6991318
Sequence
Genomic Maps
Other Genome Views
The following external sites may use different assemblies or annotations than FlyBase.
Function
Gene Ontology (GO) Annotations (9 terms)
Molecular Function (1 term)
Terms Based on Experimental Evidence (0 terms)
Terms Based on Predictions or Assertions (1 term)
CV Term
Evidence
References
inferred by curator from GO:0005921
inferred from biological aspect of ancestor with PANTHER:PTN000223951
Biological Process (4 terms)
Terms Based on Experimental Evidence (2 terms)
CV Term
Evidence
References
inferred from genetic interaction with FLYBASE:Inx3; FB:FBgn0265274
involved_in phototransduction
inferred from mutant phenotype
Terms Based on Predictions or Assertions (2 terms)
CV Term
Evidence
References
inferred from sequence or structural similarity with FLYBASE:Inx3; FB:FBgn0265274
involved_in visual behavior
inferred from sequence or structural similarity
Cellular Component (4 terms)
Terms Based on Experimental Evidence (2 terms)
CV Term
Evidence
References
inferred from direct assay
Terms Based on Predictions or Assertions (3 terms)
CV Term
Evidence
References
is_active_in gap junction
inferred from biological aspect of ancestor with PANTHER:PTN000223951
located_in membrane
non-traceable author statement
is_active_in plasma membrane
inferred from biological aspect of ancestor with PANTHER:PTN000223951
located_in plasma membrane
inferred from sequence or structural similarity with UniProtKB:Q9XYN0
Gene Group (FlyBase)
Protein Family (UniProt)
Belongs to the pannexin family. (P27716)
Protein Signatures (InterPro)
Summaries
Gene Snapshot
optic ganglion reduced (ogre) encodes one of the innexin subunits spanning the membrane 4 times. Together with the products of Inx2 and Inx3, it forms homo or hetero oligomers forming gap junctions, which allow the transfer of small solute between cells. [Date last reviewed: 2019-03-14]
Gene Group (FlyBase)
INNEXINS -
Gap junctions are intercellular channels that link the cytoplasm of neighboring cells facilitating cell-cell communication. In non-chordates they are composed of innexins. Innexins are four transmembrane proteins that assemble into hexamers around a central channel. The association of hemichannels on adjacent membranes forms the gap junction which allows the direct passage of ions and small molecules. Gap junctions may be formed from homo- or heteromultimers. (Adapted from FBrf0219962).
Protein Function (UniProtKB)
Structural component of the gap junctions. Essential for generation and/or maintenance of postembryonic neuroblasts and normal development of optic lobe.
(UniProt, P27716)
Phenotypic Description (Red Book; Lindsley and Zimm 1992)
ogre: optic ganglia-reduced (J.C. Hall)
Original allele (ogre1) recovered on the basis of simple lethality (Niklas and Cline, 1983); viable mutant (ogre2) isolated with respect to inability of adults to orient to vertical line of black-white contrast (Lipshitz and Kankel, 1985); optic lobes generally disorganized, as seen in adults expressing the viable allele, or in late pupae/pharate adults expressing a lethal allele; such lethals (all except ogre2) cause the behavioral and anatomical abnormalities just noted when heterozygous with viable allele; viability associated with one of these heteroallelic types, i.e., ogre1/ogre2 is poor, especially when reared at 18C (vs 29C); temperature shift experiments using this combination implies gene action in late larval stage; hemizygosity for lethal alleles causes development to cease in late larval-pupal stages, when parts of CNS appear abnormal (e.g., holes in sections of brain and thoracic ganglia, with severe defects appearing in the optic lobe formation centers); holes in CNS are also seen in "escapers", e.g., rare adults hemizygous for alleles other than ogre2, or heterozygous for ogre1 and ogre2; mosaic analysis suggests that CNS defects are due to action of this gene in those developing tissues (Lipshsitz and Kankel, 1985).
Summary (Interactive Fly)

gap junction protein functioning in blood-brain barrier glia - mediate the influence of metabolic changes on stem cell behavior; response of glia to nutritional signals

Gene Model and Products
Number of Transcripts
6
Number of Unique Polypeptides
1

Please see the JBrowse view of Dmel\ogre 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 P27716)

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

Low-frequency RNA-Seq exon junction(s) not annotated.

Gene model reviewed during 5.42

Gene model reviewed during 5.55

Transcript Data
Annotated Transcripts
Name
FlyBase ID
RefSeq ID
Length (nt)
Assoc. CDS (aa)
FBtr0071036
2161
362
FBtr0071037
1802
362
FBtr0309873
2158
362
FBtr0309874
2794
362
FBtr0309875
1689
362
FBtr0334881
3068
362
Additional Transcript Data and Comments
Reported size (kB)

2.9 (northern blot)

Comments
External Data
Crossreferences
Polypeptide Data
Annotated Polypeptides
Name
FlyBase ID
Predicted MW (kDa)
Length (aa)
Theoretical pI
UniProt
RefSeq ID
GenBank
FBpp0070995
42.6
362
9.08
FBpp0070996
42.6
362
9.08
FBpp0301607
42.6
362
9.08
FBpp0301608
42.6
362
9.08
FBpp0301609
42.6
362
9.08
FBpp0306903
42.6
362
9.08
Polypeptides with Identical Sequences

The group(s) of polypeptides indicated below share identical sequence to each other.

Additional Polypeptide Data and Comments
Reported size (kDa)

362 (aa); 43 (kD)

Comments
External Data
Subunit Structure (UniProtKB)

Heterooligomer of Inx2 and ogre.

(UniProt, P27716)
Crossreferences
InterPro - A database of protein families, domains and functional sites
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\ogre 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).

-0.71

Transcript Expression
in situ
Stage
Tissue/Position (including subcellular localization)
Reference
Additional Descriptive Data

Expression is almost identical to that of Inx2 transcript.

ogre transcripts are detected in embryonic, early larval and late larval RNA on northern blots. Other stages were not tested.

2.9kb ogre transcript levels are reduced in the ogre1 mutant.

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

ogre protein is found in optic formation centers and giant neuroblasts in third instar larvae.

Marker for
 
Subcellular Localization
CV Term
Evidence
References
inferred from direct assay
Expression Deduced from Reporters
Reporter: P{GMR29C07-GAL4}
Stage
Tissue/Position (including subcellular localization)
Reference
High-Throughput Expression Data
Associated Tools

JBrowse - Visual display of RNA-Seq signals

View Dmel\ogre 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
BDGP expression data - Patterns of gene expression in Drosophila embryogenesis
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
FlyExpress - Embryonic expression images (BDGP data)
  • Stages(s) 4-6
  • Stages(s) 7-8
  • Stages(s) 9-10
  • Stages(s) 11-12
  • Stages(s) 13-16
Alleles, Insertions, Transgenic Constructs, and Aberrations
Classical and Insertion Alleles ( 16 )
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 ogre
Transgenic constructs containing regulatory region of ogre
Aberrations (Deficiencies and Duplications) ( 10 )
Variants
Variant Molecular Consequences
Alleles Representing Disease-Implicated Variants
Phenotypes
Orthologs
Human Orthologs (via DIOPT v9.1)
Species\Gene Symbol
Score
Best Score
Best Reverse Score
Alignment
Complementation?
Transgene?
Homo sapiens (Human) (0)
Model Organism Orthologs (via DIOPT v9.1)
Species\Gene Symbol
Score
Best Score
Best Reverse Score
Alignment
Complementation?
Transgene?
Rattus norvegicus (Norway rat) (1)
1 of 14
Yes
Yes
Mus musculus (laboratory mouse) (0)
Xenopus tropicalis (Western clawed frog) (0)
Danio rerio (Zebrafish) (0)
Caenorhabditis elegans (Nematode, roundworm) (25)
9 of 14
Yes
No
9 of 14
Yes
No
9 of 14
Yes
No
9 of 14
Yes
No
9 of 14
Yes
Yes
9 of 14
Yes
Yes
9 of 14
Yes
No
8 of 14
No
Yes
8 of 14
No
No
8 of 14
No
Yes
8 of 14
No
No
8 of 14
No
Yes
8 of 14
No
Yes
8 of 14
No
No
8 of 14
No
No
8 of 14
No
No
8 of 14
No
Yes
8 of 14
No
Yes
8 of 14
No
No
8 of 14
No
No
8 of 14
No
No
8 of 14
No
No
3 of 14
No
Yes
3 of 14
No
No
2 of 14
No
No
Anopheles gambiae (African malaria mosquito) (6)
12 of 12
Yes
Yes
5 of 12
No
No
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:ogre. Refer to their site for version information.
Paralogs
Paralogs (via DIOPT v9.1)
Drosophila melanogaster (Fruit fly) (7)
9 of 13
9 of 13
9 of 13
9 of 13
9 of 13
9 of 13
9 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 ( 0 )
    Human Ortholog
    Disease
    Evidence
    References
    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.
    Homo sapiens (Human)
    Gene name
    Score
    OMIM
    OMIM Phenotype
    DO term
    Complementation?
    Transgene?
    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

    Please look at the allele data for full details of the genetic interactions
    Starting gene(s)
    Interaction type
    Interacting gene(s)
    Reference
    Starting gene(s)
    Interaction type
    Interacting gene(s)
    Reference
    External Data
    Subunit Structure (UniProtKB)
    Heterooligomer of Inx2 and ogre.
    (UniProt, P27716 )
    Linkouts
    BioGRID - A database of protein and genetic interactions.
    DroID - A comprehensive database of gene and protein interactions.
    MIST (protein-protein) - An integrated Molecular Interaction Database
    Pathways
    Signaling Pathways (FlyBase)
    Metabolic Pathways
    FlyBase
    External Links
    External Data
    Linkouts
    Class of Gene
    Genomic Location and Detailed Mapping Data
    Chromosome (arm)
    X
    Recombination map
    1-18
    Cytogenetic map
    Sequence location
    FlyBase Computed Cytological Location
    Cytogenetic map
    Evidence for location
    6E4-6E4
    Limits computationally determined from genome sequence between P{EP}EP1338 and P{EP}inx7EP1641
    Experimentally Determined Cytological Location
    Cytogenetic map
    Notes
    References
    6E2-6E4
    (determined by in situ hybridisation)
    Experimentally Determined Recombination Data
    Right of (cM)
    Notes
    Stocks and Reagents
    Stocks (19)
    Genomic Clones (18)
     

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

    cDNA Clones (119)
     

    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)
      RNAi and Array Information
      Linkouts
      DRSC - Results frm RNAi screens
      Antibody Information
      Laboratory Generated Antibodies
      Commercially Available Antibodies
       
      Cell Line Information
      Publicly Available Cell Lines
       
        Other Stable Cell Lines
         
          Other Comments

          Domain-swapping experiments for shakB and ogre indicate that residues crucial for innexin function are found in the intracellular loop and well as a short stretch N-terminal to the second transmembrane domain.

          Electroretinograms for molecular chimeras and rescue constructs for shakB and ogre indicate that innexins are not interchangeable in their roles of promoting normal neural development in flies.

          ogre RNA and protein expression during development has been studied.

          Genetic and developmental studies have indicated that the wild type function of ogre is crucial for and specific to postembryonic neurogenesis.

          The ogre locus has been cloned, and the expression of ogre RNA during development has been analysed.

          Developmental analysis has shown that effect of mutations at the locus are restricted to the developing and adult CNS. The time of ogre gene action is during the early and late larval period.

          Original allele (ogre1) recovered on the basis of simple lethality (Niklas and Cline, 1983); viable mutant (ogre2) isolated with respect to inability of adults to orient to vertical line of black-white contrast (Lipshitz and Kankel, 1985); optic lobes generally disorganized, as seen in adults expressing the viable allele, or in late pupae/pharate adults expressing a lethal allele; such lethals (all except ogre2) cause the behavioral and anatomical abnormalities just noted when heterozygous with viable allele; viability associated with one of these heteroallelic types, i.e., ogre1/ogre2 is poor, especially when reared at 18oC (vs 29oC); temperature shift experiments using this combination implies gene action in late larval stage; hemizygosity for lethal alleles causes development to cease in late larval-pupal stages, when parts of CNS appear abnormal (e.g., holes in sections of brain and thoracic ganglia, with severe defects appearing in the optic lobe formation centers); holes in CNS are also seen in 'escapers', e.g., rare adults hemizygous for alleles other than ogre2, or heterozygous for ogre1 and ogre2; mosaic analysis suggests that CNS defects are due to action of this gene in those developing tissues (Lipshitz and Kankel, 1985).

          Relationship to Other Genes
          Source for database merge of

          Source for merge of: ogre CG3039

          Additional comments
          Nomenclature History
          Source for database identify of
          Nomenclature comments
          Etymology
          Synonyms and Secondary IDs (21)
          Reported As
          Symbol Synonym
          CB8
          cb-8
          l(1)6Ec
          l(1)jnL3
          Name Synonyms
          Secondary FlyBase IDs
          • FBgn0000265
          • FBgn0002988
          • FBgn0029926
          Datasets (0)
          Study focus (0)
          Experimental Role
          Project
          Project Type
          Title
          Study result (0)
          Result
          Result Type
          Title
          External Crossreferences and Linkouts ( 52 )
          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/Swiss-Prot - Manually annotated and reviewed records of protein sequence and functional information
          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.
          BDGP expression data - Patterns of gene expression in Drosophila embryogenesis
          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
          InterPro - A database of protein families, domains and functional sites
          KEGG Genes - Molecular building blocks of life in the genomic space.
          MARRVEL_MODEL - MARRVEL (model organism gene)
          Linkouts
          BioGRID - A database of protein and genetic interactions.
          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
          iBeetle-Base - RNAi phenotypes in the red flour beetle (Tribolium castaneum)
          Interactive Fly - A cyberspace guide to Drosophila development and metazoan evolution
          MIST (protein-protein) - An integrated Molecular Interaction Database
          References (135)