FB2026_03 , released September 17, 2026
Gene: Dmel\ord
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General Information
Symbol
Dmel\ord
Species
D. melanogaster
Name
orientation disruptor
Annotation Symbol
CG3134
Feature Type
FlyBase ID
FBgn0003009
Gene Model Status
Stock Availability
Gene Summary
orientation disruptor (ord) encodes a chromosome-localized protein required for meiotic sister chromatid cohesion in both sexes. In oocytes, it also promotes normal formation and maintenance of the synaptonemal complex and centromere clustering. [Date last reviewed: 2019-03-14] (FlyBase Gene Snapshot)
Also Known As

orientation disrupter

Key Links
Genomic Location
Cytogenetic map
Sequence location
Recombination map
2-102
RefSeq locus
NT_033778 REGION:23271257..23275536
Sequence
Other Genome Views
The following external sites may use different assemblies or annotations than FlyBase.
Function
Gene Ontology (GO) Annotations (17 terms)
Molecular Function (1 term)
Terms Based on Experimental Evidence (1 term)
CV Term
Evidence
References
inferred from physical interaction with UniProtKB:Q9VB08
Terms Based on Predictions or Assertions (0 terms)
Biological Process (10 terms)
Terms Based on Experimental Evidence (10 terms)
CV Term
Evidence
References
inferred from mutant phenotype
inferred from direct assay
involved_in gamete generation
inferred from mutant phenotype
inferred from mutant phenotype
inferred from mutant phenotype
inferred from direct assay
involved_in meiotic cell cycle
inferred from mutant phenotype
inferred from mutant phenotype
involved_in mitotic cell cycle
inferred from mutant phenotype
inferred from mutant phenotype
Terms Based on Predictions or Assertions (0 terms)
Cellular Component (6 terms)
Terms Based on Experimental Evidence (6 terms)
CV Term
Evidence
References
located_in chromatin
inferred from direct assay
inferred from direct assay
inferred from direct assay
located_in nuclear envelope
inferred from direct assay
located_in nucleus
inferred from direct assay
Terms Based on Predictions or Assertions (0 terms)
Gene Group / Complex (FlyBase)
Protein Family (UniProt)
-
Protein Signatures (InterPro)
Summaries
Gene Snapshot
orientation disruptor (ord) encodes a chromosome-localized protein required for meiotic sister chromatid cohesion in both sexes. In oocytes, it also promotes normal formation and maintenance of the synaptonemal complex and centromere clustering. [Date last reviewed: 2019-03-14]
Protein Function (UniProtKB)
Essential for proper maintenance of sister-chromatid cohesion in both male and female meiosis. Mutations in ord cause premature separation of the sister chromatids in meiosis I and random segregation in both meiotic divisions. Required for chiasma maintenance in female meiosis. Mutations in ord reduce recombination in female meiosis.
(UniProt, Q24434)
Phenotypic Description (Red Book; Lindsley and Zimm 1992)
ord: orientation disruptor (R.S. Hawley)
In females homozygous for ord, exchange is strongly reduced. In both males and females, ord causes a dramatic increase in both reductional and equational nondisjunction as assayed genetically. In male meiosis, Goldstein observed abnormal sister-chromatid associations during prophase as well as precocious sister-chromatid separation, followed by random disjunction during anaphase I. "The bulk of the first division misbehavior consists of sister chromatids' disjoining from one another, a process which normally occurs only during the second meiotic division" (Goldstein). ord also elevates the frequency of mitotic chromosome misbehavior (Baker et al., 1978). "A substantial proportion of this mitotic instability can be accounted for by a hypothesis in which ord causes precocious sister-chromatid separation, followed by random disjunction, in somatic as well as germline cells" (Goldstein). Thus the ord locus likely specifies a function required for sister-chromatid cohesion during most or all cell divisions.
Summary (Interactive Fly)

rapidly evolving gene - involved in meiotic cohesion, chromosome core maintenance and homologous recombination

Gene Model and Products
Number of Transcripts
2
Number of Unique Polypeptides
1

Please see the JBrowse view of Dmel\ord 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 Q24434)

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 5.52

Transcript Data
Annotated Transcripts
Name
FlyBase ID
RefSeq ID
Length (nt)
Assoc. CDS (aa)
FBtr0072047
3915
479
FBtr0343199
2178
479
Additional Transcript Data and Comments
Reported size (kB)

2.7 (northern blot)

Comments
External Data
Crossreferences
Polypeptide Data
Annotated Polypeptides
Name
FlyBase ID
Predicted MW (kDa)
Length (aa)
Theoretical pI
UniProt
RefSeq ID
GenBank
FBpp0071956
55.2
479
5.91
FBpp0309889
55.2
479
5.91
Polypeptides with Identical Sequences

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

479 aa isoforms: ord-PA, ord-PB
Additional Polypeptide Data and Comments
Reported size (kDa)

479 (aa); 55 (kD predicted)

Comments
External Data
Subunit Structure (UniProtKB)

Interacts with Sce.

(UniProt, Q24434)
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\ord 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).

4.00

Transcript Expression
Additional Descriptive Data
Marker for
 
Subcellular Localization
CV Term
Polypeptide Expression
distribution deduced from reporter or direct label
Stage
Tissue/Position (including subcellular localization)
Reference
spermatocyte

Comment: meiosis I G2-meiosis II anaphase

spermatocyte
• nucleus

Comment: G2 phase of meiotic cell cycle; protein not localized to chromatin

mass spectroscopy
Stage
Tissue/Position (including subcellular localization)
Reference
Additional Descriptive Data

Protein is found in the nuclei of developing spermatocytes. It is extrachromosomal in stage S1-S3 spermatocytes (corresponding to early to mid G2 phase) but then becomes associated with chromatin during mid to late G2 phase. The ord protein is initially distributed uniformly over the chromatin but then is detected primarily at the centromere from metaphase of meiosis I through metaphase of meiosis II.

Marker for
 
Subcellular Localization
CV Term
Evidence
References
located_in chromatin
inferred from direct assay
inferred from direct assay
inferred from direct assay
located_in nuclear envelope
inferred from direct assay
located_in nucleus
inferred from direct assay
Expression Deduced from Reporters
High-Throughput Expression Data
Associated Tools

JBrowse - Visual display of RNA-Seq signals

View Dmel\ord 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 ( 16 )
For All Classical and Insertion Alleles Show
 
Other relevant insertions
Transgenic Constructs ( 15 )
For All Alleles Carried on Transgenic Constructs Show
Transgenic constructs containing/affecting coding region of ord
Transgenic constructs containing regulatory region of ord
Aberrations (Deficiencies and Duplications) ( 17 )
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
meiosis & nuclear chromosome (with Df(2R)3-70)
meiosis & nuclear chromosome | male
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) (0)
Mus musculus (laboratory mouse) (0)
Xenopus tropicalis (Western clawed frog) (0)
Danio rerio (Zebrafish) (0)
Caenorhabditis elegans (Nematode, roundworm) (0)
Anopheles gambiae (African malaria mosquito) (0)
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:ord. Refer to their site for version information.
Paralogs
Paralogs (via DIOPT v9.1)
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)
    Interacts with Sce.
    (UniProt, Q24434 )
    Linkouts
    BioGRID - A database of protein and genetic interactions.
    DroID - A comprehensive database of gene and protein interactions.
    MIST (genetic) - An integrated Molecular Interaction Database
    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)
    2R
    Recombination map
    2-102
    Cytogenetic map
    Sequence location
    FlyBase Computed Cytological Location
    Cytogenetic map
    Evidence for location
    59D4-59D4
    Limits computationally determined from genome sequence between P{lacW}l(2)k07136k07136 and P{lacW}l(2)s4830s4830&P{lacW}chrwk06908
    Experimentally Determined Cytological Location
    Cytogenetic map
    Notes
    References
    Experimentally Determined Recombination Data
    Left of (cM)
    Right of (cM)
    Notes
    Stocks and Reagents
    Stocks (20)
    Genomic Clones (27)
    cDNA Clones (2)
     

    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
        Other clones
        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

            ord is required for the maintenance of meiotic sister cohesion in oocytes.

            Flies that are double mutant for mei-S332 and ord are viable and fertile. ord is epistatic to mei-S332.

            ord is not required for mei-S332 protein to localize to meiotic centromeres.

            A balance between the activity of mei-S332 and ord is required for proper regulation of meiotic cohesion.

            Negative complementation occurs between strong alleles (typically showing poisoning activity) and weak alleles (typically are poisoned), it is not allele-specific, suggesting that protein-protein interactions are necessary for wild-type ord function. C-terminal part of ord is required to elicit negative complementation effects.

            Meiotic sister-chromatid cohesion is severely disrupted in flies lacking ord protein and the frequency of missegregation in genetic tests suggests sister chromatid cohesion may be completely abolished. C-terminal part of ord is required for both aspects of ord function. ord function is not essential for cohesion during somatic mitosis as only a slight decrease in viability is observed.

            Analysis of weak ord mutants suggests ord is required for proper centromeric cohesion after arm cohesion is released at the metaphase I/anaphase I transition. ord activity appears to promote centromeric cohesion during meiosis II but is not essential for kinetochore function during anaphase.

            ord is necessary for chromosome segregation and can interact specifically with the centromere.

            The C-terminal half of ord is essential for the normal function of the protein, unusual genetic interactions between specific ord alleles also implicates the C-terminal part in protein-protein interactions. In direction of increasing cytology: anon-59Da? ord-

            ord is essential for sister chromatid cohesion during meiosis.

            ord is required to maintain sister-chromatid cohesion during meiosis in both males an females. Mutations result in defects in cohesion before the first division.

            All alleles are fully viable, even in trans to a deficiency, therefore ord+ has no essential role in somatic mitosis, though a role in mitosis in the germ line is suggested.

            Mutations at ord cause precocious separation of sister chromatids, at earlier stages than do mutations at mei-S332.

            Mutations at ord affect sister chromatid cohesion during meiosis I in both males and females.

            Relationship to Other Genes
            Source for database merge of
            Additional comments
            Nomenclature History
            Source for database identify of
            Nomenclature comments
            Etymology
            Synonyms and Secondary IDs (8)
            Reported As
            Name Synonyms
            Secondary FlyBase IDs
              Datasets (0)
              Study focus (0)
              Experimental Role
              Project
              Project Type
              Title
              Study result (0)
              Result
              Result Type
              Title
              External Crossreferences and Linkouts ( 32 )
              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.
              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
              Interactive Fly - A cyberspace guide to Drosophila development and metazoan evolution
              MIST (genetic) - An integrated Molecular Interaction Database
              MIST (protein-protein) - An integrated Molecular Interaction Database
              References (125)