FB2026_01 , released March 12, 2026
FB2026_01 , released March 12, 2026
Gene: Dmel\borr
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General Information
Symbol
Dmel\borr
Species
D. melanogaster
Name
borealin-related
Annotation Symbol
CG4454
Feature Type
protein_coding_gene
FlyBase ID
FBgn0032105
Gene Model Status
Current
Stock Availability
9 publicly available
Gene Summary
borealin-related (borr) encodes one of the three targeting subunits for the product of aurB in the chromosomal passenger complex. It helps to target the complex to the centromere region of chromosomes and the cleavage furrow during cytokinesis. At centromeres the complex is involved both in pausing mitotic progression when there are chromosome mis-attachments and in correcting those mis-attachments. At the cleavage furrow, the complex is involved in regulating the process of abscission (cell separation). [Date last reviewed: 2019-03-07] (FlyBase Gene Snapshot)
All Summaries
Also Known As

Borealin, Bor

Key Links
Genomic Location
Cytogenetic map
30A6-30A6
Sequence location
Recombination map
2-35
RefSeq locus
NT_033779 REGION:9251472..9253118
Sequence
Get Decorated FASTA
Genomic Maps
Other Genome Views
The following external sites may use different assemblies or annotations than FlyBase.
NCBI
UCSC
Ensembl
PopFly
Function
Gene Ontology (GO) Annotations (11 terms)
Molecular Function (2 terms)
Terms Based on Experimental Evidence (2 terms)
CV Term
Evidence
References
enables DNA binding
inferred from direct assay
(Gao et al., 2008)
enables protein binding
inferred from physical interaction with FLYBASE:shrb; FB:FBgn0086656
(Capalbo et al., 2012)
Terms Based on Predictions or Assertions (0 terms)
Biological Process (2 terms)
Terms Based on Experimental Evidence (2 terms)
CV Term
Evidence
References
involved_in mitotic sister chromatid segregation
inferred from mutant phenotype
(Hanson et al., 2005)
involved_in protein localization to spindle microtubule
inferred from mutant phenotype
(Hanson et al., 2005)
Terms Based on Predictions or Assertions (1 term)
CV Term
Evidence
References
involved_in mitotic sister chromatid segregation
inferred from biological aspect of ancestor with PANTHER:PTN001815752
(GO Reference Genome Project, 2011-)
Cellular Component (7 terms)
Terms Based on Experimental Evidence (6 terms)
CV Term
Evidence
References
located_in cell cortex
inferred from direct assay
(Hanson et al., 2005)
located_in chromatin
inferred from direct assay
(Hanson et al., 2005)
part_of chromosome passenger complex
inferred from direct assay
(Capalbo et al., 2012, Gao et al., 2008)
located_in kinetochore
inferred from direct assay
(Gao et al., 2008)
located_in meiotic spindle midzone
inferred from direct assay
(Gao et al., 2008)
located_in spindle midzone
inferred from direct assay
(Hanson et al., 2005)
Terms Based on Predictions or Assertions (3 terms)
CV Term
Evidence
References
part_of chromosome passenger complex
inferred from biological aspect of ancestor with PANTHER:PTN001815752
(GO Reference Genome Project, 2011-)
is_active_in chromosome, centromeric region
inferred from biological aspect of ancestor with PANTHER:PTN001815752
(GO Reference Genome Project, 2011-)
is_active_in spindle midzone
inferred from biological aspect of ancestor with PANTHER:PTN001815752
(GO Reference Genome Project, 2011-)
Gene Group (FlyBase)
Protein Family (UniProt)
Belongs to the borealin family. (Q9VLD6)
Protein Signatures (InterPro)
Summaries
Gene Snapshot
borealin-related (borr) encodes one of the three targeting subunits for the product of aurB in the chromosomal passenger complex. It helps to target the complex to the centromere region of chromosomes and the cleavage furrow during cytokinesis. At centromeres the complex is involved both in pausing mitotic progression when there are chromosome mis-attachments and in correcting those mis-attachments. At the cleavage furrow, the complex is involved in regulating the process of abscission (cell separation). [Date last reviewed: 2019-03-07]
Gene Group (FlyBase)
MITOTOIC CHROMOSOMAL PASSENGER COMPLEX -
The Mitotic Chromosomal Passenger Complex plays several key roles in mitosis including kinetochore-microtubule attachment, spindle assembly and cytokinesis. (Adapted from FBrf0216422 and FBrf0202888).
Protein Function (UniProtKB)
Component of the chromosomal passenger complex (CPC), a complex that acts as a key regulator of embryonic mitosis. The CPC complex has essential functions at the centromere for ensuring sister chromatid cohesion, recruitment of the CPC to kinetochores, and chromosome alignment and segregation. There is no function in meiotic histone phosphorylation or spindle formation.
(UniProt, Q9VLD6)
Summary (Interactive Fly)

as a component of the chromosomal passenger complex, Borealin-related is a key regulator of mitosis - functions to control assembly and stability of bipolar spindles and faithful chromosome segregation into daughter cells - helps to target the the passenger complex to the centromere region of chromosomes and the cleavage furrow during cytokinesis - involved in regulating the process of cell separation.

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

Please see the JBrowse view of Dmel\borr 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 Q9VLD6)

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 5.44

Gene model reviewed during 5.40

Gene model reviewed during 5.45

Transcript Data
Annotated Transcripts
Name
FlyBase ID
RefSeq ID
Length (nt)
Assoc. CDS (aa)
borr-RA
FBtr0079817
NM_135435
1286
315
borr-RB
FBtr0079818
NM_164850
1298
319
Additional Transcript Data and Comments
Reported size (kB)
Comments
External Data
Crossreferences
Polypeptide Data
Annotated Polypeptides
Name
FlyBase ID
Predicted MW (kDa)
Length (aa)
Theoretical pI
UniProt
RefSeq ID
GenBank
borr-PA
FBpp0079416
34.7
315
10.80
Q9VLD6
NP_609279
AAF52757
borr-PB
FBpp0079417
35.1
319
10.75
NP_723450
AAN10690
Polypeptides with Identical Sequences

None of the polypeptides share 100% sequence identity.

Additional Polypeptide Data and Comments
Reported size (kDa)
Comments
External Data
Subunit Structure (UniProtKB)

Component of the CPC complex.

(UniProt, Q9VLD6)
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\borr using the Feature Mapper tool.

External Data
Crossreferences
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).

0.11

Transcript Expression
in situ
Stage
Tissue/Position (including subcellular localization)
Reference
embryonic stage 1 -- 3
organism

Comment: maternally deposited

(Fisher et al., 2012)
embryonic stage 4 -- 6
organism | ubiquitous
(Fisher et al., 2012)
embryonic stage 7 -- 8
organism | ubiquitous
(Fisher et al., 2012)
embryonic stage 9 -- 10
antennal primordium

Comment: reported as procephalic ectoderm primordium

(Fisher et al., 2012)
central brain primordium

Comment: reported as procephalic ectoderm primordium

(Fisher et al., 2012)
visual primordium

Comment: reported as procephalic ectoderm primordium

(Fisher et al., 2012)
dorsal head epidermis primordium

Comment: reported as procephalic ectoderm primordium

(Fisher et al., 2012)
lateral head epidermis primordium

Comment: reported as procephalic ectoderm primordium

(Fisher et al., 2012)
ventral head epidermis primordium

Comment: reported as procephalic ectoderm primordium

(Fisher et al., 2012)
organism | ubiquitous
(Fisher et al., 2012)
ventral nerve cord primordium
(Fisher et al., 2012)
embryonic stage 11 -- 12
central brain primordium
(Fisher et al., 2012)
organism | faint | ubiquitous
(Fisher et al., 2012)
procephalic neuroblast
(Fisher et al., 2012)
ventral nerve cord primordium
(Fisher et al., 2012)
embryonic stage 13 -- 16
embryonic brain
(Fisher et al., 2012)
larval nervous system
(Fisher et al., 2012)
larval ventral nerve cord
(Fisher et al., 2012)
RT-PCR
Stage
Tissue/Position (including subcellular localization)
Reference
embryonic stage -- adult stage
organism
(Gao et al., 2008)
Additional Descriptive Data
Marker for
 
Subcellular Localization
CV Term
Polypeptide Expression
Additional Descriptive Data
Marker for
 
Subcellular Localization
CV Term
Evidence
References
located_in cell cortex
inferred from direct assay
(Hanson et al., 2005)
located_in chromatin
inferred from direct assay
(Hanson et al., 2005)
part_of chromosome passenger complex
inferred from direct assay
(Capalbo et al., 2012, Gao et al., 2008)
located_in kinetochore
inferred from direct assay
(Gao et al., 2008)
located_in meiotic spindle midzone
inferred from direct assay
(Gao et al., 2008)
located_in spindle midzone
inferred from direct assay
(Hanson et al., 2005)
Expression Deduced from Reporters
High-Throughput Expression Data
Associated Tools

JBrowse - Visual display of RNA-Seq signals

View Dmel\borr in JBrowse
RNA-Seq by Region - Search RNA-Seq expression levels by exon or genomic region
Bulk Downloads
RNA-Seq RPKM values for all genes
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
Fly-FISH - A database of Drosophila embryo and larvae mRNA localization patterns
Flygut - An atlas of the Drosophila adult midgut
Images
FlyExpress - Embryonic expression images (BDGP data)
  • Stages(s) 1-3
  • Stages(s) 4-6
  • Stages(s) 7-8
  • Stages(s) 9-10
  • Stages(s) 11-12
  • Stages(s) 13-16
FlyBase Wiki
Image Based Resources
Alleles, Insertions, Transgenic Constructs, and Aberrations
Classical and Insertion Alleles ( 5 )
For All Classical and Insertion Alleles Show
 
Other relevant insertions
Transgenic Constructs ( 9 )
For All Alleles Carried on Transgenic Constructs Show
Transgenic constructs containing/affecting coding region of borr
Transgenic constructs containing regulatory region of borr
Aberrations (Deficiencies and Duplications) ( 1 )
Inferred from experimentation ( 1 )
Gene disrupted in
Df(2L)2892
(Chang et al., 2006)
Inferred from location ( 4 )
Variants
Variant Molecular Consequences
Alleles Representing Disease-Implicated Variants
Phenotypes
Orthologs
Downloads
Download All DIOPT Orthologs
Human Orthologs (via DIOPT v9.1)
Species\Gene Symbol
Score
Best Score
Best Reverse Score
Source
Compara
Domainoid
eggNOG
Hieranoid
Homologene
Inparanoid
OMA
OrthoDB
OrthoFinder
OrthoInspector
orthoMCL
Panther
Phylome
SonicParanoid
Alignment
Complementation?
Transgene?
Homo sapiens (Human) (1)
Hsap\CDCA8
1 of 14
Yes
Yes
Model Organism Orthologs (via DIOPT v9.1)
Species\Gene Symbol
Score
Best Score
Best Reverse Score
Source
Compara
Domainoid
eggNOG
Hieranoid
Homologene
Inparanoid
OMA
OrthoDB
OrthoFinder
OrthoInspector
orthoMCL
Panther
Phylome
SonicParanoid
Alignment
Complementation?
Transgene?
Rattus norvegicus (Norway rat) (1)
Rnor\Cdca8
1 of 14
Yes
Yes
Mus musculus (laboratory mouse) (1)
Mmus\Cdca8
1 of 14
Yes
Yes
Xenopus tropicalis (Western clawed frog) (2)
Xtro\cdca8
1 of 13
Yes
Yes
Xtro\cdca9
1 of 13
Yes
Yes
Danio rerio (Zebrafish) (2)
Drer\cdca8
1 of 14
Yes
Yes
Drer\cdca9
1 of 14
Yes
Yes
Caenorhabditis elegans (Nematode, roundworm) (0)
Anopheles gambiae (African malaria mosquito) (2)
Agam\AgaP_AGAP011220
11 of 12
Yes
Yes
Agam\AgaP_AGAP011219
9 of 12
No
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:borr. Refer to their site for version information.
Paralogs
Downloads
Download All DIOPT Paralogs
Paralogs (via DIOPT v9.1)
Gene Symbol
Score
Source
Compara
Domainoid
eggNOG
Homologene
Inparanoid
OMA
OrthoDB
OrthoFinder
OrthoInspector
orthoMCL
Panther
Phylome
SonicParanoid
Alignment
Drosophila melanogaster (Fruit fly) (1)
aust
7 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
    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
    Subunit Structure (UniProtKB)
    Component of the CPC complex.
    (UniProt, Q9VLD6 )
    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
    Reactome - An open-source, open access, manually curated and peer-reviewed pathway database.
    Class of Gene
    Genomic Location and Detailed Mapping Data
    Chromosome (arm)
    2L
    Recombination map
    2-35
    Cytogenetic map
    30A6-30A6
    Sequence location
    FlyBase Computed Cytological Location
    Cytogenetic map
    Evidence for location
    30A6-30A6
    Limits computationally determined from genome sequence between P{PZ}tai01351 and P{PZ}scat1&P{PZ}numb03235
    Experimentally Determined Cytological Location
    Cytogenetic map
    Notes
    References
    Experimentally Determined Recombination Data
    Location

    2-35

    (FlyBase, 2016)

    2-30.2

    (Comeron et al., 2012)
    Left of (cM)
    Right of (cM)
    Notes
    Stocks and Reagents
    Stocks (9)
    Genomic Clones (16)
     

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

    cDNA Clones (92)
     

    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

        The borr protein is a chromosomal passenger protein in all mitotic tissues studied, but is specifically replaced by aust protein for the two male meiotic divisions.

        (Gao et al., 2008)

        RNAi screen using dsRNA made from templates generated with primers directed against this gene causes defects in spindle shape and monopolar spindles when assayed in S2 cells. This phenotype can be observed when the screen is performed with or without Cdc27 dsRNA.

        (Goshima et al., 2007)

        GFP-tagged Borr co-localizes with endogenous ial and Incenp in transfected DmD8 cells.

        (Hanson and Bienz, 2005)

        RNAi-depletion of Borr in Kc167 cells results in multinucleate and polyploid cells. Loss of zygotic Borr function in the embryo results in large, polyploid cells in the ventral nerve cord and brain. The mitotic population of these VNC cells is mainly blocked in a prometaphase state, and shows markedly reduced levels of S10-phosphorylated histone H3. Unexpectedly, Borr mutant clones induced late can survive larval development; these cells display cell-autonomous mutant phenotypes reflective of their large size and mitotic defects, but can still contribute significantly to adult structures. In contrast, in Borr mutant clones induced early in larval development, the mutant cells become polyploid, as expected, but undergo apoptosis. Intriguingly, this resulted in non-autonomous perturbation of the expression patterns of developmental regulators such as ct and wg, and subsequent non-autonomous defects in adult flies, such as wing nicks and leg truncations.

        (Hanson and Bienz, 2005)

        May be the Drosophila homolog of Borealin/Dastra. dsRNA made from templates generated with primers directed against Borr is used to study the effect of Borr on mitosis and morphology in the embryo and Kc167 cells.

        (Hanson et al., 2005)

        RNAi screen using dsRNA made from templates generated with primers directed against this gene causes a binucleation phenotype when assayed in Kc167 cells.

        (Eggert et al., 2004)
        Relationship to Other Genes
        Source for database merge of
        Additional comments
        Nomenclature History
        Source for database identify of

        Source for identity of: Borr CG4454

        (Hanson, 2005.3.2, Eggert et al., 2004)
        Nomenclature comments
        Etymology
        Synonyms and Secondary IDs (10)
        Datasets (0)
        Study focus (0)
        Experimental Role
        Project
        Project Type
        Title
        Study result (0)
        Result
        Result Type
        Title
        External Crossreferences and Linkouts ( 39 )
        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
        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
        FlyAtlas - Adult expression by tissue, using Affymetrix Dros2 array
        FlyCyc Genes - Genes from a BioCyc PGDB for Dmel
        Fly-FISH - A database of Drosophila embryo and larvae mRNA localization patterns
        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
        MIST (protein-protein) - An integrated Molecular Interaction Database
        Reactome - An open-source, open access, manually curated and peer-reviewed pathway database.
        References (60)