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General Information
Symbol
Dmel\chb
Species
D. melanogaster
Name
chromosome bows
Annotation Symbol
CG32435
Feature Type
FlyBase ID
FBgn0021760
Gene Model Status
Stock Availability
Gene Snapshot
chromosome bows (chb) encodes a microtubule plus-end tracking protein that promotes stabilization of microtubule dynamics. It is required for several mitotic aspects such as kinetochore attachment and central spindle formation. chb product is also essential for construction of polarized microtubule network in egg chambers and fusome formation in spermatogenesis and oogenesis. [Date last reviewed: 2018-10-04]
Also Known As

orbit, CLASP, mast, Mast/Orbit, MESR7

Key Links
Genomic Location
Cytogenetic map
Sequence location
3L:21,172,853..21,183,278 [+]
Recombination map

3-47

RefSeq locus
NT_037436 REGION:21172853..21183278
Sequence
Other Genome Views
The following external sites may use different assemblies or annotations than FlyBase.
Function
GO Summary Ribbons
Gene Ontology (GO) Annotations (44 terms)
Molecular Function (2 terms)
Terms Based on Experimental Evidence (2 terms)
CV Term
Evidence
References
inferred from direct assay
Terms Based on Predictions or Assertions (1 term)
CV Term
Evidence
References
inferred from biological aspect of ancestor with PANTHER:PTN000490604
(assigned by GO_Central )
Biological Process (20 terms)
Terms Based on Experimental Evidence (18 terms)
CV Term
Evidence
References
inferred from mutant phenotype
inferred from mutant phenotype
inferred from mutant phenotype
inferred from mutant phenotype
(assigned by UniProt )
inferred from mutant phenotype
inferred from mutant phenotype
inferred from mutant phenotype
(assigned by UniProt )
inferred from mutant phenotype
inferred from mutant phenotype
Terms Based on Predictions or Assertions (4 terms)
CV Term
Evidence
References
inferred from biological aspect of ancestor with PANTHER:PTN001090304
(assigned by GO_Central )
inferred from biological aspect of ancestor with PANTHER:PTN000490604
(assigned by GO_Central )
inferred from biological aspect of ancestor with PANTHER:PTN000490605
(assigned by GO_Central )
inferred from biological aspect of ancestor with PANTHER:PTN000490605
(assigned by GO_Central )
Cellular Component (22 terms)
Terms Based on Experimental Evidence (19 terms)
CV Term
Evidence
References
inferred from direct assay
inferred from direct assay
(assigned by CACAO )
inferred from direct assay
inferred from direct assay
inferred from direct assay
(assigned by CACAO )
inferred from direct assay
inferred from direct assay
inferred from direct assay
inferred from direct assay
(assigned by CACAO )
inferred from direct assay
inferred from mutant phenotype
(assigned by UniProt )
inferred from direct assay
(assigned by CACAO )
inferred from direct assay
inferred from direct assay
inferred from direct assay
(assigned by CACAO )
inferred from direct assay
inferred from direct assay
(assigned by CACAO )
inferred from direct assay
Terms Based on Predictions or Assertions (6 terms)
CV Term
Evidence
References
inferred from biological aspect of ancestor with PANTHER:PTN001090304
(assigned by GO_Central )
inferred from biological aspect of ancestor with PANTHER:PTN000490604
(assigned by GO_Central )
inferred from biological aspect of ancestor with PANTHER:PTN001090304
(assigned by GO_Central )
inferred from biological aspect of ancestor with PANTHER:PTN000490605
(assigned by GO_Central )
inferred from biological aspect of ancestor with PANTHER:PTN000490605
(assigned by GO_Central )
inferred from biological aspect of ancestor with PANTHER:PTN000490605
(assigned by GO_Central )
Protein Family (UniProt)
Belongs to the CLASP family. (Q9NBD7)
Summaries
Protein Function (UniProtKB)
Microtubule plus-end tracking protein that promotes the stabilization of dynamic microtubules. Required for several aspects of mitotic spindle formation including the formation of the overlapping central spindle microtubules and kinetochore attachment. Required for the incorporation of tubulin subunits at the plus ends of kinetochore microtubules during poleward microtubule flux. Acts antagonistically to Klp10A and Klp67A to maintain metaphase spindle length. Also required for guidance of CNS axons downstream of Abl. May function to identify a subset of microtubules that probe the peripheral growth cone domain, where guidance signals exert their influence on cytoskeletal organization. Also required during oogenesis for the organization of the polarized microtubule network inside the 16-cell cyst that ensures oocyte differentiation.
(UniProt, Q9NBD7)
Summary (Interactive Fly)

microtubule-associated protein that plays an essential role facilitating the kinetochore-microtubule interaction - maternially it facilitates multiple interactions of the fusome with mitotic spindles and ring canals - zygotically it mediates the action of Slit and its receptors acting as a partner of the Abelson tyrosine kinase

Gene Model and Products
Number of Transcripts
3
Number of Unique Polypeptides
1

Please see the GBrowse view of Dmel\chb or the JBrowse view of Dmel\chb 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
Comments on Gene Model

Gene model reviewed during 5.46

Sequence Ontology: Class of Gene
Transcript Data
Annotated Transcripts
Name
FlyBase ID
RefSeq ID
Length (nt)
Assoc. CDS (aa)
FBtr0089461
5930
1491
FBtr0089460
5375
1491
FBtr0089462
5264
1491
Additional Transcript Data and Comments
Reported size (kB)

6.5, 6.0 (northern blot)

Comments
External Data
Crossreferences
Polypeptide Data
Annotated Polypeptides
Name
FlyBase ID
Predicted MW (kDa)
Length (aa)
Theoretical pI
RefSeq ID
GenBank
FBpp0088470
165.6
1491
9.21
FBpp0088469
165.6
1491
9.21
FBpp0088471
165.6
1491
9.21
Polypeptides with Identical Sequences

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

1491 aa isoforms: chb-PA, chb-PB, chb-PC
Additional Polypeptide Data and Comments
Reported size (kDa)

1492 (aa); 165 (kD observed)

Comments
External Data
Subunit Structure (UniProtKB)

Interacts with CLIP-190 and microtubules.

(UniProt, Q9NBD7)
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\chb 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
Expression Summary Ribbons
Colored tiles in ribbon indicate that expression data has been curated by FlyBase for that anatomical location. Colorless tiles indicate that there is no curated data for that location.
For complete stage-specific expression data, view the modENCODE Development RNA-Seq section under High-Throughput Expression below.
Transcript Expression
No Assay Recorded
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
Additional Descriptive Data
Marker for
 
Subcellular Localization
CV Term
Polypeptide Expression
immunohistochemistry
Stage
Tissue/Position (including subcellular localization)
Reference
mass spectroscopy
Stage
Tissue/Position (including subcellular localization)
Reference
western blot
Stage
Tissue/Position (including subcellular localization)
Reference
Additional Descriptive Data

chb protein co-localizes with microtubles in the mitotic spindle.

Marker for
Subcellular Localization
CV Term
Evidence
References
inferred from direct assay
inferred from direct assay
(assigned by CACAO )
inferred from direct assay
inferred from direct assay
inferred from direct assay
(assigned by CACAO )
inferred from direct assay
inferred from direct assay
inferred from direct assay
inferred from direct assay
(assigned by CACAO )
inferred from direct assay
inferred from mutant phenotype
(assigned by UniProt )
inferred from direct assay
(assigned by CACAO )
inferred from direct assay
inferred from direct assay
inferred from direct assay
(assigned by CACAO )
inferred from direct assay
inferred from direct assay
(assigned by CACAO )
inferred from direct assay
Expression Deduced from Reporters
High-Throughput Expression Data
Associated Tools

GBrowse - Visual display of RNA-Seq signals

View Dmel\chb in GBrowse 2
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
FLIGHT - Cell culture data for RNAi and other high-throughput technologies
FlyAtlas - Adult expression by tissue, using Affymetrix Dros2 array
Fly-FISH - A database of Drosophila embryo and larvae mRNA localization patterns
Flygut - An atlas of the Drosophila adult midgut
Images
Alleles, Insertions, and Transgenic Constructs
Classical and Insertion Alleles ( 27 )
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 chb
Transgenic constructs containing regulatory region of chb
Deletions and Duplications ( 7 )
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
anterior fascicle & synapse, with Scer\GAL4elav-C155
ganglion & mitotic cell cycle & larva
larval brain & nuclear chromosome
metaphase & condensed nuclear chromosome | maternal effect
mitotic cell cycle & centrosome | maternal effect
mitotic cell cycle & midbody | maternal effect
mitotic cell cycle & neuroblast
mitotic cell cycle & spindle | maternal effect
Nebenkern & spermatocyte
nucleus & spermatocyte
spindle & spermatocyte
Orthologs
Human Orthologs (via DIOPT v8.0)
Homo sapiens (Human) (4)
Species\Gene Symbol
Score
Best Score
Best Reverse Score
Alignment
Complementation?
Transgene?
14 of 15
Yes
Yes
13 of 15
No
Yes
1  
1 of 15
No
No
1 of 15
No
No
Model Organism Orthologs (via DIOPT v8.0)
Mus musculus (laboratory mouse) (4)
Species\Gene Symbol
Score
Best Score
Best Reverse Score
Alignment
Complementation?
Transgene?
14 of 15
Yes
Yes
13 of 15
No
Yes
1 of 15
No
No
1 of 15
No
No
Rattus norvegicus (Norway rat) (4)
10 of 13
Yes
Yes
5 of 13
No
Yes
1 of 13
No
No
1 of 13
No
No
Xenopus tropicalis (Western clawed frog) (1)
12 of 12
Yes
Yes
Danio rerio (Zebrafish) (4)
12 of 15
Yes
Yes
9 of 15
No
Yes
2 of 15
No
Yes
1 of 15
No
Yes
Caenorhabditis elegans (Nematode, roundworm) (4)
13 of 15
Yes
Yes
13 of 15
Yes
Yes
13 of 15
Yes
Yes
3 of 15
No
Yes
Arabidopsis thaliana (thale-cress) (1)
8 of 9
Yes
Yes
Saccharomyces cerevisiae (Brewer's yeast) (1)
2 of 15
Yes
Yes
Schizosaccharomyces pombe (Fission yeast) (1)
3 of 12
Yes
Yes
Orthologs in Drosophila Species (via OrthoDB v9.1) ( EOG091900QO )
Organism
Common Name
Gene
AAA Syntenic Ortholog
Multiple Dmel Genes in this Orthologous Group
Drosophila suzukii
Spotted wing Drosophila
Drosophila simulans
Drosophila sechellia
Drosophila erecta
Drosophila yakuba
Drosophila yakuba
Drosophila ananassae
Drosophila pseudoobscura pseudoobscura
Drosophila persimilis
Drosophila willistoni
Drosophila virilis
Drosophila mojavensis
Drosophila grimshawi
Orthologs in non-Drosophila Dipterans (via OrthoDB v9.1) ( EOG091500IV )
Organism
Common Name
Gene
Multiple Dmel Genes in this Orthologous Group
Musca domestica
House fly
Glossina morsitans
Tsetse fly
Lucilia cuprina
Australian sheep blowfly
Mayetiola destructor
Hessian fly
Mayetiola destructor
Hessian fly
Aedes aegypti
Yellow fever mosquito
Anopheles darlingi
American malaria mosquito
Anopheles gambiae
Malaria mosquito
Culex quinquefasciatus
Southern house mosquito
Culex quinquefasciatus
Southern house mosquito
Orthologs in non-Dipteran Insects (via OrthoDB v9.1) ( EOG090W01GS )
Organism
Common Name
Gene
Multiple Dmel Genes in this Orthologous Group
Bombyx mori
Silkmoth
Danaus plexippus
Monarch butterfly
Heliconius melpomene
Postman butterfly
Heliconius melpomene
Postman butterfly
Apis florea
Little honeybee
Apis mellifera
Western honey bee
Bombus impatiens
Common eastern bumble bee
Bombus terrestris
Buff-tailed bumblebee
Linepithema humile
Argentine ant
Megachile rotundata
Alfalfa leafcutting bee
Nasonia vitripennis
Parasitic wasp
Dendroctonus ponderosae
Mountain pine beetle
Dendroctonus ponderosae
Mountain pine beetle
Tribolium castaneum
Red flour beetle
Pediculus humanus
Human body louse
Rhodnius prolixus
Kissing bug
Cimex lectularius
Bed bug
Acyrthosiphon pisum
Pea aphid
Acyrthosiphon pisum
Pea aphid
Zootermopsis nevadensis
Nevada dampwood termite
Orthologs in non-Insect Arthropods (via OrthoDB v9.1) ( EOG090X01EX )
Organism
Common Name
Gene
Multiple Dmel Genes in this Orthologous Group
Strigamia maritima
European centipede
Stegodyphus mimosarum
African social velvet spider
Tetranychus urticae
Two-spotted spider mite
Tetranychus urticae
Two-spotted spider mite
Daphnia pulex
Water flea
Orthologs in non-Arthropod Metazoa (via OrthoDB v9.1) ( None identified )
No non-Arthropod Metazoa orthologies identified
Paralogs
Paralogs (via DIOPT v8.0)
Drosophila melanogaster (Fruit fly) (1)
1 of 10
Human Disease Associations
FlyBase Human Disease Model Reports
    Disease Model Summary Ribbon
    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 ( 1 )
    Allele
    Disease
    Interaction
    References
    Disease Associations of Human Orthologs (via DIOPT v8.0 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
    esyN Network Diagram
    Show neighbor-neighbor interactions:
    Select Layout:
    Legend:
    Protein
    RNA
    Selected Interactor(s)
    Interactions Browser

    Please see the Physical Interaction reports below for full details
    protein-protein
    Physical Interaction
    Assay
    References
    Summary of Genetic Interactions
    esyN Network Diagram
    esyN Network Key:
    Suppression
    Enhancement

    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 CLIP-190 and microtubules.
    (UniProt, Q9NBD7 )
    Linkouts
    BioGRID - A database of protein and genetic interactions.
    DroID - A comprehensive database of gene and protein interactions.
    InterologFinder - Protein-protein interactions (PPI) from both known and predicted PPI data sets.
    MIST (genetic) - An integrated Molecular Interaction Database
    MIST (protein-protein) - An integrated Molecular Interaction Database
    Pathways
    Signaling Pathways (FlyBase)
    Metabolic Pathways
    External Data
    Linkouts
    Genomic Location and Detailed Mapping Data
    Chromosome (arm)
    3L
    Recombination map

    3-47

    Cytogenetic map
    Sequence location
    3L:21,172,853..21,183,278 [+]
    FlyBase Computed Cytological Location
    Cytogenetic map
    Evidence for location
    78C1-78C2
    Limits computationally determined from genome sequence between P{lacW}l(3)L5541L5541 and P{EP}chbEP3403
    Experimentally Determined Cytological Location
    Cytogenetic map
    Notes
    References
    78C1-78C2
    (determined by in situ hybridisation)
    78C-78C
    (determined by in situ hybridisation)
    78D-78D
    (determined by in situ hybridisation)
    Experimentally Determined Recombination Data
    Left of (cM)
    Right of (cM)
    Notes
    Stocks and Reagents
    Stocks (15)
    Genomic Clones (32)
    cDNA Clones (56)
     

    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 GBrowse 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
      GenomeRNAi - A database for cell-based and in vivo RNAi phenotypes and reagents
      Antibody Information
      Laboratory Generated Antibodies
       

      polyclonal

      Commercially Available Antibodies
       
      Other Information
      Relationship to Other Genes
      Source for database identify of
      Source for database merge of

      Source for merge of: chb mast

      Source for merge of: chb NEST:bs13a06 NEST:bs17d05 NEST:bs28g05

      Source for merge of: chb BcDNA:LD31673

      Source for merge of: chb CG32435

      Source for merge of: chb anon-WO0104295

      Source for merge of: chb MESR7 orbit

      Additional comments

      First exon of release 3.1 annotation CG32435-RB split into a distinct annotation, CG33486 (which corresponds to asparagine-synthetase), in release 3.2 of the genome annotation. Release 3.2 annotation CG32435 corresponds to chb.

      Source for merge of chb MESR7 orbit was sequence comparison ( date:001216 ).

      Source for merge of chb BcDNA:LD31673 was TrEMBL update ( date:020807 ).

      Source for merge of chb CG32435 was sequence comparison ( date:021112 ).

      Source for merge of chb anon-WO0104295 was sequence comparison ( date:030908 ).

      Other Comments

      S2 cells treated with RNAi against chb show reduced poleward flux rates of tubulin subunits in mitotic spindles and suppressed α-tubulin turnover at the microtubule plus ends of the spindles. There is a significantly increased scatter of chromosomes throughout the spindle in the RNAi treated cells compared to controls. Pole-to-pole spindle lengths are significantly reduced in the RNAi treated cells compared to controls.

      RNAi screen using dsRNA made from templates generated with primers directed against this gene results in aberrantly short spindles when assayed in S2 cells. This phenotype can be observed when the screen is performed with or without Cdc27 dsRNA.

      S2 cells transfected with dsRNA made from templates generated with primers directed against this gene show shortening of the metaphase spindle.

      chb is necessary for accurate axon guidance at the ventral midline choice point during embryogenesis. chb appears to act downstream of Abl in the sli repellent pathway.

      chb is required for stem cell and cystocyte divisions during oogenesis. It is also required during mid-oogenesis for the organisation of the polarised microtubule network inside the 16-cell cyst that ensures oocyte differentiation.

      New annotation (CG32435) in release 3 of the genome annotation.

      Area matching Drosophila EST AA392551.

      chb is essential for mitosis.

      chb plays an essential role in centrosome separation and organisation of the bipolar mitotic spindle.

      chb is involved in the control of cell division.

      Origin and Etymology
      Discoverer
      Etymology

      Considering the compact chromosome structure seen in the v40 mutant the authors propose the mutation is termed chromosome bows (chb).

      Identification
      External Crossreferences and Linkouts ( 62 )
      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 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/Swiss-Prot - Manually annotated and reviewed records of protein sequence and functional information
      Other crossreferences
      Drosophila Genomics Resource Center - Drosophila Genomics Resource Center (DGRC) cDNA clones
      Eukaryotic Promoter Database - A collection of databases of experimentally validated promoters for selected model organisms.
      Fly-FISH - A database of Drosophila embryo and larvae mRNA localization patterns
      Flygut - An atlas of the Drosophila adult midgut
      GenomeRNAi - A database for cell-based and in vivo RNAi phenotypes and reagents
      InterPro - A database of protein families, domains and functional sites
      KEGG Genes - Molecular building blocks of life in the genomic space.
      modMine - A data warehouse for the modENCODE project
      Linkouts
      ApoDroso - Functional genomic database for photoreceptor development, survival and function
      BioGRID - A database of protein and genetic interactions.
      DroID - A comprehensive database of gene and protein interactions.
      DRSC - Results frm RNAi screens
      FLIGHT - Cell culture data for RNAi and other high-throughput technologies
      FlyAtlas - Adult expression by tissue, using Affymetrix Dros2 array
      FlyCyc Genes - Genes from a BioCyc PGDB for Dmel
      FlyMine - An integrated database for Drosophila genomics
      Interactive Fly - A cyberspace guide to Drosophila development and metazoan evolution
      InterologFinder - Protein-protein interactions (PPI) from both known and predicted PPI data sets.
      MIST (genetic) - An integrated Molecular Interaction Database
      MIST (protein-protein) - An integrated Molecular Interaction Database
      Synonyms and Secondary IDs (36)
      Reported As
      Symbol Synonym
      BcDNA:LD31673
      NEST:bs13a06
      NEST:bs17d05
      NEST:bs28g05
      Orbit/Mast
      anon-WO0104295
      chb/mast/orbit
      mast/orbit
      orbit/mast
      Secondary FlyBase IDs
      • FBgn0041101
      • FBgn0041587
      • FBgn0043506
      • FBgn0045153
      • FBgn0045266
      • FBgn0045320
      • FBgn0047200
      • FBgn0052435
      Datasets (0)
      Study focus (0)
      Experimental Role
      Project
      Project Type
      Title
      References (141)