FB2026_01 , released March 12, 2026
FB2026_01 , released March 12, 2026
Gene: Dmel\bif
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General Information
Symbol
Dmel\bif
Species
D. melanogaster
Name
bifocal
Annotation Symbol
CG1822
Feature Type
protein_coding_gene
FlyBase ID
FBgn0014133
Gene Model Status
Current
Stock Availability
13 publicly available
Gene Summary
bifocal (bif) encodes an actin and microtubule binding protein involved in axon guidance and regulation of axon extension. [Date last reviewed: 2019-09-19] (FlyBase Gene Snapshot)
All Summaries
Key Links
Genomic Location
Cytogenetic map
10D4-10D5
Sequence location
Recombination map
1-35
RefSeq locus
NC_004354 REGION:11678970..11694740
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 (10 terms)
Molecular Function (3 terms)
Terms Based on Experimental Evidence (3 terms)
CV Term
Evidence
References
enables actin binding
inferred from direct assay
(Sisson et al., 2000)
enables actin filament binding
inferred from direct assay
(Babu et al., 2005)
enables microtubule binding
inferred from direct assay
(Sisson et al., 2000)
Terms Based on Predictions or Assertions (1 term)
CV Term
Evidence
References
enables microtubule binding
inferred from biological aspect of ancestor with PANTHER:PTN000998963
(GO Reference Genome Project, 2011-)
Biological Process (4 terms)
Terms Based on Experimental Evidence (2 terms)
CV Term
Evidence
References
involved_in axon guidance
inferred from mutant phenotype
(Babu et al., 2005)
involved_in negative regulation of axon extension
inferred from mutant phenotype
(Ruan et al., 2002)
Terms Based on Predictions or Assertions (2 terms)
CV Term
Evidence
References
involved_in chemotaxis
inferred from biological aspect of ancestor with PANTHER:PTN000998963
(GO Reference Genome Project, 2011-)
involved_in neuronal signal transduction
inferred from biological aspect of ancestor with PANTHER:PTN000998963
(GO Reference Genome Project, 2011-)
inferred from electronic annotation with InterPro:IPR019130
(InterPro Project Members, 2004-)
Cellular Component (3 terms)
Terms Based on Experimental Evidence (1 term)
CV Term
Evidence
References
located_in cytoplasm
inferred from direct assay
(Bahri et al., 1997)
Terms Based on Predictions or Assertions (2 terms)
CV Term
Evidence
References
is_active_in nuclear membrane
inferred from biological aspect of ancestor with PANTHER:PTN000998963
(GO Reference Genome Project, 2011-)
is_active_in rough endoplasmic reticulum membrane
inferred from biological aspect of ancestor with PANTHER:PTN000998963
(GO Reference Genome Project, 2011-)
located_in rough endoplasmic reticulum membrane
inferred from electronic annotation with InterPro:IPR019130
(InterPro Project Members, 2004-)
Gene Group (FlyBase)
Protein Family (UniProt)
-
Protein Signatures (InterPro)
Summaries
Gene Snapshot
bifocal (bif) encodes an actin and microtubule binding protein involved in axon guidance and regulation of axon extension. [Date last reviewed: 2019-09-19]
Summary (Interactive Fly)

codes for a novel protein that interacts with f-actin - functions downstream of misshapen to reorganize the actin cytoskeleton - regulates targeting of the photoreceptor cell growth cone

Gene Model and Products
Number of Transcripts
7
Number of Unique Polypeptides
7

Please see the JBrowse view of Dmel\bif 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 M9PHA0)

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 5.55

Gene model reviewed during 6.61

Transcript Data
Annotated Transcripts
Name
FlyBase ID
RefSeq ID
Length (nt)
Assoc. CDS (aa)
bif-RB
FBtr0073526
NM_167295
4839
1235
bif-RC
FBtr0073527
NM_078573
5218
1108
bif-RD
FBtr0334463
NM_001272526
4665
1177
bif-RE
FBtr0334464
NM_001272527
8842
1107
bif-RF
FBtr0334465
NM_001272528
7574
1305
bif-RG
FBtr0482678
3878
943
bif-RH
FBtr0482679
2254
416
Additional Transcript Data and Comments
Reported size (kB)

7.0, 4.5 (northern blot)

(Bahri et al., 1997)
Comments
External Data
Crossreferences
Polypeptide Data
Annotated Polypeptides
Name
FlyBase ID
Predicted MW (kDa)
Length (aa)
Theoretical pI
UniProt
RefSeq ID
GenBank
bif-PB
FBpp0073371
130.1
1235
6.05
Q8IR86
NP_727547
AAN09639
bif-PC
FBpp0073372
117.6
1108
6.30
Q9VYV8
NP_511128
AAF48076
bif-PD
FBpp0306539
123.8
1177
6.47
M9PGW8
NP_001259455
AGB95298
bif-PE
FBpp0306540
117.4
1107
6.41
M9PHL6
NP_001259456
AGB95299
bif-PF
FBpp0306541
139.2
1305
6.98
M9PHA0
NP_001259457
AGB95300
bif-PG
FBpp0428598
99.3
943
5.67
bif-PH
FBpp0428599
43.4
416
4.68
Polypeptides with Identical Sequences

None of the polypeptides share 100% sequence identity.

Additional Polypeptide Data and Comments
Reported size (kDa)

1063 (aa)

(Bahri et al., 1997)
Comments
External Data
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\bif 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).

-0.94

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
(Fisher et al., 2012)
northern blot
Stage
Tissue/Position (including subcellular localization)
Reference
adult stage
adult head
(Bahri et al., 1997)
Additional Descriptive Data
Marker for
 
Subcellular Localization
CV Term
Polypeptide Expression
immunolocalization
Stage
Tissue/Position (including subcellular localization)
Reference
embryonic stage 3 -- 4
furrow canal
(Zelhof et al., 2001)
embryonic cycle 10 -- embryonic cycle 11
organism | ubiquitous
(Bahri et al., 1997)
embryonic stage 5
cell of embryo
(Zelhof et al., 2001)
embryonic stage 13 -- 16
presumptive embryonic/larval central nervous system
(Bahri et al., 1997)
embryonic stage 13 -- 17
neuron
• axon
(Bahri et al., 1997)
embryonic stage 14 -- 17
larval anterior commissure
(Bahri et al., 1997)
larval posterior commissure
(Bahri et al., 1997)
embryonic stage 16 -- 17
larval longitudinal connective
(Bahri et al., 1997)
third instar larval stage
photoreceptor cell R1 -- photoreceptor cell R8
(Bahri et al., 1997)
eye disc posterior to the morphogenetic furrow
(Bahri et al., 1997)
pupal stage
rhabdomere
(Bahri et al., 1997)
mass spectroscopy
Stage
Tissue/Position (including subcellular localization)
Reference
adult stage
adult head
(Aradska et al., 2015)
Additional Descriptive Data

In syncytial blastoderm embryos, bif protein is localized in caps above somatic nuclei and is closely associated with the plasma membrane. It is present in a roughly hexagonal pattern that corresponds to the distribution of F actin. The proteins co-localize throughout cellularization and they form rings around the remaining intracellular gaps at the leading edges of the invaginating membrane. In late embryos, bif protein is detected on axon tracts of the CNS. From stage 14, bif protein is present in the anterior and posterior commissures. From stage 16, it is observed in the longitudinal tracts. In third instar larval eye discs, bif protein is found in all photoreceptor cells as soon as they appear posterior to the morphogenetic furrow. At this stage, the localization of bif protein again shows a very strong resemblance to that of actin. Both proteins are present in the apical region of the disc. At ~55 hours of pupation, bif protein becomes localized mainly to the cytoplasmic side of the extending rhabdomeres.

(Bahri et al., 1997)
Marker for
 
Subcellular Localization
CV Term
Evidence
References
located_in cytoplasm
inferred from direct assay
(Bahri et al., 1997)
Expression Deduced from Reporters
High-Throughput Expression Data
Associated Tools

JBrowse - Visual display of RNA-Seq signals

View Dmel\bif 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
FlyBase Wiki
Image Based Resources
Alleles, Insertions, Transgenic Constructs, and Aberrations
Classical and Insertion Alleles ( 31 )
For All Classical and Insertion Alleles Show
 
Other relevant insertions
Transgenic Constructs ( 10 )
For All Alleles Carried on Transgenic Constructs Show
Transgenic constructs containing/affecting coding region of bif
Transgenic constructs containing regulatory region of bif
Aberrations (Deficiencies and Duplications) ( 2 )
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
viable
Sterility
Allele
fertile
Other Phenotypes
Allele
abnormal meiotic cell cycle | dominant
abnormal neuroanatomy
abnormal neuroanatomy, with Scer\GAL4GMR.PF
abnormal neuroanatomy, with Scer\GAL4sev.PM181
abnormal neuroanatomy | third instar larval stage
visible | recessive
Phenotype manifest in
Allele
actin filament
embryonic/larval optic lobe
eye
filamentous actin | P-stage
interommatidial bristle
interommatidial bristle | increased number
lamina
lamina anlage glial cell
lamina plexus, with Scer\GAL4GMR.PF
macrochaeta
medial lobe of larval mushroom body | third instar larval stage
medulla, with Scer\GAL4GMR.PF
ommatidium
photoreceptor cell R1 & axon
photoreceptor cell R1 & axon, with Scer\GAL4GMR.PF
photoreceptor cell R2 & axon
photoreceptor cell R2 & axon, with Scer\GAL4GMR.PF
photoreceptor cell R3 & axon
photoreceptor cell R3 & axon, with Scer\GAL4GMR.PF
photoreceptor cell R4 & axon
photoreceptor cell R4 & axon, with Scer\GAL4GMR.PF
photoreceptor cell R5 & axon
photoreceptor cell R5 & axon, with Scer\GAL4GMR.PF
photoreceptor cell R6 & axon
photoreceptor cell R6 & axon, with Scer\GAL4GMR.PF
photoreceptor cell R7 & axon
photoreceptor cell R7 & axon, with Scer\GAL4sev.PM181
photoreceptor cell R8 & axon
photoreceptor neuron, with Scer\GAL4GMR.PF
retina | P-stage
rhabdomere
rhabdomere of eye photoreceptor cell | adult stage
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\MACO1
2 of 14
Yes
No
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\Maco1
2 of 14
Yes
No
Mus musculus (laboratory mouse) (1)
Mmus\Maco1
2 of 14
Yes
No
Xenopus tropicalis (Western clawed frog) (1)
Xtro\maco1
1 of 13
Yes
No
Danio rerio (Zebrafish) (3)
Drer\maco1a
2 of 14
Yes
No
Drer\maco1b
2 of 14
Yes
No
Drer\si:dkey-12h9.6
2 of 14
Yes
No
Caenorhabditis elegans (Nematode, roundworm) (1)
Cele\maco-1
2 of 14
Yes
No
Anopheles gambiae (African malaria mosquito) (1)
Agam\AgaP_AGAP001866
5 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:bif. 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)
CG30389
2 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
    View in FlyBase Interactions Browser   View in MIST tool (external link)
    Please look at the allele data for full details of the genetic interactions
    Starting gene(s)
    Interaction type
    Interacting gene(s)
    Reference
    bif
    suppressible
    Amph
    (Zelhof et al., 2001)
    bif
    enhanceable
    Fas1
    (Bahri et al., 1997)
    Starting gene(s)
    Interaction type
    Interacting gene(s)
    Reference
    msn
    suppressible
    bif
    (Ruan et al., 2002)
    External Data
    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
    1-35
    Cytogenetic map
    10D4-10D5
    Sequence location
    FlyBase Computed Cytological Location
    Cytogenetic map
    Evidence for location
    10D4-10D5
    Limits computationally determined from genome sequence between P{EP}Ptp10DEP1172 and P{EP}bifEP395&P{EP}PhKγEP779
    Experimentally Determined Cytological Location
    Cytogenetic map
    Notes
    References
    10D-10D
    (Bahri, 1997.6.30)
    Experimentally Determined Recombination Data
    Location

    1-35

    (FlyBase, 2016)

    1-36.7

    (Comeron et al., 2012)

    1-

    (Bahri, 1997.6.30)
    Left of (cM)
    Right of (cM)
    Notes
    Stocks and Reagents
    Stocks (13)
    Genomic Clones (13)
     

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

    cDNA Clones (113)
     

    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
       

      polyclonal

      (Sastry et al., 2024, Bahri et al., 1997)
      Commercially Available Antibodies
       
      Cell Line Information
      Publicly Available Cell Lines
       
        Other Stable Cell Lines
         
          Other Comments

          bif is required for normal rhabdomere development in photoreceptor cells.

          (Bahri et al., 1997)

          Mutants in bif have disturbed morphology of the rhabdomeres in the developing eye.

          (Bahri et al., 1995)
          Relationship to Other Genes
          Source for database merge of
          Additional comments
          Nomenclature History
          Source for database identify of

          Source for identity of: bif CG1822

          (Wang, 1999.11)
          Nomenclature comments
          Etymology
          Synonyms and Secondary IDs (6)
          Datasets (0)
          Study focus (0)
          Experimental Role
          Project
          Project Type
          Title
          Study result (0)
          Result
          Result Type
          Title
          External Crossreferences and Linkouts ( 69 )
          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.
          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
          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
          References (75)