FB2026_01 , released March 12, 2026
FB2026_01 , released March 12, 2026
Gene: Dmel\byn
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General Information
Symbol
Dmel\byn
Species
D. melanogaster
Name
brachyenteron
Annotation Symbol
CG7260
Feature Type
FlyBase ID
FBgn0011723
Gene Model Status
Stock Availability
Gene Summary
brachyenteron (byn) encodes a T-domain transcriptional activator that acts in developmental specification, in particular it specifies posterior gut structures and a subset of posteriorly derived visceral muscles. [Date last reviewed: 2019-03-07] (FlyBase Gene Snapshot)
Also Known As

Trg

Key Links
Genomic Location
Cytogenetic map
Sequence location
Recombination map
3-37
RefSeq locus
NT_037436 REGION:11927693..11935919
Sequence
Genomic Maps
Other Genome Views
The following external sites may use different assemblies or annotations than FlyBase.
Function
Gene Ontology (GO) Annotations (20 terms)
Molecular Function (5 terms)
Terms Based on Experimental Evidence (2 terms)
CV Term
Evidence
References
Terms Based on Predictions or Assertions (4 terms)
CV Term
Evidence
References
Biological Process (13 terms)
Terms Based on Experimental Evidence (4 terms)
CV Term
Evidence
References
inferred from expression pattern
inferred from mutant phenotype
inferred from mutant phenotype
involved_in midgut development
inferred from mutant phenotype
Terms Based on Predictions or Assertions (10 terms)
CV Term
Evidence
References
traceable author statement
inferred from biological aspect of ancestor with PANTHER:PTN000137774
traceable author statement
inferred from biological aspect of ancestor with PANTHER:PTN001681641
traceable author statement
involved_in mesoderm formation
inferred from biological aspect of ancestor with PANTHER:PTN001681641
traceable author statement
Cellular Component (2 terms)
Terms Based on Experimental Evidence (1 term)
CV Term
Evidence
References
located_in nucleus
inferred from direct assay
Terms Based on Predictions or Assertions (2 terms)
CV Term
Evidence
References
is_active_in chromatin
inferred from biological aspect of ancestor with PANTHER:PTN004251338
is_active_in nucleus
inferred from biological aspect of ancestor with PANTHER:PTN004251338
Gene Group (FlyBase)
Protein Family (UniProt)
-
Summaries
Gene Snapshot
brachyenteron (byn) encodes a T-domain transcriptional activator that acts in developmental specification, in particular it specifies posterior gut structures and a subset of posteriorly derived visceral muscles. [Date last reviewed: 2019-03-07]
Gene Group (FlyBase)
T-BOX TRANSCRIPTION FACTORS -
The T-box transcription factors are sequence-specific DNA binding proteins that regulate transcription. They are characterized by a conserved DNA-binding immunoglobulin-fold domain of 180-200 amino acids, known as T-box, named after its founding member, the mouse T protein. (Adapted from FBrf0218841).
Protein Function (UniProtKB)
Required for the specification of the hindgut and anal pads.
(UniProt, P55965)
Summary (Interactive Fly)

transcription factor - brachyury homolog - essential for the development of hindgut, anal pads and Malpighian tubules - mediates specification of caudalbvisceral mesoderm

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

Please see the JBrowse view of Dmel\byn 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 P55965)

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

Gene model reviewed during 5.45

Transcript Data
Annotated Transcripts
Name
FlyBase ID
RefSeq ID
Length (nt)
Assoc. CDS (aa)
FBtr0332070
2618
697
FBtr0332071
2650
599
Additional Transcript Data and Comments
Reported size (kB)

2.6 (longest cDNA)

Comments
External Data
Crossreferences
Polypeptide Data
Annotated Polypeptides
Name
FlyBase ID
Predicted MW (kDa)
Length (aa)
Theoretical pI
UniProt
RefSeq ID
GenBank
FBpp0304380
72.1
697
7.17
FBpp0304381
62.2
599
8.31
Polypeptides with Identical Sequences

None of the polypeptides share 100% sequence identity.

Additional Polypeptide Data and Comments
Reported size (kDa)
Comments
External Data
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\byn 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).

-0.50

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

At stage 5, byn expression overlaps the expression domains of dpp (dorsal surface plus poles) and brk (ventral surface).

Transcription of byn commences at the beginning of embryonic cycle 14 in the posterior terminal region from 0-20% egg length. During cellularization, transcripts recede from the pole and become confined to a ring of cells of which the ventral cells form the posterior part of the ventral furrow, while the dorsal and lateral cells form the primordia of the proctodeum and anal pads. The dorsal and lateral cells are internalized by the amnioproctodeal invagination during gastrulation. The proctodeum continues to express byn during germ band extension. Expression is maintained in the hindgut and anal pads until the end of embryogenesis.

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

byn protein is first detected in the blastoderm in a ring of cells mostly comprising the proctodeal primordium and in the primordia of the anal pads and the hindgut. During germ band extension, the protein is confined to the proctodeum. In the fully retracted germ band, it is found in the hindgut and anal pads.

Marker for
 
Subcellular Localization
CV Term
Evidence
References
located_in nucleus
inferred from direct assay
Expression Deduced from Reporters
Reporter: P{GawB}bynGal4
Stage
Tissue/Position (including subcellular localization)
Reference
adult pylorus

Comment: posterior to zone of wg expression

adult hindgut

Comment: posterior to zone of wg expression

Reporter: P{PZ}bynapro
Stage
Tissue/Position (including subcellular localization)
Reference
High-Throughput Expression Data
Associated Tools

JBrowse - Visual display of RNA-Seq signals

View Dmel\byn 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
Alleles, Insertions, Transgenic Constructs, and Aberrations
Classical and Insertion Alleles ( 11 )
For All Classical and Insertion Alleles Show
 
Other relevant insertions
Transgenic Constructs ( 8 )
For All Alleles Carried on Transgenic Constructs Show
Transgenic constructs containing/affecting coding region of byn
Transgenic constructs containing regulatory region of byn
Aberrations (Deficiencies and Duplications) ( 8 )
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
Orthologs
Human Orthologs (via DIOPT v9.1)
Species\Gene Symbol
Score
Best Score
Best Reverse Score
Alignment
Complementation?
Transgene?
Homo sapiens (Human) (17)
11 of 14
Yes
Yes
10 of 14
No
Yes
3 of 14
No
No
3 of 14
No
No
2 of 14
No
No
2 of 14
No
No
2 of 14
No
No
2 of 14
No
No
4  
2 of 14
No
No
5  
2 of 14
No
No
2 of 14
No
No
1  
2 of 14
No
No
2 of 14
No
No
2 of 14
No
No
2 of 14
No
No
2 of 14
No
No
2 of 14
No
No
Model Organism Orthologs (via DIOPT v9.1)
Species\Gene Symbol
Score
Best Score
Best Reverse Score
Alignment
Complementation?
Transgene?
Rattus norvegicus (Norway rat) (17)
11 of 14
Yes
Yes
4 of 14
No
Yes
3 of 14
No
No
2 of 14
No
No
2 of 14
No
No
2 of 14
No
No
2 of 14
No
No
2 of 14
No
No
2 of 14
No
No
2 of 14
No
No
2 of 14
No
No
2 of 14
No
No
2 of 14
No
No
2 of 14
No
No
1 of 14
No
No
1 of 14
No
No
1 of 14
No
No
Mus musculus (laboratory mouse) (17)
11 of 14
Yes
Yes
1  
9 of 14
No
Yes
3 of 14
No
No
2 of 14
No
No
2 of 14
No
No
2 of 14
No
No
2 of 14
No
No
2 of 14
No
No
2 of 14
No
No
2 of 14
No
No
2 of 14
No
No
2 of 14
No
No
2 of 14
No
No
2 of 14
No
No
2 of 14
No
No
2 of 14
No
No
2 of 14
No
No
Xenopus tropicalis (Western clawed frog) (17)
7 of 13
Yes
Yes
7 of 13
Yes
Yes
2 of 13
No
No
1 of 13
No
Yes
1 of 13
No
No
1 of 13
No
Yes
1 of 13
No
No
1 of 13
No
No
1 of 13
No
No
1 of 13
No
No
1 of 13
No
No
1 of 13
No
No
1 of 13
No
No
1 of 13
No
No
1 of 13
No
No
1 of 13
No
No
1 of 13
No
No
Danio rerio (Zebrafish) (25)
11 of 14
Yes
Yes
10 of 14
No
Yes
10 of 14
No
Yes
3 of 14
No
No
2 of 14
No
No
2 of 14
No
No
2 of 14
No
No
2 of 14
No
No
2 of 14
No
No
2 of 14
No
No
2 of 14
No
No
2 of 14
No
No
2 of 14
No
No
2 of 14
No
No
2 of 14
No
No
2 of 14
No
No
2 of 14
No
No
2 of 14
No
No
2 of 14
No
No
1 of 14
No
No
1 of 14
No
Yes
1 of 14
No
No
1 of 14
No
No
1 of 14
No
No
1 of 14
No
No
Caenorhabditis elegans (Nematode, roundworm) (22)
2 of 14
Yes
No
2 of 14
Yes
No
2 of 14
Yes
No
2 of 14
Yes
No
2 of 14
Yes
No
2 of 14
Yes
No
2 of 14
Yes
No
2 of 14
Yes
No
2 of 14
Yes
No
2 of 14
Yes
No
2 of 14
Yes
No
2 of 14
Yes
No
2 of 14
Yes
No
2 of 14
Yes
No
2 of 14
Yes
No
2 of 14
Yes
No
2 of 14
Yes
No
2 of 14
Yes
No
2 of 14
Yes
No
2 of 14
Yes
Yes
2 of 14
Yes
No
2 of 14
Yes
No
Anopheles gambiae (African malaria mosquito) (12)
9 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:byn. Refer to their site for version information.
Paralogs
Paralogs (via DIOPT v9.1)
Drosophila melanogaster (Fruit fly) (8)
4 of 13
4 of 13
4 of 13
3 of 13
3 of 13
3 of 13
3 of 13
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 ( 1 )
    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.
    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

    Please see the Physical Interaction reports below for full details
    protein-protein
    Physical Interaction
    Assay
    References
    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
    suppressible
    External Data
    Linkouts
    BioGRID - A database of protein and genetic interactions.
    DroID - A comprehensive database of gene and protein interactions.
    Pathways
    Signaling Pathways (FlyBase)
    Metabolic Pathways
    FlyBase
    External Links
    External Data
    Linkouts
    Class of Gene
    Genomic Location and Detailed Mapping Data
    Chromosome (arm)
    3L
    Recombination map
    3-37
    Cytogenetic map
    Sequence location
    FlyBase Computed Cytological Location
    Cytogenetic map
    Evidence for location
    68E3-68E3
    Limits computationally determined from genome sequence between P{PZ}CycA02461&P{PZ}CycA03946 and P{PZ}rols08232&P{lacW}l(3)j2D3j2D3
    Experimentally Determined Cytological Location
    Cytogenetic map
    Notes
    References
    68D-68E
    (determined by in situ hybridisation)
    Experimentally Determined Recombination Data
    Location
    Left of (cM)
    Right of (cM)
    Notes
    Stocks and Reagents
    Stocks (7)
    Genomic Clones (34)
    cDNA Clones (3)
     

    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

                  byn injected into Xenopus embryos exhibits a strong endoderm-inducing activity.

                  byn, supported by fkh, mediates the early specification of the caudal visceral mesoderm along with zfh1. The functions of byn in the mesoderm of Drosophila are comparable to the roles of the vertebrate Brachyury genes during gastrulation.

                  Like zfh1, byn is required for the migration of the caudal visceral mesoderm, but unlike zfh1, it is not required for gonadal mesoderm development.

                  cad acts in hindgut development through fog, fkh and wg, but does not play a role in activating tll, hkb, byn and bowl which are also required for proper hindgut development. cad, fkh, byn and wg constitute a conserved constellation of genes that plays a required role in gastrulation and gut development.

                  Phenotypic analysis demonstrates byn is required to regulate specific gene activity in the primordia of the anal pads and hindgut. In the absence of byn activity, programmed cell death occurs in the primordia resulting in reduced and abnormal anal pads and hindgut. byn is also required for the formation of midgut restrictions and elongation of the Malpighian tubules. tll is necessary and sufficient to activate byn.

                  byn plays a key role in the development of tissues derived from the proctodeum.

                  byn is involved in the specification of the hindgut and anal pads and is a target for regulation by tll and hkb.

                  byn is required for specification of the hindgut and anal pads.

                  Product is detected by an antibody against the mouse T gene.

                  Relationship to Other Genes
                  Source for database merge of
                  Additional comments
                  Nomenclature History
                  Source for database identify of

                  Source for identity of: byn CG7260

                  Nomenclature comments
                  Etymology

                  The mutant phenotype and the similarity of the encoded gene product to the vertebrate Brachyury protein caused the gene named to be changed from "Trg" to "brachyenteron" ("byn"), or "short gut".

                  Synonyms and Secondary IDs (21)
                  Datasets (0)
                  Study focus (0)
                  Experimental Role
                  Project
                  Project Type
                  Title
                  Study result (0)
                  Result
                  Result Type
                  Title
                  External Crossreferences and Linkouts ( 35 )
                  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
                  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.
                  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
                  References (112)