FB2026_01 , released March 12, 2026
FB2026_01 , released March 12, 2026
Gene: Dmel\janA
Open Close
General Information
Symbol
Dmel\janA
Species
D. melanogaster
Name
janus A
Annotation Symbol
CG7933
Feature Type
protein_coding_gene
FlyBase ID
FBgn0001280
Gene Model Status
Current
Stock Availability
3 publicly available
Enzyme Name (EC)
phosphohistidine phosphatase (3.9.1.3)
Gene Summary
JanA and janB regulate somatic sex differentiation. (UniProt, P20348)
Contribute a Gene Snapshot for this gene.
All Summaries
Also Known As

janus, Y

Key Links
Genomic Location
Cytogenetic map
99D3-99D3
Sequence location
Recombination map
3-100
RefSeq locus
NT_033777 REGION:30038622..30039533
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 (3 terms)
Molecular Function (1 term)
Terms Based on Experimental Evidence (0 terms)
Terms Based on Predictions or Assertions (1 term)
CV Term
Evidence
References
enables protein histidine phosphatase activity
inferred from biological aspect of ancestor with PANTHER:PTN000262360
(GO Reference Genome Project, 2011-)
Biological Process (1 term)
Terms Based on Experimental Evidence (1 term)
CV Term
Evidence
References
involved_in sex differentiation
inferred from expression pattern
(Yanicostas et al., 1989)
Terms Based on Predictions or Assertions (0 terms)
Cellular Component (1 term)
Terms Based on Experimental Evidence (0 terms)
Terms Based on Predictions or Assertions (1 term)
CV Term
Evidence
References
is_active_in cytosol
inferred from biological aspect of ancestor with PANTHER:PTN000262360
(GO Reference Genome Project, 2011-)
Gene Group (FlyBase)
Protein Family (UniProt)
Belongs to the janus family. (P20348)
Protein Signatures (InterPro)
Catalytic Activity (EC/Rhea)
protein histidine phosphatase activity
(1) N(tele)-phospho-L-histidyl-[protein] + H2O = L-histidyl-[protein] + phosphate (3.9.1.3)
(2) N(pros)-phospho-L-histidyl-[protein] + H2O = L-histidyl-[protein] + phosphate (3.9.1.3)
Summaries
Gene Group (FlyBase)
PROTEIN HISTIDINE PHOSPHATASES -
Protein histidine phosphatases catalyze the removal of a phosphate group from a histidine residue in a protein.
Protein Function (UniProtKB)
JanA and janB regulate somatic sex differentiation.
(UniProt, P20348)
Phenotypic Description (Red Book; Lindsley and Zimm 1992)
jan: janus
Two partially overlapping genes, janA and janB, regulate the expression of somatic sex differentiation. janA is expressed in a complex way in both males and females; janB is only expressed in males (Yanicostas et al., 1989).
Gene Model and Products
Number of Transcripts
3
Number of Unique Polypeptides
2

Please see the JBrowse view of Dmel\janA 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 P20348)

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

Low-frequency RNA-Seq exon junction(s) not annotated.

Gene model reviewed during 5.47

Transcript Data
Annotated Transcripts
Name
FlyBase ID
RefSeq ID
Length (nt)
Assoc. CDS (aa)
janA-RA
FBtr0085597
NM_176586
661
119
janA-RB
FBtr0085596
NM_176585
679
135
janA-RC
FBtr0085595
NM_206588
682
119
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
janA-PA
FBpp0089165
13.3
119
5.63
NP_788763
AAO41613
janA-PB
FBpp0084962
15.2
135
7.62
P20348
NP_788762
AAN14209
janA-PC
FBpp0084961
13.3
119
5.63
NP_996311
AAS65231
Polypeptides with Identical Sequences

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

119 aa isoforms: janA-PA, janA-PC
Additional Polypeptide Data and Comments
Reported size (kDa)

135, 119 (aa); 12 (kD predicted)

(Yanicostas et al., 1989)
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\janA 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).

3.57

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
hindgut anlage in statu nascendi
(Fisher et al., 2012)
organism | segmentally repeated
(Fisher et al., 2012)
organism | ubiquitous
(Fisher et al., 2012)
embryonic stage 7 -- 8
dorsal ectoderm
(Fisher et al., 2012)
foregut anlage
(Fisher et al., 2012)
hindgut anlage
(Fisher et al., 2012)
organism | segmentally repeated
(Fisher et al., 2012)
organism | faint | ubiquitous
(Fisher et al., 2012)
posterior endoderm
(Fisher et al., 2012)
ventral ectoderm
(Fisher et al., 2012)
embryonic stage 9 -- 10
anterior endoderm
(Fisher et al., 2012)
dorsal ectoderm
(Fisher et al., 2012)
foregut primordium
(Fisher et al., 2012)
inclusive hindgut primordium
(Fisher et al., 2012)
organism | segmentally repeated
(Fisher et al., 2012)
organism | faint | ubiquitous
(Fisher et al., 2012)
posterior endoderm
(Fisher et al., 2012)
ventral ectoderm
(Fisher et al., 2012)
embryonic stage 11 -- 12
anterior midgut primordium
(Fisher et al., 2012)
dorsal sensory complex primordium
(Fisher et al., 2012)
foregut primordium
(Fisher et al., 2012)
hindgut proper primordium
(Fisher et al., 2012)
posterior pharyngeal sense organ primordium
(Fisher et al., 2012)
organism | segmentally repeated
(Fisher et al., 2012)
organism | faint | ubiquitous
(Fisher et al., 2012)
posterior midgut primordium
(Fisher et al., 2012)
ventral sensory complex anlage
(Fisher et al., 2012)
embryonic stage 13 -- 16
dorsal sensory complex proper primordium

Comment: reported as dorsal/lateral sensory complexes

(Fisher et al., 2012)
embryonic foregut
(Fisher et al., 2012)
embryonic hindgut
(Fisher et al., 2012)
embryonic/larval midgut
(Fisher et al., 2012)
posterior pharyngeal sense organ
(Fisher et al., 2012)
organism | segmentally repeated
(Fisher et al., 2012)
organism | faint | ubiquitous
(Fisher et al., 2012)
ventral sensory complex primordium
(Fisher et al., 2012)
northern blot
Stage
Tissue/Position (including subcellular localization)
Reference
embryonic stage -- adult stage
(Yanicostas et al., 1989)
larval stage -- adult stage | male
organism
(Yanicostas et al., 1989)
adult stage | male
(Yanicostas et al., 1989)
Additional Descriptive Data
Marker for
 
Subcellular Localization
CV Term
Polypeptide Expression
Additional Descriptive Data
Marker for
 
Subcellular Localization
CV Term
Evidence
References
Expression Deduced from Reporters
High-Throughput Expression Data
Associated Tools

JBrowse - Visual display of RNA-Seq signals

View Dmel\janA 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 ( 1 )
For All Classical and Insertion Alleles Show
 
Other relevant insertions
Transgenic Constructs ( 6 )
For All Alleles Carried on Transgenic Constructs Show
Transgenic constructs containing/affecting coding region of janA
Transgenic constructs containing regulatory region of janA
Aberrations (Deficiencies and Duplications) ( 1 )
Inferred from experimentation ( 1 )
Gene disrupted in
Df(3R)X3F
(Schweisguth et al., 1990)
Inferred from location ( 4 )
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, with Dcr-2UAS.cDa, Scer\GAL4elav.PLu
viable, with Scer\GAL4Mef2.PR
viable, with Scer\GAL4pnr-MD237
viable, with Scer\GAL4tin.CΔ4
Phenotype manifest in
Allele
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\PHPT1
14 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\Phpt1
14 of 14
Yes
Yes
Mus musculus (laboratory mouse) (1)
Mmus\Phpt1
13 of 14
Yes
Yes
Xenopus tropicalis (Western clawed frog) (3)
Xtro\phpt1
11 of 13
Yes
Yes
Xtro\LOC100494164
6 of 13
No
Yes
Xtro\qrich2
1 of 13
No
No
Danio rerio (Zebrafish) (2)
Drer\phpt1
13 of 14
Yes
Yes
Drer\si:dkey-51e6.1
11 of 14
No
Yes
Caenorhabditis elegans (Nematode, roundworm) (1)
Cele\phip-1
14 of 14
Yes
Yes
Anopheles gambiae (African malaria mosquito) (1)
Agam\AgaP_AGAP002078
12 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:janA. 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) (3)
CG18662
5 of 13
janB
4 of 13
ocn
4 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?
    PHPT1; phosphohistidine phosphatase 1
    14 of 14
    610167
        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
        Starting gene(s)
        Interaction type
        Interacting gene(s)
        Reference
        Starting gene(s)
        Interaction type
        Interacting gene(s)
        Reference
        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)
        3R
        Recombination map
        3-100
        Cytogenetic map
        99D3-99D3
        Sequence location
        FlyBase Computed Cytological Location
        Cytogenetic map
        Evidence for location
        99D3-99D3
        Limits computationally determined from genome sequence between P{PZ}ncd05884 and P{lacW}l(3)s2500s2500
        Experimentally Determined Cytological Location
        Cytogenetic map
        Notes
        References
        Experimentally Determined Recombination Data
        Location

        3-100

        (FlyBase, 2016)

        3-97.4

        (Comeron et al., 2012)
        Left of (cM)
        Right of (cM)
        Notes
        Stocks and Reagents
        Stocks (3)
        Genomic Clones (15)
         

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

        cDNA Clones (37)
         

        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

            Expression is enriched in embryonic gonads.

            (Shigenobu et al., 2006)

            The molecular organization of the 'rp49-Sry-jan' gene cluster, including gene order, direction of transcription and partial overlap of the janA and janB genes is strictly conserved between D.melanogaster and D.pseudoobscura.pseudoobscura. In D.melanogaster the translation initiation codons of the divergently transcribed Sry-β and janA are separated by only 378bp, whereas the corresponding distance is only 176bp in D.pseudoobscura.pseudoobscura. Promoter analysis reveals that despite the physical proximity of the two genes, their transcription is regulated by separate cis-acting sequences.

            (Yanicostas et al., 1995)

            Analysis of the expression of a number of janB-Ecol\lacZ constructs shows that the testis-specific expression of janB is mediated by a short DNA sequence (from -174 to +107bp) that is located entirely within the last exon of the upstream, partially overlapping, janA gene. The presence in cis of an active janA gene leads to a reduced accumulation of janB-Ecol\lacZ hybrid RNA, supporting the hypothesis that janA transcription interferes with the function of the janB cis-regulatory elements.

            (Yanicostas and Lepesant, 1990)

            janA and janB, two partially overlapping genes transcribed in the same direction, have been cloned and sequenced, and their expression patterns have been analysed.

            (Yanicostas et al., 1989)

            One of two partially overlapping genes, janA and janB, regulate the expression of somatic sex differentiation. janA is expressed in a complex way in both males and females; janB is only expressed in males (Yanicostas, Vincent and Lepesant, 1989).

            Relationship to Other Genes
            Source for database merge of

            Source for merge of: janA BcDNA:AT12574

            (FlyBase, 1996-)
            Additional comments

            Source for merge of janA BcDNA:AT12574 was shared cDNA (AT12574) ( date:030530 ).

            (FlyBase, 1996-)
            Nomenclature History
            Source for database identify of
            Nomenclature comments
            Etymology
            Synonyms and Secondary IDs (9)
            Datasets (0)
            Study focus (0)
            Experimental Role
            Project
            Project Type
            Title
            Study result (0)
            Result
            Result Type
            Title
            External Crossreferences and Linkouts ( 42 )
            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
            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
            iBeetle-Base - RNAi phenotypes in the red flour beetle (Tribolium castaneum)
            MIST (protein-protein) - An integrated Molecular Interaction Database
            References (57)