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General Information
Symbol
Dmel\fkh
Species
D. melanogaster
Name
fork head
Annotation Symbol
CG10002
Feature Type
FlyBase ID
FBgn0000659
Gene Model Status
Stock Availability
Gene Snapshot
fork head (fkh) encodes a winged-helix nuclear transcription factor most studied for its role in salivary gland formation, where it is required for salivary gland viability, invagination, and maintaining expression of other early-expressed salivary gland transcription factors. It works with the product of sage to activate expression of salivary gland specific gene products, such as secreted proteins and their modifying enzymes. [Date last reviewed: 2019-03-07]
Also Known As

Secretion enhancer-binding protein 2, Sebp2

Key Links
Genomic Location
Cytogenetic map
Sequence location
3R:28,580,976..28,585,264 [-]
Recombination map

3-96

RefSeq locus
NT_033777 REGION:28580976..28585264
Sequence
Other Genome Views
The following external sites may use different assemblies or annotations than FlyBase.
Function
GO Summary Ribbons
Protein Family (UniProt)
-
Summaries
Gene Group (FlyBase)
FORK HEAD BOX TRANSCRIPTION FACTORS -
The forkhead box family of transcription factors are sequence-specific DNA binding proteins that regulate transcription. They are characterized by approximately 110 amino acid DNA-binding domain known as the forkhead or winged helix. (Adapted from FBrf0173142).
Pathway (FlyBase)
Insulin-like Receptor Signaling Pathway Core Components -
The Insulin-like Receptor (IR) signaling pathway in Drosophila is initiated by the binding of an insulin-like peptides to the Insulin-like receptor (InR). (Adapted from FBrf0232297, FBrf0230017 and FBrf0229989.)
Protein Function (UniProtKB)
Fkh promotes terminal as opposed to segmental development. In the absence of fkh, this developmental switch does not occur. The nuclear localization of the fkh protein suggest that fkh regulates the transcription of other, subordinate, genes.
(UniProt, P14734)
Phenotypic Description (Red Book; Lindsley and Zimm 1992)
fkh: fork head
Embryonic lethal. fkh+ appears to be required in the most anterior and posterior regions of the embryo; in amorphic mutants homeotic transformation effects the appearance of post-oral head structures in these terminal domains. The ectopic head structures are sometimes associated with thoracic structures anteriorly and anterior tail structures posteriorly. Thus fkh mutations produce transformations directed to the center involving structures normally found in different parasegments. Anteriorly, esophagus and proventriculus, derivatives of the ectodermal stomodaeum, are absent but not the pharynx or the hypopharyngeal organ, which resides on the anterior surface of the embryo; parts of the head skeleton are distorted; other parts apparently normal. Salivary glands absent. Posteriorly, anal pads and Malpighian tubules, derivatives of the ectodermal proctodaeum, are absent; replaced by anterior tail structures and post-oral head structures; supernumerary anal sensilla and dorsal hairs also present. Anterior and posterior fkh domains are beyond the regions controlled by ANTC and BXC, respectively; however ectopic expression of ANTC and BXC expression can occur in the fkh domains of fkh but not fkh+ embryos. No maternal effect. Homozygous fkh clones in adult cuticle completely normal in structure indicating no requirements for fkh+ in imaginal disk development. In situ hybridization reveals transcript in two terminal domains shortly before blastoderm cellularization occupying 5% embryonic length anteriorly and 15% posteriorly. fkh protein first detected in posterior domain at the end of syncytial blastoderm and the anterior domain at the beginning of cellularization. Expression continues in the derivatives of the ectodermal stomodaeum and proctodaeum throughout gastrulation. In addition fkh protein is detected in the midgut, the salivary glands, the central nervous system, and the yolk cells.
Summary (Interactive Fly)

winged-helix nuclear transcription factor - plays two roles in the formation of the embryonic salivary glands: an early role in promoting survival of the secretory cells, and a later role in secretory cell invagination works with bHLH protein Sage to activate expression of salivary gland specific gene products, such as secreted proteins and their modifying enzymes

Gene Model and Products
Number of Transcripts
5
Number of Unique Polypeptides
3

Please see the GBrowse view of Dmel\fkh or the JBrowse view of Dmel\fkh 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 5.55

Gene model reviewed during 5.44

Double stop-codon suppression (UGA, UAA) postulated; FBrf0216884,

gene_with_stop_codon_read_through ; SO:0000697

Gene model reviewed during 5.40

Gene model reviewed during 6.02

Sequence Ontology: Class of Gene
Transcript Data
Annotated Transcripts
Name
FlyBase ID
RefSeq ID
Length (nt)
Assoc. CDS (aa)
FBtr0085321
3280
510
FBtr0300259
4030
510
FBtr0330333
4030
692
FBtr0345227
4289
510
FBtr0346765
4030
518
Additional Transcript Data and Comments
Reported size (kB)

4.2 (northern blot)

Comments
External Data
Crossreferences
Polypeptide Data
Annotated Polypeptides
Name
FlyBase ID
Predicted MW (kDa)
Length (aa)
Theoretical pI
RefSeq ID
GenBank
FBpp0084690
54.3
510
8.71
FBpp0289487
54.3
510
8.71
FBpp0303365
74.4
692
8.54
FBpp0311419
54.3
510
8.71
FBpp0312360
55.2
518
8.71
Polypeptides with Identical Sequences

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

510 aa isoforms: fkh-PA, fkh-PB, fkh-PD
Additional Polypeptide Data and Comments
Reported size (kDa)

510 (aa); 54 (kD)

Comments

fkh protein is used as a marker for the epithelium of the foregut and hindgut primordia.

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\fkh using the Feature Mapper tool.

External Data
Crossreferences
Eukaryotic Promoter Database - A collection of databases of experimentally validated promoters for selected model organisms.
Linkouts
Gene Ontology (25 terms)
Molecular Function (4 terms)
Terms Based on Experimental Evidence (2 terms)
CV Term
Evidence
References
Terms Based on Predictions or Assertions (3 terms)
CV Term
Evidence
References
inferred from biological aspect of ancestor with PANTHER:PTN000930906
(assigned by GO_Central )
inferred from electronic annotation with InterPro:IPR013638
(assigned by InterPro )
inferred from electronic annotation with InterPro:IPR013638
(assigned by InterPro )
Biological Process (19 terms)
Terms Based on Experimental Evidence (14 terms)
CV Term
Evidence
References
Terms Based on Predictions or Assertions (10 terms)
CV Term
Evidence
References
inferred from biological aspect of ancestor with PANTHER:PTN000930906
(assigned by GO_Central )
inferred from biological aspect of ancestor with PANTHER:PTN000930906
(assigned by GO_Central )
traceable author statement
inferred from biological aspect of ancestor with PANTHER:PTN000930906
(assigned by GO_Central )
non-traceable author statement
Cellular Component (2 terms)
Terms Based on Experimental Evidence (2 terms)
CV Term
Evidence
References
Terms Based on Predictions or Assertions (1 term)
CV Term
Evidence
References
inferred from biological aspect of ancestor with PANTHER:PTN000930906
(assigned by GO_Central )
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
antennal primordium

Comment: reported as procephalic ectoderm primordium

central brain primordium

Comment: reported as procephalic ectoderm primordium

visual primordium

Comment: reported as procephalic ectoderm primordium

dorsal head epidermis primordium

Comment: reported as procephalic ectoderm primordium

lateral head epidermis primordium

Comment: reported as procephalic ectoderm primordium

ventral head epidermis primordium

Comment: reported as procephalic ectoderm primordium

salivary gland body primordium

Comment: reported as salivary gland body specific anlage

northern blot
Stage
Tissue/Position (including subcellular localization)
Reference
Additional Descriptive Data

Expression assayed at stages 9, 11, 13, and 17. Expression may be continuous between assayed stages in some tissues.

In early embryos, fkh expression forms a posterior and an anterior cap. At later developmental stages fkh transcript expression is used to label the elongating malpighian tubules.

fkh transcripts are detected in blastoderm embryos in the terminal domains from 0-15% egg length and from 95-100% egg length.

Marker for
Subcellular Localization
CV Term
Polypeptide Expression
No Assay Recorded
Stage
Tissue/Position (including subcellular localization)
Reference
dissected tissue
Stage
Tissue/Position (including subcellular localization)
Reference
immunolocalization
Stage
Tissue/Position (including subcellular localization)
Reference
in situ
Stage
Tissue/Position (including subcellular localization)
Reference
Additional Descriptive Data

fkh protein gradually disappears from the salivary gland nuclei, but remains strong in the imaginal rings that will later form the adult salivary gland.

fkh protein is used as a marker for the epithelium of the foregut and hindgut primordia.

fkh protein is expressed in the ectodermal cells of the developing embryonic foregut. Expression stops sharply at the ectodermal/endodermal boundary.

In csw mutant embryos, the posterior fkh domain is reduced posteriorly.

fkh protein isdetected shortly after the onset of fkh transcription. It is firstdetected in the posterior domain at the end of the syncytial blastodermstage and in the anterior domain at the beginning of the cellularblastoderm stage. By the end of cellular blastoderm, the expressiondomains cover 0-13% egg length and 94-100% egg length. Double stainingwith the ftz antibody indicates that the posterior domain covers theregion posterior to parasegment 15. Subsequently, the anterior domain ofexpression expands such that by germ band elongation it covers theanterior midgut and stomodeal primordia. Yolk nuclei also stain. Later, itis expressed in the developing salivary glands and in the CNS.

Marker for
Subcellular Localization
CV Term
Evidence
References
Expression Deduced from Reporters
Reporter: P{fkh-GAL4.14-3}
Stage
Tissue/Position (including subcellular localization)
Reference
Reporter: P{fkh-GAL4.H}
Stage
Tissue/Position (including subcellular localization)
Reference
Reporter: P{fkh-lacZ.250}
Stage
Tissue/Position (including subcellular localization)
Reference
Reporter: P{lacZ}fkhF223
Stage
Tissue/Position (including subcellular localization)
Reference
Reporter: P{NXl.lacZ}
Stage
Tissue/Position (including subcellular localization)
Reference
High-Throughput Expression Data
Associated Tools

GBrowse - Visual display of RNA-Seq signals

View Dmel\fkh 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
BDGP expression data - Patterns of gene expression in Drosophila embryogenesis
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
FlyExpress - Embryonic expression images (BDGP data)
  • Stages(s) 4-6
  • Stages(s) 7-8
  • Stages(s) 9-10
  • Stages(s) 11-12
  • Stages(s) 13-16
Alleles, Insertions, and Transgenic Constructs
Classical and Insertion Alleles ( 18 )
For All Classical and Insertion Alleles Show
 
Other relevant insertions
Transgenic Constructs ( 16 )
For All Alleles Carried on Transgenic Constructs Show
Transgenic constructs containing/affecting coding region of fkh
Transgenic constructs containing regulatory region of fkh
Deletions and Duplications ( 18 )
Phenotypes
For more details about a specific phenotype click on the relevant allele symbol.
Lethality
Allele
Other Phenotypes
Allele
Phenotype manifest in
Allele
embryonic brain & ganglion mother cell
Orthologs
Human Orthologs (via DIOPT v7.1)
Homo sapiens (Human) (20)
Species\Gene Symbol
Score
Best Score
Best Reverse Score
Alignment
Complementation?
Transgene?
11 of 15
Yes
Yes
10 of 15
No
Yes
6 of 15
No
Yes
1 of 15
No
No
1 of 15
No
No
1 of 15
No
No
1 of 15
No
No
1 of 15
No
No
1 of 15
No
No
1 of 15
No
No
 
1 of 15
No
No
1 of 15
No
No
1 of 15
No
No
1 of 15
No
No
1 of 15
No
No
1 of 15
No
No
1 of 15
No
No
1 of 15
No
No
1 of 15
No
No
1 of 15
No
No
Model Organism Orthologs (via DIOPT v7.1)
Mus musculus (laboratory mouse) (14)
Species\Gene Symbol
Score
Best Score
Best Reverse Score
Alignment
Complementation?
Transgene?
11 of 15
Yes
Yes
9 of 15
No
Yes
6 of 15
No
Yes
1 of 15
No
No
1 of 15
No
No
1 of 15
No
No
1 of 15
No
No
1 of 15
No
No
1 of 15
No
No
1 of 15
No
No
1 of 15
No
No
1 of 15
No
No
1 of 15
No
No
1 of 15
No
No
Rattus norvegicus (Norway rat) (11)
9 of 13
Yes
Yes
5 of 13
No
Yes
3 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
Xenopus tropicalis (Western clawed frog) (12)
9 of 12
Yes
Yes
7 of 12
No
Yes
7 of 12
No
Yes
1 of 12
No
No
1 of 12
No
No
1 of 12
No
No
1 of 12
No
No
1 of 12
No
No
1 of 12
No
No
1 of 12
No
No
1 of 12
No
No
1 of 12
No
No
Danio rerio (Zebrafish) (15)
11 of 15
Yes
Yes
9 of 15
No
Yes
9 of 15
No
Yes
3 of 15
No
Yes
1 of 15
No
No
1 of 15
No
No
1 of 15
No
No
1 of 15
No
No
1 of 15
No
No
1 of 15
No
No
1 of 15
No
No
1 of 15
No
No
1 of 15
No
No
1 of 15
No
No
1 of 15
No
No
Caenorhabditis elegans (Nematode, roundworm) (4)
6 of 15
Yes
Yes
1 of 15
No
No
1 of 15
No
No
1 of 15
No
No
Arabidopsis thaliana (thale-cress) (0)
No records found.
Saccharomyces cerevisiae (Brewer's yeast) (3)
2 of 15
Yes
No
1 of 15
No
No
1 of 15
No
No
Schizosaccharomyces pombe (Fission yeast) (3)
2 of 12
Yes
No
1 of 12
No
No
1 of 12
No
No
Orthologs in Drosophila Species (via OrthoDB v9.1) ( EOG091909A1 )
Organism
Common Name
Gene
AAA Syntenic Ortholog
Multiple Dmel Genes in this Orthologous Group
Drosophila melanogaster
fruit fly
Drosophila suzukii
Spotted wing Drosophila
Drosophila suzukii
Spotted wing Drosophila
Drosophila suzukii
Spotted wing Drosophila
Drosophila simulans
Drosophila sechellia
Drosophila erecta
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) ( EOG091507ZY )
Organism
Common Name
Gene
Multiple Dmel Genes in this Orthologous Group
Musca domestica
House fly
Glossina morsitans
Tsetse fly
Lucilia cuprina
Australian sheep blowfly
Lucilia cuprina
Australian sheep blowfly
Mayetiola destructor
Hessian fly
Aedes aegypti
Yellow fever mosquito
Aedes aegypti
Yellow fever mosquito
Anopheles darlingi
American malaria mosquito
Anopheles gambiae
Malaria mosquito
Culex quinquefasciatus
Southern house mosquito
Orthologs in non-Dipteran Insects (via OrthoDB v9.1) ( EOG090W08HZ )
Organism
Common Name
Gene
Multiple Dmel Genes in this Orthologous Group
Bombyx mori
Silkmoth
Danaus plexippus
Monarch 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
Nasonia vitripennis
Parasitic wasp
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
Zootermopsis nevadensis
Nevada dampwood termite
Orthologs in non-Insect Arthropods (via OrthoDB v9.1) ( EOG090X0C7Q )
Organism
Common Name
Gene
Multiple Dmel Genes in this Orthologous Group
Strigamia maritima
European centipede
Ixodes scapularis
Black-legged tick
Stegodyphus mimosarum
African social velvet spider
Tetranychus urticae
Two-spotted spider mite
Daphnia pulex
Water flea
Orthologs in non-Arthropod Metazoa (via OrthoDB v9.1) ( EOG091G0HW9 )
Organism
Common Name
Gene
Multiple Dmel Genes in this Orthologous Group
Strongylocentrotus purpuratus
Purple sea urchin
Strongylocentrotus purpuratus
Purple sea urchin
Strongylocentrotus purpuratus
Purple sea urchin
Strongylocentrotus purpuratus
Purple sea urchin
Strongylocentrotus purpuratus
Purple sea urchin
Ciona intestinalis
Vase tunicate
Ciona intestinalis
Vase tunicate
Ciona intestinalis
Vase tunicate
Ciona intestinalis
Vase tunicate
Ciona intestinalis
Vase tunicate
Ciona intestinalis
Vase tunicate
Gallus gallus
Domestic chicken
Gallus gallus
Domestic chicken
Gallus gallus
Domestic chicken
Gallus gallus
Domestic chicken
Gallus gallus
Domestic chicken
Gallus gallus
Domestic chicken
Paralogs
Paralogs (via DIOPT v7.1)
Drosophila melanogaster (Fruit fly) (9)
3 of 10
3 of 10
3 of 10
2 of 10
2 of 10
1 of 10
1 of 10
1 of 10
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 ( 0 )
    Allele
    Disease
    Interaction
    References
    Disease Associations of Human Orthologs (via DIOPT v7.1 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
    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
    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 (protein-protein) - An integrated Molecular Interaction Database
    Pathways
    Signaling Pathways (FlyBase)
    Insulin-like Receptor Signaling Pathway Core Components -
    The Insulin-like Receptor (IR) signaling pathway in Drosophila is initiated by the binding of an insulin-like peptides to the Insulin-like receptor (InR). (Adapted from FBrf0232297, FBrf0230017 and FBrf0229989.)
    Metabolic Pathways
    External Data
    Linkouts
    KEGG Pathways - Wiring diagrams of molecular interactions, reactions and relations.
    Reactome - An open-source, open access, manually curated and peer-reviewed pathway database.
    Genomic Location and Detailed Mapping Data
    Chromosome (arm)
    3R
    Recombination map

    3-96

    Cytogenetic map
    Sequence location
    3R:28,580,976..28,585,264 [-]
    FlyBase Computed Cytological Location
    Cytogenetic map
    Evidence for location
    98D5-98D5
    Limits computationally determined from genome sequence between P{PZ}l(3)0648706487 and P{EP}EP3390EP3390
    Experimentally Determined Cytological Location
    Cytogenetic map
    Notes
    References
    98D2-98D3
    (determined by in situ hybridisation)
    29E-29E
    (determined by in situ hybridisation)
    98D1-98E1
    (determined by in situ hybridisation)
    Location based on the common breakpoints of several translocations.
    Experimentally Determined Recombination Data
    Left of (cM)
    Right of (cM)
    Notes
    Stocks and Reagents
    Stocks (14)
    Genomic Clones (16)
     

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

    cDNA Clones (51)
     

    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 sequences
    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
    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
    Commercially Available Antibodies
     
    Other Information
    Relationship to Other Genes
    Source for database identify of
    Source for database merge of
    Additional comments
    Other Comments

    Under fed conditions, fkh has a negative effect on growth. Under conditions of starvation, reduction of fkh levels attenuates the size reduction associated with these conditions.

    fkh protects the salivary glands from hormone-induced death until a stage-specific, hormone-induced loss of the protein earmarks the tissue for destruction in response to future hormone exposure.

    Downregulation of fkh at puparium formation is necessary for proper repression of Sgs4.

    fkh has at least two roles in the formation of embryonic salivary glands; an early role in promoting survival of secretory cells and a later role in secretory cell invagination, specifically in the constriction of the apical surface membrane.

    byn, supported by fkh, mediates the early specification of the caudal visceral mesoderm along with zfh1.

    The amino terminal of the Scr homeodomain is necessary for the specific activation of the fkh 37bp fkh250 element in vivo.

    In a sample of 79 genes with multiple introns, 33 showed significant heterogeneity in G+C content among introns of the same gene and significant positive correspondence between the intron and the third codon position G+C content within genes. These results are consistent with selection adding against preferred codons at the start of genes.

    Mutants are isolated in an EMS mutagenesis screen to identify zygotic mutations affecting germ cell migration at discrete points during embryogenesis: mutants exhibit gap pattern defects.

    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.

    hh, wg and dpp are required for the establishment of signaling centres that coordinate morphogenesis in the hindgut epithelium. Activation of these genes in the developing hindgut and foregut requires fkh.

    The distinction between pregland and preduct cells is made by the combination of two spatially separated negative regulatory steps: the Egfr signaling pathway represses fkh in the preduct cells and fkh represses duct specific genes in the pregland cells. trh is a duct-specific gene activator and is one of the targets of fkh repression.

    fkh protein strongly interacts with the proximal element of Sgs3 and it regulates Sgs3 tissue-specific expression. fkh is expressed in the appropriate tissue and is bound to many loci including the Sgs genes on polytene chromosomes.

    fkh is required for stomodeal nervous system development.

    The organisation of the tail region of the embryo is documented from studies of cuticular markers enabling a more direct comparison between homologous structures on the embryo and larval cuticle.

    In salivary gland development the activity of fkh prevents the expression of duct-specific cells, and in preduct cells the spi group signalling pathway prevents the expression of gland specific markers. fkh is repressed by spi group signalling, which is strongest in the most ventral cells of the epidermis.

    Identified by virtue of their products binding the Sgs4 regulatory region in a mobility shift assay.

    fkh and cnc homeotic genes are required for the maintenance of segment polarity gene expression in the foregut. fkh is required for the continued expression of the oesopharyngeal domains of wg and hh expression past stage 10.

    Scr is required to activate fkh expression, which then acts to maintain its own expression.

    trx gene product binds within an 8.4kb regulatory region that directs fkh expression in several embryonic tissues.

    The limits of the mesoderm primordium do not depend on tll or fkh.

    Co-crystal structure of the HNF-3/fork head DNA-recognition motif resembles histone H5.

    The analogous expression patterns of fkh and rat hepatocyte nuclear factor 3, together with similar findings for rat hepatocyte nuclear factor 4 and Hnf4, suggest evolutionary relationships between a group of genes involved in gut formation in invertebrates and mammals.

    Seven genes isolated by low stringency hybridization to a probe containing coding sequences for fkh domain conserved in the rodent hepatocyte enriched nuclear transcription factor. All seven genes include a 110 amino acid conserved sequence, overall amino acid identity varies between 45% and 62%, and two are accounted for by the two slp genes slp1 and slp2. The remaining five are fd59A, fd64A, fd78E, fd96Ca and fd96Cb.

    fkh is highly homologous to the rat hepatocyte nuclear factor-3 gene family.

    Zygotically active locus involved in the terminal developmental program in the embryo.

    The effect of fkh on hb and ftz expression has been studied.

    fkh mutants exhibit transformation of nonsegmental terminal regions into segmental derivatives, especially deletions of hindgut and Malpighian tubules.

    A sequence comparison between fkh and the rat HNF-3A gene suggests the existence of a new class of transcription factors that is conserved between Drosophila and mammals. The name "fork head" domain is suggested for the characteristic DNA binding motif.

    A number of cis regulatory elements within the genomic DNA of the fkh gene have been identified.

    The molecular identification, structure and expression pattern of the fkh gene product demonstrate that it is localized in the nucleus and may act as a transcriptional regulator.

    fkh is required in the very anterior and posterior ectodermal regions of the embryo. Inactive fkh causes homeotic transformations, the appearance of post-oral head structures in the terminal domains. There is no morphological evidence for the expression of fkh in the cells of the female germ line. Mitotic recombination demonstrates that fkh is not required in a cell autonomous manner for normal development of the imaginal discs.

    fkh mutants display a forked head skeleton and no anal pads.

    Embryonic lethal. fkh+ appears to be required in the most anterior and posterior regions of the embryo; in amorphic mutants homeotic transformation effects the appearance of post-oral head structures in these terminal domains. The ectopic head structures are sometimes associated with thoracic structures anteriorly and anterior tail structures posteriorly. Thus fkh mutations produce transformations directed to the center involving structures normally found in different parasegments. Anteriorly, esophagus and proventriculus, derivatives of the ectodermal stomodaeum, are absent but not the pharynx or the hypopharyngeal organ, which resides on the anterior surface of the embryo; parts of the head skeleton are distorted; other parts apparently normal. Salivary glands absent. Posteriorly, anal pads and Malpighian tubules, derivatives of the ectodermal proctodaeum, are absent; replaced by anterior tail structures and post-oral head structures; supernumerary anal sensilla and dorsal hairs also present. Anterior and posterior fkh domains are beyond the regions controlled by ANTC and BXC, respectively; however ectopic expression of ANTC and BXC expression can occur in the fkh domains of fkh but not fkh+ embryos. No maternal effect. Homozygous fkh clones in adult cuticle completely normal in structure indicating no requirements for fkh+ in imaginal disk development. In situ hybridization reveals transcript in two terminal domains shortly before blastoderm cellularization occupying 5% embryonic length anteriorly and 15% posteriorly. fkh protein first detected in posterior domain at the end of syncytial blastoderm and the anterior domain at the beginning of cellularization. Expression continues in the derivatives of the ectodermal stomodaeum and proctodaeum throughout gastrulation. In addition fkh protein is detected in the midgut, the salivary glands, the central nervous system and the yolk cells.

    Origin and Etymology
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    Etymology
    Identification
    External Crossreferences and Linkouts ( 60 )
    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/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
    BDGP expression data - Patterns of gene expression in Drosophila embryogenesis
    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
    iBeetle-Base - RNAi phenotypes in the red flour beetle (Tribolium castaneum)
    KEGG Genes - Molecular building blocks of life in the genomic space.
    modMine - A data warehouse for the modENCODE project
    SignaLink - A signaling pathway resource with multi-layered regulatory networks.
    Linkouts
    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.
    KEGG Pathways - Wiring diagrams of molecular interactions, reactions and relations.
    MIST (protein-protein) - An integrated Molecular Interaction Database
    Reactome - An open-source, open access, manually curated and peer-reviewed pathway database.
    Synonyms and Secondary IDs (15)
    Reported As
    Symbol Synonym
    fkh
    (Babski et al., 2019, Krmpot et al., 2019, Ray et al., 2019, Shokri et al., 2019, Campbell et al., 2018, Davie et al., 2018, Garner et al., 2018, Hernández de Madrid and Casanova, 2018, Lan et al., 2018, Rajpurohit et al., 2018, Rastogi et al., 2018, Segal et al., 2018, Bolukbasi et al., 2017, Chung et al., 2017, Bielmeier et al., 2016, Hernández et al., 2015, Schertel et al., 2015, Sivanantharajah and Percival-Smith, 2015, Archbold et al., 2014, Aleksic et al., 2013, Burlin and Tillib, 2013, Combs and Eisen, 2013, Fox et al., 2013, Knowles and Biggin, 2013, Li and Gilmour, 2013, Merabet and Hudry, 2013, Rousso et al., 2013, Saunders et al., 2013, Spokony and White, 2013.5.10, Hudry et al., 2012, Nikulova et al., 2012, Papadopoulos et al., 2012, Fowlkes et al., 2011, Jungreis et al., 2011, Kaplan et al., 2011, Lelli et al., 2011, Maruyama et al., 2011, Weake et al., 2011, Bülow et al., 2010, Cook and Cook, 2010.5.7, Ismat et al., 2010, Joshi et al., 2010, Kazemian et al., 2010, Kong et al., 2010, Kong et al., 2010, Wheeler et al., 2009, Wolfstetter et al., 2009, Cook et al., 2008.7.11, Juven-Gershon et al., 2008, Liu and Lehmann, 2008, Maruyama et al., 2008, Miguel-Aliaga et al., 2008, Segal et al., 2008, Srinivasan et al., 2008, Wheeler et al., 2008, Xu et al., 2008, Cao et al., 2007, Christensen et al., 2007.10.29, de Velasco et al., 2007, Harris and Beckendorf, 2007, Joshi et al., 2007, Lechner et al., 2007, Lehmann et al., 2007, Ryakhovskiy and Tillib, 2007, Ryakhovskiy and Tillib, 2007, Sprecher et al., 2007, Thummel, 2007, Kobayashi et al., 2006, Moran and Jimenez, 2006, Noro et al., 2006, Wheeler et al., 2006, Brown and Feder, 2005, Burgler and Macdonald, 2005, Copley, 2005, Lee and Frasch, 2004, Wang et al., 2004, Williams et al., 2004, Gim et al., 2001, Myat et al., 2000, Sugimura et al., 2000, Lehmann and Korge, 1996)
    Secondary FlyBase IDs
    • FBgn0015292
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    References (318)