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General Information
Symbol
Dmel\fu
Species
D. melanogaster
Name
fused
Annotation Symbol
CG6551
Feature Type
FlyBase ID
FBgn0001079
Gene Model Status
Stock Availability
Gene Snapshot
In progress.Contributions welcome.
Key Links
Genomic Location
Cytogenetic map
Sequence location
X:18,657,755..18,661,204 [+]
Recombination map

1-60

RefSeq locus
NC_004354 REGION:18657755..18661204
Sequence
Other Genome Views
The following external sites may use different assemblies or annotations than FlyBase.
Function
GO Summary Ribbons
Protein Family (UniProt)
Belongs to the protein kinase superfamily. Ser/Thr protein kinase family. (P23647)
Summaries
Gene Group (FlyBase)
OTHER CONVENTIONAL PROTEIN KINASE DOMAIN KINASES -
The group of 'other conventional protein kinase domain kinases' consists of kinases with a conventional eukaryotic protein kinase domain that do not fit into any of the other major groups. This grouping is described in FBrf0201870.
Pathway (FlyBase)
Hedgehog Signaling Pathway Core Components -
The hedgehog signaling pathway is initiated by hedgehog (hh) ligand binding to the extracellular domain of patched receptor (ptc), leading to the derepression of smoothened (smo) activity. Activation of the atypical GPCR smo results in the accumulation of the transcriptional activator form of cubitus interruptus (ci) and the derepression/activation of hh target genes. In the absence of hh, smo is repressed by ptc and ci is processed to a truncated repressor form. (Adapted from FBrf0220683 and FBrf0231236).
Negative Regulators of BMP Signaling Pathway -
Negative regulators of Bone Morphogenetic Protein (BMP) signaling down-regulate the pathway, ultimately resulting in the decreased nuclear activity of the Mad/Med transcription factor complex.
Protein Function (UniProtKB)
Probable serine/threonine-protein kinase; maternally required for correct patterning in the posterior part of each embryonic metamere. May be involved in control of cell division during metamorphosis and ovarian development. May interact with costal-2.
(UniProt, P23647)
Phenotypic Description (Red Book; Lindsley and Zimm 1992)
fu: fused
thumb
fu: fused
Edith M. Wallace, unpublished.
Veins L3 and L4 fused from base to beyond anterior crossvein with elimination of anterior crossvein and first basal cell. L3 and L4 fused at tip; this fusion may reach back to basal cell. L3 may be thickened and branched to varying degrees; L4 may be partially or completely absent. Mosaic wings in which the posterior compartment is nearly entirely fu/fu may develop normally; alternatively, patches of + tissue in a fu wing may develop a fu phenotype (Fausto-Sterling, 1978, Dev. Biol. 63: 358-69). Wings usually extended; flightless owing to cuticle defect (Deak). Ocelli reduced or absent; bristles of ocellar region small or absent. Eyes small and slightly rough. Phototactic response normal (Benzer, 1967, Proc. Nat. Acad. Sci. USA 58: 1112-19). Anterior scutellar bristles reduced in number and scutellum shortened. Female late to eclose and has decreased longevity. Ovaries histologically normal at eclosion but with half the normal number of ovarioles (Beatty, 1949, Proc. Roy. Soc. Edinburgh, B 63: 249-70); fecundity 4% normal. Developing egg chambers may fuse or become tumorous with age (King, Burnett, and Staley, 1957, Growth 21: 239-61 (fig.)]. All aspects of phenotype respond in a coordinated fashion to experimental manipulation (Wust and Hanratty, 1979, Can. J. Genet. Cytol. 21: 335-46). Proportion of tumorous egg chambers increases by 6% per day. Females raised at 18 show only 10% the tumor development of those raised at 25. Tumor formation also enhanced by presence of YS (King, 1969, Nat. Cancer Inst. Monogr. 31: 323-45). Ovarian effects in females carrying fu and a deficiency for fu [i.e. In(1)ClLy4R = In(1)4A5-B1;17A6-B1L1A8-B1;18A3-4R] are more extreme than those in fu homozygote (King, 1959, DIS 33: 142-43; 1970). Alleles vary in strength; measures of ovarian tumor formation revealed that fu1 = fu14 > fu7 > fu13 > fu11 = fu12 [Smith and King, 1966, J. Nat. Cancer Inst. 36: 445-63 (fig.)]. fu/fu ovaries transplanted into fu+ hosts develop autonomously in regard to fertility (Clancy and Beadle, 1937, Biol. Bull. 72: 47-56; Sobels, 1950, Experientia 6: 139-40) and tumor formation (Smith, Bodenstein, and King, 1965, J. Exp. Zool. 159: 333-36). The few normal-appearing eggs that are laid by fu/fu females produce adults only if they have been fertilized by fu+-bearing sperm (Lynch, 1919, Genetics 4: 501-33). Eggs fertilized by fu- or Y-bearing sperm, with rare exceptions (Counce), develop into embryos that become abnormal 5-51/2 hr after fertilization. Lethal embryos exhibit incompletely penetrant segment polarity defects in which the anterior denticle-belt-bearing half of each segment shows mirror-image duplication replacing the naked cuticle of the posterior half; more pronounced in thoracic segments; penetrance in right and left hemisegments at the same level is not necessarily correlated. (Nusslein-Volhard and Wieschaus, 1980, Nature 287: 795-801, Gergen and Wieschaus, 1986, Wilhelm Roux's Arch. Dev. Biol. 195: 49-62). Elimination of regions of dorsal pattern and occasional head defects are also observed. fu eggs from fu/+ mothers develop normally. Segment polarity defects autonomous in mosaics (Gergen and Wieschaus). Heterozygous daughters from homozygous mothers on the other hand, often have abnormal abdominal segmentation and, as embryos, have abnormal musculature. This is a maternal effect not found in the reciprocal cross, and it is temperature sensitive (Armstrong and Sobels). RK1.
fu31
Homozygous and hemizygous females and hemizygous males die in pupal stage; lethality suppressible by Su(fu). fu31/fu41 and fu31/Y have all segments entirely duplicated; lack mouth hooks and some have no head. fu31/+ embryos from such clones exhibit very low paternal rescue; small correction of segmental phenotype, low hatch, and preadult mortality (Busson, Limbourg-Bouchon, Mariol, Preat and Lamour-Isnard, 1988, Roux's Arch. Dev. Biol. 197: 221-30).
fu33
A temperature-sensitive allele. fu wing-vein phenotype occurs at all temperatures; ocelli absent when raised at 22 but not at 17. TSP for absence of anterior ocellus from second instar through pupal stage, for posterior ocelli restricted to late third instar and early pupal stage. Flightless when raised at 22 or 29 but not at 17; wings held horizontally perpendicular to body at 29. Musculature abnormal when raised at restrictive temperatures [Homyk and Grigliatti, 1983, Dev. Genet. 4: 77-97 (fig.)].
fu40
fu40/Y sons of fu40/+ mothers die as late pupae or newly emerged adults; lethality suppressible by Su(fu). fu embryos produced by homozygous germ-line clones are mostly lethal (70%); those that hatch mostly achieve adulthood (Perrimon and Mahowald, 1987, Dev. Biol. 119: 587-600).
Summary (Interactive Fly)

serine/threonine kinase - segment polarity gene - cytoplasmic component of Hedgehog signaling pathway - Phosphorylation of the atypical kinesin Costal2 by Fused induces the partial disassembly of the Smoothened-Fused-Costal2-Cubitus interruptus complex in Hedgehog signalling

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

Please see the GBrowse view of Dmel\fu or the JBrowse view of Dmel\fu 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 5.51

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

Sequence Ontology: Class of Gene
Transcript Data
Annotated Transcripts
Name
FlyBase ID
RefSeq ID
Length (nt)
Assoc. CDS (aa)
FBtr0074602
3251
805
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
RefSeq ID
GenBank
FBpp0074373
90.4
805
6.66
Polypeptides with Identical Sequences

There is only one protein coding transcript and one polypeptide associated with this gene

Additional Polypeptide Data and Comments
Reported size (kDa)

805 (aa); 90 (kD predicted)

Comments
External Data
Crossreferences
MEROPS - An information resource for peptidases (also termed proteases, proteinases and proteolytic enzymes) and the proteins that inhibit them.
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\fu 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 (19 terms)
Molecular Function (4 terms)
Terms Based on Experimental Evidence (3 terms)
CV Term
Evidence
References
Terms Based on Predictions or Assertions (1 term)
CV Term
Evidence
References
inferred from electronic annotation with InterPro:IPR000719, InterPro:IPR002290, InterPro:IPR017441
(assigned by InterPro )
Biological Process (11 terms)
Terms Based on Experimental Evidence (10 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:PTN001122621
(assigned by GO_Central )
Cellular Component (4 terms)
Terms Based on Experimental Evidence (3 terms)
CV Term
Evidence
References
inferred from physical interaction with FLYBASE:cos; FB:FBgn0000352
inferred from physical interaction with FLYBASE:ci; FB:FBgn0004859
inferred from direct assay
inferred from physical interaction with FLYBASE:Su(fu); FB:FBgn0005355
Terms Based on Predictions or Assertions (1 term)
CV Term
Evidence
References
inferred from biological aspect of ancestor with PANTHER:PTN000541535
(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
in situ
Stage
Tissue/Position (including subcellular localization)
Reference
northern blot
Stage
Tissue/Position (including subcellular localization)
Reference
Additional Descriptive Data

Transcript is detected starting in the midgermarium in cells corresponding to mature 16-cell germline-cysts and prefollicular and follicual cells. Transcript is detected in stage 2 and 3 egg chambers with both somatic and germline cell expression.

fu transcripts are most abundant in early embryos and adult females. They are also observed at low levels in larvae, pupae, and adult males. Transcripts are first detected by in situ hybridization at stage S8 of oogenesis in nurse cells and appear to flow in the oocyte as oogenesis proceeds. fu transcripts are uniformly distributed in preblastoderm embryos, are located in cortical cells at the cellular blastoderm stage, and are present in all germ layers at similar levels in germ band extended embryos. They are not detected after germ band retraction. In imaginal discs, fu transcripts are present in all cells but are more abundant in wing than in leg discs.

The 3.2kb fu transcript is present at much higher levels in females than males. It is also present in 0-3hr and 3-6hr embyros.

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

fu protein isdetected in a pattern completely overlapping that of its transcript in the germarium and early egg chambers. The protein is detected in the cytoplasm.

Marker for
 
Subcellular Localization
CV Term
Evidence
References
inferred from physical interaction with FLYBASE:cos; FB:FBgn0000352
inferred from physical interaction with FLYBASE:ci; FB:FBgn0004859
inferred from direct assay
inferred from physical interaction with FLYBASE:Su(fu); FB:FBgn0005355
Expression Deduced from Reporters
High-Throughput Expression Data
Associated Tools

GBrowse - Visual display of RNA-Seq signals

View Dmel\fu in GBrowse 2
RNA-Seq by Region - Search RNA-Seq expression levels by exon or genomic region
Reference
See Gelbart and Emmert, 2013 for analysis details and data files for all genes.
Developmental Proteome: Life Cycle
Developmental Proteome: Embryogenesis
External Data and Images
Linkouts
FLIGHT - Cell culture data for RNAi and other high-throughput technologies
FlyAtlas - Adult expression by tissue, using Affymetrix Dros2 array
Fly-FISH - A database of Drosophila embryo and larvae mRNA localization patterns
Flygut - An atlas of the Drosophila adult midgut
Images
Alleles, Insertions, and Transgenic Constructs
Classical and Insertion Alleles ( 78 )
For All Classical and Insertion Alleles Show
 
Other relevant insertions
Transgenic Constructs ( 92 )
For All Alleles Carried on Transgenic Constructs Show
Transgenic constructs containing/affecting coding region of fu
Transgenic constructs containing regulatory region of fu
Deletions and Duplications ( 29 )
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
macrochaeta & tarsal segment 5 | distal
microchaeta & tarsal segment 1
microchaeta & tarsal segment 2
microchaeta & tarsal segment 3
microchaeta & tarsal segment 4
microchaeta & tarsal segment 5
Orthologs
Human Orthologs (via DIOPT v7.1)
Homo sapiens (Human) (2)
Species\Gene Symbol
Score
Best Score
Best Reverse Score
Alignment
Complementation?
Transgene?
9 of 15
Yes
Yes
 
1 of 15
No
Yes
Model Organism Orthologs (via DIOPT v7.1)
Mus musculus (laboratory mouse) (2)
Species\Gene Symbol
Score
Best Score
Best Reverse Score
Alignment
Complementation?
Transgene?
8 of 15
Yes
Yes
1 of 15
No
Yes
Rattus norvegicus (Norway rat) (2)
7 of 13
Yes
Yes
1 of 13
No
Yes
Xenopus tropicalis (Western clawed frog) (2)
4 of 12
Yes
Yes
1 of 12
No
Yes
Danio rerio (Zebrafish) (2)
10 of 15
Yes
Yes
1 of 15
No
Yes
Caenorhabditis elegans (Nematode, roundworm) (1)
1 of 15
Yes
Yes
Arabidopsis thaliana (thale-cress) (1)
3 of 9
Yes
Yes
Saccharomyces cerevisiae (Brewer's yeast) (2)
1 of 15
Yes
No
1 of 15
Yes
No
Schizosaccharomyces pombe (Fission yeast) (0)
No records found.
Orthologs in Drosophila Species (via OrthoDB v9.1) ( EOG0919036B )
Organism
Common Name
Gene
AAA Syntenic Ortholog
Multiple Dmel Genes in this Orthologous Group
Drosophila melanogaster
fruit fly
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) ( EOG0915037W )
Organism
Common Name
Gene
Multiple Dmel Genes in this Orthologous Group
Musca domestica
House fly
Glossina morsitans
Tsetse fly
Lucilia cuprina
Australian sheep blowfly
Mayetiola destructor
Hessian fly
Aedes aegypti
Yellow fever mosquito
Anopheles gambiae
Malaria mosquito
Culex quinquefasciatus
Southern house mosquito
Orthologs in non-Dipteran Insects (via OrthoDB v9.1) ( EOG090W02ZY )
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
Dendroctonus ponderosae
Mountain pine beetle
Tribolium castaneum
Red flour beetle
Tribolium castaneum
Red flour beetle
Tribolium castaneum
Red flour 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) ( EOG090X02WQ )
Organism
Common Name
Gene
Multiple Dmel Genes in this Orthologous Group
Strigamia maritima
European centipede
Strigamia maritima
European centipede
Strigamia maritima
European centipede
Daphnia pulex
Water flea
Orthologs in non-Arthropod Metazoa (via OrthoDB v9.1) ( EOG091G04G9 )
Organism
Common Name
Gene
Multiple Dmel Genes in this Orthologous Group
Strongylocentrotus purpuratus
Purple sea urchin
Strongylocentrotus purpuratus
Purple sea urchin
Gallus gallus
Domestic chicken
Paralogs
Paralogs (via DIOPT v7.1)
Drosophila melanogaster (Fruit fly) (3)
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
    esyN Network Diagram
    Show neighbor-neighbor interactions:
    Select Layout:
    Legend:
    Protein
    RNA
    Selected Interactor(s)
    Interactions Browser

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

    Please look at the allele data for full details of the genetic interactions
    Starting gene(s)
    Interaction type
    Interacting gene(s)
    Reference
    suppressible
    Starting gene(s)
    Interaction type
    Interacting gene(s)
    Reference
    enhanceable
    suppressible
    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 (genetic) - An integrated Molecular Interaction Database
    MIST (protein-protein) - An integrated Molecular Interaction Database
    Pathways
    Signaling Pathways (FlyBase)
    Hedgehog Signaling Pathway Core Components -
    The hedgehog signaling pathway is initiated by hedgehog (hh) ligand binding to the extracellular domain of patched receptor (ptc), leading to the derepression of smoothened (smo) activity. Activation of the atypical GPCR smo results in the accumulation of the transcriptional activator form of cubitus interruptus (ci) and the derepression/activation of hh target genes. In the absence of hh, smo is repressed by ptc and ci is processed to a truncated repressor form. (Adapted from FBrf0220683 and FBrf0231236).
    Negative Regulators of BMP Signaling Pathway -
    Negative regulators of Bone Morphogenetic Protein (BMP) signaling down-regulate the pathway, ultimately resulting in the decreased nuclear activity of the Mad/Med transcription factor complex.
    Metabolic Pathways
    External Data
    Genomic Location and Detailed Mapping Data
    Chromosome (arm)
    X
    Recombination map

    1-60

    Cytogenetic map
    Sequence location
    X:18,657,755..18,661,204 [+]
    FlyBase Computed Cytological Location
    Cytogenetic map
    Evidence for location
    17D1-17D1
    Limits computationally determined from genome sequence between P{EP}EP443EP443&P{EP}BxEP1383 and P{EP}Pk17EEP438
    Experimentally Determined Cytological Location
    Cytogenetic map
    Notes
    References
    17C4-17C6
    (determined by in situ hybridisation)
    17C-17E
    (determined by in situ hybridisation)
    Experimentally Determined Recombination Data
    Location
    Left of (cM)
    Right of (cM)
    Notes
    Stocks and Reagents
    Stocks (26)
    Genomic Clones (12)
     

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

    cDNA Clones (25)
     

    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)
    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
     
    Developmental Studies Hybridoma Bank - Monoclonal antibodies for use in research
    Other Information
    Relationship to Other Genes
    Source for database identify of

    Source for identity of: fu CG6551

    Source for database merge of
    Additional comments

    No complementation observed in 120 heteroallelic combinations (Wurst and Hanratty, 1979).

    Other Comments

    smo protein promotes the relocalisation of fu protein from vesicles to the plasma membrane in response to hh signaling and reciprocally, fu protein controls the stability and phosphorylation of smo protein.

    fu blocks cos binding with smo through phosphorylation of cos, leading to cell-surface accumulation of smo.

    fu regulates the stability of cos through phosphorylation.

    fu has the ability to directly bind both cos and smo (in a hh-independent manner).

    Identified as a component of the hh signalling pathway in a genome-wide RNAi screen. dsRNA made from templates generated with primers directed affects the extent of expression of a hh signaling reporter construct in Clone 8 cells.

    dsRNA made from templates generated with primers directed against this gene tested in RNAi screen for effects on Kc167 and S2R+ cell morphology.

    9 alleles of fu have been recovered in a screen for mutations with smo-like mutant phenotypes in clones in the wing.

    fu protein phosphorylates cos protein. The primary site of phosphorylation is Ser-572, with Ser-931 being phosphorylated to a lesser extent.

    fu participates in to partially redundant pathways to regulate ci nuclear import; the kinase function plays a positive role by inhibiting Su(fu), and the regulatory domain plays a negative role in conjunction with cos.

    fu may stimulate the hh pathway, not by promoting the formation of ciact, but rather by facilitating its entry into the nucleus.

    fu is required autonomously in anterior cells neighboring hh to maintain ptc and wg expression.

    Using the yeast two-hybrid method and an in vitro binding assay it is demonstrated that Su(fu), ci and fu can interact directly to form a trimolecular complex, with Su(fu) binding to both its partners simultaneously. In the absence of hh signalling results propose that Su(fu) inhibits ci by binding to it and that, upon reception of the hh signal, fu is activated and counteracts Su(fu), leading to the activation of ci.

    Su(fu) and fu modify wing phenotypes due to hh signalling.

    hh elicits signal transduction via a complex that includes the products of the fu, ci and cos genes. The complex binds with high affinity to microtubules in the absence of hh protein, but not when hh is present. The complex may facilitate signalling from hh by governing access of the ci product to the nucleus.

    Mutations in the catalytic domain of the fu protein abolish both its biological function and its association with cos protein.

    Genetic and molecular analysis of both endogenous and in vitro induced fu mutant alleles has been performed to characterise the function of fu and to assess the role of the different fu protein domains.

    fu protein is phosphorylated during embryogenesis as a result of hh activity. Results from cell culture studies suggest that fu and Pka-C1 function downstream of hh but in parallel pathways that eventually converge distal to fu.

    The small lobe of fu may play a role in generating the neomorphic cos phenotype displayed by an unregulated fu protein in a Su(fu)- background.

    DNA comparison of fu and Dvir\fu identifies regions conserved during evolution: the 268 amino acid kinase domain and a domain within the third exon. Stretches of conserved sequences are also observed in the 5' and 3' untranslated sequences.

    Mutations at the fu locus result in morphological defects in the adult compound eye and mechano-sensory bristles. Genetic analysis reveals that sca enhances the fu phenotype suggesting a possible interaction between fu and sca.

    fu and hh modulate the post-transcriptional regulation of ci protein.

    Genetic and molecular data suggest that fu and Su(fu) could act through a competitive posttransductional modification of a common target in the hh signalling pathway.

    Scer\GAL4 under the control of wg, en, h and prd driving the expression of fu genomic fragment downstream of a UAS element has been used to test phenotypic rescue of fu- embryos be localised fu expression.

    The migration of wing glial cells is affected by N and fu, which both affect axonogenesis, suggesting that the two processes are tightly associated.

    Direct wg autoregulation differs from wg signalling to adjacent cells in the importance of fu, smo and ci relative to sgg and arm.

    Mutants display hyperplastic phenotype, tissue overgrowth in mitotic recombination clones and in the germline.

    fu and ci are required for normal wg transcription, acting downstream of ptc to regulate wg transcription. Transcriptional control of ptc is mediated by fu and ci.

    Segment polarity mutations cause stripes of abnormal patterning within sectors of the leg disc, which may be mediated by regional perturbations in growth.

    Competence of cells to express wg is independent of their ability to receive the hh signal. wg activation requires the function of fu, this suggests that the putative hh signal is transduced by the serine/threonine kinase that fu encodes.

    The genetic hierarchy regulating female germ-line sex determination includes tra, tra2, dsx, fu, otu, ovo, snf and Sxl. fu, otu, ovo and snf function upstream of Sxl.

    fu alleles are qualitatively classified and the molecular bases underlying the classification reflects the functional organisation of the fu gene locus.

    The structure of the fu transcription unit, its temporal and spatial expression are analysed.

    wg and en expression patterns are studied in all known segment polarity mutants to investigate the requirement of other segment polarity genes in mediating the maintenance of wg and en.

    Wing phenotype and maternally determined lethality of fu mutants suppressed by loss of function mutations at Su(fu).

    Segmentation genes interacting with fu have been identified.

    Mutations in fu cause extra longitudinal or transverse veins with plexated vein phenotypes. kn, fu and shf act synergistically against Px, px, net, dsr and emc.

    Molecular data suggests that fu encodes a putative Ser/Thr protein kinase.

    The kn and fu loci belong to the knot phenotypic group within the 'excess-of-vein' mutant class. Mutants generate a medial shift in the position of the longitudinal veins, sensilla and chaetae. Double mutants are superadditive in vein pattern defects.

    Role of fu in neurogenesis has been studied.

    Molecular analysis of fu mutations reveals that they fall into two groups; large deficiencies or, point mutations or extremely small deletions. Both class of mutations interact with Su(fu) and cos.

    Genetic analysis of viable and lethal alleles of fu has been performed and demonstrates that zygotic expression of fu is required for normal metamorphosis, while maternal expression is necessary for a normal segmentation pattern.

    DNA sequences thought to contain fu have been identified and injected into fu mutant embryos: partial rescue of the mutant phenotype was obtained.

    Veins L3 and L4 fused from base to beyond anterior crossvein with elimination of anterior crossvein and first basal cell. L3 and L4 fused at tip; this fusion may reach back to basal cell. L3 may be thickened and branched to varying degrees; L4 may be partially or completely absent. Mosaic wings in which the posterior compartment is nearly entirely fu/fu may develop normally; alternatively, patches of + tissue in a fu wing may develop a fu phenotype (Fausto-Sterling, 1978). Wings usually extended; flightless owing to cuticle defect (Deak, 1976). Ocelli reduced or absent; bristles of ocellar region small or absent. Eyes small and slightly rough. Phototactic response normal (Benzer, 1967). Anterior scutellar bristles reduced in number and scutellum shortened. Female late to eclose and has decreased longevity. Ovaries histologically normal at eclosion but with half the normal number of ovarioles (Beatty, 1949); fecundity 4% normal. Developing egg chambers may fuse or become tumorous with age (King, Burnett, and Staley, 1957). All aspects of phenotype respond in a coordinated fashion to experimental manipulation (Wust and Hanratty, 1979). Proportion of tumorous egg chambers increases by 6% per day. Females raised at 18oC show only 10% the tumor development of those raised at 25oC. Tumor formation also enhanced by presence of YS (King, 1969). Ovarian effects in females carrying fu and a deficiency for fu <up>E.G. In(1)ClLy4R</up> are more extreme than those in fu homozygote (King, 1959). Alleles vary in strength; measures of ovarian tumor formation revealed that fu1 = fu14 > fu7 > fu13 > fu11 = fu12 (Smith and King, 1966). fu/fu ovaries transplanted into fu+ hosts develop autonomously in regard to fertility (Clancy and Beadle, 1937) (Sobels, 1950) and tumor formation (Smith, Bodenstein and King, 1965). The few normal-appearing eggs that are laid by fu/fu females produce adults only if they have been fertilized by fu+-bearing sperm (Lynch, 1919). Eggs fertilized by fu- or Y-bearing sperm, with rare exceptions (Counce, 1956), develop into embryos that become abnormal 5-5.5 hr after fertilization. Lethal embryos exhibit incompletely penetrant segment polarity defects in which the anterior denticle-belt-bearing half of each segment shows mirror-image duplication replacing the naked cuticle of the posterior half; more pronounced in thoracic segments; penetrance in right and left hemisegments at the same level is not necessarily correlated. (Nusslein-Volhard and Wieschaus, 1980; Gergen and Wieschaus, 1986). Elimination of regions of dorsal pattern and occasional head defects are also observed. fu eggs from fu/+ mothers develop normally. Segment polarity defects autonomous in mosaics (Gergen and Wieschaus, 1986). Heterozygous daughters from homozygous mothers on the other hand, often have abnormal abdominal segmentation and, as embryos, have abnormal musculature. This is a maternal effect not found in the reciprocal cross and it is temperature-sensitive (Armstrong and Sobels).

    Origin and Etymology
    Discoverer

    Bridges, 4th Nov. 1912.

    Etymology
    Identification
    External Crossreferences and Linkouts ( 56 )
    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
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    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
    Reactome - An open-source, open access, manually curated and peer-reviewed pathway database.
    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.
    MEROPS - An information resource for peptidases (also termed proteases, proteinases and proteolytic enzymes) and the proteins that inhibit them.
    modMine - A data warehouse for the modENCODE project
    SignaLink - A signaling pathway resource with multi-layered regulatory networks.
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    BioGRID - A database of protein and genetic interactions.
    DPiM - Drosophila Protein interaction map
    DroID - A comprehensive database of gene and protein interactions.
    DRSC - Results frm RNAi screens
    Developmental Studies Hybridoma Bank - Monoclonal antibodies for use in research
    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 (genetic) - An integrated Molecular Interaction Database
    MIST (protein-protein) - An integrated Molecular Interaction Database
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