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General Information
Symbol
Dmel\sev
Species
D. melanogaster
Name
sevenless
Annotation Symbol
CG18085
Feature Type
FlyBase ID
FBgn0003366
Gene Model Status
Stock Availability
Enzyme Name (EC)
Receptor protein-tyrosine kinase (2.7.10.1)
Gene Snapshot
Also Known As

DmHD-265, DROSEV1

Key Links
Genomic Location
Cytogenetic map
Sequence location
X:11,071,441..11,086,299 [-]
Recombination map

1-33

RefSeq locus
NC_004354 REGION:11071441..11086299
Sequence
Other Genome Views
The following external sites may use different assemblies or annotations than FlyBase.
Function
GO Summary Ribbons
Gene Ontology (GO) Annotations (15 terms)
Molecular Function (5 terms)
Terms Based on Experimental Evidence (3 terms)
CV Term
Evidence
References
inferred from physical interaction with FLYBASE:drk; FB:FBgn0004638
inferred from physical interaction with UniProtKB:P98081
(assigned by UniProt )
inferred from physical interaction with FLYBASE:boss; FB:FBgn0000206
Terms Based on Predictions or Assertions (2 terms)
CV Term
Evidence
References
inferred from electronic annotation with InterPro:IPR000719, InterPro:IPR002011, InterPro:IPR017441
(assigned by InterPro )
inferred from biological aspect of ancestor with PANTHER:PTN001230349
(assigned by GO_Central )
Biological Process (8 terms)
Terms Based on Experimental Evidence (4 terms)
CV Term
Evidence
References
Terms Based on Predictions or Assertions (4 terms)
CV Term
Evidence
References
inferred from biological aspect of ancestor with PANTHER:PTN001230349
(assigned by GO_Central )
inferred from biological aspect of ancestor with PANTHER:PTN001230349
(assigned by GO_Central )
inferred from biological aspect of ancestor with PANTHER:PTN002814742
(assigned by GO_Central )
inferred from biological aspect of ancestor with PANTHER:PTN001230349
(assigned by GO_Central )
Cellular Component (2 terms)
Terms Based on Experimental Evidence (1 term)
CV Term
Evidence
References
Terms Based on Predictions or Assertions (2 terms)
CV Term
Evidence
References
inferred from biological aspect of ancestor with PANTHER:PTN001230349
(assigned by GO_Central )
inferred from biological aspect of ancestor with PANTHER:PTN001230349
(assigned by GO_Central )
Gene Group (FlyBase)
Protein Family (UniProt)
Belongs to the protein kinase superfamily. Tyr protein kinase family. Insulin receptor subfamily. (P13368)
Catalytic Activity (EC)
Experimental Evidence
-
Predictions / Assertions
ATP + a [protein]-L-tyrosine = ADP + a [protein]-L-tyrosine phosphate (2.7.10.1)
Summaries
Pathway (FlyBase)
Sevenless Signaling Pathway Core Components -
The specification of the R7 photoreceptor cell in each ommatidium of the developing Drosophila eye is dependent on activation of Sevenless receptor tyrosine kinase, which acts via the canonical Ras/Raf/MAP kinase cascade to promote the expression of lz and pros. sev, expressed in presumptive R7 cells, is activated by binding to Bride of Sevenless (boss), a seven-transmembrane protein expressed in R8 cells. (Adapted from FBrf0127283 and FBrf0221727).
Gene Group (FlyBase)
RECEPTOR TYROSINE KINASES -
Receptor tyrosine kinases (RTK) are single-pass transmembrane receptors expressed on the plasma membrane. Upon the binding of an extracellular signalling molecule (e.g. growth factors, hormones), RTKs dimerize leading to the activation of the intracellular tyrosine kinase domain and intermolecular phosphorylation. The phosphotyrosines function as specific sites for the assembly, phosphorylation and activation of downstream signaling molecules. (Adapted from PMID:20602996).
Protein Function (UniProtKB)
Receptor for an extracellular signal required to instruct a cell to differentiate into an R7 photoreceptor. The ligand for sev is the boss (bride of sevenless) protein on the surface of the neighboring R8 cell.
(UniProt, P13368)
Phenotypic Description (Red Book; Lindsley and Zimm 1992)
sev: sevenless
Homozygotes and hemizygotes lack the R7 rhabdomere in all ommatidia; the R7 photoreceptor cell instead develops as an accessory lens-secreting cell, the equatorial cone cell (Tomlinson and Ready, 1986, 1987). Cell autonomous in mosaics (Harris et al.). Mosaic analysis demonstrates that sev+ product is required only in the presumptive photoreceptor 7 cell and is therefore involved in receiving signals from neighboring cells. Electroretinograms normal; defective in response to ultraviolet; in T-maze tests sev flies prefer visible to ultraviolet wavelengths and green light to darkness; slight preference for blue wavelengths over ultraviolet used in selecting mutant alleles (Gerresheim, 1988, Behav. Genet. 18: 227-46). In the presence of Phb the preference of green light to darkness is reversed for sev1 and sev10 but not for six other unspecified alleles; the absence of R7 is unaffected by Phb (Ballinger and Benzer, 1988, Proc. Nat. Acad. Sci. 85: 3960-64). Gene expression demonstrated by in situ hybridization and immune staining to take place in developing eye imaginal disc, near and posterior to the morphogenetic furrow, during ommatidial differentiation. Protein present transiently in at least nine cells in each developing ommatidium and is detectable before any overt differentiation of R7 observed (Tomlinson et al., 1987; Banerjee et al., 1987a). Transient expression of sev+ by means of a transformed construct under control of the Hsp70 promoter in a sev background results in a narrow stripe of ommatidia that contain photoreceptor cell 7 in eyes that are otherwise sevenless; the position and time of expression required for normal function are highly restricted (Bowtell, Simon, and Rubin, 1989, Cell 56: 931-36).
Summary (Interactive Fly)

transmembrane - receptor TK - required for the development of the R7 photoreceptor - Sevenless signaling from somatic cells is required to ensure that the niche develops in the anterior region of the male embryonic gonads

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

Please see the JBrowse view of Dmel\sev 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 5.50

Sequence Ontology: Class of Gene
Transcript Data
Annotated Transcripts
Name
FlyBase ID
RefSeq ID
Length (nt)
Assoc. CDS (aa)
FBtr0073393
8171
2554
Additional Transcript Data and Comments
Reported size (kB)

8.6 (northern blot)

Comments
External Data
Crossreferences
Polypeptide Data
Annotated Polypeptides
Name
FlyBase ID
Predicted MW (kDa)
Length (aa)
Theoretical pI
RefSeq ID
GenBank
FBpp0073249
287.2
2554
6.32
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)

2554 (aa); 288 (kD predicted)

Comments
External Data
Subunit Structure (UniProtKB)

May form a complex with drk and Sos. Binds the phosphotyrosine interaction domain (PID) of Dab.

(UniProt, P13368)
Domain

It is unclear whether the potential membrane spanning region near the N-terminus is present as a transmembrane domain in the native protein or serves as a cleaved signal sequence.

(UniProt, P13368)
Linkouts
Sequences Consistent with the Gene Model
Nucleotide / Polypeptide Records
 
Mapped Features

Click to get a list of regulatory features (enhancers, TFBS, etc.) and gene disruptions (point mutations, indels, etc.) within or overlapping Dmel\sev 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
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

sev is expressed in a male-specific manner in a subset of somatic gonadal precursors in the posterior portion of the gonad. Expression begins at embryonic stage 13 and persists until the end of embryogenesis.

sev transcript is detected in bodies at one third the level of heads.

Marker for
 
Subcellular Localization
CV Term
Polypeptide Expression
mass spectroscopy
Stage
Tissue/Position (including subcellular localization)
Reference
Additional Descriptive Data
Marker for
 
Subcellular Localization
CV Term
Evidence
References
Expression Deduced from Reporters
High-Throughput Expression Data
Associated Tools

GBrowse - Visual display of RNA-Seq signals

View Dmel\sev 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
Alleles, Insertions, and Transgenic Constructs
Classical and Insertion Alleles ( 42 )
For All Classical and Insertion Alleles Show
 
Other relevant insertions
Transgenic Constructs ( 41 )
For All Alleles Carried on Transgenic Constructs Show
Transgenic constructs containing/affecting coding region of sev
Transgenic constructs containing regulatory region of sev
Deletions and Duplications ( 38 )
Not disrupted in
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 v8.0)
Homo sapiens (Human) (11)
Species\Gene Symbol
Score
Best Score
Best Reverse Score
Alignment
Complementation?
Transgene?
14 of 15
Yes
Yes
2 of 15
No
No
16  
2 of 15
No
No
2 of 15
No
No
1 of 15
No
No
1 of 15
No
No
1  
1 of 15
No
Yes
1 of 15
No
Yes
1 of 15
No
Yes
1 of 15
No
Yes
1 of 15
No
Yes
Model Organism Orthologs (via DIOPT v8.0)
Mus musculus (laboratory mouse) (10)
Species\Gene Symbol
Score
Best Score
Best Reverse Score
Alignment
Complementation?
Transgene?
15 of 15
Yes
Yes
2 of 15
No
No
2 of 15
No
No
1 of 15
No
No
1 of 15
No
No
1 of 15
No
Yes
1 of 15
No
No
1 of 15
No
Yes
1 of 15
No
Yes
1 of 15
No
Yes
Rattus norvegicus (Norway rat) (10)
13 of 13
Yes
Yes
2 of 13
No
No
2 of 13
No
Yes
2 of 13
No
No
1 of 13
No
No
1 of 13
No
No
1 of 13
No
No
1 of 13
No
Yes
1 of 13
No
Yes
1 of 13
No
Yes
Xenopus tropicalis (Western clawed frog) (5)
3 of 12
Yes
Yes
1 of 12
No
No
1 of 12
No
No
1 of 12
No
Yes
1 of 12
No
Yes
Danio rerio (Zebrafish) (12)
6 of 15
Yes
Yes
2 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
Yes
1 of 15
No
Yes
1 of 15
No
Yes
1 of 15
No
Yes
1 of 15
No
Yes
Caenorhabditis elegans (Nematode, roundworm) (6)
6 of 15
Yes
Yes
1 of 15
No
No
1 of 15
No
Yes
1 of 15
No
No
1 of 15
No
No
1 of 15
No
Yes
Arabidopsis thaliana (thale-cress) (0)
No records found.
Saccharomyces cerevisiae (Brewer's yeast) (0)
No records found.
Schizosaccharomyces pombe (Fission yeast) (0)
No records found.
Ortholog(s) in Drosophila Species (via OrthoDB v9.1) ( EOG0919004L )
Organism
Common Name
Gene
AAA Syntenic Ortholog
Multiple Dmel Genes in this Orthologous Group
Drosophila suzukii
Spotted wing Drosophila
Drosophila simulans
Drosophila sechellia
Drosophila erecta
Drosophila yakuba
Drosophila ananassae
Drosophila pseudoobscura pseudoobscura
Drosophila persimilis
Drosophila virilis
Drosophila mojavensis
Drosophila grimshawi
Orthologs in non-Drosophila Dipterans (via OrthoDB v9.1) ( EOG0915002V )
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 darlingi
American malaria mosquito
Anopheles darlingi
American malaria mosquito
Anopheles gambiae
Malaria mosquito
Culex quinquefasciatus
Southern house mosquito
Orthologs in non-Dipteran Insects (via OrthoDB v9.1) ( EOG090W0029 )
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
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
Acyrthosiphon pisum
Pea aphid
Acyrthosiphon pisum
Pea aphid
Zootermopsis nevadensis
Nevada dampwood termite
Orthologs in non-Insect Arthropods (via OrthoDB v9.1) ( EOG090X0024 )
Organism
Common Name
Gene
Multiple Dmel Genes in this Orthologous Group
Strigamia maritima
European centipede
Stegodyphus mimosarum
African social velvet spider
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) ( EOG091G003T )
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
Gallus gallus
Domestic chicken
Gallus gallus
Domestic chicken
Gallus gallus
Domestic chicken
Paralogs
Paralogs (via DIOPT v8.0)
Drosophila melanogaster (Fruit fly) (19)
4 of 10
3 of 10
2 of 10
2 of 10
2 of 10
2 of 10
2 of 10
2 of 10
2 of 10
2 of 10
2 of 10
2 of 10
2 of 10
2 of 10
2 of 10
2 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 v8.0 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
    suppressible
    Starting gene(s)
    Interaction type
    Interacting gene(s)
    Reference
    External Data
    Subunit Structure (UniProtKB)
    May form a complex with drk and Sos. Binds the phosphotyrosine interaction domain (PID) of Dab.
    (UniProt, P13368 )
    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)
    Sevenless Signaling Pathway Core Components -
    The specification of the R7 photoreceptor cell in each ommatidium of the developing Drosophila eye is dependent on activation of Sevenless receptor tyrosine kinase, which acts via the canonical Ras/Raf/MAP kinase cascade to promote the expression of lz and pros. sev, expressed in presumptive R7 cells, is activated by binding to Bride of Sevenless (boss), a seven-transmembrane protein expressed in R8 cells. (Adapted from FBrf0127283 and FBrf0221727).
    Metabolic Pathways
    External Data
    Linkouts
    KEGG Pathways - Wiring diagrams of molecular interactions, reactions and relations.
    Genomic Location and Detailed Mapping Data
    Chromosome (arm)
    X
    Recombination map

    1-33

    Cytogenetic map
    Sequence location
    X:11,071,441..11,086,299 [-]
    FlyBase Computed Cytological Location
    Cytogenetic map
    Evidence for location
    10A4-10A4
    Limits computationally determined from genome sequence between P{EP}EP1321EP1321&P{EP}CG2061EP1537 and P{EP}CG11756EP1610
    Experimentally Determined Cytological Location
    Cytogenetic map
    Notes
    References
    Cytogenetic location of 10A1--10A2 based on known data for C901, v and sev, previous data described in FBrf0073632, and comparison with the physical map (Release 5.8).
    10A1-10B2
    (determined by in situ hybridisation)
    10A1-10A2
    (determined by in situ hybridisation)
    Experimentally Determined Recombination Data
    Location

    1-33.4

    Right of (cM)
    Notes
    Stocks and Reagents
    Stocks (10,541)
    Genomic Clones (24)
    cDNA Clones (5)
     

    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 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
        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
         

        monoclonal

        Commercially Available Antibodies
         
        Other Information
        Relationship to Other Genes
        Source for database identify of

        Source for identity of: sev CG18085

        Source for database merge of
        Additional comments

        Identified by PCR fragment; relationship to other protein tyrosine kinase genes not known.

        Other Comments

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

        csw and activated sev proteins are associated in vivo in a manner that does not require either csw SH2 domain function or tyrosine phosphorylation of sev protein.

        Mutant eye phenotype suggests sev function is restricted to R7 photoreceptor determination.

        Oligomeric forms of the secreted extracellular domain of boss, Exboss, bind the sev receptor in vitro.

        Phylogenetic analysis of the PTK family.

        The csw SH2-containing tyrosine phosphatase is required during signalling by sev, Ras85D and phl.

        The protein encoded by dos is a csw substrate and may also be a direct or indirect target for the tyrosine kinase activity of sev. Mutations that inactivate dos dominantly enhance the effects of reduced csw activity and suppress the effects of either excessive sev or csw activity. Results indicate that dos is a crucial component of the sev signalling pathway and strongly suggest that dephosphorylation of dos by csw promotes R7 photoreceptor differentiation.

        pros gene becomes transcriptionally activated at a low level in all sev-competent cells prior to sev signaling and this requires the activities of Ras85D and two ETS transcription factors, aop and pnt. Restriction of high level pros expression to the R7 cell appears as a subsequent event, which requires sev activation of the Ras85D kinase pathway.

        dos functions upstream or independent of Ras85D and defines a signalling pathway that is independent of direct binding of the drk SH2/SH3 adaptor protein to the sev receptor tyrosine kinase.

        Studies of interaction between argos and members of the Ras/MAPK pathway demonstrate the argos gene product is a negative regulator of signal transduction that acts upstream of the Ras/MAPK cascade.

        Variation of a microsatellite within the sev locus has been studied in North American populations of D.melanogaster.

        A drk-independent interaction between Sos and sev has been proposed that is likely mediated by the pleckstrin homology domain within the amino terminus of Sos.

        Tyr2546 in the cytoplasmic tail of the sev protein is required for drk protein binding though a mutation in this site does not completely block sev function in vivo.

        Jra is required downstream of the sev signalling pathway for development in the eye.

        In vitro studies show that boss activates tyrosine phosphorylation of the sev receptor and the transmembrane domain of boss is necessary for its function. A soluble form of boss acts as an antagonist of the sev receptor both in vivo and in vitro.

        Functional interchangeability of D.melanogaster and D.virilis sev and boss were demonstrated using chimeric genes.

        Dosage-dependent genetic interaction between S and sev, Ras85D and Sos (involved in receptor tyrosine kinase signalling) supports a role for S in cell-cell signalling.

        As part of a study of an R7-lacking strain of D.virilis, the surface of a sev mutant eye was examined by scanning electron microscopy: occasional irregularities where two surface hairs relace the usual one per ommatidium were described.

        Antibody staining demonstrates that the entire boss protein is internalized by sev-expressing tissue culture cells and by the R7 precursor cell in the developing eye imaginal disc demonstrating the receptor mediated transfer of a transmembrane ligand.

        Results obtained using a constitutively active sevenless kinase show that competence to develop as neuronal cells is spatially and temporally limited to sevenless-expressing cells, thereby revealing that the expression of sev marks a preexisting pattern of developmental potential. sev and sina act in a pathway required for neuronal development, rather than R7 cell fate per se.

        The phl serine/threonine kinase plays a crucial role in the R7 pathway: the response to sev gene product activity is dependent on phl function, and a constitutively activated phl protein can induce R7 cell development in the absence of sev function. Genetic evidence suggests that phl acts downstream of Ras85D and upstream of sina in this signal transduction pathway.

        Mutations of Gap1 are capable of suppressing sev and boss amorphic mutations and of triggering normal R7 development. Gap1 functions downstream of boss and sev in determining the R7 cell fate.

        Some aspect of R7 differentiation is independent of the genetic pathway involving sev, boss and sina as some P{HZ}klgH214 expression is present in R7 of sev mutants.

        Receptor cell R7 can be produced in the absence of sev+ by disrupting aop.

        Increased sev activity in cells where sev is normally expressed results in ligand-independent formation of multiple R7-like cells per ommatidium by changing the fate of ommatidial precursor cells. sev activity is sufficient for the specification of R7 cell fate.

        A 475bp fragment within the sev gene that contains sequences required for the correct expression of sev has been identified by studying the expression of a number of sev-Ecol\lacZ fusion constructs.

        The R8 photoreceptor neuron induces a neighbouring cell to assume an R7 cell fate. The induction is mediated by two transmembrane proteins encoded by sev and boss.

        Suppression of sev by Sos is allele-specific.

        A genetic screen for mutations that decrease the effectiveness of signalling by sev identified 7 genes, enhancers of sevenless, that when mutated make the phenotype of sevB4 more severe.

        The R7 cell shows a strict requirement for sev gene function. sev expressing cells that do not contact R8 are competent to respond to the boss inductive cue, the R1-R6 precursor cells are unable to respond to the boss inductive cue.

        sev is required for the transformation of the presumptive R7 cell into an R1-6 type photoreceptor by the ectopic expression of ro.

        The presence of ena mutants has no effect on the sev phenotype.

        Mutant analysis of sev (unspecified) provides evidence for the participation of a G0-like protein in learning and memory. Sex-dependent enhancement in pertussis toxin catalysed ADP-ribosylation with respect to wild type: attributed in part to an increase in the α subunit of the G0-like protein.

        The predicted amino acid sequences of D.melanogaster sev and Dvir\sev have been compared.

        Heat induction of sev demonstrates that the sev product is exclusively required during a brief period of ommatidial assembly to specify an R7 photoreceptor. sev protein is not required in the adult for R7 cell function.

        Enhancer sequences within the body of the sev gene are required for the correct level of sev expression.

        Analysis of sev protein expressed in Drosophila tissue culture cells shows that sev protein has protein tyrosine kinase activity, and that the mature protein is formed by proteolytic cleavage of a precursor.

        Mutant analysis demonstrates that sev defines a class of tyrosine kinases likely to be involved in cell-cell communication during development.

        The sev gene, required for photoreceptor R7 development, encodes a putative cell surface receptor bearing a cytoplasmic tyrosine kinase domain.

        Homozygotes and hemizygotes lack the R7 rhabdomere in all ommatidia; the R7 photoreceptor cell instead develops as an accessory lens-secreting cell, the equatorial cone cell (Tomlinson and Ready, 1986; Tomlinson and Ready, 1987). Cell autonomous in mosaics (Harris, Stark and Walker, 1976). Mosaic analysis demonstrates that sev+ product is required only in the presumptive photoreceptor 7 cell and is therefore involved in receiving signals from neighboring cells. Electroretinograms normal; defective in response to ultraviolet; in T-maze tests sev flies prefer visible to ultraviolet wavelengths and green light to darkness; slight preference for blue wavelengths over ultraviolet used in selecting mutant alleles (Gerresheim, 1988). In the presence of Ppb the preference of green light to darkness is reversed for sev1 and sev10 but not for six other unspecified alleles; the absence of R7 is unaffected by Ppb (Ballinger and Benzer, 1988). Gene expression demonstrated by in situ hybridization and immune staining to take place in developing eye imaginal disc, near and posterior to the morphogenetic furrow, during ommatidial differentiation. Protein present transiently in at least nine cells in each developing ommatidium and is detectable before any overt differentiation of R7 observed (Tomlinson, Bowtell, Hafen and Rubin, 1987; Banerjee, Renfranz, Hinton, Rabin and Benzer, 1987). Transient expression of sev+ by means of a transformed construct under control of the Hsp70 promoter in a sev background results in a narrow stripe of ommatidia that contain photoreceptor cell 7 in eyes that are otherwise sevenless; the position and time of expression required for normal function are highly restricted (Bowtell, Simon and Rubin, 1989).

        Origin and Etymology
        Discoverer
        Etymology
        Identification
        External Crossreferences and Linkouts ( 360 )
        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 (genetic) - An integrated Molecular Interaction Database
        MIST (protein-protein) - An integrated Molecular Interaction Database
        Synonyms and Secondary IDs (14)
        Reported As
        Symbol Synonym
        HD-265
        sev
        (Nye et al., 2020, Cassidy et al., 2019, Courgeon and Desplan, 2019, Donde et al., 2019, Escobedo et al., 2019, Mele and Johnson, 2019, Tomlinson et al., 2019, Duan et al., 2018, Gene Disruption Project members, 2018-, Palmer et al., 2018, Ashton-Beaucage et al., 2016, Blick et al., 2016, Kim et al., 2016, Mavromatakis and Tomlinson, 2016, Aradska et al., 2015, Baril et al., 2014, Ting et al., 2014, Ting et al., 2014, Vernes, 2014, Wernet et al., 2014, Zhimulev et al., 2014, Zhu et al., 2014, Eguchi et al., 2013, Jukam et al., 2013, Ly et al., 2013, Mora et al., 2013, Ozkan et al., 2013, Sopko and Perrimon, 2013, Holbrook et al., 2012, Mavromatakis and Tomlinson, 2012, Nfonsam et al., 2012, Thao et al., 2012, Weber et al., 2012, Whitworth et al., 2012, Yoshioka et al., 2012, Zhou et al., 2012, Charlton-Perkins et al., 2011, Tomlinson et al., 2011, Vasiliauskas et al., 2011, Vatolina et al., 2011, Almudi et al., 2010, Baig et al., 2010, Jumbo-Lucioni et al., 2010, Kitadate and Kobayashi, 2010, Yamaguchi et al., 2010, Almudi et al., 2009, Babenko et al., 2009, Bhattacharya and Baker, 2009, Birkholz et al., 2009, Birkholz et al., 2009, Ni et al., 2009, Ninov et al., 2009, Shi and Noll, 2009, Gao et al., 2008, Gao et al., 2008, Le Garrec and Kerszberg, 2008, Miller et al., 2008, Petrovic and Hummel, 2008, Tomasi et al., 2008, Wang et al., 2008, Yamaguchi et al., 2008, Zheng and Carthew, 2008, Almudí et al., 2007, Kitadate et al., 2007, Mecklenburg, 2007, Ting et al., 2007, Kim et al., 2006, Sese et al., 2006, Wernet et al., 2006, Mikeladze-Dvali et al., 2005, Hall, 2003, Pazman et al., 2000, Robertson et al., 2000, Levine et al., 1997, Biggs et al., 1994, Matsushime and Shibuya, 1990)
        Secondary FlyBase IDs
        • FBgn0022796
        • FBgn0026795
        • FBgn0026831
        • FBgn0026832
        Datasets (0)
        Study focus (0)
        Experimental Role
        Project
        Project Type
        Title
        References (621)