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General Information
Symbol
Dmel\sn
Species
D. melanogaster
Name
singed
Annotation Symbol
CG32858
Feature Type
FlyBase ID
FBgn0003447
Gene Model Status
Stock Availability
Gene Snapshot
singed (sn) encodes a member of the fascin family of actin-binding proteins. Fascin proteins organize F-actin into parallel bundles, and are required for the formation of actin-based cellular protrusions. The bundling activity of the product of sn is regulated by phosphorylation. [Date last reviewed: 2019-03-14]
Also Known As
fascin, fs(1)K418, fs(1)M45
Key Links
Genomic Location
Cytogenetic map
Sequence location
X:7,964,024..7,986,601 [+]
Recombination map
1-22
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 fascin family. (Q24524)
Molecular Function (GO)
[Detailed GO annotations]
Experimental Evidence
-
Predictions / Assertions
Summaries
Protein Function (UniProtKB)
Acts as an actin bundling protein (PubMed:1723709, PubMed:19729655). May have a role in the asymmetric organization and/or movement of cytoplasmic components (PubMed:1723709). It has a role in somatic cells during the formation of adult bristles and hairs, and in the female germline during oogenesis (PubMed:1723709, PubMed:19729655).
(UniProt, Q24524)
Phenotypic Description (Red Book; Lindsley and Zimm 1992)
sn: singed
thumb
sn: singed
From Mohr, 1922, Z. Indukt. Abstamm. Vererbungsl. 28: 1-22.
Macrochaetae deformed, from short and gnarled to wavy, depending on allele. Similarly, microchaetae may be straight or wavy. Electron-microscope examination of developing bristle shaft shows flattened fiber bundles around periphery, which occupy but 5% of cross-sectional profile, compared to wild type, which have fiber bundles that are circular in cross section and occupy 20% of cross-sectional area [Overton, 1967, J. Morph. 122: 367-80 (fig.)]. Females homozygous for the most extreme alleles are completely sterile; vitellogenesis defective. Eggs laid by sn1 homozygotes are normal in number, but are short, blunt, and wrinkled with small blunt dorsal appendages [Mohr, 1922, Z. Indukt. Abstamm. Vererbungsl. 28: 1-22 (fig.)]. Sterility autonomous in transplants (sn1; Clancy and Beadle, 1937, Biol. Bull. 72: 47-56; Perrimon and Gans, 1983, Dev. Biol. 100: 365-73). Heterozygotes between female-sterile and fertile alleles are fertile, between female sterile alleles are sterile.
sn36a
Macrochaetae gnarled in a fairly extreme manner. Microchaetae wild type. sn36a is only allele to cause pronounced reduction in replication of oocyte nurse cell DNA [King and Burnett, 1957, Growth 21: 263-80 (fig.)]. Also causes more extreme retardation of vitellogenesis than other female-sterile sn alleles (Bender). sn36a sn4 homozygote has nearly normal bristles and is sterile. RK1.
sn49
A strong allele of sn recovered from a natural population. Associated with simultaneous mutation to club wing, clw, a defect in wing expansion with low penetrance. sn49 is unstable, producing an array of derivatives that are in turn stable or unstable. and the expression of clw differs among them. It mutates to sn+ and back at a rate of approximately 10-3; a rare moderate singed derivative exhibits an approximately ten-fold elevation in mutation frequency, mutating either back to the strong allele or to an unstable normal allele; a single extreme singed derivative of a normal derivative of the moderate allele produces strong-singed and non-singed derivatives, which can in turn revert to the extreme allele and in the case of the strong derivative to non singed (Yurchenko, Zakharov, and Golubovsky, 1984, Mol. Gen. Genet. 194: 279-85).
sn63-15
Moderate sn phenotype. Prototype type B mutable allele; mutation rate 0.1 to 1.2%. Produces both extreme singed and normal-appearing derivatives as well as an array of intermediate phenotypes. In addition strongly reversible alleles (25-50 x more mutable than parental allele) are produced. This allele also associated with increased rate of mutation to fw.
sn77-27
Extreme sn phenotype. Prototype type A mutable allele; mutates to an unstable sn+, which mutates back to extreme alleles; no intermediate alleles recovered.
sncm
An allele of sn that is mutable in dysgenic but not in non-dysgenic genotypes. Mutation takes place in two directions; one is to apparent stable reversions and the other to a more extreme phenotype, snex, which is in turn unstable.
snw: singed-weak
Weak singed phenotype, probably class 2. Highly mutable in dysgenic genotypes; 40% to 60% of offspring are either normal (sn(+)) or extreme singed (sne) in phenotype. These derivatives are in turn mutable, but at much lower levels. Completely stable in non-dysgenic genotypes.
Summary (Interactive Fly)
fascin homolog - crosslinks actin filaments - the gnarled, kinky bristle phenotype is due to the lack of Actin filament bundles in both large and small bristles - regulates nuclear actin during oogenesis - required for blood cell migration during embryogenesis
Gene Model and Products
Number of Transcripts
4
Number of Unique Polypeptides
1

Please see the GBrowse view of Dmel\sn or the JBrowse view of Dmel\sn 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
Low-frequency RNA-Seq exon junction(s) not annotated.
Annotated transcripts do not represent all supported alternative splices within 5' UTR.
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)
FBtr0071101
3101
512
FBtr0071102
3358
512
FBtr0301677
2451
512
FBtr0301679
2322
512
Additional Transcript Data and Comments
Reported size (kB)
3.6, 3.3, 3.0 (northern blot)
Comments
External Data
Crossreferences
Polypeptide Data
Annotated Polypeptides
Name
FlyBase ID
Predicted MW (kDa)
Length (aa)
Theoretical pI
RefSeq ID
GenBank
FBpp0071057
57.3
512
7.01
FBpp0071058
57.3
512
7.01
FBpp0290891
57.3
512
7.01
FBpp0290893
57.3
512
7.01
Polypeptides with Identical Sequences

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

512 aa isoforms: sn-PA, sn-PB, sn-PE, sn-PG
Additional Polypeptide Data and Comments
Reported size (kDa)
512 (aa); 57 (kD observed)
512 (aa); 57 (kD predicted)
Comments
Bacterially expressed sn protein is able to bundle F-actin in vitro.
External Data
Subunit Structure (UniProtKB)
Interacts with Rab35, with stronger binding to the Rab35-GTP form compared to the Rab35-GDP form.
(UniProt, Q24524)
Crossreferences
InterPro - A database of protein families, domains and functional sites
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\sn 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 (23 terms)
Molecular Function (3 terms)
Terms Based on Experimental Evidence (0 terms)
Terms Based on Predictions or Assertions (3 terms)
CV Term
Evidence
References
inferred from sequence or structural similarity with UniProtKB:Q16658
(assigned by UniProt )
inferred from sequence or structural similarity with UniProtKB:Q16658
(assigned by UniProt )
inferred from biological aspect of ancestor with PANTHER:PTN000058080
(assigned by GO_Central )
inferred from electronic annotation with InterPro:IPR022768, InterPro:IPR024703
(assigned by InterPro )
Biological Process (15 terms)
Terms Based on Experimental Evidence (14 terms)
CV Term
Evidence
References
inferred from mutant phenotype
inferred from mutant phenotype
inferred from mutant phenotype
inferred from mutant phenotype
inferred from mutant phenotype
inferred from mutant phenotype
inferred from mutant phenotype
inferred from mutant phenotype
Terms Based on Predictions or Assertions (3 terms)
CV Term
Evidence
References
inferred from biological aspect of ancestor with PANTHER:PTN000058080
(assigned by GO_Central )
inferred from biological aspect of ancestor with PANTHER:PTN000058080
(assigned by GO_Central )
inferred from biological aspect of ancestor with PANTHER:PTN000058080
(assigned by GO_Central )
Cellular Component (5 terms)
Terms Based on Experimental Evidence (5 terms)
CV Term
Evidence
References
inferred from direct assay
inferred from direct assay
inferred from direct assay
inferred from direct assay
colocalizes_with nuclear periphery
inferred from direct assay
(assigned by CACAO )
Terms Based on Predictions or Assertions (1 term)
CV Term
Evidence
References
inferred from biological aspect of ancestor with PANTHER:PTN000058080
(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
distribution deduced from reporter
Stage
Tissue/Position (including subcellular localization)
Reference
in situ
Stage
Tissue/Position (including subcellular localization)
Reference
organism | ubiquitous

Comment: maternally deposited

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

northern blot
Stage
Tissue/Position (including subcellular localization)
Reference
Additional Descriptive Data
sn transcript is expressed in the head (procephalic) mesoderm starting at embryonic stage 8, becoming prominent at stages 9-10. sn transcript is expressed in circulating hemocytes throughout embryogenesis, in the CNS from stage 11, and in epidermal cells forming apical extensions from stage 14-16. sn is not detected in crystal cells.
Marker for
 
Subcellular Localization
CV Term
Polypeptide Expression
distribution deduced from reporter (Gal4 UAS)
Stage
Tissue/Position (including subcellular localization)
Reference
immunolocalization
Stage
Tissue/Position (including subcellular localization)
Reference
mass spectroscopy
Stage
Tissue/Position (including subcellular localization)
Reference
western blot
Stage
Tissue/Position (including subcellular localization)
Reference
Additional Descriptive Data
The sn protein is found in the cytoplasm of nurse cells and the cytoplasm of the developing bristles of the pupa.
sn protein is expressed during oogenesis, and during pupal bristle formation. In stage 9 egg chambers, sn protein is present in border cells and posterior follicle cells. In early stage 10, centripetal follicle cells express sn protein. Although sn protein is present in the nurse cell cytoplasm from early oogenesis, the amounts of the protein increase dramatically early in stage 10. By late stage 10, when the actin filament bundles form, the nurse cell cytoplasm contains high amounts of sn protein, and the high levels persist through stage 11. sn protein is also expressed during bristle formation. In pupae, the cytoplasm of extending bristles and tormogen cells express sn protein.
Marker for
Subcellular Localization
CV Term
Evidence
References
inferred from direct assay
inferred from direct assay
inferred from direct assay
inferred from direct assay
colocalizes_with nuclear periphery
inferred from direct assay
(assigned by CACAO )
Expression Deduced from Reporters
High-Throughput Expression Data
Associated Tools

GBrowse - Visual display of RNA-Seq signals

View Dmel\sn 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) 1-3
  • 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 ( 207 )
For All Classical and Insertion Alleles Show
 
Other relevant insertions
Transgenic Constructs ( 17 )
For All Alleles Carried on Transgenic Constructs Show
Transgenic constructs containing/affecting coding region of sn
Transgenic constructs containing regulatory region of sn
Deletions and Duplications ( 39 )
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
actin filament & egg chamber
actin filament & neuron (with sn3)
actin filament & neuron (with snX2)
macrochaeta & actin filament
microchaeta & actin filament
nurse cell & nucleus
Orthologs
Human Orthologs (via DIOPT v7.1)
Homo sapiens (Human) (3)
Species\Gene Symbol
Score
Best Score
Best Reverse Score
Alignment
Complementation?
Transgene?
13 of 15
Yes
Yes
13 of 15
Yes
Yes
5 of 15
No
Yes
Model Organism Orthologs (via DIOPT v7.1)
Mus musculus (laboratory mouse) (3)
Species\Gene Symbol
Score
Best Score
Best Reverse Score
Alignment
Complementation?
Transgene?
13 of 15
Yes
Yes
12 of 15
No
Yes
5 of 15
No
Yes
Rattus norvegicus (Norway rat) (3)
12 of 13
Yes
Yes
6 of 13
No
Yes
5 of 13
No
Yes
Xenopus tropicalis (Western clawed frog) (2)
12 of 12
Yes
Yes
7 of 12
No
Yes
Danio rerio (Zebrafish) (4)
9 of 15
Yes
Yes
9 of 15
Yes
Yes
9 of 15
Yes
Yes
8 of 15
No
Yes
Caenorhabditis elegans (Nematode, roundworm) (3)
1 of 15
Yes
Yes
1 of 15
Yes
No
1 of 15
Yes
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.
Orthologs in Drosophila Species (via OrthoDB v9.1) ( EOG091905JK )
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 willistoni
Drosophila virilis
Drosophila mojavensis
Drosophila grimshawi
Orthologs in non-Drosophila Dipterans (via OrthoDB v9.1) ( EOG091504JX )
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 gambiae
Malaria mosquito
Culex quinquefasciatus
Southern house mosquito
Orthologs in non-Dipteran Insects (via OrthoDB v9.1) ( EOG090W040I )
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
Zootermopsis nevadensis
Nevada dampwood termite
Orthologs in non-Insect Arthropods (via OrthoDB v9.1) ( EOG090X03X5 )
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
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) ( EOG091G0C6S )
Organism
Common Name
Gene
Multiple Dmel Genes in this Orthologous Group
Strongylocentrotus purpuratus
Purple sea urchin
Strongylocentrotus purpuratus
Purple sea urchin
Ciona intestinalis
Vase tunicate
Gallus gallus
Domestic chicken
Gallus gallus
Domestic chicken
Paralogs
Paralogs (via DIOPT v7.1)
Drosophila melanogaster (Fruit fly) (0)
No records found.
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 ( 1 )
    Human Ortholog
    Disease
    Evidence
    References
    Modifiers Based on Experimental Evidence ( 0 )
    Allele
    Disease
    Interaction
    References
    Comments on Models/Modifiers Based on Experimental Evidence ( 0 )
     
    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.
    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
    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
    Starting gene(s)
    Interaction type
    Interacting gene(s)
    Reference
    External Data
    Subunit Structure (UniProtKB)
    Interacts with Rab35, with stronger binding to the Rab35-GTP form compared to the Rab35-GDP form.
    (UniProt, Q24524 )
    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
    Gene Group - Pathway Membership (FlyBase)
    External Data
    Linkouts
    Genomic Location and Detailed Mapping Data
    Chromosome (arm)
    X
    Recombination map
    1-22
    Cytogenetic map
    Sequence location
    X:7,964,024..7,986,601 [+]
    FlyBase Computed Cytological Location
    Cytogenetic map
    Evidence for location
    7D1-7D2
    Limits computationally determined from genome sequence between P{EP}EP1243 and P{EP}snEP1217
    Experimentally Determined Cytological Location
    Cytogenetic map
    Notes
    References
    7D-7D
    (determined by in situ hybridisation)
    7C1-7D5
    (determined by in situ hybridisation)
    Determined by deficiency mapping (details unspecified).
    Experimentally Determined Recombination Data
    Notes
    Stocks and Reagents
    Stocks (488)
    Genomic Clones (24)
    cDNA Clones (264)
     

    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)
    Other 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
     
    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: sn CG1536
    Source for database merge of
    Source for merge of: sn CG15331
    Additional comments
    Annotations CG1536 and CG15331 merged as CG32858 in release 3 of the genome annotation.
    Bender has classified sn alleles into four classes: class 1 = female sterile with gnarled macrochaetae and kinky microchaetae; class 2 = female fertile with kinky macrochaetae only; class 3 = female fertile with gnarled macrochaetae and kinky microchaetae; class 4 = female sterile with gnarled macrochaetae only. To these Golubovsky and Kozlovskaya (1978) have added class 5 = kinky microchaetae only. Derivative alleles have sometimes been designated generically as "snf", "snm", "sns" and "snext", for faint, moderate, strong and extreme phenotypes; these symbols do not specify particular alleles (e.g., Zakharov and Golubovsky, 1984). Unstable alleles also classed as "snA" and "snB", "snA" alleles mutating to normal and back to the original phenotype only and "snB" alleles mutating to an array of intermediate states as well as to normal.
    Other Comments
    sn is an important determinant of class III neuron dendrite morphology, and is necessary for the formation of the characteristic spiked protrusions which are the terminal branchlets of this neuron class.
    dsRNA made from templates generated with primers directed against this gene tested in RNAi screen for effects on Kc167 and S2R+ cell morphology.
    dsRNA made from templates generated with primers directed against this gene is tested in an RNAi screen for effects on actin-based lamella formation.
    Definitive denticle belt phenotypes (abnormal hairs and/or bristles) are foreshadowed by abnormal organisation of the actin cytoskeleton in embryonic epidermal cells.
    One of a class of genes with TATA-less promoters that have a subset of the conserved DPE sequence.
    Single amino acid mutations in the fascin encoded by sn disrupt actin bundling function.
    In(1)T2. ymos wY1 snmY1 strain suppresses y gene mutability and activates sn gene mutability.
    sn is required for actin filament bundle formation in the cytoplasm of nurse cells during oogenesis and for organised actin filament bundle formation in the cellular extension that forms a bristle.
    Mutant sn nurse cells lack actin halo and transport of cytoplasm is blocked.
    Superunstable mutations generated in crosses of π2 strain to a wa strain or its derivatives. Each superunstable mutation gives rise to a large family of new super-unstable mutations with a wide range of phenotypic expression. Mutations with the same phenotype often differ in the specificity of their potential for further mutation. Each superunstable mutation is associated with a specific, "paired", reversible mutation. Active transposase encoded by P elements is necessary to maintain superinstability. X transposable element is also implicated in the mutability system.
    The effects of varying degrees of P-element activity and X irradiation on snw mutability are assessed. Analysis of the combined effects of P-element activity, X irradiation and either excision or post-replication DNA repair on sterility and fecundity is performed.
    Site selected mutagenesis and isolation of sn mutations.
    Four independently obtained families of super-unstable mutations at the sn locus have been studied.
    Alleles show P cytotype-dependent sterility and aberrant oocyte morphology in a P cytotype genetic background.
    Mutations in sn induced by P-M hybrid dysgenesis have been analysed to determine why sn is a hotspot for mutation during P-M hybrid dysgenesis.
    Mutant alleles are useful as markers in clonal analysis.
    Locus divided into three recombinationally different sites from distal to proximal: (sn3 and sn36a) (sn2 and sn4) (sn1, sn5 and sn50k) (Ives and Noyes, 1951; Hexter, 1955a; Hexter, 1955b). Of these, sn3 and sn36a show lesions between -0.9 and 0.0 kb, whereas sn2 has a lesion between 8.0 and 10.5. The others show no detectable molecular lesions and are presumed to be point mutations within the coding region between 11.1 and 13.8 kb.
    Macrochaetae deformed, from short and gnarled to wavy, depending on allele. Similarly, microchaetae may be straight or wavy. Electron-microscope examination of developing bristle shaft shows flattened fiber bundles around periphery, which occupy but 5% of cross-sectional profile, compared to wild type, which have fiber bundles that are circular in cross-section and occupy 20% of cross-sectional area (Overton, 1967). Females homozygous for the most extreme alleles are completely sterile; vitellogenesis defective. Eggs laid by sn1 homozygotes are normal in number, but are short, blunt and wrinkled with small blunt dorsal appendages (Mohr, 1922. Sterility autonomous in transplants (sn1; Clancy and Beadle, 1937; Perrimon and Gans, 1983). Heterozygotes between female-sterile and fertile alleles are fertile, between female sterile alleles are sterile. The sn locus seems to be a very favorable site for P-element insertion; a number of alleles have been isolated from natural populations in the USSR or are derivatives thereof. These alleles are highly mutable, generating innumerable derivative mutable normal-appearing and extreme singed alleles; some have been shown to carry P-element sequences at sn (Golubovsky, Ivanov, and Green, 1977; Green, 1977). Also some display slight increases in the rate of nondisjunction from Basc (Golubovsky, 1983).
    Origin and Etymology
    Discoverer
    Etymology
    Identification
    External Crossreferences and Linkouts ( 58 )
    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)
    InterPro - A database of protein families, domains and functional sites
    KEGG Genes - Molecular building blocks of life in the genomic space.
    modMine - A data warehouse for the modENCODE project
    Linkouts
    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
    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.
    MIST (genetic) - An integrated Molecular Interaction Database
    MIST (protein-protein) - An integrated Molecular Interaction Database
    Synonyms and Secondary IDs (16)
    Reported As
    Symbol Synonym
    CG15331
    fs(1)A1057
    fs(1)K1421
    fs(1)K473
    fs(1)K743
    Name Synonyms
    Secondary FlyBase IDs
    • FBgn0040925
    Datasets (0)
    Study focus (0)
    Experimental Role
    Project
    Project Type
    Title
    References (381)