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General Information
Symbol
Dmel\ss
Species
D. melanogaster
Name
spineless
Annotation Symbol
CG6993
Feature Type
FlyBase ID
FBgn0003513
Gene Model Status
Stock Availability
Gene Snapshot
spineless (ss) encodes a protein that plays a key role in defining the distal regions of the antenna and the leg. Its stochastic expression in R7 photoreceptors also controls the expression of color Rhodopsins (the product of Rh4 vs. the product of Rh3) in the two subsets of ommatidia. [Date last reviewed: 2019-03-21]
Also Known As
aristapedia
Key Links
Genomic Location
Cytogenetic map
Sequence location
3R:16,374,434..16,403,690 [-]
Recombination map
3-58
Sequence
Other Genome Views
The following external sites may use different assemblies or annotations than FlyBase.
Function
GO Summary Ribbons
Protein Family (UniProt)
-
Molecular Function (GO)
[Detailed GO annotations]
Summaries
Gene Group (FlyBase)
BASIC HELIX-LOOP-HELIX TRANSCRIPTION FACTORS -
Basic helix-loop-helix (bHLH) transcription factors are sequence-specific DNA-binding proteins that regulate transcription. They are characterized by a 60 amino acid region comprising a basic DNA binding domain followed by a HLH motif formed from two amphipathic α-helices connected by a loop. bHLH transcription factors form homo- and hetero-dimeric complexes, which bind to a E box consensus sequence. (Adapted from PMID:15186484).
Phenotypic Description (Red Book; Lindsley and Zimm 1992)
ss: spineless
Mutations at the spineless locus display three different phenotypes: (1) The spineless phenotype is characterized by the reduction in size of all bristles; (2) the aristapedia phenotype corresponds to the transformation of distal antennal segments, specifically the arista and the distal portion of the third antennal segment, into distal mesothoracic leg segments, i.e., tarsal segments; and (3) leg-segment fusion manifested as fusion of tarsal segments on all eight legs. Homeotic tissue does not conform to developmental compartment boundaries; therefore, ss does not qualify as a selector gene (Struhl). Expression of these phenotypes varies among alleles. Some alleles show only the spineless phenotype. Aristapedia alleles, symbolized ssa, vary in expression; weak alleles show a swelling of the third antennal joint and rudimentary tarsal transformation of the base of the arista; as expression becomes more extreme, more tarsal joints are formed until in the most extreme alleles four tarsal segments and terminal claws are formed. Tarsal fusions are characteristic of extreme aristapedia alleles.
ssv: spineless-variegated
Variegates for spineless character but completely mutant for aristapedia. Male sterile. RK2A.
ss1
Bristles only a little larger than hairs; dorsocentrals least reduced; postscutellars erect. No effect on legs or aristae. Growth of bristles slows during development [Lees and Waddington, 1943, Proc. Roy. Soc. (London), Ser. B 131: 87-110]. Dominant to aristapedia phenotype of all ssa alleles. RK1.
ssa: spineless-aristapedia
thumb
ssa: spineless-aristapedia
From Bridges and Brehme, 1944, Carnegie Inst. Washington Publ. No. 552: 179.
Antennae and aristae tarsuslike; mean number of tarsal segments = 4.0; incidence of claws = 97.1% (Garcia-Bellido, 1968, Genetics 59: 487-99); classified as an intermediate allele by Struhl. Third joint of antenna like parts of a tarsal row but with broad, flat, plate-like lobes below. Tarsal segments of legs display intermediate level of fusion (Struhl). Bristles like those of a medium to slight Minute. Frequent extra dorsocentral bristles. Transformed tissue is leg tissue in every attribute tested. Transformed tarsi elicit behavioral response similar to that of normal legs when exposed to sugar solutions (Deak, 1976, Nature 260: 252-54). Regions of aristae converted into tarsi not affected by mutants affecting aristae (e.g., th and al) but are affected by those operating on tarsi (e.g., fj, d, app, and ey) [Waddington, 1939, Growth, Suppl. 1, pp. 37-44; Braun, 1940, Genetics 25: 143-49; Mglinetz and Ivanov, 1975, Genetika 11(#11): 27-33; 1976, Genetika 12(#12): 87-94]. Dissociated cells from ssa antennal disks aggregate with dissociated leg-disk cells but not with those from wild-type antennal disks (Garcia-Bellido). Antennal disks from ssa larvae give rise to leg-like structures when transplanted into wild-type hosts as do both duplicated and regenerated antennal disks formed from eye-antenna-disk fragments (Gehring and Schubiger, 1975, J. Embryol. Exp. Morph. 33: 459-69); when disks are pretreated with colchicine, the developing structures are more aristalike (Vogt, 1947, Experientia 3: 156-59). Homozygous clones of ssa tissue produce antennal leg tissue when induced before (Roberts, 1964, Genetics 49: 593-98) but not after (Postlethwait and Girton, 1974, Genetics 76: 767-74) mid-third instar. Large clones conform to anterior and posterior compartments comparable to those induced in normal mesothoracic legs [Morata and Lawrence, 1979, Dev. Biol. 70: 355-71 (fig.)]. No maternal effect; temperature independent.
ssa40a
Cold sensitive; phenotype normal in flies raised at 29; fully penetrant at 17 [mean number of tarsal segments = 2.8; incidence of tarsal claws = 1.3% as recorded by Garcia-Bellido (1968, Genetics 59: 487-99) probably in flies raised at 25]. Phenocritical stage in first half of third instar [Grigliatti and Suzuki, 1971, Proc. Nat. Acad. Sci. USA 68: 1307-11 (fig.)]. Shifts from 17 to 29 early in third instar restrict transformation to base of arista; distal extent of transformation increases as shift is effected later in development (Grigliatti and Suzuki). Opposite response to temperature for antennal transformation but not tarsal fusion reported by Mglinetz (1977, Genetika 13: 70-75). Developmental compartments demonstrated in antennal legs [Morata and Lawrence, 1979, Dev. Biol. 70: 355-71 (fig.)].
ssaB: spineless-aristapedia of Bridges
Bristles of female like a slight Minute, especially postscutellars. At 25, aristae inconspicuously thickened at base, plumed or threadlike for rest of extent. At 18 penetrance is 7% and expression weak; at 14, ssaB enhanced and resembles ssa; al causes reduction of ssaB arista at 25 but has no effect on transformed arista at 14 (Villee, 1943, J. Exp. Zool. 93: 75-98). Legs frequently have lumps at second joint of tarsi; more pronounced in male and result in doubling of sex combs, which are strung along first and second fused joints. Eyes a little flattened. Except at low temperatures, all characters slight and may overlap wild type. ssaB/ss1 has slight Minute phenotype but wild-type legs and aristae. ssaB/ssaSp like ssaSp with large tarsal aristae. RK2. Struhl (1982, Genetics 102: 737-49) and Posakony.
*ssaH (A. Hannah Alava)
Homozygous viable and fertile. Displays enlargement of base of arista. Increased number of sex-comb teeth on basitarsus of first leg in males (12-38 with mean of 24 teeth per leg).
*ssasnB (A. Hannah Alava)
Description incomplete. Extreme fusion of tarsal segments; basitarsus of male first leg has 20-50 sex-comb teeth (mean = 40); sex-comb teeth not uncommon on second leg.
ssC1
Reported to be homozygous lethal and lethal in combination with Df(3R)bxd100 (Bownes, Bournias-Vardiabasis, and Spare, 1979, Mol. Gen. Genet. 174: 67-74); however both of these combinations viable in the hands of
*ssiso53: spineless-isoallele
Homozygote is wild type. ssiso53/ssa, ssiso53/ssa63c, and ssiso53/ssa53e have thickened proximal segments of aristae, like ssaB. RK3.
Summary (Interactive Fly)
bHLH PAS domain transcription factor - plays a central role in defining the distal regions of both the antenna and leg
Gene Model and Products
Number of Transcripts
3
Number of Unique Polypeptides
2

Please see the GBrowse view of Dmel\ss or the JBrowse view of Dmel\ss 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 5.48
Annotated transcripts do not represent all possible combinations of alternative exons and/or alternative promoters.
Gene model reviewed during 5.56
Sequence Ontology: Class of Gene
Transcript Data
Annotated Transcripts
Name
FlyBase ID
RefSeq ID
Length (nt)
Assoc. CDS (aa)
FBtr0083318
5184
884
FBtr0306026
4019
1015
FBtr0306027
3997
1015
Additional Transcript Data and Comments
Reported size (kB)
5.4 (northern blot)
Comments
External Data
Crossreferences
Polypeptide Data
Annotated Polypeptides
Name
FlyBase ID
Predicted MW (kDa)
Length (aa)
Theoretical pI
RefSeq ID
GenBank
FBpp0082768
97.7
884
8.06
FBpp0297168
111.2
1015
7.62
FBpp0297169
111.2
1015
7.62
Polypeptides with Identical Sequences

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

1015 aa isoforms: ss-PC, ss-PD
Additional Polypeptide Data and Comments
Reported size (kDa)
Comments
External Data
Linkouts
Sequences Consistent with the Gene Model
Mapped Features

Click to get a list of regulatory features (enhancers, TFBS, etc.) and gene disruptions (point mutations, indels, etc.) within or overlapping Dmel\ss 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 (18 terms)
Molecular Function (2 terms)
Terms Based on Experimental Evidence (2 terms)
CV Term
Evidence
References
Terms Based on Predictions or Assertions (0 terms)
Biological Process (14 terms)
Terms Based on Experimental Evidence (11 terms)
CV Term
Evidence
References
Terms Based on Predictions or Assertions (3 terms)
CV Term
Evidence
References
inferred from biological aspect of ancestor with PANTHER:PTN000837813
(assigned by GO_Central )
inferred from biological aspect of ancestor with PANTHER:PTN000837813
(assigned by GO_Central )
inferred from electronic annotation with InterPro:IPR039091
(assigned by InterPro )
Cellular Component (2 terms)
Terms Based on Experimental Evidence (2 terms)
CV Term
Evidence
References
inferred from high throughput direct assay
inferred from direct assay
Terms Based on Predictions or Assertions (0 terms)
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
Additional Descriptive Data
ss transcripts are expressed in embryos starting in stage 8 in a crescent just anterior to the cephalic furrow. As germ band extension proceeds, expression is observed in the maxillary, labial, mandibular, and antennal segments. This is followed by a patch of expression in the thoracic segments that corresponds to the leg anlage. Expression is also observed in the peripheral nervous system. ss transcripts are first detected in leg discs in 2nd instar larvae in a central ring that corresponds to the presumptive tarsal region. The ring fades by late third instar. ss is then expressed in a patch in the anterior-proximal part of the disc that gives rise to thoracic structures. Staining in the antennal disc is first detected in 2nd instar larvae and is located in an oval patch in the central portion of the disc. After disc eversion, the limits of the intense ss staining corresponds to the boundary between the second and third antennal segments. In late third instar, ss is expressed in the part of the disc corresponding to the maxillary palp anlage. In the wing disc, ss expression is in the region corresponding to the presumptive notum and the wing hinge. Expression is also observed in the haltere, genital, and labial discs and in the morphogenetic furrow in the eye disc. At pupariation, expression is observed in sensory organ precursor cells in most discs. At later stages, expression is seen in developing bristle cells but not in the associated socket cells.
Marker for
 
Subcellular Localization
CV Term
Polypeptide Expression
immunolocalization
Stage
Tissue/Position (including subcellular localization)
Reference
Additional Descriptive Data
ss protein is expressed in a subset of photoreceptor cells in the adult retina, in on/off manner. Expression in cells in the dorsal third region of the retina, relative to the equator is lower than in the other regions.
ss is expressed in the dorsal-proximal region of the 2nd thoracic and third thoracic leg discs. Expression is first detected in the mid third instar larval stage and persists at least until the early pupal stage. The distal region of the ss domain overlaps with the most proximal region of the al domain.
Marker for
 
Subcellular Localization
CV Term
Evidence
References
inferred from high throughput direct assay
inferred from direct assay
Expression Deduced from Reporters
Reporter: P{ss-Gal4.K}
Stage
Tissue/Position (including subcellular localization)
Reference
Reporter: P{ss-lacZ.B6.9}
Stage
Tissue/Position (including subcellular localization)
Reference
Stage
Tissue/Position (including subcellular localization)
Reference
adult brain cell body rind

Comment: adult brain cortex and possibly cell bodies in glial sheath

adult gnathal ganglion | restricted

Comment: part of the adult subesophageal ganglion

High-Throughput Expression Data
Associated Tools

GBrowse - Visual display of RNA-Seq signals

View Dmel\ss 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) 9-10
  • Stages(s) 11-12
  • Stages(s) 13-16
Alleles, Insertions, and Transgenic Constructs
Classical and Insertion Alleles ( 75 )
For All Classical and Insertion Alleles Show
 
Other relevant insertions
Transgenic Constructs ( 20 )
For All Alleles Carried on Transgenic Constructs Show
Transgenic constructs containing/affecting coding region of ss
Transgenic constructs containing regulatory region of ss
Deletions and Duplications ( 37 )
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
dendrite & dorsal multidendritic neuron ddaB | somatic clone
dendrite & dorsal multidendritic neuron ddaC, with Scer\GAL4ppk.PG
dendrite & dorsal multidendritic neuron ddaC | somatic clone
dendrite & dorsal multidendritic neuron ddaD | somatic clone
dendrite & dorsal multidendritic neuron ddaE
dendrite & dorsal multidendritic neuron ddaE (with ss134)
dendrite & dorsal multidendritic neuron ddaE (with ssD115.7)
dendrite & dorsal multidendritic neuron ddaE | somatic clone
dendrite & dorsal multidendritic neuron ddaF | somatic clone
dendrite & lateral multidendritic neuron ldaB | somatic clone
dendrite & tracheal innervating neuron, with Scer\GAL4477
Orthologs
Human Orthologs (via DIOPT v7.1)
Homo sapiens (Human) (3)
Species\Gene Symbol
Score
Best Score
Best Reverse Score
Alignment
Complementation?
Transgene?
11 of 15
Yes
Yes
 
7 of 15
No
Yes
1 of 15
No
No
Model Organism Orthologs (via DIOPT v7.1)
Mus musculus (laboratory mouse) (2)
Species\Gene Symbol
Score
Best Score
Best Reverse Score
Alignment
Complementation?
Transgene?
10 of 15
Yes
Yes
 
8 of 15
Yes
No
Rattus norvegicus (Norway rat) (2)
10 of 13
Yes
Yes
7 of 13
No
Yes
Xenopus tropicalis (Western clawed frog) (3)
6 of 12
Yes
Yes
1 of 12
No
Yes
1 of 12
No
No
Danio rerio (Zebrafish) (5)
11 of 15
Yes
Yes
9 of 15
Yes
No
7 of 15
No
Yes
7 of 15
No
Yes
1 of 15
No
Yes
Caenorhabditis elegans (Nematode, roundworm) (1)
12 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) ( EOG091902KZ )
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) ( EOG091501OD )
Organism
Common Name
Gene
Multiple Dmel Genes in this Orthologous Group
Musca domestica
House fly
Glossina morsitans
Tsetse 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
Orthologs in non-Dipteran Insects (via OrthoDB v9.1) ( EOG090W03J7 )
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
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) ( EOG090X0Q3W )
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
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) ( EOG091G16AJ )
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
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 ( 0 )
    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.
    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
    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
    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
    Genomic Location and Detailed Mapping Data
    Chromosome (arm)
    3R
    Recombination map
    3-58
    Cytogenetic map
    Sequence location
    3R:16,374,434..16,403,690 [-]
    FlyBase Computed Cytological Location
    Cytogenetic map
    Evidence for location
    89B14-89B15
    Limits computationally determined from genome sequence between P{PZ}gish04895&P{EP}EP3171 and P{lacW}CSN5L4032
    Experimentally Determined Cytological Location
    Cytogenetic map
    Notes
    References
    89C1-89C2
    (determined by in situ hybridisation)
    Experimentally Determined Recombination Data
    Location
    Left of (cM)
    Notes
    Stocks and Reagents
    Stocks (80)
    Genomic Clones (27)
    cDNA Clones (17)
     

    Please Note This section lists cDNAs and ESTs that fall within the genomic extent of the gene model, which may include cDNAs and ESTs of genes within introns, or of overlapping genes. Please see GBrowse for alignment of the cDNAs and ESTs to the gene model.

    cDNA clones, fully sequences
    BDGP DGC clones
    Other clones
      Drosophila Genomics Resource Center cDNA clones

      For each fully sequenced cDNA the DGRC maintains various forms of the cDNA (e.g tagged or untagged) in several different host vectors for subsequent cloning and expression in Drosophila and Drosophila cell lines.

        cDNA Clones, End Sequenced (ESTs)
        BDGP DGC clones
          RNAi and Array Information
          Linkouts
          DRSC - Results frm RNAi screens
          GenomeRNAi - A database for cell-based and in vivo RNAi phenotypes and reagents
          Antibody Information
          Laboratory Generated Antibodies
           
          Commercially Available Antibodies
           
          Other Information
          Relationship to Other Genes
          Source for database identify of
          Source for database merge of
          Additional comments
          Other Comments
          ss regulates dendrite diversity in the dendritic arborization sensory neurons.
          The ss gene product is incapable of high-affinity, specific binding of 3H-TCDD or 3H-BNF.
          ss and tgo proteins interact to control antennal and tarsal development.
          Loss of function alleles cause three major phenotypes: transformation of distal antenna to leg, deletion of distal leg, and reduction in the size of most bristles. Ectopic expression causes transformation of the maxillary palp and distal leg to distal antenna, and induces formation of ectopic antenna in the rostral membrane.
          ss plays a central role in defining the distal regions of both the antenna and the leg. Loss of function phenotypes suggest that ss played a central role in the evolution of distal structures in arthropod limbs.
          Mutants do not exhibit defects in the denticle belt of hairs of the larvae.
          Results suggests that ss interacts with genes of homeotic complexes: ss gene is capable of repressing the effect of ANTC and BXC gene products on the formation of distal structure of the antennae and leg.
          Varied sensitivities of the antenna-to-leg transformation are found both spatially and temporally.
          Mutations at the spineless locus display three different phenotypes: (1) The spineless phenotype is characterized by the reduction in size of all bristles; (2) the aristapedia phenotype corresponds to the transformation of distal antennal segments, specifically the arista and the distal portion of the third antennal segment, into distal mesothoracic leg segments, i.e., tarsal segments; and (3) leg-segment fusion manifested as fusion of tarsal segments on all eight legs. Expression of these phenotypes varies among alleles. Some alleles show only the spineless phenotype. Aristapedia alleles, symbolized ssa, vary in expression; weak alleles show a swelling of the third antennal joint and rudimentary tarsal transformation of the base of the arista; as expression becomes more extreme, more tarsal joints are formed until in the most extreme alleles four tarsal segments and terminal claws are formed. Tarsal fusions are characteristic of extreme aristapedia alleles.
          Effects of ss mutations on geotaxis measured in a Hirsch-type geotaxis maze: alleles of the "aristapedia" type show extremely positive geotaxis.
          Homeotic tissue does not conform to developmental compartment boundaries; therefore, ss does not qualify as a selector gene.
          Origin and Etymology
          Discoverer
          Etymology
          Identification
          External Crossreferences and Linkouts ( 57 )
          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/TrEMBL - Automatically annotated and unreviewed records of protein sequence and functional information
          Other crossreferences
          BDGP expression data - Patterns of gene expression in Drosophila embryogenesis
          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
          Reactome - An open-source, open access, manually curated and peer-reviewed pathway database.
          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
          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
          Reactome - An open-source, open access, manually curated and peer-reviewed pathway database.
          Synonyms and Secondary IDs (11)
          Reported As
          Secondary FlyBase IDs
            Datasets (0)
            Study focus (0)
            Experimental Role
            Project
            Project Type
            Title
            References (233)