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General Information
Symbol
Dmel\sna
Species
D. melanogaster
Name
snail
Annotation Symbol
CG3956
Feature Type
FlyBase ID
FBgn0003448
Gene Model Status
Stock Availability
Gene Snapshot
snail (sna) encodes a transcription factor that contributes to embryonic mesoderm development, epithelial to mesenchymal transition and asymmetric cell division. [Date last reviewed: 2019-03-14]
Also Known As

Sco, l(2)br28, l(2)br29, l(2)35Db, br29

Key Links
Genomic Location
Cytogenetic map
Sequence location
2L:15,476,593..15,478,260 [-]
Recombination map

2-51

RefSeq locus
NT_033779 REGION:15476593..15478260
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 snail C2H2-type zinc-finger protein family. (P08044)
Summaries
Gene Group (FlyBase)
C2H2 ZINC FINGER TRANSCRIPTION FACTORS -
Zinc finger C2H2 transcription factors are sequence-specific DNA binding proteins that regulate transcription. They possess DNA-binding domains that are formed from repeated Cys2His2 zinc finger motifs. (Adapted from PMID:1835093, FBrf0220103 and FBrf0155739).
Protein Function (UniProtKB)
Essential for the correct specification of ventral-dorsal patterns.
(UniProt, P08044)
Phenotypic Description (Red Book; Lindsley and Zimm 1992)
sna: snail
Embryonic lethal. Partially dorsalized. In homozygotes for strong alleles, ventral furrow not formed at gastrulation; however, endoderm invaginates, cephalic furrow formed, and germ-band elongation takes place. Embryo has few if any mesodermally derived internal tissues. Homozygotes for weak alleles gastrulate normally, but die as late embryos without differentiating normal internal tissues. Many embryos make normal ectodermal derivatives: larval hypoderm with normal or reduced denticle belts, mouth hooks, and spiracles, but tracheae seen only in weaker alleles. Head involution abnormal and anterior end of embryo twisted in the egg owing to extra length. Some embryos fail to make normal cuticle and resemble long folded tubes filled with yolk. sna heterozygotes produced from mothers heterozygous for dl or a deficiency for dl show reduced viability; this effect is more extreme at elevated temperatures. Defect in sna embryos enhanced by heterozygosity for Df(2L)75c or Df(2L)fn2. No maternal effect in germ-line clones. No effect on pattern of ftz expression (Carroll, Winslow, Twombly, and Scott, 1987, Development 99: 327-32). sna/+ embryos have delayed ventral furrow formation.
Summary (Interactive Fly)

transcription factor - zinc finger - DV polarity - a transcriptional repressor - acts to restrict neuroectoderm and neural fate in the invaginating mesoderm - mutants display a massive derepression of mesectoderm - controls proliferation of ovarian epithelial follicle stem cells

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

Please see the GBrowse view of Dmel\sna or the JBrowse view of Dmel\sna 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 5.52

Sequence Ontology: Class of Gene
Transcript Data
Annotated Transcripts
Name
FlyBase ID
RefSeq ID
Length (nt)
Assoc. CDS (aa)
FBtr0080739
1668
390
Additional Transcript Data and Comments
Reported size (kB)

1.7 (northern blot)

Comments
External Data
Crossreferences
Polypeptide Data
Annotated Polypeptides
Name
FlyBase ID
Predicted MW (kDa)
Length (aa)
Theoretical pI
RefSeq ID
GenBank
FBpp0080298
43.0
390
8.21
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)

390 (aa); 43 (kD predicted)

Comments
External Data
Crossreferences
InterPro - A database of protein families, domains and functional sites
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\sna 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 (24 terms)
Molecular Function (7 terms)
Terms Based on Experimental Evidence (6 terms)
CV Term
Evidence
References
Terms Based on Predictions or Assertions (2 terms)
CV Term
Evidence
References
inferred from biological aspect of ancestor with PANTHER:PTN001227002
(assigned by GO_Central )
inferred from biological aspect of ancestor with PANTHER:PTN001227002
(assigned by GO_Central )
Biological Process (16 terms)
Terms Based on Experimental Evidence (12 terms)
CV Term
Evidence
References
Terms Based on Predictions or Assertions (6 terms)
CV Term
Evidence
References
Cellular Component (1 term)
Terms Based on Experimental Evidence (1 term)
CV Term
Evidence
References
inferred from direct assay
Terms Based on Predictions or Assertions (1 term)
CV Term
Evidence
References
inferred from biological aspect of ancestor with PANTHER:PTN001227002
(assigned by GO_Central )
inferred from sequence or structural similarity
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
anterior endoderm anlage

Comment: anlage in statu nascendi

endoderm anlage

Comment: anlage in statu nascendi

mesoderm anlage

Comment: anlage in statu nascendi

trunk mesoderm anlage

Comment: anlage in statu nascendi

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
radioisotope in situ
Stage
Tissue/Position (including subcellular localization)
Reference
Additional Descriptive Data

In stage 12 embryos, sna is expressed in both the anterior and posterior lobes of the optic primordium.

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

sna transcript expression is first detected during the cellular blastoderm stage, in presumptive mesodermal cells. Mesodermal expression fades during germband elongation, when sna expression begins to be detected in the ectoderm. The initial pair-rule pattern of sna expression gives way to a segmentally repeated pattern of cells interconnected by longitudinal rows of cells also expressing sna. Neuroblasts will delaminate at approximately the sites of these longitudinal rows of cells during the S1 phase of neuroblast segregation. At about 5.5 hours, sna expression is seen in both the nascent neuroblasts and in ectodermal cells. As neuroblast segregation nears completion at about 5.5 to 6 hours, sna expression is restricted to the neuroblast layer. By 6.5 to 7 hours, sna transcript is expressed in all neuroblasts and in PNS precursors. As in the CNS, sna transcript expression in the PNS begins in neurectodermal patches. Later, sna transcript is detected in sensory mother cells. At about 9 to 10 hours, sna is expressed in the postmitotic cells of the PNS and CNS. Starting at about 11 hours,and continuing into the first larval instar, sna is expressed in the precursors of the wing and haltere discs.

In wild type embryos at embryonic cycle 13, sna transcript is found at low levels ventrally in a region 12 to 14 nuclei-wide. At embryonic cycle 14, sna transcript is expressed at higher levels and in about an 18 cell-wide strip (the presumptive mesoderm), and the borders of expression continue to be fuzzy. By the onset of cellularization, the borders of sna transcript expression in the 18 ventral cells have sharpened, and end at the mesoderm-neurectoderm boundary. In a twi mutant background, level of sna transcript remains low, and is limited to the ventral-most 12-14 cells.

The early accumulation of sna transcript in wild-type embryos is consistent with the role of sna in mesoderm formation, but its later expression pattern suggests that sna might have additional functions. Prior to gastrulation, sna transcript is detected in the mesoderm and anterior midgut anlagen. Before germ band elongation at stages 7-9, sna transcript is present at the dorsal surface of the amnioproctodeal invagination and in the anterior midgut rudiment. Starting at late stage 8, and persisting through stage 11, sna transcript is also observed in some large neurectodermal cells, presumably neuroblast precursors and segregated neuroblasts. Later in embryogenesis, sna is expressed in cells which might be the precursors of the peripheral nervous system (stage 10), P cells (stages 11-14), dorsal mesothoracic disc (stage 13), dorsal metathoracic disc (stage 13), and Bolwig photoreceptor organs (stage 13).

Both twi and sna transcript are first detectable during nuclear cycle 12 as a diffuse band half the width of the presumptive mesoderm. Although the expression patterns of sna and twi transcript and protein are similar early in embryogenesis, there are some subtle differences. At mid-cellularization, the sna transcript and protein expression boundaries sharply delimit the presumptive mesoderm. At the same time, twi transcript and protein is expressed in a gradient that extends slightly past the sna expression zone into the presumptive ectoderm. The twi transcript and protein expression pattern gets sharper later, during gastrulation. twi protein is expressed in the mesoderm throughout germ band extension, whereas the sna protein product disappears from the mesoderm partway through germ band extension, and appears in neurectodermal cells which might be neuroblasts.

High levels of sna transcript are detected in northern blots of embryos 2-4 hours after egg-laying. The levels decrease dramatically, but are still detectable, 4-6 hours after egg-laying.

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

At stage 5 of embryogenesis, sna protein is expressed ventrally, in the presumptive mesoderm, while esg protein is expressed in the dorsal region. By stage 13, both sna and esg proteins are expressed in presumptive wing and haltere discs. At stage 15, sna and esg proteins are also expressed in the genital disc. The esg protein is detected in the posterior spiracle and in the presumptive leg discs at stage 15, while the sna protein is expressed in a far smaller number of cells in the presumptive leg discs.

While sna transcript is expressed at high levels in in the neurectoderm, sna protein is not detected in these cells. sna transcript and protein expression overlap in other tissues such as presumptive mesodermal cells during the blastoderm stage, and in postmitotic neurons.

sna transcript is first detected during the syncytial blastoderm stage, whereas sna protein expression is first detected during gastrulation. After this initial lag, the expression of sna protein and transcript overlap to a great extent, with some differences apparent after the start of germ band elongation at stage 7. In stage 6 of embryogenesis, sna protein is detected in the mesoderm and the anterior midgut primordium. At stage 7, it is found in the anterior and posterior transverse furrows, as well as the cephalic furrow. Between stages 9 and 11, sna protein is present in the neurectoderm. In late embryogenesis, weak staining is observed in presumptive wing and haltere discs.

Both twi and sna transcript are first detectable during nuclear cycle 12 as a diffuse band half the width of the presumptive mesoderm. Although the expression patterns of sna and twi transcript and protein are similar early in embryogenesis, there are some subtle differences. At mid-cellularization, the sna transcript and protein expression boundaries sharply delimit the presumptive mesoderm. At the same time, twi transcript and protein is expressed in a gradient that extends past the sna expression zone into the presumptive ectoderm. The twi transcript and protein expression pattern gets sharper later, during gastrulation. twi protein is expressed in the mesoderm throughout germ band extension, whereas the sna protein product disappears from the mesoderm partway through germ band extension, and appears in neurectodermal cells which might be neuroblasts.

Marker for
 
Subcellular Localization
CV Term
Evidence
References
inferred from direct assay
Expression Deduced from Reporters
Reporter: P{0.8}
Stage
Tissue/Position (including subcellular localization)
Reference
Reporter: P{0.25kbsna-lacZ}
Stage
Tissue/Position (including subcellular localization)
Reference
Reporter: P{1.6kbsna-lacZ}
Stage
Tissue/Position (including subcellular localization)
Reference
Reporter: P{2.2kbsna-lacZ}
Stage
Tissue/Position (including subcellular localization)
Reference
Reporter: P{2.8kbsna-lacZ}
Stage
Tissue/Position (including subcellular localization)
Reference
Reporter: P{6.0kbsna-lacZ}
Stage
Tissue/Position (including subcellular localization)
Reference
Reporter: P{A1.3}
Stage
Tissue/Position (including subcellular localization)
Reference
Reporter: P{Δd1Δd4}
Stage
Tissue/Position (including subcellular localization)
Reference
Reporter: P{Δd5Δd10}
Stage
Tissue/Position (including subcellular localization)
Reference
Reporter: P{Δt1Δt2}
Stage
Tissue/Position (including subcellular localization)
Reference
Reporter: P{HR}
Stage
Tissue/Position (including subcellular localization)
Reference
Reporter: P{HR-p}
Stage
Tissue/Position (including subcellular localization)
Reference
Reporter: P{NB}
Stage
Tissue/Position (including subcellular localization)
Reference
Reporter: P{RE-p}
Stage
Tissue/Position (including subcellular localization)
Reference
Reporter: P{RP}
Stage
Tissue/Position (including subcellular localization)
Reference
Reporter: P{RP-p}
Stage
Tissue/Position (including subcellular localization)
Reference
Reporter: P{TD-p}
Stage
Tissue/Position (including subcellular localization)
Reference
Reporter: P{W0.1}
Stage
Tissue/Position (including subcellular localization)
Reference
Reporter: P{W0.05}
Stage
Tissue/Position (including subcellular localization)
Reference
Reporter: P{W0.18}
Stage
Tissue/Position (including subcellular localization)
Reference
Reporter: P{W0.25}
Stage
Tissue/Position (including subcellular localization)
Reference
High-Throughput Expression Data
Associated Tools

GBrowse - Visual display of RNA-Seq signals

View Dmel\sna 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 ( 41 )
For All Classical and Insertion Alleles Show
 
Other relevant insertions
Transgenic Constructs ( 56 )
For All Alleles Carried on Transgenic Constructs Show
Transgenic constructs containing/affecting coding region of sna
Transgenic constructs containing regulatory region of sna
Deletions and Duplications ( 163 )
Disrupted in
Not disrupted in
Phenotypes
For more details about a specific phenotype click on the relevant allele symbol.
Lethality
Allele
Other Phenotypes
Allele
Phenotype manifest in
Allele
abdominal dorsal multidendritic neuron ddaE & dendrite
dorsal multidendritic neuron ddaE & dendrite
scutellar bristle & tormogen cell, with Scer\GAL4455.2
scutellar bristle & trichogen cell, with Scer\GAL4455.2
Orthologs
Human Orthologs (via DIOPT v7.1)
Homo sapiens (Human) (5)
Species\Gene Symbol
Score
Best Score
Best Reverse Score
Alignment
Complementation?
Transgene?
7 of 15
Yes
No
6 of 15
No
Yes
6 of 15
No
Yes
2 of 15
No
No
2 of 15
No
No
Model Organism Orthologs (via DIOPT v7.1)
Mus musculus (laboratory mouse) (7)
Species\Gene Symbol
Score
Best Score
Best Reverse Score
Alignment
Complementation?
Transgene?
7 of 15
Yes
Yes
7 of 15
Yes
No
6 of 15
No
Yes
2 of 15
No
No
2 of 15
No
No
1 of 15
No
No
1 of 15
No
Yes
Rattus norvegicus (Norway rat) (6)
6 of 13
Yes
Yes
6 of 13
Yes
Yes
6 of 13
Yes
Yes
2 of 13
No
No
2 of 13
No
No
1 of 13
No
No
Xenopus tropicalis (Western clawed frog) (2)
5 of 12
Yes
No
4 of 12
No
Yes
Danio rerio (Zebrafish) (7)
7 of 15
Yes
No
5 of 15
No
Yes
5 of 15
No
Yes
4 of 15
No
Yes
2 of 15
No
No
1 of 15
No
No
1 of 15
No
No
Caenorhabditis elegans (Nematode, roundworm) (4)
5 of 15
Yes
No
3 of 15
No
No
1 of 15
No
No
1 of 15
No
No
Arabidopsis thaliana (thale-cress) (1)
1 of 9
Yes
No
Saccharomyces cerevisiae (Brewer's yeast) (4)
1 of 15
Yes
Yes
1 of 15
Yes
No
1 of 15
Yes
Yes
1 of 15
Yes
Yes
Schizosaccharomyces pombe (Fission yeast) (0)
No records found.
Orthologs in Drosophila Species (via OrthoDB v9.1) ( EOG09190B5M )
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
Drosophila grimshawi
Orthologs in non-Drosophila Dipterans (via OrthoDB v9.1) ( EOG091505W9 )
Organism
Common Name
Gene
Multiple Dmel Genes in this Orthologous Group
Musca domestica
House fly
Glossina morsitans
Tsetse fly
Lucilia cuprina
Australian sheep blowfly
Orthologs in non-Dipteran Insects (via OrthoDB v9.1) ( None identified )
No non-Dipteran orthologies identified
Orthologs in non-Insect Arthropods (via OrthoDB v9.1) ( EOG090X093K )
Organism
Common Name
Gene
Multiple Dmel Genes in this Orthologous Group
Strigamia maritima
European centipede
Strigamia maritima
European centipede
Ixodes scapularis
Black-legged tick
Stegodyphus mimosarum
African social velvet spider
Tetranychus urticae
Two-spotted spider mite
Daphnia pulex
Water flea
Orthologs in non-Arthropod Metazoa (via OrthoDB v9.1) ( EOG091G0Q0V )
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
Ciona intestinalis
Vase tunicate
Gallus gallus
Domestic chicken
Gallus gallus
Domestic chicken
Gallus gallus
Domestic chicken
Paralogs
Paralogs (via DIOPT v7.1)
Drosophila melanogaster (Fruit fly) (33)
4 of 10
3 of 10
3 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
1 of 10
1 of 10
1 of 10
1 of 10
1 of 10
1 of 10
1 of 10
1 of 10
1 of 10
1 of 10
1 of 10
1 of 10
1 of 10
1 of 10
1 of 10
1 of 10
1 of 10
1 of 10
1 of 10
1 of 10
1 of 10
1 of 10
Human Disease Associations
FlyBase Human Disease Model Reports
Disease Model Summary Ribbon
Disease Ontology (DO) Annotations
Models Based on Experimental Evidence ( 0 )
Allele
Disease
Evidence
References
Potential Models Based on Orthology ( 2 )
Human Ortholog
Disease
Evidence
References
Modifiers Based on Experimental Evidence ( 1 )
Allele
Disease
Interaction
References
Disease Associations of Human Orthologs (via DIOPT v7.1 and OMIM)
Note that ortholog calls supported by only 1 or 2 algorithms (DIOPT score < 3) are not shown.
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
Signaling Pathways (FlyBase)
Metabolic Pathways
External Data
Linkouts
Genomic Location and Detailed Mapping Data
Chromosome (arm)
2L
Recombination map

2-51

Cytogenetic map
Sequence location
2L:15,476,593..15,478,260 [-]
FlyBase Computed Cytological Location
Cytogenetic map
Evidence for location
35D2-35D2
Limits computationally determined from genome sequence between P{EP}esgEP633&P{PZ}esg07082 and P{lacW}CycEk05007&P{lacW}CycEk02602
Experimentally Determined Cytological Location
Cytogenetic map
Notes
References
35D1-35D2
(determined by in situ hybridisation)
Experimentally Determined Recombination Data
Left of (cM)
Right of (cM)
Notes
Stocks and Reagents
Stocks (368)
Genomic Clones (11)
 

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

cDNA Clones (156)
 

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

Source for identity of: sna CG3956

Source for database merge of
Additional comments

The "Sco" (Scutoid) mutant allele was previously listed as an allele of noc in FlyBase, as genetic analysis showed that a high dose of the wild-type noc gene suppresses the expressivity of the Sco phenotype, suggesting that Sco was an antimorphic allele of noc (FBrf0038047). However, FBrf0111871 shows that Sco is in fact an antimorphic allele of sna, and the mutant phenotype is caused by ectopic expression of sna in the eye-antennal and wing imaginal discs.  The Sco allele is therefore now listed as an allele of sna in FlyBase.  FBrf0111871 suggests that the reason that noc in trans affects the expressivity of Sco may be due to transvection effects, as they show that mutations in z, a mediator of transvection, also affect the Sco mutant phenotype.

Other Comments

DNA-protein interactions: genome-wide binding profile assayed for sna protein in 2-3 hr embryos; see BDTNP1_TFBS_sna collection report.

dsRNA has been made from templates generated with primers directed against this gene. RNAi of sna causes dorsal overextension of primary dendrites in ddaD and ddaE neurons. For such neurons, the most distal branchpoint is located 25 microns or further from the distal tip of the primary dendrite. However, branching of these dendrites is almost completely blocked. RNAi also causes defects in muscle, defects in dendrite morphogenesis and reproducible defects in da dendrite development.

The normal location of the ventral furrow in embryos with uniformly expressed fog suggests the existence of a fog-independent pathway determining mesoderm-specific cell behaviours and invagination. Epistasis experiments indicate this pathway requires sna but not twi expression.

CtBP mediates transcriptional repression by the kni, Kr and sna products in the Drosophila embryo.

In vitro binding assays, gene dosage studies and transgenic repression assays suggest that CtBP may be required for kni-mediated repression in the early embryo.

Analysis of sna mutant alleles suggests that different target genes respond to different functional levels of sna protein.

Expression of esg in the neuroectoderm is studied, the expression pattern prefigures that of the ASC genes. Dorsoventral pattern of esg expression in the blastoderm is determined by three independent repressive cues (dpp, sna and twi).

esg and sna function as intrinsic determinants of wing cell fate. esg and sna expression in the wing are maintained by their auto- and crossactivation, and control the same set of genes required for wing development.

The Kr and sna proteins function as short range repressors, which can mediate either quenching or direct repression of a transcription complex, depending on the location of repressor sites. Local quenching and dominant repression require close linkage of the repressor with either upstream activators or the transcription complex.

Molecular analysis suggests that sna protein acts over distances of 50-150bp to block the activity, but not the binding, of the dl activator to the rho 650bp enhancer.

sna can mediate efficient repression when bound 50-100bp from upstream activator sites. Repression does not depend in proximity of sna-binding sites to the transcription initiation site.

Deletion analysis of the sna promoter suggests that sequences directing expression in the CNS can be separated from those required for expression in the PNS.

sna is sufficient to induce the formation of an attenuated ventral furrow in the absence of twi+ gene activity. Expression of sna in the absence of twi uncouples ventral furrow formation and mesoderm differentiation, invaginating cells fail to express various mesoderm marker genes.

twi, sna, hkb and tll gene products define the positions of the primordia of the germ layers and thereby the regions in which the blastoderm epithelium will invaginate.

Lack of Mef2 gene expression in sna mutant embryos suggests that Mef2 lies downstream in the regulatory pathway.

Mesodermal fate is determined where sna and twi but not hkb are expressed. Anteriorly, hkb together with sna determines endodermal fate, and hkb together with twi and sna are required for foregut development.

Promoter fusions using elements of the twi, rho, da and sna promoters indicate that low affinity dl-binding sites restrict target gene expression to the presumptive mesoderm, where there are peak levels of dl expression, while high affinity sites in other target genes permit expression in ventrolateral regions where dl levels are intermediate. Activation by low levels of dl in lateral regions depends on cooperative interaction between dl and other basic helix loop helix proteins. Promoters containing the Et (rho) or Eds (dl and sna) E boxes display opposite behaviour in da and twi mutants, suggesting they are regulated by different basic helix loop helix proteins.

The DNA-binding site repertoire of the sna protein has been defined. The consensus sna DNA-binding sequence is 5' G/A A/t G/A A CAGGTC C/t A C 3'.

Activation of cnc in intercalary and mandibular primordia requires zygotic gap gene products, activation by btd and repression by oc (anteriorly) or sna (ventrally).

In mutant embryos lacking the entire mesoderm or failing to differentiate the visceral mesoderm, the anterior and posterior midgut primordia form but do not migrate properly. The cells of these primordia fail to arrange into an epithelium.

sna mutants fail to differentiate ventrally derived mesoderm.

Expression patterns of various sna-Ecol\lacZ reporter gene constructs have revealed that 2.8kb of sna 5' flanking sequence contains most of the cis-regulatory elements responsible for both the early and late phases of normal sna pattern.

sna proposed to be a target of the dl morphogen. A sna repressor site has been found in the neural ectoderm expression region (NEE) of rho. Disruption of sna binding site causes derepression of rho expression in the ventral region therefore sna is responsible for establishing the mesoderm/neurectoderm boundary before gastrulation.

The binding of sna protein to sites within sim regulatory sequences has been studied.

The zygotically acting DV genes repress ac expression within specific DV domains.

Sequence alignments of orthologous fragments of hb, Kr and sna from a variety of arthropods and other phyla show that amino acid differences are not normally correlated with evolutionary distance between respective species. Amino acids directly involved in DNA binding are the most conserved, and binding specificity of a hb finger from different species is not changed.

The expression of sna RNA and protein throughout embryogenesis has been studied.

The effect of the terminal system on the expression of 2 zygotic genes involved in dorsoventral patterning, sna and dpp, is mediated by a reduction in dl activity by the terminal system. Due to this interaction the poles adopt a more dorsalised fate than their counterparts in the middle of the embryo.

Establishment of the mesoderm neuroectoderm boundary involves the interaction of twi, sna and dl proteins.

sna prevents expression in the mesoderm of genes that are destined to be active only in more lateral or dorsal regions.

Mutations in zygotic ventral class gene sna interact with RpII140wimp.

In sna mutant embryos the ventral furrow fails to form at gastrulation resulting in an absence of all mesodermal derivatives in the mature embryo.

Polar expression of sna requires genes of the terminal group.

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

17 additional alleles are discussed but are not named.

twi and sna have been shown to independently control different aspects of ventral cell behaviour during gastrulation.

The sna mutant phenotype is enhanced zygotically by haploidy of the elbow-noc region and the interval defined by lace and CycE on the second chromosome.

Origin and Etymology
Discoverer
Etymology
Identification
External Crossreferences and Linkouts ( 37 )
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
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
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
SignaLink - A signaling pathway resource with multi-layered regulatory networks.
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
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.
MIST (genetic) - An integrated Molecular Interaction Database
MIST (protein-protein) - An integrated Molecular Interaction Database
Synonyms and Secondary IDs (18)
Reported As
Symbol Synonym
sna
(Banerjee et al., 2019, Campbell et al., 2019, Cardozo Gizzi et al., 2019, Gracia et al., 2019, Guo et al., 2019, Heist et al., 2019, Herrera-Perez and Kasza, 2019, Johnson and Toettcher, 2019, Shokri et al., 2019, Zhang et al., 2019, Bischof et al., 2018, Campbell et al., 2018, Khajouei and Sinha, 2018, Chambers et al., 2017, Fukaya et al., 2017, Houtz et al., 2017, Karaiskos et al., 2017, Koenecke et al., 2017, Requena et al., 2017, Simões et al., 2017, Transgenic RNAi Project members, 2017-, Fukaya et al., 2016, Kwon et al., 2016, Levario et al., 2016, Ma et al., 2016, Narbonne-Reveau et al., 2016, Sandler and Stathopoulos, 2016, Sarov et al., 2016, Urbansky et al., 2016, Weng and Wieschaus, 2016, Doggett et al., 2015, Lim et al., 2015, Lin et al., 2015, Monfort and Furlong, 2015.1.15, O'Connell and Reeves, 2015, Rauzi et al., 2015, Samee et al., 2015, Schertel et al., 2015, Ambrosi et al., 2014, Fu et al., 2014, Jiang and Singh, 2014, Mannervik, 2014, Park et al., 2014, Rembold et al., 2014, Sánchez-Higueras et al., 2014, Slattery et al., 2014, Spahn et al., 2014, Tevy et al., 2014, Chen et al., 2013, Dresch et al., 2013, Enuameh et al., 2013, Garcia et al., 2013, Lagha et al., 2013, Li and Gilmour, 2013, Saunders et al., 2013, Webber et al., 2013, Andrioli et al., 2012, Aswani et al., 2012, Haskel-Ittah et al., 2012, Holmqvist et al., 2012, Japanese National Institute of Genetics, 2012.5.21, Konikoff et al., 2012, Kvon et al., 2012, Murray et al., 2012, Park and Hong, 2012, Popkova et al., 2012, Reeves et al., 2012, Rushlow and Shvartsman, 2012, Turki-Judeh and Courey, 2012, Cave et al., 2011, Dunipace et al., 2011, Kuzin et al., 2011, Li et al., 2011, Lynch and Roth, 2011, Mathew et al., 2011, Mrinal et al., 2011, Nègre et al., 2011, Nien et al., 2011, Ozdemir et al., 2011, Pruteanu-Malinici et al., 2011, Richter et al., 2011, Tom et al., 2011, Tsurumi et al., 2011, Aerts et al., 2010, Biehs et al., 2010, Bothma et al., 2010, Fernandez-Sanchez et al., 2010, Frise et al., 2010, Martin et al., 2010, Roote, 2010.1.4, Birkholz et al., 2009, Fontenele et al., 2009, Liberman et al., 2009, Lu et al., 2009, Martin et al., 2009, Pouille et al., 2009, Weber et al., 2009, Frise et al., 2008, Jennings et al., 2008, Liang et al., 2008, Li et al., 2008, Qi et al., 2008, Ratnaparkhi et al., 2008, Yu and Small, 2008, Beltran et al., 2007, Geng and MacDonald, 2007, Seher et al., 2007, Wang et al., 2007, Zeitlinger et al., 2007, Zinzen and Papatsenko, 2007, Anderson et al., 2006, Carneiro et al., 2006, Jennings et al., 2006, Lim and Tomlinson, 2006, Philippakis et al., 2006, Prothmann et al., 2006, Ratnaparkhi et al., 2006, ten Bosch et al., 2006, Wheeler et al., 2006, Reeves and Posakony, 2005, Stathopoulos and Levine, 2005, Ronshaugen and Levine, 2004, Cowden and Levine, 2003, Jia et al., 2002, Gim et al., 2001)
Name Synonyms
snail
(Das et al., 2016, Matsuda et al., 2016, Narbonne-Reveau et al., 2016, Ou et al., 2016, Tseng et al., 2016, Wieschaus and Nüsslein-Volhard, 2016, Boija and Mannervik, 2015, Bothma et al., 2015, Lin et al., 2015, Monfort and Furlong, 2015.1.15, Rauzi et al., 2015, Sanchez-Díaz et al., 2015, Ambrosi et al., 2014, Guilgur et al., 2014, Nie et al., 2014, Rembold et al., 2014, Singari et al., 2014, Fontenele et al., 2013, Lagha et al., 2013, Manning et al., 2013, Merino et al., 2013, Haskel-Ittah et al., 2012, Yang et al., 2012, Kuzin et al., 2011, Ozdemir et al., 2011, Tom et al., 2011, Yokoyama and Nakamura, 2011, Biehs et al., 2010, Ismat et al., 2010, Martin et al., 2010, Birkholz et al., 2009, Fernandez-Gonzalez et al., 2009, Fontenele et al., 2009, Martin et al., 2009, Pouille et al., 2009, Crocker et al., 2008, Ishihara and Shibata, 2008, Jennings et al., 2008, Li et al., 2008, Qi et al., 2008, Ratnaparkhi et al., 2008, Copley et al., 2007, De Renzis et al., 2007, Geng and MacDonald, 2007, Hsouna et al., 2007, Kolsch et al., 2007, Nagel et al., 2007, Peng et al., 2007, Seher et al., 2007, Wang et al., 2007, Zeitlinger et al., 2007, Anderson et al., 2006, Biemar et al., 2006, De Renzis et al., 2006, Jennings et al., 2006, Lawrence, 2006, Montell, 2006, Papatsenko et al., 2006, Prothmann et al., 2006, Ratnaparkhi et al., 2006, ten Bosch et al., 2006, Wheeler et al., 2006, Leptin, 2005, Gurunathan et al., 2004, Cowden and Levine, 2003, Andrew et al., 2000, Alberga, 1987.12.4, Boulay et al., 1987)
Secondary FlyBase IDs
  • FBgn0016654
Datasets (3)
Study focus (3)
Experimental Role
Project
Project Type
Title
  • bait_protein
ChIP-chip identification of binding sites for transcription factors that regulate mesodermal development.
  • bait_protein
ChIP characterization of transcription factor genome binding, Berkeley Drosophila Transcription Factor Network Project.
  • bait_protein
Genome-wide localization of transcription factors by ChIP-chip and ChIP-Seq.
References (644)