FB2026_01 , released March 12, 2026
FB2026_01 , released March 12, 2026
Gene: Dmel\Saf-B
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General Information
Symbol
Dmel\Saf-B
Species
D. melanogaster
Name
Scaffold attachment factor B
Annotation Symbol
CG6995
Feature Type
protein_coding_gene
FlyBase ID
FBgn0039229
Gene Model Status
Current
Stock Availability
10 publicly available
Gene Summary
Contribute a Gene Snapshot for this gene.
All Summaries
Also Known As

SAFB

Key Links
Genomic Location
Cytogenetic map
96A23-96A23
Sequence location
Recombination map
3-85
RefSeq locus
NT_033777 REGION:24817464..24822350
Sequence
Get Decorated FASTA
Genomic Maps
Other Genome Views
The following external sites may use different assemblies or annotations than FlyBase.
NCBI
UCSC
Ensembl
PopFly
Function
Gene Ontology (GO) Annotations (7 terms)
Molecular Function (3 terms)
Terms Based on Experimental Evidence (0 terms)
Terms Based on Predictions or Assertions (3 terms)
CV Term
Evidence
References
enables mRNA binding
inferred from sequence or structural similarity
(Lasko, 2000)
enables nucleic acid binding
inferred from electronic annotation with InterPro:IPR035979
(InterPro Project Members, 2004-)
enables RNA binding
inferred from electronic annotation with InterPro:IPR000504
(InterPro Project Members, 2004-)
Biological Process (1 term)
Terms Based on Experimental Evidence (1 term)
CV Term
Evidence
References
involved_in regulation of alternative mRNA splicing, via spliceosome
inferred from high throughput mutant phenotype
(Park et al., 2004)
Terms Based on Predictions or Assertions (0 terms)
Cellular Component (3 terms)
Terms Based on Experimental Evidence (2 terms)
CV Term
Evidence
References
located_in nuclear matrix
inferred from direct assay
(Alfonso-Parra and Maggert, 2010)
located_in nucleoplasm
inferred from direct assay
(Alfonso-Parra and Maggert, 2010)
Terms Based on Predictions or Assertions (1 term)
CV Term
Evidence
References
is_active_in nucleus
inferred from biological aspect of ancestor with PANTHER:PTN001038533
(GO Reference Genome Project, 2011-)
located_in nucleus
inferred by curator from GO:0000381
(Park et al., 2004)
Gene Group (FlyBase)
Protein Family (UniProt)
-
Protein Signatures (InterPro)
Summaries
Gene Model and Products
Number of Transcripts
4
Number of Unique Polypeptides
3

Please see the JBrowse view of Dmel\Saf-B 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
Structure
Protein 3D structure   (Predicted by AlphaFold)   (AlphaFold entry Q8IMV6)

If you don't see a structure in the viewer, refresh your browser.
Model Confidence:
  • Very high (pLDDT > 90)
  • Confident (90 > pLDDT > 70)
  • Low (70 > pLDDT > 50)
  • Very low (pLDDT < 50)

AlphaFold produces a per-residue confidence score (pLDDT) between 0 and 100. Some regions with low pLDDT may be unstructured in isolation.

Experimentally Determined Structures
Crossreferences
Comments on Gene Model

Gene model reviewed during 5.45

Gene model reviewed during 6.04

Transcript Data
Annotated Transcripts
Name
FlyBase ID
RefSeq ID
Length (nt)
Assoc. CDS (aa)
Saf-B-RB
FBtr0084700
NM_170169
3124
928
Saf-B-RD
FBtr0331696
NM_001276002
2085
279
Saf-B-RE
FBtr0392911
NM_001316518
4332
270
Saf-B-RF
FBtr0392912
NM_001316517
4003
270
Additional Transcript Data and Comments
Reported size (kB)
Comments
External Data
Crossreferences
Polypeptide Data
Annotated Polypeptides
Name
FlyBase ID
Predicted MW (kDa)
Length (aa)
Theoretical pI
UniProt
RefSeq ID
GenBank
Saf-B-PB
FBpp0084078
102.1
928
7.53
Q8IMV6
NP_733041
AAN14018
Saf-B-PD
FBpp0304085
30.5
279
4.13
A0A0B4KGV9
NP_001262931
AGB96311
Saf-B-PE
FBpp0352253
29.7
270
4.15
A0A126GV03
NP_001303447
ALI30637
Saf-B-PF
FBpp0352254
29.7
270
4.15
A0A126GV03
NP_001303446
ALI30638
Polypeptides with Identical Sequences

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

270 aa isoforms: Saf-B-PE, Saf-B-PF
Additional Polypeptide Data and Comments
Reported size (kDa)
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\Saf-B using the Feature Mapper tool.

External Data
Crossreferences
Eukaryotic Promoter Database - A collection of databases of experimentally validated promoters for selected model organisms.
Linkouts
Expression Data
Testis-specificity index

The testis specificity index was calculated from modENCODE tissue expression data by Vedelek et al., 2018 to indicate the degree of testis enrichment compared to other tissues. Scores range from -2.52 (underrepresented) to 5.2 (very high testis bias).

-0.89

Transcript Expression
in situ
Stage
Tissue/Position (including subcellular localization)
Reference
embryonic stage 1 -- 3
organism

Comment: maternally deposited

(Fisher et al., 2012)
embryonic stage 1 -- 4
organism | ubiquitous | uniform

Comment: maternally deposited

(Alfonso-Parra and Maggert, 2010)
embryonic stage 4 -- 5
organism | ubiquitous | uniform
(Alfonso-Parra and Maggert, 2010)
embryonic stage 4 -- 6
organism
(Fisher et al., 2012)
embryonic stage 7 -- 8
organism | ubiquitous
(Fisher et al., 2012)
embryonic stage 9 -- 10
organism | ubiquitous
(Fisher et al., 2012)
embryonic stage 10 -- 14
presumptive embryonic/larval central nervous system
(Alfonso-Parra and Maggert, 2010)
embryonic stage 11 -- 12
organism | ubiquitous
(Fisher et al., 2012)
embryonic stage 13 -- 16
organism | ubiquitous
(Fisher et al., 2012)
embryonic stage 15 -- 17
larval central nervous system
(Alfonso-Parra and Maggert, 2010)
larval stage
larval central nervous system
(Alfonso-Parra and Maggert, 2010)
third instar larval stage
larval brain
(Alfonso-Parra and Maggert, 2010)
imaginal disc
(Alfonso-Parra and Maggert, 2010)
oogenesis
nurse cell
(Alfonso-Parra and Maggert, 2010)
oocyte
(Alfonso-Parra and Maggert, 2010)
spermatogenesis
spermatocyte
(Alfonso-Parra and Maggert, 2010)
RT-PCR
Stage
Tissue/Position (including subcellular localization)
Reference
embryonic stage -- adult stage
organism
(Alfonso-Parra and Maggert, 2010)
adult stage | female
adult head
(Alfonso-Parra and Maggert, 2010)
adult thorax & adult abdomen

Comment: assayed together

(Alfonso-Parra and Maggert, 2010)
adult stage | male
adult head
(Alfonso-Parra and Maggert, 2010)
adult thorax & adult abdomen

Comment: assayed together

(Alfonso-Parra and Maggert, 2010)
Additional Descriptive Data

Saf-B transcript is detected all stages assayed, and in both the heads and bodies of adult males and females. Saf-B transcript is loaded into eggs during oogenesis, and is ubiquitously distributed in early embryos. By germband extension, Saf-B transcript expression is more pronounced in the nervous system than in other tissues. This CNS-enriched expession pattern is preserved through the remainder of embryogenesis, and larval development, with high levels of expression observed in imaginal discs and brain lobes of third instar larvae. Expression is not detected in germline stem cells, but is observed in developing spermatocytes, nurse cells, and oocytes.

(Alfonso-Parra and Maggert, 2010)
Marker for
 
Subcellular Localization
CV Term
Polypeptide Expression
mass spectroscopy
Stage
Tissue/Position (including subcellular localization)
Reference
adult stage
adult head
(Aradska et al., 2015)
Additional Descriptive Data
Marker for
 
Subcellular Localization
CV Term
Evidence
References
located_in nuclear matrix
inferred from direct assay
(Alfonso-Parra and Maggert, 2010)
located_in nucleoplasm
inferred from direct assay
(Alfonso-Parra and Maggert, 2010)
Expression Deduced from Reporters
High-Throughput Expression Data
Associated Tools

JBrowse - Visual display of RNA-Seq signals

View Dmel\Saf-B in JBrowse
RNA-Seq by Region - Search RNA-Seq expression levels by exon or genomic region
Bulk Downloads
RNA-Seq RPKM values for all genes
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
DRscDB - A single-cell RNA-seq resource for data mining and data comparison across species
EMBL-EBI Single Cell Expression Atlas - Single cell expression across species
FlyAtlas - Adult expression by tissue, using Affymetrix Dros2 array
FlyAtlas2 - A Drosophila melanogaster expression atlas with RNA-Seq, miRNA-Seq and sex-specific data
Fly-FISH - A database of Drosophila embryo and larvae mRNA localization patterns
Flygut - An atlas of the Drosophila adult midgut
Images
FlyBase Wiki
Image Based Resources
Alleles, Insertions, Transgenic Constructs, and Aberrations
Classical and Insertion Alleles ( 4 )
For All Classical and Insertion Alleles Show
 
Other relevant insertions
Transgenic Constructs ( 8 )
For All Alleles Carried on Transgenic Constructs Show
Transgenic constructs containing/affecting coding region of Saf-B
Transgenic constructs containing regulatory region of Saf-B
Aberrations (Deficiencies and Duplications) ( 1 )
Inferred from experimentation ( 1 )
Gene disrupted in
Df(3R)Exel6200
(Ryder, 2004.4.26)
Inferred from location ( 6 )
Variants
Variant Molecular Consequences
Alleles Representing Disease-Implicated Variants
Phenotypes
For more details about a specific phenotype click on the relevant allele symbol.
Other Phenotypes
Allele
visible, with Scer\GAL4GMR.PU
Phenotype manifest in
Allele
eye, with Scer\GAL4GMR.PU
Orthologs
Downloads
Download All DIOPT Orthologs
Human Orthologs (via DIOPT v9.1)
Species\Gene Symbol
Score
Best Score
Best Reverse Score
Source
Compara
Domainoid
eggNOG
Hieranoid
Homologene
Inparanoid
OMA
OrthoDB
OrthoFinder
OrthoInspector
orthoMCL
Panther
Phylome
SonicParanoid
Alignment
Complementation?
Transgene?
Homo sapiens (Human) (5)
Hsap\SAFB2
10 of 14
Yes
Yes
1  
Hsap\SAFB
10 of 14
Yes
Yes
1  
Hsap\SLTM
9 of 14
No
Yes
Hsap\HNRNPUL1
1 of 14
No
No
1  
Hsap\SRSF4
1 of 14
No
No
1  
Model Organism Orthologs (via DIOPT v9.1)
Species\Gene Symbol
Score
Best Score
Best Reverse Score
Source
Compara
Domainoid
eggNOG
Hieranoid
Homologene
Inparanoid
OMA
OrthoDB
OrthoFinder
OrthoInspector
orthoMCL
Panther
Phylome
SonicParanoid
Alignment
Complementation?
Transgene?
Rattus norvegicus (Norway rat) (4)
Rnor\Safb
9 of 14
Yes
Yes
Rnor\Safb2
7 of 14
No
Yes
Rnor\Sltm
7 of 14
No
Yes
Rnor\Srsf4
1 of 14
No
No
Mus musculus (laboratory mouse) (4)
Mmus\Safb2
10 of 14
Yes
Yes
Mmus\Safb
10 of 14
Yes
Yes
Mmus\Sltm
9 of 14
No
Yes
Mmus\Srsf4
1 of 14
No
No
Xenopus tropicalis (Western clawed frog) (6)
Xtro\sltm
7 of 13
Yes
Yes
Xtro\safb
6 of 13
No
Yes
Xtro\acin1
1 of 13
No
No
Xtro\ccnh
1 of 13
No
No
Xtro\eif4g2
1 of 13
No
No
Xtro\srsf4
1 of 13
No
No
Danio rerio (Zebrafish) (3)
Drer\safb
9 of 14
Yes
Yes
Drer\sltm
7 of 14
No
Yes
Drer\hnrnpul1
1 of 14
No
No
Caenorhabditis elegans (Nematode, roundworm) (2)
Cele\phm-2
7 of 14
Yes
Yes
Cele\acin-1
1 of 14
No
No
Anopheles gambiae (African malaria mosquito) (2)
Agam\AgaP_AGAP001298
10 of 12
Yes
Yes
Agam\AgaP_AGAP000463
1 of 12
No
Yes
Arabidopsis thaliana (thale-cress) (8)
Atha\AT4G35785
3 of 13
Yes
No
Atha\SR45a
3 of 13
Yes
No
Atha\ATRZ-1A
1 of 13
No
No
Atha\AtRZ-1c
1 of 13
No
Yes
Atha\CCR1
1 of 13
No
No
Atha\RS31a
1 of 13
No
No
Atha\RS31
1 of 13
No
No
Atha\RS40
1 of 13
No
No
Saccharomyces cerevisiae (Brewer's yeast) (0)
Schizosaccharomyces pombe (Fission yeast) (3)
Spom\SPAC25G10.01
1 of 12
Yes
No
Spom\SPBC4F6.14
1 of 12
Yes
No
Spom\srp1
1 of 12
Yes
No
Escherichia coli (enterobacterium) (0)
Other Organism Orthologs (via OrthoDB)
Data provided directly from OrthoDB:Saf-B. Refer to their site for version information.
Paralogs
Downloads
Download All DIOPT Paralogs
Paralogs (via DIOPT v9.1)
Gene Symbol
Score
Source
Compara
Domainoid
eggNOG
Homologene
Inparanoid
OMA
OrthoDB
OrthoFinder
OrthoInspector
orthoMCL
Panther
Phylome
SonicParanoid
Alignment
Drosophila melanogaster (Fruit fly) (1)
CG30122
1 of 13
Human Disease Associations
FlyBase Human Disease Model Reports
    Disease Ontology (DO) Annotations
    Models Based on Experimental Evidence ( 0 )
    Allele
    Disease
    Evidence
    References
    Potential Models Based on Orthology ( 0 )
    Human Ortholog
    Disease
    Evidence
    References
    Modifiers Based on Experimental Evidence ( 0 )
    Allele
    Disease
    Interaction
    References
    Disease Associations of Human Orthologs (via DIOPT v9.1 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?
    SAFB2; scaffold attachment factor B2
    10 of 14
    608066
         
        SAFB; scaffold attachment factor B
        10 of 14
        602895
             
            SLTM; SAFB like transcription modulator
            9 of 14
            620992
                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
                Pathways
                Signaling Pathways (FlyBase)
                Metabolic Pathways
                FlyBase
                External Links
                External Data
                Linkouts
                Reactome - An open-source, open access, manually curated and peer-reviewed pathway database.
                Class of Gene
                Genomic Location and Detailed Mapping Data
                Chromosome (arm)
                3R
                Recombination map
                3-85
                Cytogenetic map
                96A23-96A23
                Sequence location
                FlyBase Computed Cytological Location
                Cytogenetic map
                Evidence for location
                96A23-96A23
                Limits computationally determined from genome sequence between P{PZ}crb07207&P{PZ}BRWD305842 and P{EP}CycB3EP3127
                Experimentally Determined Cytological Location
                Cytogenetic map
                Notes
                References
                Experimentally Determined Recombination Data
                Location

                3-85

                (FlyBase, 2016)

                3-84.8

                (Comeron et al., 2012)
                Left of (cM)
                Right of (cM)
                Notes
                Stocks and Reagents
                Stocks (10)
                Genomic Clones (16)
                 

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

                cDNA Clones (73)
                 

                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 JBrowse for alignment of the cDNAs and ESTs to the gene model.

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

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

                  cDNA Clones, End Sequenced (ESTs)
                  BDGP DGC clones
                  Other clones
                  RNAi and Array Information
                  Linkouts
                  DRSC - Results frm RNAi screens
                  Antibody Information
                  Laboratory Generated Antibodies
                   
                  Commercially Available Antibodies
                   
                  Cell Line Information
                  Publicly Available Cell Lines
                   
                    Other Stable Cell Lines
                     
                      Other Comments
                      Relationship to Other Genes
                      Source for database merge of
                      Additional comments
                      Nomenclature History
                      Source for database identify of

                      Source for identity of: Saf-B CG6995

                      (Alfonso-Parra and Maggert, 2010)
                      Nomenclature comments
                      Etymology
                      Synonyms and Secondary IDs (8)
                      Datasets (0)
                      Study focus (0)
                      Experimental Role
                      Project
                      Project Type
                      Title
                      Study result (0)
                      Result
                      Result Type
                      Title
                      External Crossreferences and Linkouts ( 55 )
                      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/GCRP - The gene-centric reference proteome (GCRP) provides a 1:1 mapping between genes and UniProt accessions in which a single 'canonical' isoform represents the product(s) of each protein-coding gene.
                      UniProt/TrEMBL - Automatically annotated and unreviewed records of protein sequence and functional information
                      Other crossreferences
                      AlphaFold DB - AlphaFold provides open access to protein structure predictions for the human proteome and other key proteins of interest, to accelerate scientific research.
                      BDGP expression data - Patterns of gene expression in Drosophila embryogenesis
                      DRscDB - A single-cell RNA-seq resource for data mining and data comparison across species
                      EMBL-EBI Single Cell Expression Atlas - Single cell expression across species
                      FlyAtlas2 - A Drosophila melanogaster expression atlas with RNA-Seq, miRNA-Seq and sex-specific data
                      FlyMine - An integrated database for Drosophila genomics
                      InterPro - A database of protein families, domains and functional sites
                      KEGG Genes - Molecular building blocks of life in the genomic space.
                      MARRVEL_MODEL - MARRVEL (model organism gene)
                      Linkouts
                      Drosophila Genomics Resource Center - Drosophila Genomics Resource Center (DGRC) cDNA clones
                      DroID - A comprehensive database of gene and protein interactions.
                      DRSC - Results frm RNAi screens
                      Eukaryotic Promoter Database - A collection of databases of experimentally validated promoters for selected model organisms.
                      FlyAtlas - Adult expression by tissue, using Affymetrix Dros2 array
                      FlyCyc Genes - Genes from a BioCyc PGDB for Dmel
                      Fly-FISH - A database of Drosophila embryo and larvae mRNA localization patterns
                      Flygut - An atlas of the Drosophila adult midgut
                      FlyMet - A comprehensive tissue-specific metabolomics resource for Drosophila.
                      iBeetle-Base - RNAi phenotypes in the red flour beetle (Tribolium castaneum)
                      MIST (protein-protein) - An integrated Molecular Interaction Database
                      Reactome - An open-source, open access, manually curated and peer-reviewed pathway database.
                      References (64)