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osk oskar [ Drosophila melanogaster (fruit fly) ]

Gene ID: 41066, updated on 31-Mar-2026
Official Symbol
oskprovided by FlyBase
Official Full Name
oskarprovided by FlyBase
Primary source
FLYBASE:FBgn0003015
Locus tag
Dmel_CG10901
See related
AllianceGenome:FB:FBgn0003015
Gene type
protein coding
RefSeq status
REVIEWED
Organism
Drosophila melanogaster
Lineage
Eukaryota; Metazoa; Ecdysozoa; Arthropoda; Hexapoda; Insecta; Pterygota; Neoptera; Endopterygota; Diptera; Brachycera; Muscomorpha; Ephydroidea; Drosophilidae; Drosophila; Sophophora
Also known as
CG10901; Dm-osk; Dmel\CG10901; norka; Osk; OSK; Oskar
Summary
Enables mRNA binding activity. Involved in several processes, including axis specification; pole cell formation; and thermosensory behavior. Located in P granule; germ cell nucleus; and posterior cell cortex. Is expressed in several structures, including egg chamber; germarium region 2b; germline cell; ovary; and pole granule. [provided by Alliance of Genome Resources, Jul 2025]
Orthologs
all
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Try the new Transcripts and proteins table
See osk in Genome Data Viewer
Location:
85B7-85B7; 3-48 cM
Exon count:
4
Annotation release Status Assembly Chr Location
Release 6.54 current Release 6 plus ISO1 MT (GCF_000001215.4) 3R NT_033777.3 (8935126..8938395)
Release 5.57 previous assembly Release 5 (GCF_000001215.2) 3R NT_033777.2 (4760848..4764117)

Chromosome 3R - NT_033777.3Genomic Context describing neighboring genes Neighboring gene polychaetoid Neighboring gene transfer RNA:Arginine-TCG 2-3 Neighboring gene transfer RNA:Arginine-TCG 2-4 Neighboring gene antisense RNA:CR44020 Neighboring gene long non-coding RNA:osk Neighboring gene Succinyl-coenzyme A synthetase beta subunit, ADP-forming Neighboring gene uncharacterized protein Neighboring gene ichor

Go to nucleotide: Graphics FASTA GenBank

Related articles in PubMed

  1. Evolution of germ plasm assembly and function among the insects. Kemph A, et al. Curr Opin Insect Sci, 2022 Apr. PMID 35123121, Free PMC Article
  2. Structure of Drosophila Oskar reveals a novel RNA binding protein. Yang N, et al. Proc Natl Acad Sci U S A, 2015 Sep 15. PMID 26324911, Free PMC Article
  3. Quantitative mRNA Imaging with Dual Channel qFIT Probes to Monitor Distribution and Degree of Hybridization. Gaspar I, et al. ACS Chem Biol, 2018 Mar 16. PMID 29378392
  4. The structure of the SOLE element of oskar mRNA. Simon B, et al. RNA, 2015 Aug. PMID 26089324, Free PMC Article
  5. Oskar gains weight. Ryder SP. Nat Struct Mol Biol, 2006 Apr. PMID 16715044

See all (816) citations in PubMed

GeneRIFs: Gene References Into Functions

What's a GeneRIF?
  1. Localization of oskar mRNA by agglomeration in ribonucleoprotein granules.
    Title: Localization of oskar mRNA by agglomeration in ribonucleoprotein granules.
  2. Structural basis for binding of Drosophila Smaug to the GPCR Smoothened and to the germline inducer Oskar.
    Title: Structural basis for binding of Drosophila Smaug to the GPCR Smoothened and to the germline inducer Oskar.
  3. Cup is essential for oskar mRNA translational repression during early Drosophila oogenesis.
    Title: Cup is essential for oskar mRNA translational repression during early Drosophila oogenesis.
  4. Proteins rather than mRNAs regulate nucleation and persistence of Oskar germ granules in Drosophila.
    Title: Proteins rather than mRNAs regulate nucleation and persistence of Oskar germ granules in Drosophila.
  5. An RNA-based feed-forward mechanism ensures motor switching in oskar mRNA transport.
    Title: An RNA-based feed-forward mechanism ensures motor switching in oskar mRNA transport.
  6. Liquid-to-solid phase transition of oskar ribonucleoprotein granules is essential for their function in Drosophila embryonic development.
    Title: Liquid-to-solid phase transition of oskar ribonucleoprotein granules is essential for their function in Drosophila embryonic development.
  7. Different roles for the adjoining and structurally similar A-rich and poly(A) domains of oskar mRNA: Only the A-rich domain is required for oskar noncoding RNA function, which includes MTOC positioning.
    Title: Different roles for the adjoining and structurally similar A-rich and poly(A) domains of oskar mRNA: Only the A-rich domain is required for oskar noncoding RNA function, which includes MTOC positioning.
  8. Receptor-mediated yolk uptake is required for oskar mRNA localization and cortical anchorage of germ plasm components in the Drosophila oocyte.
    Title: Receptor-mediated yolk uptake is required for oskar mRNA localization and cortical anchorage of germ plasm components in the Drosophila oocyte.
  9. Opposing roles for Egalitarian and Staufen in transport, anchoring and localization of oskar mRNA in the Drosophila oocyte.
    Title: Opposing roles for Egalitarian and Staufen in transport, anchoring and localization of oskar mRNA in the Drosophila oocyte.
  10. Bacterial contribution to genesis of the novel germ line determinant oskar.
    Title: Bacterial contribution to genesis of the novel germ line determinant oskar.
Submit: New GeneRIF Correction See all GeneRIFs (64)
Products Interactant Other Gene Complex Source Pubs Description

Homology

Gene Ontology Provided by FlyBase

Function Evidence Code Pubs
enables mRNA binding IDA
Inferred from Direct Assay
more info
 PubMed 
Process Evidence Code Pubs
involved_in P granule assembly IMP
Inferred from Mutant Phenotype
more info
 PubMed 
involved_in P granule organization IMP
Inferred from Mutant Phenotype
more info
 PubMed 
involved_in cortical actin cytoskeleton organization IMP
Inferred from Mutant Phenotype
more info
 PubMed 
involved_in germ cell development IMP
Inferred from Mutant Phenotype
more info
 PubMed 
involved_in long-term memory TAS
Traceable Author Statement
more info
 PubMed 
involved_in oocyte microtubule cytoskeleton polarization IMP
Inferred from Mutant Phenotype
more info
 PubMed 
involved_in oogenesis IMP
Inferred from Mutant Phenotype
more info
 PubMed 
involved_in pole cell formation IMP
Inferred from Mutant Phenotype
more info
 PubMed 
involved_in pole cell formation TAS
Traceable Author Statement
more info
 PubMed 
involved_in pole plasm assembly IMP
Inferred from Mutant Phenotype
more info
 PubMed 
involved_in pole plasm assembly TAS
Traceable Author Statement
more info
 PubMed 
involved_in pole plasm mRNA localization TAS
Traceable Author Statement
more info
 PubMed 
involved_in pole plasm protein localization TAS
Traceable Author Statement
more info
 PubMed 
involved_in posterior abdomen determination IMP
Inferred from Mutant Phenotype
more info
 PubMed 
involved_in protein localization to nucleus IMP
Inferred from Mutant Phenotype
more info
 PubMed 
involved_in regulation of mRNA stability IMP
Inferred from Mutant Phenotype
more info
 PubMed 
involved_in regulation of oskar mRNA translation TAS
Traceable Author Statement
more info
 PubMed 
involved_in segmentation IMP
Inferred from Mutant Phenotype
more info
 PubMed 
involved_in thermosensory behavior IMP
Inferred from Mutant Phenotype
more info
 PubMed 
involved_in visual behavior IMP
Inferred from Mutant Phenotype
more info
 PubMed 
involved_in visual learning IMP
Inferred from Mutant Phenotype
more info
 PubMed 
Component Evidence Code Pubs
located_in P granule IDA
Inferred from Direct Assay
more info
 PubMed 
located_in cell cortex IDA
Inferred from Direct Assay
more info
 PubMed 
located_in cytoplasm IDA
Inferred from Direct Assay
more info
 PubMed 
located_in endosome IEA
Inferred from Electronic Annotation
more info
  
located_in germ cell nucleus IDA
Inferred from Direct Assay
more info
 PubMed 
located_in pole plasm TAS
Traceable Author Statement
more info
 PubMed 
located_in posterior cell cortex IDA
Inferred from Direct Assay
more info
 PubMed 
Preferred Names
oskar
Names
CG10901-PA
CG10901-PC
dmoskar
osk-PA
osk-PC

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Genome Annotation

The following sections contain reference sequences that belong to a specific genome build. Explain

Reference assembly

Genomic

  1. NT_033777.3 Reference assembly

    Range
    8935126..8938395
    Download
    GenBank, FASTA, Sequence Viewer (Graphics)

mRNA and Protein(s)

  1. NM_206464.3 → NP_996186.1  oskar, isoform C

    See identical proteins and their annotated locations for NP_996186.1

    Status: REVIEWED

    UniProtKB/Swiss-Prot
    P25158
    Conserved Domains (1) summary
    cd09972
    Location:16 → 98
    LOTUS_TDRD_OSKAR; The first LOTUS domain in Oskar and Tudor-containing proteins 5 and 7

  2. NM_169248.4 → NP_731295.1  oskar, isoform A

    See identical proteins and their annotated locations for NP_731295.1

    Status: REVIEWED

    UniProtKB/Swiss-Prot
    P25158, Q59DY0, Q95TT0, Q9V3P1
    UniProtKB/TrEMBL
    E8NH25
    Related
    FBpp0081435
    Conserved Domains (1) summary
    cd09972
    Location:154 → 236
    LOTUS_TDRD_OSKAR; The first LOTUS domain in Oskar and Tudor-containing proteins 5 and 7
Nucleotide Protein
Heading Accession and Version
Protein Accession Links
GenPept Link UniProtKB Link
P25158.1 P25158

Gene LinkOut

The following LinkOut resources are supplied by external providers. These providers are responsible for maintaining the links.

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