FB2025_01 , released February 20, 2025
Gene: Dmel\Yp2
Open Close
General Information
Symbol
Dmel\Yp2
Species
D. melanogaster
Name
Yolk protein 2
Annotation Symbol
CG2979
Feature Type
FlyBase ID
FBgn0005391
Gene Model Status
Stock Availability
Gene Summary
Vitellogenin is the major yolk protein of eggs where it is used as a food source during embryogenesis. Vitellogenins and their receptor yl/yolkless are required for maintenance of microtubule plus-end orientation towards the posterior pole of oocytes (PubMed:33891588). Involved in polarized localization of germ plasm components, such as osk mRNA and vas protein, to the oocyte posterior cortex (PubMed:33891588). Receptor-mediated endocytosis by yl/yolkless is crucial for actin reorganization, mediated by osk isoform A/Long, required to anchor germ plasm components to the oocyte cortex (PubMed:33891588). (UniProt, P02844)
Contribute a Gene Snapshot for this gene.
Also Known As

YP, fs(1)K313, vitellogenin, fs(1)M35, yolk protein

Key Links
Genomic Location
Cytogenetic map
Sequence location
Recombination map
1-30
RefSeq locus
NC_004354 REGION:10050951..10052636
Sequence
Genomic Maps
Other Genome Views
The following external sites may use different assemblies or annotations than FlyBase.
Function
Gene Ontology (GO) Annotations (6 terms)
Molecular Function (2 terms)
Terms Based on Experimental Evidence (1 term)
CV Term
Evidence
References
inferred from high throughput direct assay
Terms Based on Predictions or Assertions (1 term)
CV Term
Evidence
References
NOT enables lipase activity
inferred from key residues
Biological Process (2 terms)
Terms Based on Experimental Evidence (0 terms)
Terms Based on Predictions or Assertions (2 terms)
CV Term
Evidence
References
inferred from biological aspect of ancestor with PANTHER:PTN008325466
traceable author statement
non-traceable author statement
Cellular Component (2 terms)
Terms Based on Experimental Evidence (0 terms)
Terms Based on Predictions or Assertions (2 terms)
CV Term
Evidence
References
traceable author statement
is_active_in extracellular space
inferred from biological aspect of ancestor with PANTHER:PTN008325466
Gene Group (FlyBase)
Protein Family (UniProt)
Belongs to the AB hydrolase superfamily. Lipase family. (P02844)
Summaries
Protein Function (UniProtKB)
Vitellogenin is the major yolk protein of eggs where it is used as a food source during embryogenesis. Vitellogenins and their receptor yl/yolkless are required for maintenance of microtubule plus-end orientation towards the posterior pole of oocytes (PubMed:33891588). Involved in polarized localization of germ plasm components, such as osk mRNA and vas protein, to the oocyte posterior cortex (PubMed:33891588). Receptor-mediated endocytosis by yl/yolkless is crucial for actin reorganization, mediated by osk isoform A/Long, required to anchor germ plasm components to the oocyte cortex (PubMed:33891588).
(UniProt, P02844)
Phenotypic Description (Red Book; Lindsley and Zimm 1992)
Yp2
Structural gene for the yolk protein YP2 found in recently-emerged female flies. Protein migrates at different rates in SDS-polyacrylamide gels when encoded by the electrophoretic variants Yp2F (fast) and Yp2S (slow), alleles that are female fertile and produce normal amounts of YP2. A mutant Yp2M (=Yp212-1245) is female fertile but lays fewer eggs than normal (Mohler, Postlethwait, and Shirk) and does not contain yolk protein in the hemolymph or ovaries.
Gene Model and Products
Number of Transcripts
2
Number of Unique Polypeptides
1

Please see the JBrowse view of Dmel\Yp2 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 P02844)

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 5.49

Transcript Data
Annotated Transcripts
Name
FlyBase ID
RefSeq ID
Length (nt)
Assoc. CDS (aa)
FBtr0071424
1553
442
FBtr0339648
1616
442
Additional Transcript Data and Comments
Reported size (kB)

1.67, 1.6 (northern blot)

Comments
External Data
Crossreferences
Polypeptide Data
Annotated Polypeptides
Name
FlyBase ID
Predicted MW (kDa)
Length (aa)
Theoretical pI
UniProt
RefSeq ID
GenBank
FBpp0071359
49.7
442
8.18
FBpp0308710
49.7
442
8.18
Polypeptides with Identical Sequences

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

442 aa isoforms: Yp2-PA, Yp2-PB
Additional Polypeptide Data and Comments
Reported size (kDa)

442 (aa); 49.6 (kD predicted)

Comments
External Data
Post Translational Modification

Tyrosine sulfation occurs in the female only and plays an essential functional role.

(UniProt, P02844)
Crossreferences
InterPro - A database of protein families, domains and functional sites
Linkouts
Sequences Consistent with the Gene Model
Nucleotide / Polypeptide Records
 
Mapped Features

Click to get a list of regulatory features (enhancers, TFBS, etc.) and gene disruptions (point mutations, indels, etc.) within or overlapping Dmel\Yp2 using the Feature Mapper tool.

External Data
Crossreferences
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).

-0.60

Transcript Expression
expression microarray
Stage
Tissue/Position (including subcellular localization)
Reference
in situ
Stage
Tissue/Position (including subcellular localization)
Reference
cyst cell of testis

Comment: chronlogically variable expression

Additional Descriptive Data
Marker for
 
Subcellular Localization
CV Term
Polypeptide Expression
mass spectroscopy
Stage
Tissue/Position (including subcellular localization)
Reference
western blot
Stage
Tissue/Position (including subcellular localization)
Reference
seminal vesicle

Comment: chronlogically variable expression

Additional Descriptive Data
Marker for
 
Subcellular Localization
CV Term
Evidence
References
Expression Deduced from Reporters
Reporter: P{Yp2.M13.G1}
Stage
Tissue/Position (including subcellular localization)
Reference
High-Throughput Expression Data
Associated Tools

JBrowse - Visual display of RNA-Seq signals

View Dmel\Yp2 in JBrowse
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
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
Alleles, Insertions, Transgenic Constructs, and Aberrations
Classical and Insertion Alleles ( 8 )
For All Classical and Insertion Alleles Show
 
Other relevant insertions
Transgenic Constructs ( 11 )
For All Alleles Carried on Transgenic Constructs Show
Transgenic constructs containing/affecting coding region of Yp2
Transgenic constructs containing regulatory region of Yp2
Aberrations (Deficiencies and Duplications) ( 2 )
Variants
Variant Molecular Consequences
Alleles Representing Disease-Implicated Variants
Phenotypes
Orthologs
Human Orthologs (via DIOPT v9.1)
Species\Gene Symbol
Score
Best Score
Best Reverse Score
Alignment
Complementation?
Transgene?
Homo sapiens (Human) (10)
4 of 14
Yes
No
4 of 14
Yes
No
4 of 14
Yes
No
4 of 14
Yes
No
3 of 14
No
No
1  
3 of 14
No
No
3 of 14
No
No
2 of 14
No
No
2 of 14
No
No
2 of 14
No
No
Model Organism Orthologs (via DIOPT v9.1)
Species\Gene Symbol
Score
Best Score
Best Reverse Score
Alignment
Complementation?
Transgene?
Rattus norvegicus (Norway rat) (9)
4 of 14
Yes
No
4 of 14
Yes
No
4 of 14
Yes
No
3 of 14
No
No
2 of 14
No
No
2 of 14
No
No
2 of 14
No
No
2 of 14
No
No
2 of 14
No
No
Mus musculus (laboratory mouse) (9)
4 of 14
Yes
No
4 of 14
Yes
No
4 of 14
Yes
No
3 of 14
No
No
3 of 14
No
No
3 of 14
No
No
3 of 14
No
No
2 of 14
No
No
2 of 14
No
Yes
Xenopus tropicalis (Western clawed frog) (13)
2 of 13
Yes
No
2 of 13
Yes
No
2 of 13
Yes
No
2 of 13
Yes
No
1 of 13
No
Yes
1 of 13
No
No
1 of 13
No
No
1 of 13
No
No
1 of 13
No
No
1 of 13
No
No
1 of 13
No
No
1 of 13
No
No
1 of 13
No
No
Danio rerio (Zebrafish) (8)
3 of 14
Yes
No
3 of 14
Yes
No
3 of 14
Yes
No
2 of 14
No
No
2 of 14
No
No
2 of 14
No
No
2 of 14
No
No
1 of 14
No
No
Caenorhabditis elegans (Nematode, roundworm) (0)
Anopheles gambiae (African malaria mosquito) (24)
3 of 12
Yes
Yes
Arabidopsis thaliana (thale-cress) (0)
Saccharomyces cerevisiae (Brewer's yeast) (0)
Schizosaccharomyces pombe (Fission yeast) (0)
Escherichia coli (enterobacterium) (0)
Other Organism Orthologs (via OrthoDB)
Data provided directly from OrthoDB:Yp2. Refer to their site for version information.
Paralogs
Paralogs (via DIOPT v9.1)
Drosophila melanogaster (Fruit fly) (32)
5 of 13
5 of 13
5 of 13
5 of 13
5 of 13
5 of 13
4 of 13
4 of 13
4 of 13
4 of 13
4 of 13
4 of 13
4 of 13
4 of 13
4 of 13
4 of 13
4 of 13
4 of 13
4 of 13
4 of 13
3 of 13
3 of 13
3 of 13
3 of 13
3 of 13
3 of 13
3 of 13
3 of 13
3 of 13
3 of 13
3 of 13
2 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.
    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:
    Show/hide secondary interactors 
    (data from AllianceMine provided by esyN)
    Select Layout:
    Legend:
    Protein
    RNA
    Selected Interactor(s)
    Other Interaction Browsers

    Please see the Physical Interaction reports below for full details
    protein-protein
    Physical Interaction
    Assay
    References
    Summary of Genetic Interactions
    esyN Network Diagram
    Other Interaction Browsers
    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.
    MIST (protein-protein) - An integrated Molecular Interaction Database
    Pathways
    Signaling Pathways (FlyBase)
    Metabolic Pathways
    FlyBase
    External Links
    Reactome Metabolic Pathways - An open-source, open access, manually curated and peer-reviewed metabolic pathway database.
    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)
    X
    Recombination map
    1-30
    Cytogenetic map
    Sequence location
    FlyBase Computed Cytological Location
    Cytogenetic map
    Evidence for location
    9A5-9A5
    Limits computationally determined from genome sequence between P{EP}nejEP1149&P{EP}nejEP1179 and P{EP}α-Man-IEP1628&P{EP}α-Man-IEP1307
    Experimentally Determined Cytological Location
    Cytogenetic map
    Notes
    References
    8F-9A
    (determined by in situ hybridisation)
    8F-9B
    (determined by in situ hybridisation)
    Experimentally Determined Recombination Data
    Location
    Left of (cM)
    Right of (cM)
    Notes
    Stocks and Reagents
    Stocks (5)
    Genomic Clones (9)
     

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

    cDNA Clones (513)
     

    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)
    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

        The p47 polypeptide seen previously in ACF (ATP-utilizing chromatin assembly and remodeling factor) fractions (FBrf0095281) has been found to be identical to Yp2 and appears to have been a contaminant in these earlier ACF fractions.

        20-Hydroxyecdysone, but not juvenile hormone, regulation of yolk protein gene expression can be mapped to cis-acting DNA sequences. It is not clear whether regulation by 20-hydroxyecdysone is direct or indirect. Methoprene up-regulation is only observed when native yolk protein genes are assayed, suggesting that it may operate through influencing stability of the message.

        Proteins which specifically bind the Yp1/Yp2 ovarian enhancer 1 element have been identified.

        By comparing methylation by Ecol\dam methylase between euchromatic and heterochromatic genes it was determined that the heterochromatic state does not prevent methylase accessibility in vivo.

        srp is expressed in the ovaries of adult flies where it produces an ovary specific protein isoform. The srp protein binds to a 12bp ovarian follicle cell-specific regulatory element located between the divergently transcribed Yp1 and Yp2. The 12bp element activates both in vivo and in vitro transcription of Yp1 and Yp2.

        Insertion of the gypsy\su(Hw)BR into the Yp1 Yp2 intergenic region does not alter temporal or tissue-specific expression of the Adh or Ecol\lacZ reporter genes but does repress the Yp1 Yp2 fat body enhancer elements.

        The yolk protein genes Yp1 and Yp2 are only expressed in the ovary and fat body of females if they are supplied with proteinaceous food. Several regulatory regions have been shown to independently confer nutritional regulation on the expression of Yp1 and Yp2.

        343bp of immediately upstream Yp2 sequences are sufficient for expression in the fat bodies.

        Pattern of osmium zinc iodide staining in the cortical cytoplasm varies in relation to the number of yolk protein structural genes.

        CrebA protein binds to the fat body specific enhancers of Dmul\Adh1, Adh, Yp1 and Yp2 and may be an important component of tissue specific regulation.

        Newly synthesised yolk proteins in normal and mutant strains share secretory vesicles with putative vitelline membrane proteins. Translocation of follicle cell yolk protein is not through the membrane along the interfollicular spaces, but directly through plasmalemma facing the oocyte.

        Evolutionary conservation of specificity of yolk protein uptake by the oocyte is studied throughout Diptera.

        Female flies with varying numbers of Yp1, Yp2 and Yp3 genes have been generated. Each yolk protein gene makes an equivalent contribution to the fecundity and fertility of the female, and they do not individually provide unique functions to the embryo. The number of eggs laid by a female depends on the number of genes encoding yolk proteins present in the genome, and the probability of an egg producing an adult depends on the number of yolk protein genes present in the mother.

        The male and female products of dsx when expressed in E.coli bind specifically to the fat body enhancer (FBE) of Yp1 and Yp2. This demonstrates a direct interaction between the sex determination hierarchy and a target gene.

        Yp1 and Yp2 are transcribed in the same sub-populations of ovarian follicle cells. This expression is directed by two enhancers: ovarian enhancer 1, located in the 1226bp intergenic region, and ovarian enhancer 2 located within the first exon of Yp2.

        Two cis-acting regions influence the transcription of both Yp1 and Yp2 in the ovaries. One is located in the 1224bp intergenic region and determines the stage and cell type specificity of ovarian transcription. The other is in the first intron of Yp2 and acts across the Yp2 promoter region to stimulate Yp1 transcription in ovaries.

        The site of tyrosine sulfation in the Yp2 protein has been identified.

        Yolk proteins share a certain homologous domains with human low-density lipoproteins and human lipoprotein lipase.

        The sex-, time- and tissue-specific expression of the Yp1 and Yp2 genes, divergently transcribed and separated by 1225bp, indicates that there are two tissue-specifying elements acting on each gene. One is necessary for expression in fat body and the other for expression in the ovary.

        Yp2 has been cloned and sequenced, and compared with Yp1. The intergenic region between Yp1 and Yp2 has also been sequenced.

        Yp2 has been cloned.

        The exon-intron structure of Yp2 has been determined.

        The three major yolk proteins (encoded by Yp1, Yp2 and Yp3) have been isolated from mature eggs and characterised.

        Hormonal and genetic regulation of yolk formation has been reviewed.

        Structural gene for the yolk protein YP2 found in recently-emerged female flies. Protein migrates at different rates in SDS-polyacrylamide gels when encoded by the electrophoretic variants Yp2F (fast) and Yp2S (slow), alleles that are female fertile and produce normal amounts of YP2. A mutant Yp2M (=Yp212-1245) is female fertile but lays fewer eggs than normal (Mohler, Postlethwait and Shirk) and does not contain yolk protein in the hemolymph or ovaries.

        Relationship to Other Genes
        Source for database merge of
        Additional comments
        Nomenclature History
        Source for database identify of
        Nomenclature comments
        Etymology
        Synonyms and Secondary IDs (19)
        Reported As
        Symbol Synonym
        fs(1)A59
        Secondary FlyBase IDs
        • FBgn0000847
        • FBgn0004046
        Datasets (0)
        Study focus (0)
        Experimental Role
        Project
        Project Type
        Title
        Study result (0)
        Result
        Result Type
        Title
        External Crossreferences and Linkouts ( 42 )
        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/Swiss-Prot - Manually annotated and reviewed records of protein sequence and functional information
        UniProt/TrEMBL - Automatically annotated and unreviewed records of protein sequence and functional information
        Other crossreferences
        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
        BioGRID - A database of protein and genetic interactions.
        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
        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.
        MIST (protein-protein) - An integrated Molecular Interaction Database
        Reactome - An open-source, open access, manually curated and peer-reviewed pathway database.
        Reactome Metabolic Pathways - An open-source, open access, manually curated and peer-reviewed metabolic pathway database.
        References (275)