FB2026_02 , released June 18, 2026
Gene: Dmel\ao
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General Information
Symbol
Dmel\ao
Species
D. melanogaster
Name
abnormal oocyte
Annotation Symbol
CG6093
Feature Type
protein_coding_gene
FlyBase ID
FBgn0000018
Gene Model Status
Current
Stock Availability
15 publicly available
Gene Summary
abnormal oocyte (abo) encodes a negative regulator of histone transcription genes by its binding to their regulatory regions. abo mutations cause a maternal-effect lethality that can be rescued by specific regions of heterochromatin during early embryogenesis. [Date last reviewed: 2018-09-06] (FlyBase Gene Snapshot)
All Summaries
Also Known As

abo

Key Links
Genomic Location
Cytogenetic map
32C1-32C1
Sequence location
Recombination map
2-44
RefSeq locus
NT_033779 REGION:10973443..10975293
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 (10 terms)
Molecular Function (3 terms)
Terms Based on Experimental Evidence (1 term)
CV Term
Evidence
References
enables chromatin binding
inferred from direct assay
(Berloco et al., 2001)
Terms Based on Predictions or Assertions (2 terms)
CV Term
Evidence
References
enables ubiquitin protein ligase binding
inferred from biological aspect of ancestor with PANTHER:PTN000332575
(GO Reference Genome Project, 2011-)
enables ubiquitin-like ligase-substrate adaptor activity
inferred from biological aspect of ancestor with PANTHER:PTN000332575
(GO Reference Genome Project, 2011-)
Biological Process (4 terms)
Terms Based on Experimental Evidence (2 terms)
CV Term
Evidence
References
involved_in negative regulation of transcription by RNA polymerase II
inferred from mutant phenotype
(Berloco et al., 2001)
involved_in oogenesis
inferred from mutant phenotype
(Malva et al., 1994)
Terms Based on Predictions or Assertions (2 terms)
CV Term
Evidence
References
involved_in positive regulation of proteasomal ubiquitin-dependent protein catabolic process
inferred from biological aspect of ancestor with PANTHER:PTN000332575
(GO Reference Genome Project, 2011-)
involved_in protein ubiquitination
inferred from biological aspect of ancestor with PANTHER:PTN000332575
(GO Reference Genome Project, 2011-)
Cellular Component (3 terms)
Terms Based on Experimental Evidence (2 terms)
CV Term
Evidence
References
located_in nucleus
inferred from direct assay
(Berloco et al., 2001)
located_in polytene chromosome
inferred from direct assay
(Berloco et al., 2001)
Terms Based on Predictions or Assertions (1 term)
CV Term
Evidence
References
part_of cullin-RING ubiquitin ligase complex
inferred from biological aspect of ancestor with PANTHER:PTN000332575
(GO Reference Genome Project, 2011-)
Gene Group (FlyBase)
Protein Family (UniProt)
-
Protein Signatures (InterPro)
Summaries
Gene Snapshot
abnormal oocyte (abo) encodes a negative regulator of histone transcription genes by its binding to their regulatory regions. abo mutations cause a maternal-effect lethality that can be rescued by specific regions of heterochromatin during early embryogenesis. [Date last reviewed: 2018-09-06]
Phenotypic Description (Red Book; Lindsley and Zimm 1992)
abo: abnormal oocyte
Probability of survival of embryos produced by abo/abo mothers reduced; male embryos more severely affected than female embryos. Both preblastoderm and postblastoderm embryonic death observed; partial rescue of postblastoderm mortality effected by paternally inherited abo+ allele; partial rescue of preblastoderm mortality by heterochromatic ABO elements located in Xh between 3/4 and 7/8 of the distance from the centromere, in YL region h10-11, in YS region h19, in 2R proximal, and perhaps in other heterochromatic regions (Pimpinelli, Sullivan, Prout, and Sandler, 1985, Genetics 109: 701-24). Gradual loss of phenotype in homozygous abo stocks accompanied by increase in quantity of ribosomal DNA (Krider and Levine, 1975, Genetics 81: 501-13). New restriction fragments appear in Hind III/Hae III double digests of such homozygous lines probed with nontranscribed spacer sequences of ribosomal genes (Graziani, Vicari, Boncinelli, Malva, Manzi, and Mariani, 1981, Proc. Nat. Acad. Sci. USA 78: 7662-64). abo phenotype returns with subsequent maintenance in heterozygous condition. Homozygous abo females exhibit moderate decrease in recombination with concommitant increase in exceptional progeny (Carpenter and Sandler, 1974, Genetics 76: 453-75).
Gene Model and Products
Number of Transcripts
1
Number of Unique Polypeptides
1

Please see the JBrowse view of Dmel\ao 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 Q9VKM4)

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 5.44

Low-frequency RNA-Seq exon junction(s) not annotated.

Gene model reviewed during 5.50

Transcript Data
Annotated Transcripts
Name
FlyBase ID
RefSeq ID
Length (nt)
Assoc. CDS (aa)
ao-RA
FBtr0080168
NM_080045
1794
539
Additional Transcript Data and Comments
Reported size (kB)

1.8 (northern blot)

(Tomkiel et al., 1995)
Comments
External Data
Crossreferences
Polypeptide Data
Annotated Polypeptides
Name
FlyBase ID
Predicted MW (kDa)
Length (aa)
Theoretical pI
UniProt
RefSeq ID
GenBank
ao-PA
FBpp0079757
62.4
539
7.62
Q9VKM4
NP_524784
AAF53040
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)
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\ao 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).

0.97

Transcript Expression
Additional Descriptive Data
Marker for
 
Subcellular Localization
CV Term
Polypeptide Expression
Additional Descriptive Data
Marker for
 
Subcellular Localization
CV Term
Evidence
References
located_in nucleus
inferred from direct assay
(Berloco et al., 2001)
located_in polytene chromosome
inferred from direct assay
(Berloco et al., 2001)
Expression Deduced from Reporters
High-Throughput Expression Data
Associated Tools

JBrowse - Visual display of RNA-Seq signals

View Dmel\ao 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
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 ( 12 )
For All Classical and Insertion Alleles Show
 
Other relevant insertions
Transgenic Constructs ( 10 )
For All Alleles Carried on Transgenic Constructs Show
Transgenic constructs containing/affecting coding region of ao
Transgenic constructs containing regulatory region of ao
Aberrations (Deficiencies and Duplications) ( 7 )
Variants
Variant Molecular Consequences
Alleles Representing Disease-Implicated Variants
Phenotypes
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) (1)
Hsap\DET1
13 of 14
Yes
Yes
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) (1)
Rnor\Det1
13 of 14
Yes
Yes
Mus musculus (laboratory mouse) (1)
Mmus\Det1
12 of 14
Yes
Yes
Xenopus tropicalis (Western clawed frog) (2)
Xtro\det1
10 of 13
Yes
Yes
Xtro\creb1
1 of 13
No
No
Danio rerio (Zebrafish) (1)
Drer\det1
12 of 14
Yes
Yes
Caenorhabditis elegans (Nematode, roundworm) (0)
Anopheles gambiae (African malaria mosquito) (1)
Agam\AgaP_AGAP001900
11 of 12
Yes
Yes
Arabidopsis thaliana (thale-cress) (1)
Atha\DET1
12 of 13
Yes
Yes
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:ao. Refer to their site for version information.
Paralogs
Downloads
Download All DIOPT Paralogs
Paralogs (via DIOPT v9.1)
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?
    DET1; DET1 partner of COP1 E3 ubiquitin ligase
    13 of 14
    608727
        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
        Interaction Browsers
        View in FlyBase Interactions Browser   View in MIST tool (external link)
        Please see the Physical Interaction reports below for full details
        RNA-protein
        Physical Interaction
        Assay
        References
        ao - Marf1
        anti tag coimmunoprecipitation, nucleotide sequence identification, quantitative reverse transcription pcr
        (Kawaguchi et al., 2020)
        Summary of Genetic Interactions
        Interaction Browsers
        View in FlyBase Interactions Browser   View in MIST tool (external link)
        Please look at the allele data for full details of the genetic interactions
        Starting gene(s)
        Interaction type
        Interacting gene(s)
        Reference
        ao
        enhanceable
        AO-X
        (Malva et al., 1985)
        Starting gene(s)
        Interaction type
        Interacting gene(s)
        Reference
        External Data
        Linkouts
        DroID - A comprehensive database of gene and protein interactions.
        Pathways
        Signaling Pathways (FlyBase)
        Metabolic Pathways
        FlyBase
        External Links
        External Data
        Linkouts
        KEGG Pathways - A collection of manually drawn pathway maps representing knowledge of molecular interaction, reaction and relation networks.
        Reactome - An open-source, open access, manually curated and peer-reviewed pathway database.
        Class of Gene
        Genomic Location and Detailed Mapping Data
        Chromosome (arm)
        2L
        Recombination map
        2-44
        Cytogenetic map
        32C1-32C1
        Sequence location
        FlyBase Computed Cytological Location
        Cytogenetic map
        Evidence for location
        32C1-32C1
        Limits computationally determined from genome sequence between P{PZ}dbf1 and P{lacW}SCARk03107
        Experimentally Determined Cytological Location
        Cytogenetic map
        Notes
        References
        32C-32C
        (determined by in situ hybridisation)
        (Tomkiel et al., 1995)
        32E-32E
        (determined by in situ hybridisation)
        (Cavaliere et al., 1991)
        Experimentally Determined Recombination Data
        Location

        2-44

        (FlyBase, 2016)

        2-37.1

        (Comeron et al., 2012)

        2-44.0

        Left of (cM)
        (Tomkiel et al., 1995)
        Right of (cM)
        (Tomkiel et al., 1995)
        Notes

        abo2 mapped between 2-41.7 and 2-43.1, abo1 mapped to 2-44.0.

        (Tomkiel et al., 1995)

        Mapped with respect to J.

        Stocks and Reagents
        Stocks (15)
        Genomic Clones (17)
         

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

        cDNA Clones (11)
         

        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

                    abo appears to be a negative regulator of histone transcription.

                    (Berloco et al., 2001)

                    The insertion of the blood transposon in region 32E causes the pleiotropic abo mutant phenotype.

                    (Cavaliere et al., 1991)

                    Progeny survival from abo mothers depends in part upon the maternal dosage of ABO-X heterochromatin: recovery of daughters decreased if the mother was ABO-X-/ABO-X- and increased if they received an ABO-X- X chromosome from a heterozygote mother. These results suggest an interactive effect between the ABO-X deficient X and the ABO-X heterochromatin in the maternal genome. The ABO-X heterochromatin on the X chromosome rescues zygotes from the abo maternal effect prior to the completion of the first zygotic division.

                    (Tomkiel et al., 1991)

                    Maintained homozygous abo stocks show a decrease in maternally-induced embryonic lethality over time. The altered genetic factors responsible are abo-responsive heterochromatic rescuing regions that act zygotically, dominantly and additively to reduce lethality. The regions map to the second and X chromosome in the maintained homozygous abo stock.

                    (Sullivan and Pimpinelli, 1986)

                    Embryos, especially male, from females homozygous for abo mutant alleles have a reduced probability of survival, dying both before and after blastoderm formation. Postblastoderm lethality can be partially rescued by a paternal wild-type allele and preblastoderm lethality by the maternal effect of heterochromatic elements on the X, Y and 2R (defined as ABO-X, ABO-YL, ABO-YS and ABO-2R).

                    Relationship to Other Genes
                    Source for database merge of

                    Source for merge of: abo CG6093

                    (Bayraktaroglu, 2000.11.2)
                    Additional comments
                    Nomenclature History
                    Source for database identify of

                    Source for identity of: ao abo

                    (FlyBase, 2009-)
                    Nomenclature comments

                    "ao" was substituted for the gene symbol "abo", which is highly offensive when used to refer to the Aborigine, the native people of Australia.

                    (FlyBase, 2009-)
                    Etymology
                    Synonyms and Secondary IDs (6)
                    Datasets (0)
                    Study focus (0)
                    Experimental Role
                    Project
                    Project Type
                    Title
                    Study result (0)
                    Result
                    Result Type
                    Title
                    External Crossreferences and Linkouts ( 36 )
                    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.
                    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)
                    KEGG Pathways - A collection of manually drawn pathway maps representing knowledge of molecular interaction, reaction and relation networks.
                    Reactome - An open-source, open access, manually curated and peer-reviewed pathway database.
                    References (81)