FB2026_02 , released June 18, 2026
Allele: Dmel\Exo84Z4840
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General Information
Symbol
Dmel\Exo84Z4840
Species
D. melanogaster
Name
FlyBase ID
FBal0388731
Feature type
allele
Associated gene
Dmel\Exo84
Associated Insertion(s)
Carried in Construct
Also Known As
onr142-5, Exo84onr, onr
Key Links
Allele class

hypomorphic allele - genetic evidence

Mutagen
Nature of the Allele
Allele class

hypomorphic allele - genetic evidence

(Blankenship et al., 2007)
Mutagen
ethyl methanesulfonate
(Giansanti et al., 2004)
Progenitor genotype
Cytology
Description

Amino acid replacement: ?582term.

(Blankenship et al., 2007)

Nucleotide substitution: C?T.

(Blankenship et al., 2007)
Mutations Mapped to the Genome
Curation Data
Type
Location
Additional Notes
References
Variant Molecular Consequences
Associated Sequence Data
DDBJ / EMBL / GenBank
DNA sequence
Protein sequence
 
UniProtKB/Swiss-Prot
    UniProtKB/TrEMBL
      Expression Data
      Reporter Expression
      Additional Information
      Statement
      Reference
       
      Marker for
      Reflects expression of
      Reporter construct used in assay
      Human Disease Associations
      Disease Ontology (DO) Annotations
      Models Based on Experimental Evidence ( 0 )
      Disease
      Evidence
      References
      Modifiers Based on Experimental Evidence ( 0 )
      Disease
      Interaction
      References
      Comments on Models/Modifiers Based on Experimental Evidence ( 0 )
       
      Disease-implicated variant(s)
       
      Phenotypic Data
      Phenotypic Class
      Phenotype Manifest In

      contractile ring & meiotic telophase I | male

      (Giansanti et al., 2004)

      contractile ring & meiotic telophase I | male (with Df(3R)Espl1)

      (Giansanti et al., 2004)

      contractile ring & meiotic telophase II | male

      (Giansanti et al., 2004)

      contractile ring & meiotic telophase II | male (with Df(3R)Espl1)

      (Giansanti et al., 2004)

      embryo | embryonic stage 16

      (Campbell et al., 2009)

      embryonic/first instar larval cuticle | heat sensitive (with Df(3R)Espl3)

      (Blankenship et al., 2007)

      epidermal cell

      (Campbell et al., 2009)

      Nebenkern

      (Giansanti et al., 2004)

      Nebenkern (with Df(3R)Espl1)

      (Giansanti et al., 2004)

      spermatid (with Df(3R)Espl3)

      (Fabian et al., 2010)

      spermatid & nucleus | supernumerary

      (Giansanti et al., 2004)

      spermatid & nucleus | supernumerary (with Df(3R)Espl1)

      (Giansanti et al., 2004)

      spermatid cyst (with Df(3R)Espl3)

      (Fabian et al., 2010)

      spindle & meiotic telophase I | male

      (Giansanti et al., 2004)

      spindle & meiotic telophase I | male (with Df(3R)Espl1)

      (Giansanti et al., 2004)

      spindle & meiotic telophase II | male

      (Giansanti et al., 2004)

      spindle & meiotic telophase II | male (with Df(3R)Espl1)

      (Giansanti et al., 2004)
      Detailed Description
      Statement
      Reference

      Testes from exo84onr/Df(3R)Espl3 flies show severe defects in spermatid elongation, with round cysts that completely lack polarity.

      (Fabian et al., 2010)

      Loss of epidermal cell polarity in stage 11 exo84onr mutant embryos is not mirrored in the tubules, where cell polarity and tissue integrity are maintained. However, stage 16 mutant tubules are abnormally shaped having failed to complete tissue extension.

      (Campbell et al., 2009)

      When exo84onr/Df(3R)Espl3 females are mated to exo84onr heterozygous males, 61% of the resulting embryos fail to hatch. The epithelial structure is established correctly in these embryos, but degenerates by stage 10, when the epithelial cells display a rounded morphology and have a multilayered organisation.

      Embryos derived from exo84onr/Df(3R)Espl3 females mated to exo84onr heterozygous males form small scraps of cuticle at 25[o]C, whereas at 20[o]C they show a weak defect in cuticle formation, resulting in small ventral holes in the cuticle.

      (Blankenship et al., 2007)

      A large proportion of onrZ4840 mutant spermatids have one large nebenkern with four nuclei of normal size, indicating a cytokinetic failure in both meiotic divisions. A smaller proportion have two nuclei and a large nebenkern, indicating failure of only one of the meiotic divisions. Occasionally spermatids are seen (<8% of cases) with three nuclei, which may be due to failure of cytokinesis in the first meiotic division, followed by budding off of only one daughter cell in the second meiotic division. Additionally, a significant proportion (15%) of spermatids have more than four nuclei, which may result from defects in the mitotic divisions preceding mitosis. onrZ4840/Df(3R)Espl1 mutants never have spermatids with three nuclei, but do show the two, four and more than four nuclei phenotypes. During early telophase of onrZ4840 spermatocytes, there is an actin ring of normal appearance and and a normal central spindle. However, as telophase progresses the actin ring fails to fully constrict and the central spindle either becomes less dense or completely disorganized. The cleavage furrow initiates ~10 minutes after anaphase onset as in wild type, but shows a limited ingression and then regresses leading to a failure of cytokinesis. onrZ4840/Df(3R)Espl1 mutants show the same phenotype.

      (Giansanti et al., 2004)
      External Data
      Interactions
      Show genetic interaction network for Enhancers & Suppressors
      Phenotypic Class
      Phenotype Manifest In
      Additional Comments
      Genetic Interactions
      Statement
      Reference

      The cuticle defects seen at 20[o]C in embryos derived from exo84onr/Df(3R)Espl3 females mated to exo84onr heterozygous males are enhanced by sec5E13 and also by sec6KG08199 (in each case both parents are heterozygous for the second mutation).

      The cuticle defects seen at 20[o]C in embryos derived from exo84onr/Df(3R)Espl3 females mated to exo84onr heterozygous males are enhanced by crbunspecified.

      The cuticle defects seen at 25[o]C in embryos derived from exo84onr/Df(3R)Espl3 females mated to exo84onr heterozygous males are suppressed by l(2)gl4 or dlg114.

      The cuticle defects seen at 22[o]C in embryos derived from exo84onr/Df(3R)Espl3 females mated to exo84onr heterozygous males are suppressed by expression of crbScer\UAS.cWa under the control of Scer\GAL4unspecified and are enhanced by expression of l(2)glScer\UAS.cBa under the control of Scer\GAL4unspecified.

      (Blankenship et al., 2007)
      Xenogenetic Interactions
      Statement
      Reference
      Complementation and Rescue Data
      Rescued by

      Exo84Z4840/Df(3R)Espl3 is rescued by Exo84+t4.5

      (Blankenship et al., 2007)
      Comments
      Images (0)
      Mutant
      Wild-type
      Stocks (1)
      Notes on Origin
      Discoverer
      External Crossreferences and Linkouts ( 0 )
      Synonyms and Secondary IDs (10)
      Reported As
      Symbol Synonym
      Exo84
      (Fabian et al., 2010)
      Exo84Z4840
      Exo84onr
      (Gupta et al., 2018, Blankenship et al., 2007)
      exo84Z4840
      exo84onr
      onr
      (Gupta et al., 2018, Fabian et al., 2010)
      onr142-5
      (Giansanti et al., 2015, Campbell et al., 2009, Blankenship et al., 2007)
      onrZ4840
      onrz4840
      (Giansanti et al., 2015)
      Name Synonyms
      onion rings
      (Fabian et al., 2010)
      Secondary FlyBase IDs
      • FBal0178574
      • FBal0220805
      References (7)