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General Information
D. melanogaster
FlyBase ID
Feature type
Associated gene
Associated Insertion(s)
Carried in Construct
Allele class
Nature of the Allele
Allele class
Mutations Mapped to the Genome
Additional Notes
point mutation
Nucleotide change:


Amino acid change:

K377term | aurA-PA

Reported amino acid change:



Site of nucleotide substitution in mutant inferred by FlyBase based on reported amino acid change.

Associated Sequence Data
DNA sequence
Protein sequence
Progenitor genotype
Nature of the lesion

Amino acid replacement: K377term.

Expression Data
Reporter Expression
Additional Information
Marker for
Reflects expression of
Reporter construct used in assay
Human Disease Associations
Disease Ontology (DO) Annotations
Models Based on Experimental Evidence ( 1 )
Modifiers Based on Experimental Evidence ( 1 )
model of  brain cancer
is ameliorated by Nl1N-ts1
is ameliorated by dapUAS.cLa
Comments on Models/Modifiers Based on Experimental Evidence ( 0 )
Phenotypic Data
Phenotypic Class
Phenotype Manifest In
Detailed Description

aurA8839 homozygous larvae display a marked brain overgrowth with highly increased number of neuroblasts and mitotic index, increased rate of aneu- or polyploid cells and highly condensed chromosomes in mitotic cells due to significantly prolonged M phase relative to controls. However, no lagging chromatids (indicative of incorrect spindle attachment) are observed during anaphase and telophase. The mutant brain tissue has the ability to efficiently induce tumor formation in an tissue allograft assay. The neuroblast number, the mitotic index and rate of ploidy defects is increased also in brains from aurA8839/aurA17961 transheterozygotes.

Homozygous aur8839 mutants exhibit increased brain volume at the wandering third instar larval stage. The increased size of the brain lobes in this mutant is associated with increased subperineurial glia ploidy. Both the ploidy of mononucleate subperineurial glia and the number of nuclei in multinucleate subperineurial glial cell increases. The increased ploidy results in a functional blood-brain barrier despite the large neuronal mass. Only a small fraction of the aur8839 mutant brains display dye permeability.

aur8839 mutants do not exhibit polyploidy in endocyclic larval salivary gland cells.

Mutants show a massive increase in larval brain neuroblasts, developing more than 1000 central brain neuroblasts at stages where wild-type larvae have only 95-100 neuroblasts. The central nervous system is expanded compared to wild type in the mutant larvae. The orientation of the mitotic spindle is essentially randomised relative to the apical/basal cortical polarity axis in mutant metaphase neuroblasts, in contrast to wild-type metaphase neuroblasts where the mitotic spindle is aligned within 150 of the center of the apical/basal cortical polarity axis. Mutant neuroblasts also have defects in telophase spindle orientation, with approximately 15% of the neuroblasts dividing symmetrically.

Homozygous larval brains contain supernumerary neuroblasts. At 24 hours after larval hatching (ALH) the number of neuroblasts in the brain is similar in mutant and wild-type larvae, however, in mutant larvae the number of neuroblasts increases dramatically during larval life, to more than a thousand at 120 ALH during an extended larval life. The number of apoptotic cells in the mutant larval brain appears normal.

The brain can grow up to 10 times the wild-type size in mutant larvae.

External Data
Show genetic interaction network for Enhancers & Suppressors
Phenotypic Class
Phenotype Manifest In
Enhanced by
NOT Enhanced by
Suppressed by

aurA8839 has neuroblast | supernumerary & larval brain phenotype, suppressible by dapUAS.cLa/Scer\GAL4wor.PA

aurA8839 has neuroblast | supernumerary & larval brain phenotype, suppressible by aPKCunspecified

aurA8839 has neuroblast | supernumerary & larval brain phenotype, suppressible by Scer\GAL4wor.PA/numbPTB.UAS.GFP

aurA8839 has neuroblast | supernumerary & larval brain phenotype, suppressible by Nl1N-ts1

NOT suppressed by

aurA8839 has spindle & neuroblast & larva phenotype, non-suppressible by Scer\GAL4wor.PA/numbUAS.cWa

Additional Comments
Genetic Interactions

The increased number of brain neuroblast (NB) cells characteristic for aurA8839 mutant third instar larvae is slightly elevated further by combination with homozygous mad2G6595, whereas the increased mitotic index, the highly condensed chromosome appearance in mitotic cells and the tumorigenic potential of the double mutant tissue in an allograft assay are not significantly affected compared to aurA8839 single mutant. The delay in the timing of mitotic cell cycle events is ameliorated in aurA8839;mad2G6595 brain NBs compared to aurA8839 cells but not wild-type level, no lagging chromatids (indicative of incorrect spindle attachment) are observed during anaphase and telophase.

aurA8839;Sas-4s2214;mad2G6595 triple mutants show high rate of ploidy defects in third instar larval brains, the number of neuroblasts or the mitotic cells is highly increased relative to wild-type but significantly different from aurA8839;Sas-4s2214 double mutants.

The increased neuroblast number and mitotic index seen in aurA8839/aurA17961 transheterozygote larvae is not enhanced by combination with BubR1KEN.T:Disc\RFP-mRFP,BubR1k06109 (the mitotic index in the double mutants is even slightly decreased), whereas the rate of ploidy defects is increased compared to either of the single gene mutants.

Xenogenetic Interactions
Complementation and Rescue Data
Images (0)
Stocks (0)
Notes on Origin
External Crossreferences and Linkouts ( 0 )
Synonyms and Secondary IDs (4)
Reported As
Name Synonyms
Secondary FlyBase IDs
    References (6)