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General Information
Symbol
Dmel\SkpA1
Species
D. melanogaster
Name
FlyBase ID
FBal0177902
Feature type
allele
Associated gene
Associated Insertion(s)
Carried in Construct
Key Links
Nature of the Allele
Mutations Mapped to the Genome
 
Type
Location
Additional Notes
References
Associated Sequence Data
DNA sequence
Protein sequence
 
 
Progenitor genotype
Cytology
Nature of the lesion
Statement
Reference

The P{EP}skpAEP1423 element is completely excised, along with 1782bp 3' of the insertion site, which removes the skpA ORF.

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
Detailed Description
Statement
Reference

skpA1 mutant neuroblast clones result in mushroom body γ neurons retain many larval axons at 24 hours after puparium formation that are pruned in wild type. In wandering third instar larvae the dorsal and medial axons are projected normally but the axon branches are less dense than in wild type.

skpA1 embryos develop normally and hatch at wild-type rates. Most mutant larvae die within four days of hatching and any surviving larvae grow slower than wild type and fail to pupate. In skpA1 larvae, imaginal discs are either entirely absent or rudimentary. Virtually all cells in such rudimentary discs are undergoing apoptosis. The size of the CNS fails to significantly increase in skpA1 mutants past 3 days after egg deposition (AED). This is caused by a reduction in cell proliferation, in the form of G1 arrest, rather than an increase in apoptosis. skpA1 CNS cells often contain supernumerary centrosomes; as many as 17 have been observed in a single diploid cell. These appear to result from multiple rounds of centrosome duplication in the same cell cycle, as the centrosomes show no signs of fragmentation and cells appear to complete cytokinesis. The supernumerary centrosomes are able to nucleate microtubules and cluster into two poles to form a pseudo-bipolar spindle with the chromosomes positioned at a normal metaphase plate. This appears to form a compensatory mechanism that allows cells to progress to anaphase. As mitosis progresses, some of these centrosomes may become deactivated, as only a subset remain associated with the bulk of the spindle microtubules and some spindle poles are detached from any centrosome. In older skpA1 larvae (from 3.5 days AED onwards), the ratio of cells in metaphase to anaphase is higher than wild type and those cells found in anaphase tend not to contain so many supernumerary centrosomes. This suggests that the cells containing supernumerary centrosomes become arrested in metaphase. The interphase nuclei of skpA1 cells frequently show aberrant chromatin condensation. Clonal analysis shows that the supernumerary centrosomes, delayed cell cycle and abnormally condensed chromatin defects are all cell autonomous. Nuclei from the fat body and gut of skpA1 larvae contain less DNA than wild type and undergo endoreduplication at a much lower rate than wild type. In contrast, levels of endoreduplication are not significantly different in skpA1 larval salivary glands compared to wild type.

External Data
Interactions
Show genetic interaction network for Enhancers & Suppressors
Phenotypic Class
Suppressor of
Statement
Reference

skpA[+]/SkpA1 is a suppressor of visible phenotype of DrefUAS.cSa, Scer\GAL4GMR.PS

Phenotype Manifest In
NOT suppressed by
Statement
Reference

SkpA1 has centrosome | increased number phenotype, non-suppressible by CycEk05007

Suppressor of
Statement
Reference

skpA[+]/SkpA1 is a suppressor of eye phenotype of DrefUAS.cSa, Scer\GAL4GMR.PS

Additional Comments
Genetic Interactions
Statement
Reference

skpA1/+ suppresses the rough eye phenotype caused by expression of DrefScer\UAS.cSa under the control of Scer\GAL4GMR.PS.

A greater proportion of CycEk05007; skpA1 double mutant cells are arrested in G1 phase compared to CycEk05007 single mutants. The CycEk05007; skpA1 double mutants show the same supernumerary centrosome phenotype as the skpA1 single mutants.

Xenogenetic Interactions
Statement
Reference
Complementation and Rescue Data
Fails to complement
Comments

The neuromuscular junction overgrowth phenotype (increase in number of boutons) seen in larvae derived from SkpAGD65/SkpA1 females is completely rescued by expression of SkpAScer\UAS.T:Zzzz\FLAG,T:Ivir\HA1 under the control of Scer\GAL4elav.PU, while expression under the control of Scer\GAL4G7 does not rescue the phenotype.

Images (0)
Mutant
Wild-type
Stocks (1)
Notes on Origin
Discoverer
External Crossreferences and Linkouts ( 0 )
Synonyms and Secondary IDs (2)
Reported As
Name Synonyms
Secondary FlyBase IDs
    References (7)