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General Information
Symbol
Dmel\sqhAX3
Species
D. melanogaster
Name
FlyBase ID
FBal0035707
Feature type
allele
Associated gene
Associated Insertion(s)
Carried in Construct
Mutagen
    Nature of the Allele
    Mutagen
    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

    5kb deletion removing most of the transcription unit.

    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 ( 1 )
    Disease
    Interaction
    References
    Comments on Models/Modifiers Based on Experimental Evidence ( 0 )
     
    Phenotypic Data
    Phenotypic Class
    Phenotype Manifest In
    Detailed Description
    Statement
    Reference

    sqhAX3 homozygous clonal neuroblasts in the larval brain fail to divide.

    sqhAX3 heterozygotes do not show significant differences in wing size, as compared to controls.

    The mitochondria in the neurons of heterozygous sqhAX3 adult brains are markedly elongated compared to controls.

    Approximately 38% of sqhAX3/Y stage 16 embryos show laterality defects in the proventriculus and anterior midgut. The laterality of the other parts of the embryonic gut, including the hindgut and the posterior part of the midgut is normal in these mutants. The proventriculus and the anterior midgut do not rotate (as in wild-type) in these mutants at stages 15 to 17.

    Homozygous stage 16 embryos have shorter dorsal trunks than normal, although they are contiguous.

    Single cell clones of sqhAX3 exhibit an increased apical cell area. Adherens junctions in multiple cell clones are intact.

    sqhAX3 mutant follicle cell clones are extremely flat and appear stretched. In many mutant egg chambers there are gaps in the follicular epithelium, suggesting that stretching of the follicle cells eventually disrupts the monolayer. These cells still retain polarity. The shape change found in the mutant follicle cell clones alters the morphology of the egg chamber, with the germ line cyst bulging out in regions covered by sqhAX3 mutant follicle cells.

    sqhAX3 mutant follicle cell clones show a reduced number of phospho-His3-positive cells, huge nuclei, and abnormally large cells, indicating a defect in cytokinesis.

    Mutant embryos exhibit defects in germ band elongation.

    When a border cell is homozygous for sqhAX3 (part of a somatic clone), but is surrounded by wild-type border cells, it migrates with the cluster and sends out long cellular projections. However, such cells are often left behind by the migrating border cell cluster. Left behind mutant cells do not initiate migration on their own, and form abnormally long and convoluted cellular extensions.

    Homozygous clones in the mushroom body result in proliferation defects in neuroblasts.

    Most homozygotes die during the first larval instar stage. Homozygous germ line clones produce a few highly abnormal egg chambers, with 64% of the egg chambers having less than half the normal number of nurse cells, and 24% being comprised of just two large cells, apparently nurse cells, with large nuclei. 60% of the egg chambers contain at least one, and often several, binuclear or multinuclear nurse cells. The most advanced egg chambers attain the size and shape expected for stage 11-12, although the oocyte occupies an abnormally small volume in these egg chambers, and chorion deposition is seen around both the oocyte and nurse cells. Most ring canals are deformed. The oocyte is at the anterior of the egg chamber in 5% of cases. No eggs are laid.

    Lethal either as a late embryo or early larva, with variable dorsal closure defects, depending on the maternal dose.

    External Data
    Interactions
    Show genetic interaction network for Enhancers & Suppressors
    Phenotypic Class
    Enhanced by
    Suppressed by
    Statement
    Reference
    Enhancer of
    Statement
    Reference

    sqhAX3/sqh[+] is an enhancer of visible phenotype of Scer\GAL4hs.PB, towUAS.cCa

    Suppressor of
    NOT Suppressor of
    Statement
    Reference
    Phenotype Manifest In
    Enhanced by
    Suppressed by
    Statement
    Reference
    Enhancer of
    Statement
    Reference
    Suppressor of
    Statement
    Reference
    NOT Suppressor of
    Statement
    Reference

    sqhAX3/sqh[+] is a non-suppressor of wing phenotype of Scer\GAL4nub-AC-62, ykiUAS.cXa.Tag:FLAG

    Additional Comments
    Genetic Interactions
    Statement
    Reference

    A zip3 heterozygous background enhances the loss of rotation in the proventriculus and anterior midgut seen in sqhAX3/Y mutants.

    An average of 4.5% osupd-4, sqhAX3 homozygous mutant embryos show germ-band extension defects, much reduced compared to osupd-4 homozygous mutant embryos. Ectopic apical cell constriction defects are rescued in osupd-4, sqhAX3 homozygous mutant embryos.

    The multiple wing hair phenotype caused by expression of towScer\UAS.cCa under the control of Scer\GAL4hs.PB using heat shock at 24 hours after puparium formation is enhanced if the flies are also carrying one copy of sqhAX3.

    sqhAX3 follicle cell clones maintain their rectangular shape when cyst growth is blocked in ovoD1 mutants, whereas sqhAX3 cells are deformed when the cyst grows. The cyst bulges out underneath the sqhAX3 clones only in the wild-type background, not in ovoD1 mutant cysts.

    Xenogenetic Interactions
    Statement
    Reference

    One copy of sqhAX3 enhances the increase in mitochondria length seen when Hsap\MAPTR406W.Scer\UAS is expressed under the control of Scer\GAL4elav.PU.

    sqhAX3 embryos which carry sqhRLC.T:Avic\GFP-S65T and which also express slmbScer\UAS.T:Zzzz\vhhGFP4 under the control of Scer\GAL4332.3 in the postmitotic amnioserosa cells show a dorsal open phenotype.

    Complementation and Rescue Data
    Partially rescued by

    sqhAX3 is partially rescued by sqhE20.E21

    Not rescued by
    Comments

    Expression of sqhRLC.T:Avic\GFP-S65T rescues the loss of rotation in the proventriculus and anterior midgut seen in sqhAX3/Y.

    Expressing one copy of the sqhE20.E21 transgene substantially restores both oogenesis and subsequent axial expansion in sqhAX3 germline clones.

    Homozygous lethality is fully rescued by sqhA20.T:Zzzz\FLAG, partially rescued by sqhE21.T:Zzzz\FLAG (sqhAX3 animals carrying sqhE21.T:Zzzz\FLAG survive to the late pupal stage) and by sqhA21.T:Zzzz\FLAG (sqhAX3 animals carrying sqhA21.T:Zzzz\FLAG survive to the early pupal stage), and not rescued by sqhA20.A21.T:Zzzz\FLAG (sqhAX3 animals carrying sqhA20.A21.T:Zzzz\FLAG die as first instar larvae). Homozygous female germline clones expressing sqhA20.A21.T:Zzzz\FLAG have phenotypes nearly indistinguishable from homozygous female germline clones that do not carry sqhA20.A21.T:Zzzz\FLAG. The morphology of egg chambers derived from homozygous female germline clones expressing sqhA21.T:Zzzz\FLAG is grossly normal, with a well-differentiated oocyte and accompanying nurse cells. However, 73% of egg chambers contain at least one binuclear cell, and 80% contain less than 15 nurse cells. Substantial nurse cell cytoplasm remains untransferred even by stage 13 in many egg chambers. These clones produce some eggs. Approximately 23% of eggs laid by females carrying homozygous germline clones expressing sqhA21.T:Zzzz\FLAG and fertilised by males homozygous for a sqh+ transgene begin development, but they do not hatch. Nuclear migration in these eggs is often isotropic, producing a spherical cloud of nuclei. Approximately 80% of egg chambers derived from homozygous female germline clones expressing sqhE21.T:Zzzz\FLAG appear wild-type. 15% contain fewer than 15 nurse cells, and only 9% contain any binuclear cells. Stage 13 egg chambers containing significant amounts of nurse cell cytoplasm are relatively common, although 80% of eggs are wild-type in length. Approximately 60% of eggs laid by females carrying homozygous germline clones expressing sqhE21.T:Zzzz\FLAG and fertilised by males homozygous for a sqh+ transgene begin development, and 41% of these embryos hatch. 46% of these larvae reach adulthood.

    Images (0)
    Mutant
    Wild-type
    Stocks (2)
    Notes on Origin
    Discoverer
    External Crossreferences and Linkouts ( 0 )
    Synonyms and Secondary IDs (6)
    References (53)