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General Information
D. melanogaster
FlyBase ID
Feature type
Associated gene
Associated Insertion(s)
Carried in Construct
Also Known As
Key Links
Nature of the Allele
Mutations Mapped to the Genome
Additional Notes
Nucleotide change:


Amino acid change:

R130C | usp-PA; R130C | usp-PB

Associated Sequence Data
DNA sequence
Protein sequence
Progenitor genotype

Polytene chromosomes normal.

Nature of the lesion

Amino acid replacement: R?C. The amino acid replacement is at a phosphate contacting Arginine residue within the second zinc finger of the DNA binding domain.

Missense mutation in the DNA-binding domain.

Nucleotide substitution: C?T. Amino acid replacement: R130C. Mutation is in the conserved arginine residues in the DNA binding domain (DBD).

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 ( 0 )
Modifiers Based on Experimental Evidence ( 0 )
Comments on Models/Modifiers Based on Experimental Evidence ( 0 )
Disease-implicated variant(s)
Phenotypic Data
Phenotypic Class
Phenotype Manifest In
Detailed Description

Expression of usphs.PO using a single 30 minute 37oC heat pulse during the first larval instar stage is sufficient to rescue more than 70% of usp4 animals to the third instar stage. These rescued animals often wander only a short distance from the food near the end of the third instar stage.

Homozygous clones in the eye imaginal disc that lie posterior to the morphogenetic furrow have an abnormal arrangement of developing photoreceptor clusters. The clusters are irregularly spaced and differentiate prematurely, although they contain the normal number of cells. Movement of the morphogenetic furrow is accelerated where it passes through a homozygous clone. This displacement of the furrow is not caused by excess proliferation of usp4 cells in the clone.

Heterozygotes display thoracic defects ranging from mild, slight separation of the microchaetes and macrochaetes along the dorsal midline, to severe, a cleft extending through both the notum and scutellum. Flies also have bent and misshapen sensory bristles and develop severely knarled legs.

Females with usp mutant germ cells give rise to fully viable and fertile female usp mutant heterozygotes, but non-viable usp mutant/Y males. Most of these males die just prior to hatching, with the rest dying shortly after. The unhatched embryos have cuticular scarring in the region posterior of A9. In contrast usp mutant/Y males derived from germ cells with functional usp hatch and die between the first and second instar periods, with no gross cuticular defects. usp4 mosaic females mutant in the germline lay very few unfertilised eggs, in contrast to usp4 homozygous females (mutant both soma and germline), indicating that the fertilisation defect in these homozygotes is due to lack of usp in the soma.

Lethality occurs during embryonic and larval stages. Phenotype of homozygous germ line clones is maternal effect lethal.

Homozygous usp4 germline generates misshapen eggs.

External Data
Show genetic interaction network for Enhancers & Suppressors
Phenotypic Class
Phenotype Manifest In
Additional Comments
Genetic Interactions

usp4/+ ; Df(2L)let-7-CKO1/+ ; P{W8,let-7-CΔlet-7} animals have defects in the mushroom body α/β lobes: the lobes may appear slim.

usp4/+ ; EcRQ50st/+ animals have defects in the mushroom body α/β lobes: the lobes may appear slim or the β lobes may be fused.

Xenogenetic Interactions

Mutant larvae rescued by one copy of usp::Cten\Usp-1d-c die at the late third instar stage. Rescued usp4 mutants show a cessation of movement during the late third instar, but larvae show no sign of prepupal tanning except along the denticle belts of the midsegments. The addition of a second copy of usp::Cten\Usp-1d-c leads to further tanning of larvae, but they continue to fail to undergo pupal contraction, and anterior spiracle eversion is incomplete. The addition of three and four copies does allow some adults to survive.

Complementation and Rescue Data
Rescued by
Not rescued by

The usp4 eye imaginal disc phenotype is rescued by usptOa but not by uspGMR.PZ.

Images (0)
Stocks (2)
Notes on Origin
External Crossreferences and Linkouts ( 0 )
Synonyms and Secondary IDs (4)
References (20)