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General Information
D. melanogaster
FlyBase ID
Feature type
Associated gene
Associated Insertion(s)
Carried in Construct
Also Known As
shrub4-1, shrb4-1, shrub4
Key Links
Allele class
Nature of the Allele
Allele class
Mutations Mapped to the Genome
Additional Notes
Associated Sequence Data
DNA sequence
Protein sequence
Progenitor genotype
Nature of the lesion

A 31bp deletion in the 2nd exon causes the shrb4 phenotype.

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 ( 1 )
Comments on Models/Modifiers Based on Experimental Evidence ( 0 )
Disease-implicated variant(s)
Phenotypic Data
Phenotypic Class
Phenotype Manifest In
Detailed Description

shrb4 homozygosity is cell lethal in the wing disc, as no clones are observed.

shrb4/shrb4 MARCM ddaC mutant clones show dendrite pruning defects at 18hr APF, compared to controls.

shrb4 mutants do not exhibit an eye phenotype.

shrb4 mutants exhibit increased dendritic branching. Mutant ddaA neurons exhibit spine-like protrusions that are much longer than on wild-type ddaA neurons.

shrb4 zygotic mutant embryos do not exhibit detectable axon guidance or fasciculation defects in central nervous system and sensory neurons. However, some DA (dendritic arborisation) neurons exhibit abnormal axonal branching.

shrb4 mutant embryos die before reaching the larval stage. At 15-16 hours after egg-laying, dorsal dendrites in shrb4 mutants exhibit multiple dorsally oriented branches, compared to wild-type dorsal dendrites, which exhibit two dorsally oriented dendrites. At 17-18 and 19-20 hours after egg-laying, dendritic arborization (DA) neurons exhibit greatly reduced dendritic fields, with lateral branches often failing to reach the adjacent segment boundaries. The average dendritic field of dorsal clusters is reduced in shrb4 mutant embryos. Dendritic growth is similarly affected in embryos with the shrb4 mutation in trans with Df(2R)Np5 or In(2LR)w45-32n.

The shape of the dendritic trees of shrb4 mutant somatic clone ddaE neurons is similar to that in wild-type, but the number of dendritic termini is increased significantly because of an increase in fine, higher-order branches. shrb4 mutant clones of ddaF and ddaB neurons exhibit similar results. shrb4 ddaC somatic clone neurons exhibit a nearly 100% increase in dendritic termini. They also exhibit a high degree of branching complexity near the cell body. Dendritic fields of shrb4 ddaC somatic clones are also reduced in size. shrb4 mutant ddaA or ddaD neurons extend longer spine-like protrusions, in comparison to wild-type.

shrb4 mutant PNS neuron clones exhibit ectopic axonal branches in 21% in cases.

Exhibits reduced lateral branches in the dorsal cluster of embryonic dendrites. The dorsal dendrites extend only a fraction of the normal length and produce a few weakly elaborating lateral branches. The dendritic field in stage 17 embryos is drastically reduced. This is seen in over 95% of embryos. Mutants show no gross defects in muscle, anterior-posterior or dorsal-ventral patterning. The number of peripheral nervous system (PNS) neurons is the same as in wild-type. es and ch neurons retain their single dendrite morphology. There is no detectable abnormality in PNS and central nervous system axons.

External Data
Show genetic interaction network for Enhancers & Suppressors
Phenotypic Class
Suppressed by
Enhancer of
Suppressor of

shrb[+]/shrb4 is a suppressor of lethal - all die before end of larval stage | cold sensitive phenotype of Vps609.2

Phenotype Manifest In
Enhancer of
Additional Comments
Genetic Interactions

Expression of Rab7GD11800 does not suppress the ectopic N activation phenotype in shrb4 follicle cell clones.

The wing phenotype caused by expression of l(2)gd1Scer\UAS.cJa under the control of Scer\GAL4C5 is strongly modified if the flies are also heterozygous for shrb4.

Xenogenetic Interactions

A single copy of shrb4 significantly enhances the Hsap\CHMP2BIntron5.Scer\UAS Scer\GAL4GMR.PF phenotype in 1-day-old flies.

A shrb4 heterozygous background significantly enhances the Scer\GAL4GMR.PF :Hsap\CHMP2BIntron5.Scer\UAS phenotype.

Expression of Mmus\Chmp4bScer\UAS.cSa under the control of Scer\GAL4109(2)80 partially rescues the lethality of shrb4 mutants (to approximately 70% survival rate).

Expression of Mmus\Chmp4cScer\UAS.cSa under the control of Scer\GAL4109(2)80 partially rescues the lethality of shrb4 mutants (to approximately 40% survival rate).

Complementation and Rescue Data
Partially rescued by

Rescue of shrb4 embryonic lethality with shrbScer\UAS.cSa, under the control of Scer\GAL4αTub84B.PL allows survival of 99% of mutant embryos to the third instar larval stage.

Expression of two copies of shrbScer\UAS.cSa in neurons of the peripheral nervous system, under the control of Scer\GAL4109(2)80, rescues the average dendritic field size of dorsal cluster DA neurons in shrb4 mutants to near wild-type levels. The rescued dorsal clusters contain a number of lateral branches that are largely absent in shrb4 mutant clusters

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Stocks (0)
Notes on Origin

Induced on: a chromosome containing Avic\GFPS65T.Scer\UAS driven by Scer\GAL4109(2)80.

External Crossreferences and Linkouts ( 0 )
Synonyms and Secondary IDs (4)
References (14)