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General Information
D. melanogaster
FlyBase ID
Feature type
Associated gene
Associated Insertion(s)
Carried in Construct
Also Known As
rbp5, rbpt376, rbp5
Key Links
Nature of the Allele
Mutations Mapped to the Genome
Additional Notes
Associated Sequence Data
DNA sequence
Protein sequence
Progenitor genotype
Nature of the lesion

Expression of Sgs3, Sgs4, Sgs5 and Eig71Eg genes was reduced to less than 3% of wild type levels.

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

Mutants show defects in destruction of the larval salivary glands, having persistant larval salivary glands at the pupal stage. Leg elongation in th pupae is also blocked.

Unlike wild-type pupae, the salivary glands and larval abdominal muscles fail to die in mutants during pupation. The salivary glands look normal during prepupal development, the glands dive at head eversion as normal, but do not fall apart. The muscle degeneration that is apparent about two hours before head eversion in wild-type prepupae is not seen in mutants, although the muscles appear less organised than at earlier stages. Similarly, intact muscles can be seen after head eversion in mutant pupae more tha one day after puparium formation. Significant muscle contractions are apparent in early mutant pupae starting at head eversion and continuing for as long as 5 hours (muscle contractions in wild-type animals are only evident for 2.7-3 hours after head eversion).

brrbp-5 mutant pupae exhibit DNA fragmentation in the salivary gland as normal.

brrbp-5/Y eye discs do not show any defects. Homozygous clones in the eye disc appear normal.

Mutant salivary gland cells lack large eosin positive vacuoles and plasma membranes and show variable chromosome banding - - phenotypes associated with autophagy initiating in salivary gland cells but not progressing.

Larval salivary glands are not destroyed by 22 hours after puparium formation in brrbp-5 pupae, in contrast to wild-type pupae where they are completely destroyed by 16 hours after puparium formation.

92% of the dorsoventral indirect flight muscles (DVMs) of hemizygous males have defects, generally either being absent or detached dorsally, although 2% of fibres are detached from the ventral epidermal muscle attachment site (EMA), leaving a remnant in the dorsal thorax. Some dorsal longitudinal muscles (DLMs) have ectopically-attached fibres. Approximately half the tergotrochanteral muscles (TTMs) have defects, including absent muscle, dorsal detachment and ectopic dorsal attachment. In mosaic animals containing hemizygous clones in a heterozygous background, all indirect flight muscles (IFMs) on a given side of the thorax have the same genotype. Mosaic analysis indicates that DVMs with mutant dorsal EMAs have the most severe phenotypes, regardless of the genotype of the muscle or the ventral EMA. Mosaic analysis indicates that the DLMs only show ectopic attachments when the EMAs are mutant. Only TTMs that have mutant ventral EMAs show defects in mosaic animals.

Homozygotes arrest development at the early pupal or pharate adult stages. Males have a reduced number of bristles on each sternite. Over 50% of brrbp-5/Y males carrying two copies of either brBRcore.Q1.Z1.hs or brBRcore.TNT.Q1.Z1.hs are rescued to eclosion when brBRcore.Q1.Z1.hs or brBRcore.TNT.Q1.Z1.hs is expressed using a 33oC heat shock in 6 hour prepupae followed by a 37oC heat shock just after head emergence. The brrbp-5 reduced bristle phenotype is rescued, but the rescued flies have a weak malformed leg and wing phenotype. brBRcore.Z4.hs partially rescues brrbp-5/Y males; these animals do not survive to eclosion, but a significant number progress further into pupal development than control animals. brZ2.hs and brBRcore.NS.Z3.hs do not rescue brrbp-5/Y males.

DVM are virtually eliminated (a deficit in thoracic muscle precursors). DLM fibres often remain fused at their ends rather than splitting from three primordia into six DLM fibres. DLM, TTM and the few surviving DVM fibres occupy incorrect attachment sites on the dorsal thorax at epidermal locations normally occupied by other muscle fibres.

Homozygotes die as late pupae.

Males pupariate normally and die during the pupal period at the beginning of eye development. Head eversion is not affected. Double heterozygotes with Eip74EFneo24 or Eip74EFDL-1 show no effect on development. Heterozygous females and mutant males that are also homozygous for Eip74EFneo24 pupariate normally. Half of each group die during prepupal development, resembling severe phenotype Eip74EFneo24 mutants. 8% of Eip74EFneo24 flies display novel phenotypes. Head eversion fails and rudimentary appendages/cryptocephalic head structures develop. Proportion of Eip74EFDL-1 flies showing either a prepupal or pharate lethal phenotype is unchanged as the effective dose of 'rbp'+ is reduced.

Heterozygotes with brrbp-2 display reduced mechanosensory bristles on the maxillary palps and indentations on the surface of the eye.

The Pig1 to Sgs4 switch fails to occur during mid-third instar.

Pupae die at the beginning of eye formation.

brrbp-5/brnpr-6 combination is lethal, rare adult escapers show a reduction of the bristle number on the palpus. Heterozygotes with Df(1)br25 have normal viability and reduced bristle number on the palpus.

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

brrbp-5/br[+] is a suppressor of visible | dominant phenotype of B1

Phenotype Manifest In
Suppressor of

brrbp-5/br[+] is a suppressor of eye phenotype of B1

Additional Comments
Genetic Interactions
Xenogenetic Interactions
Complementation and Rescue Data
Images (0)
Stocks (0)
Notes on Origin

Strong 'rbp' allele.

External Crossreferences and Linkouts ( 0 )
Synonyms and Secondary IDs (9)
References (45)