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General Information
Symbol
Dmel\Arr25
Species
D. melanogaster
Name
FlyBase ID
FBal0098951
Feature type
allele
Associated gene
Associated Insertion(s)
Carried in Construct
Nature of the Allele
Mutations Mapped to the Genome
 
Type
Location
Additional Notes
References
point mutation
Nucleotide change:

T8648766R

Amino acid change:

Y20term | Arr2-PA

Reported amino acid change:

Y20term

Comment:

Site of nucleotide substitution in mutant inferred by FlyBase based on reported amino acid change.

Associated Sequence Data
DNA sequence
Protein sequence
 
 
Progenitor genotype
Cytology
Nature of the lesion
Statement
Reference

Amino acid replacement: Y20term.

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 )
 
Phenotypic Data
Phenotypic Class
Phenotype Manifest In
Detailed Description
Statement
Reference

Compound action potentials can be evoked by sound in the antennal nerve of mutant flies, but the sound particle velocities required to elicit the response is increased compared to wild type. The displacement response of the antenna over a range of sound particle velocities is linearised, indicating loss of mechanical amplification.

In whole-cell voltage-clamp recording of dissociated ommatidia from Arr25 flies, the response to brief flashes of UV light inactivates normally but then fails to rapidly reach baseline leaving a secondary peak that decays over several seconds.

The response to a brief flash in dissociated ommatidia from Arr25 flies shows a prolonged decay lasting several seconds, the tail of which can be fitted with a single exponential of approximately 1400ms. This slow deactivation is due to single photons exciting trains of quantum bumps, with refractory periods ranging from 50 to approximately 150ms. In Ca[2+]-free conditions, responses in Arr25 flies are prolonged compared to wildtype, with an intermediate time course observed for Arr25 heterozygotes.

In regular cyclic illuminating conditions, 7 day old mutant flies have smaller rhabdomeres than normal and have large intracellular vacuoles in the photoreceptors. The shape of the rhabdomere is normal in these flies.

The termination speed of photoresponses in Arr25 flies is slower than for wild-type flies.

In an electroretinogram of dark-reared, newly eclosed Arr25 mutant flies, photoreceptor receptor cells rapidly depolarise and remain depolarised during the light stimulus, as in wild-type, but once the light stimulus is terminated the photoreceptor cells re-polarise very slowly, taking about four times longer to terminate the response.

Eyes from Arr25 mutant flies exposed to 5 days of constant light show severe retinal degeneration. Large intracellular holes develop and the ommatidial organization is completely lost.

Eyes from Arr25 mutant flies exposed to a 12-hour light/dark cycle from 30 days show severe and almost complete retinal degeneration, with all except the R7 rhabdomere completely missing.

Arr25 mutants display retinal axon termination responses that are comparably slow after both long (3-seconds) and short (0.2-seconds), compared to wild-type.

Endocytosis of ninaE is normal in Arr25 mutants.

Light-induced currents of Arr25 photoreceptor cells are almost identical to those of wild-type flies.

4-day-old Arr25 mutants show slightly smaller and abnormally shaped rhabdomeres, relative to wild type.

The reduction in electroretinogram (ERG) amplitude seen in flies exposed to constant light is greatly suppressed by Arr25 or Arr25/Arr23KQ. However, retinal degeneration and rate of loss of the deep pseudopupil in Arr25/Arr23KQ flies exposed to constant light is the same as that seen in wild-type flies exposed to constant light.

The termination of the electroretinogram (ERG) response to light is slower in Arr25 flies than in wild-type flies. Preexposure to light has very little impact on the rate of termination of the ERG in Arr25 flies, in contrast to wild-type flies where preexposure to light increases the speed of termination of the ERG response. The termination of the electroretinogram (ERG) response to light is slower in Arr25 flies carrying Arr23KQ than in wild-type flies. Preexposure to white light for 10 minutes results in an increase in the rate of termination of the ERG (as occurs in wild-type flies), but the rate of termination is much slower than in wild-type flies.

After 6 days of exposure to continuous room light, null Arr2 mutants exhibit a light dependant retinal degeneration phenotype. The photoreceptor rhabdomeres are present, but numerous large intra cellular vacuoles completely disrupt ommatidial organisation.

Flies show complete retinal degeneration based on deep pseudopupil analysis after 3-4 days of light exposure. No significant degeneration is seen in the dark, even after several weeks of exposure. Electroretinograms of mutant flies have marked defects in inactivation kinetics, with an increase in the time required to reach 85% inactivation.

External Data
Interactions
Show genetic interaction network for Enhancers & Suppressors
Phenotypic Class
Enhanced by
Statement
Reference
NOT suppressed by
Statement
Reference
Enhancer of
Statement
Reference
Suppressor of
Statement
Reference
Phenotype Manifest In
Enhanced by
Statement
Reference
Suppressed by
Statement
Reference

Arr25 has retina phenotype, suppressible by su(rdgA)4040

Arr25 has eye phenotype, suppressible by norpA7

Arr25 has retina phenotype, suppressible by norpA7

Arr25 has ommatidium phenotype, suppressible by norpA7

NOT suppressed by
Statement
Reference

Arr25 has ommatidium phenotype, non-suppressible by ninaE17/Rh3Rh1+3

Arr25 has eye phenotype, non-suppressible by BacA\p35GMR.PH

Arr25 has ommatidium phenotype, non-suppressible by BacA\p35GMR.PH

Arr25 has retina phenotype, non-suppressible by BacA\p35GMR.PH

Enhancer of
Statement
Reference
Suppressor of
Statement
Reference

Arr25 is a suppressor of eye photoreceptor cell phenotype of Arr11

Arr25 is a suppressor of ommatidial cluster & endocytic vesicle phenotype of Arr11

Arr25 is a suppressor of rhabdomere phenotype of Arr11

Arr25 is a suppressor | partially of rhabdomere phenotype of trp14

Arr25 is a suppressor | partially of rhabdomere phenotype of trp9

Arr25 is a suppressor | partially of retina phenotype of ninaEpp100

Arr25 is a suppressor | partially of rhabdomere phenotype of ninaEpp100

Arr25/Gαq1 is a suppressor of retina phenotype of ninaEpp100

Arr23KQ/Arr25 is a suppressor of retina phenotype of norpA7

Arr25 is a suppressor of rhabdomere R5 phenotype of norpA7

Arr25 is a suppressor of rhabdomere R6 phenotype of norpA7

Arr25 is a suppressor of rhabdomere R1 phenotype of norpA7

Arr25 is a suppressor of photoreceptor cell R1 phenotype of rdgB5

Arr25 is a suppressor of photoreceptor cell R2 phenotype of rdgB5

Arr25 is a suppressor of photoreceptor cell R3 phenotype of rdgB5

Arr25 is a suppressor of photoreceptor cell R4 phenotype of rdgB5

Arr25 is a suppressor of photoreceptor cell R5 phenotype of rdgB5

Arr25 is a suppressor of photoreceptor cell R6 phenotype of rdgB5

Arr25 is a suppressor of photoreceptor cell phenotype of rdgB5

Arr25 is a suppressor of retina phenotype of rdgB5

Arr25 is a suppressor of eye phenotype of norpA7

Arr25 is a suppressor of retina phenotype of norpA7

Arr25 is a suppressor of rhabdomere R2 phenotype of norpA7

Arr25 is a suppressor of rhabdomere R3 phenotype of norpA7

Arr25 is a suppressor of rhabdomere R4 phenotype of norpA7

Additional Comments
Genetic Interactions
Statement
Reference

In whole-cell voltage-clamp recording of dissociated ommatidia from Arr25 flies carrying Rh3Rh1+3 and mutant for ninaE17, the response to brief flashes of UV light inactivates normally but then fails to rapidly reach baseline leaving a secondary peak that decays over several seconds.

The average size of the peripheral rhabdomeres in 7 day old tadr1 ; Arr25 double mutant flies is smaller than that of tadr1 and Arr25 single mutants.

The termination speed of photoresponses in Camtates-2; Arr25 double mutants is much slower than those of either single mutant.

When Arr11 mutants are also mutant for Arr25, photoreceptor degeneration is suppressed in adults and ninaE endocytosis is restored in pupae.

Arr25 partially suppresses the retinal degeneration seen in trp14 or trp9 single mutant flies when they are maintained under a 12 hour light-12 hour dark cycle; the double mutants contain the normal number of rhabdomeres at 14 days after eclosion, although the size of the rhabdomeres is reduced compared to controls.

Light-induced currents of Arr25, ninaEpp100 double mutant photoreceptor cells show a large increase in light sensitivity relative to ninaEpp100 cells, the sensitivity is significantly less than wild-type cells. Arr25, ninaEpp100 photoreceptors produce anomalous constitutive currents in the dark, like ninaEpp100 single mutant photoreceptors. In Arr25, ninaEpp100 double mutants, retinal degeneration is significantly slowed but not abolished, when flies are kept in either constant light or constant darkness.

Gα49B1; Arr25, ninaEpp100 triple mutants show a suppression of the retinal degeneration phenotypes seen in ninaEpp100 single mutants. The triple mutants exhibit only very minor rhabdomeric abnormalities after 40 days.

The loss of the deep pseudopupil seen in norpA7 animals is suppressed by Arr25/Arr23KQ, although the rhabdomeres of these animals reared for 2 weeks in a 12 hour light/12 hour dark cycle do not have normal morphology.

norpA7, Arr25 double mutants completely rescue the degeneration observed in individual mutant and result in an ommatidial structure that closely resembles wild-type. The a light dependant retinal degeneration phenotype seen in rdgB5 is partially rescued by Arr25. The a light dependant retinal degeneration phenotype seen in Arr25 is not rescued by BacA\p35GMR.PH.

Xenogenetic Interactions
Statement
Reference
Complementation and Rescue Data
Fails to complement
Comments
Images (0)
Mutant
Wild-type
Stocks (0)
Notes on Origin
Discoverer
External Crossreferences and Linkouts ( 0 )
Synonyms and Secondary IDs (7)
References (17)