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General Information
Symbol
Dmel\trpl302
Species
D. melanogaster
Name
FlyBase ID
FBal0050670
Feature type
allele
Associated gene
Associated Insertion(s)
Carried in Construct
Also Known As
trplp302
Nature of the Allele
Mutations Mapped to the Genome
 
Type
Location
Additional Notes
References
point mutation
Nucleotide change:

C9761962T

Amino acid change:

Q302term | trpl-PA; Q302term | trpl-PB; Q302term | trpl-PD

Comment:

site of nucleic acid difference inferred by FlyBase curator based on reported amino acid change

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

Mutation is predicted to truncate the protein before the first transmembrane segment.

Amino acid replacement: ?302term.

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

trpl302 mutant adults show normal preference for less solid sucrose-agarose food than a harder one (higher agarose conc., same sucrose content) one in a two-way food choice assay.

Mutant flies show a deficit in gustatory aversion to 6mM camphor in a two way-choice test. Camphor-induced action potentials in S6 taste sensilla are greatly reduced in the mutant flies compared to wild type.

Mutant flies show normal olfactory avoidance of 6mM camphor in a direct airborne repellent test.

Mis-expression of trplScer\UAS.cZa in L2 sensilla under the control of Scer\GAL4Gr5a.PUn in a trpl302 background results in these sensilla showing a physiological responses to camphor, but not to other bitter tastants such as quinine and strychnine.

trpl302 homozygotes show decreased avoidance to CO2, as compared to heterozygous and wild-type controls; in agreement, mutants show decreased electrophysiological responses of the basiconica rich region of the 3rd antennal segment to CO2 exposure, as compared to controls. These homozygotes do not exhibit changes in the number of ab1C neurons.

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. Nonlinear mechanical amplification is significantly reduced compared to wild type.

trpl302 mutants show a sustained response to prolonged light.

Mutant flies exhibit the wild type avoidance of aristolochic acid in food choice assays.

Mutant adults show normal avoidance of 1% citronellal in a direct airborne repellent test (DART) assay.

The normal preference of third instar larvae for 17.5[o]C over 14[o]C in a two-way choice test is eliminated in trpl302 and trpl302/trplMB03075 larvae.

trpl302 mutant class IV dendritic arborization neurons do not exhibit a statistically significant difference in firing in response to light.

trpl302 mutants retain a preference for 18[o]C (i.e. are thermotactic).

capa stimulated fluid transport rates are significantly reduced in Malpighian tubules from trpl302 animals compared to control tubules, while the basal rate of secretion is unaffected.

Mutant flies show an electroretinogram response that is similar to wild-type in response to a 10 second pulse of light.

The reduction in electroretinogram (ERG) amplitude seen in flies exposed to constant light is not suppressed by trpl302.

Wild-type flies kept in the dark are significantly more sensitive to background light than wild-type flies kept in the light or trpl302 flies kept in light or darkness.

Mutant phenotype can be detected using ERG and intracellular recording techniques after prolonged stimuli. The receptor potential has a smaller sustained component than wild type, with altered time course of decay, though peak responses are similar. The response is accompanied by oscillations during stimulus and hyperpolarization after stimulus termination. Mutants also show inability to adapt to dim background illuminations. Refractory period and response latency are wild type.

When IBMX is applied to trpl302 mutant flies the macroscopic response is slowed in a way that is no different to that of wild type flies exposed to IBMX.

Erev in mutant photoreceptors shows a small but statistically highly significant positive shift compared to wild type. Light sensitive conductance is even more permeable to Na+ than wild type. Permeability to Li+ is roughly the same in wild type, trpl302 and trp2 mutants. In general the permeability of mutant photoreceptors to Ca2+, Na+, Li+, Ba2+, Mg2+ and Mn2+ is higher than that for wild type. The I-V relationship of the light sensitive conductance is similar to that of wild type in always showing a pronounced dual rectification. Shows no biphasic reversal potential behaviour with lowered external calcium. Estimated single channel conductance is 4pS. La3+ completely blocks the light response. Light sensitive conductance is facilitated by Ca2+.

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

trpl302 has photoreceptor cell phenotype, enhanceable by trp2

trpl302 has photoreceptor cell phenotype, enhanceable by trp9

trpl302 has photoreceptor cell phenotype, enhanceable by inaF-DP106x

Suppressor of
Statement
Reference

trp1/trpl302 is a suppressor of ommatidium & microvillus phenotype of rdgA1

trp1/trpl302 is a suppressor of ommatidium phenotype of rdgA1

trp2/trpl302 is a suppressor of ommatidium & microvillus phenotype of rdgA1

trp2/trpl302 is a suppressor of ommatidium phenotype of rdgA1

trpl302/trp9 is a suppressor of ommatidium & microvillus phenotype of rdgA1

trpl302/trp9 is a suppressor of ommatidium phenotype of rdgA1

NOT Suppressor of
Statement
Reference

trpl302 is a non-suppressor of retina | adult stage phenotype of Culde01982

trpl302 is a non-suppressor of photoreceptor cell | adult stage phenotype of Culde01982

trpl302 is a non-suppressor of phenotype of rdgA1

Other
Additional Comments
Genetic Interactions
Statement
Reference

The progressive light-dependent retinal degeneration (loss of photoreceptor cells and rhabdomeres) characteristic for Culde01982 mutant adults is not suppressed by combination with trpl302.

Electroretinograms of trpl302, trp9 double homozygotes show a complete lack of response to light stimuli, as compared to either single mutant.

The trpl302; trp9 double mutant has no functional trp and trpl channels and shows no response to light.

Dissociated Xport1, trpl302 double mutant ommatidia show a residual response to brief light flashes; sensitivity is reduced ~500-fold with respect to wild type and 25-fold with respect to Xport1.

Illumination of dissociated, patch-clamped ommatidia from trp9;trpl302 double mutants show activation of the whole phototransduction cascade, do not show any light-induced current or Ca[2+] influx, but do show a normal light-dependent modulation of the delayed rectifier current mediated by Shab channels. Increasing the light level by a factor of ten results in an upregulation of approximately 30% and recovery to baseline within 30 minutes, similar to wildtype controls.

trp9; trpl302 individual photoreceptors form the correct number of synapses per

presynaptic terminal independently of cartridge composition. The photoreceptor terminals of these mutants show an increase in glial invaginations.

capa stimulated fluid transport rates are significantly reduced in Malpighian tubules from trpl302 trp9 animals compared to control tubules, while the basal rate of secretion is unaffected.

trpl302 ; trp14 flies show a electroretinogram response in response to a 10 second pulse of light that is similar to that seen in trp14 single mutants.

trpl302 ; trpL612F.ninaE trp9 flies have a wild-type electroretinogram response.

trpl302 ; trpninaE.PW trp9 flies have a wild-type electroretinogram response.

trpl302 ; trpR671Q.ninaE trp9 flies have a transient electroretinogram response to a 10 second pulse of light.

trp9 ; trpl302 double mutants show a reduced depolarisation response to anoxia in the photoreceptors compared to wild-type flies; the amplitude of anoxia-induced depolarisation in the double mutants is half that of wild type and the response kinetics are much slower than normal.

In trp9,trpl302 double mutants the second, large phase depolarization response to anoxia (caused by N2 and measured in the eye by extracellular voltage change recordings), fails, indicating that the small but not the large phase of the response resulted from accumulation of K+ in the extracellular space. In trp9, trpl302 double mutants the Ca2+ response to anoxia is virtually abolished.

Excised patches from rhabdomeral membranes show no sustained spontaneous activity nor high frequency burst-like behavior in trp9,trpl302 double mutants.

Rhabdomeres of trpl302,inaD1 double mutants are intact in 1 day old flies. ERG light responses of trpl302,inaD1 and trpl302,trp2 are small and transient, but the response amplitude of trpl302,inaD1 is significantly smaller than that of trpl302,trp2. Similarly, refractory period and response latency defects are more severe for trpl302,inaD1 than for trpl302,trp2.

In trp1, trpl302 double mutants light sensitive channels are not activated by the application of linolenic acid, whereas they are activated in single mutant channels.

Double mutant analysis comparing the receptor potentials of trpl302 with inaFP106x; trpl302 or trp2; trpl302 or trp9; trpl302 showed that the effects of inaFP106x are as severe as those of trp2 and are specific to the trp channel.

Behavioural rhythms of trp9 trpl302 double mutants show reduced resetting in response to a pulse of light.

trpl302; trp2 double mutants are almost blind as judged by response to saturating ultraviolet flashes and ERG recordings. trpl302; trp1 double mutants are blind.

Whole-cell patch-clamp recordings of photoreceptors display sensitivity and response kinetics indistinguishable from wild type. trpl302; trp2 mutants display a dramatic loss of responsiveness, the residual current is due to a small amount of functional trp channel. trpl302; trp2 mutants exhibit a dramatic bump phenotype.

Xenogenetic Interactions
Statement
Reference

The presence of trp::trplninaE.trp1-675.trpl681-1124.T:Avic\GFP-EGFP in trpl302; trp9 double mutants results in a response to light that declines towards baseline during prolonged intense light.

The presence of trp::trplninaE.trpl1-336.T:Avic\GFP-EGFP in trpl302; trp9 double mutants results in a response to light that declines towards baseline during prolonged intense light.

The presence of trp::trplninaE.trpl1-336.trp328-675.trpl681-1124.T:Avic\GFP-EGFP in trpl302; trp9 double mutants results in a response to light that declines towards baseline during prolonged intense light.

The presence of trp::trplninaE.trp1-328.trpl336-681.trp675-1275.T:Avic\GFP-EGFP in trpl302; trp9 double mutants results in a response to light that declines towards baseline during prolonged intense light.

Complementation and Rescue Data
Comments

Expression of trplScer\UAS.cZa under the control of either Scer\GAL4Gr66a.PD or Scer\GAL4trpl.PZ restores normal camphor avoidance and camphor-induced action potentials in S6 sensilla in trpl302 flies.

Reintroduction of trplhs.PN to trpl302; trp2 mutants rescues the defect and restores visual physiology. Photoreceptor cells produce quantum bumps (the unitary event of a single photon) that are indistinguishable from wild type.

Images (0)
Mutant
Wild-type
Stocks (1)
Notes on Origin
Discoverer
External Crossreferences and Linkouts ( 0 )
Synonyms and Secondary IDs (4)
References (48)