FB2026_02 , released June 18, 2026
Allele: Dmel\trp9
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General Information
Symbol
Dmel\trp9
Species
D. melanogaster
Name
FlyBase ID
FBal0017163
Feature type
allele
Associated gene
Associated Insertion(s)
Carried in Construct
Also Known As
trp343, trpP343
Key Links
Genomic Maps

Nature of the Allele
Progenitor genotype
Cytology
Description

Mutation in the first base of the 5' splice site of intron 7.

Nucleotide substitution: G?A.

Mutations Mapped to the Genome
Curation Data
Type
Location
Additional Notes
References
Nucleotide change:

G29917798A

Reported nucleotide change:

G?A

Comment:

G to A mutation in the splice donor site of intron 7.

Variant Molecular Consequences
Associated Sequence Data
DNA sequence
Protein sequence
 
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 )
 
Disease-implicated variant(s)
 
Phenotypic Data
Phenotypic Class
Phenotype Manifest In
Detailed Description
Statement
Reference

Like wild-type, trp9 heterozygous flies carrying any of the following transgenic alleles: trpninaE.PV, trpS936D.ninaE or trpS936D.ninaE do not display oscillating voltage electroretinogram (ERG) response upon constant light stimulation.

Dark-adapted trp9/+;trpninaE.PV flies show no significant changes in the onset of the frequency-locked response to oscillating light of either low (10Hz) or high (70Hz) frequency compared to wild-type flies, no defects are observed in light-adapted flies at high frequency either.

The frequency response of light-adapted trp9/+;trpS936A.ninaE flies to oscillating light of gradually increasing frequencies is comparable to controls at both low and high stimulus frequencies. Dark-adapted flies show no significant changes in the onset of the frequency-locked response to oscillating light of low (10Hz) frequency, but unlike wild-type flies they display a quick (<0.3s) frequency-locked response also at high (70Hz) frequency (wild-type flies take about 8s). Light-adapted flies at high frequency show normal quick onset, same as wild-type.

The electroretinogram response of light-adapted trp9/+;trpS936D.ninaE flies to oscillating light of gradually increasing frequencies is comparable to controls at lower stimulus frequencies, but mean oscillation amplitude of the response drops significantly at higher frequencies relative to controls. Dark-adapted flies show no significant changes in the onset of the frequency-locked response to oscillating light of either low (10Hz) or high (70Hz) frequency compared to wild-type flies. However, there is no difference in the timing of the onset of frequency-locked response between dark-adapted and light-adapted flies as both take about 8s to show response (similar to the onset time of dark-adapted controls), whereas in light-adapted wild-type flies it takes less than 0.3s until they display frequency-locked response.

trp9 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.

The integrity of photoreceptor cells show light-dependent degeneration (including loss of rhabdomere structures in the retina) in trp9/trp9 homozygous mutant clones in the eye (in 10 day old flies compared to 1 day old); ERG recordings show a transient response to light.

The gustatory aversion of mutant flies to 6mM camphor in a two way-choice test is not significantly different from that seen in wild-type flies.

trp9 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.

trp9 mutants show a decline in the light response towards baseline during prolonged intense light.

Mutants show an abnormal, transient response during prolonged light stimulation compared to wild type.

trp9 mutants exhibit retinal degeneration. There is no sign of secretory pathway membrane accumulations. At 2 weeks, mutants display a severe retinal phenotype - this is significantly attenuated when flies are reared in constant darkness.

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.

Mutant third instar larvae show the same preference for 17.5[o]C over 14[o]C in a two-way choice test as do wild-type controls.

trpidl-B-1/trp9 and trpidl-B-2/trp9 animals show a transient electroretinogram response.

trp9 mutants retain a preference for 18[o]C (i.e. are thermotactic).

Mutants have no prolonged depolarising afterpotential in their electroretinogram in response to blue light stimulus. The mutant flies have a prolonged refractory period after stimulation.

The light-triggered translocation of trplninaE.T:Avic\GFP-EGFP is abolished in trp9 flies.

The light response of trp9 mutants is very different to wild-type flies, which have a sustained response during illumination and the response to the first and second light pulses are virtually identical. Intensity-response relationships (V-log I curves) of trp9 mutants are shifted to higher levels of light intensity by about 1 log unit as compared to wild-type flies.

trplninaE.T:Avic\GFP-EGFP is not internalised in trp9 mutant photoreceptors.

The maximum rate of capa stimulated fluid transport in Malpighian tubules from trp9 animals is not significantly different from that of wild-type tubules, and the basal rate of secretion is also unaffected.

Mutant flies have electroretinogram defects, showing only a transient response to light (60% deactivation time is 1.5 +/- 0.2 seconds).

Mutant flies show light-dependent degeneration of rhabdomeres; when maintained under a 12 hour light-12 hour dark cycle rhabdomeres begin to disappear between 7-10 days after eclosion, and almost no rhabdomeres remain after 14 days. In contrast, when maintained in the dark, the number of rhabdomeres per ommatidium does not decrease, even 30 days after eclosion, although the size of the rhabdomeres is reduced in 30 day old mutant flies compared to wild-type controls.

trp9 mutants do not exhibit the light dependent architectural changes seen in wild-type rhabdomeres.

trp9 flies carrying trp3.cHa have severely mutant electroretinograms. trp9 flies carrying trp1234.cHa have severely mutant electroretinograms. The rhabdomeres appear normal in trp9 flies at 0, 3 and 7 days after eclosion. trp9 flies carrying trp3.cHa have nearly normal rhabdomeres at day 0 post-eclosion, although some rhabdomeres appear to be splitting up. By day 3 post-eclosion, most rhabdomeres are no longer detectable. trp9 flies carrying trp1234.cHa show degeneration of the rhabdomeres. trp9 flies carrying trp124.cHa have normal rhabdomeres at 0, 3 and 7 days after eclosion.

In normal Ca2+, the light induced current (LIC) in trp9 mutant photoreceptors decays towards baseline with two distinct kinetic components; a rapid (subsecond) decay which is similar to, although slightly slower than, the Ca2+-dependent inactivation seen in wild-type photoreceptors, and a much slower decay which returns the current to baseline over a period of 1-5 seconds. Stimuli that induce decay under normal conditions still induce decay in Ca2+-free conditions. However, the fast component is absent and responses now decay with a single exponential time course which is about 3 times faster than the slower component seen in the presence of Ca2+.

The trp9 ERG shows the typical decline towards baseline during illumination, whereas the Ca2+ signal is transient and relatively small. Anoxia initially activates the slow and small phase of the voltage response, though the second faster phase of the voltage and Ca2+ signal are of significantly smaller amplitude than wild type. This effect persists for as long as the anoxia is applied. No significant change in Ca<up>2+</up> out is observed during the initial 2 mins of anoxia.

ERG shows no sustained response during prolonged light stimulation, reduced peak amplitude and longer than normal response latency.

The small electroretinogram responses seen in trpP365/trp9 flies are not "transient" but have a maintained component that persists throughout the duration of the stimulus.

The phenotypes of inaFP106x, trp9 and trp2 are similar with respect to rapid time course of decay of potential during stimulus, V-logI curves, latency and recovery of response from a previous stimulation.

trp9 photoreceptors in zero extracellular calcium sustain robust light-induced currents.

External Data
Interactions
Show genetic interaction network for Enhancers & Suppressors
Phenotypic Class
NOT Enhanced by
Statement
Reference
Suppressed by
Statement
Reference

trp9 has abnormal neuroanatomy phenotype, suppressible by CalxB

trp9 has abnormal neuroanatomy phenotype, suppressible by Arr25

Enhancer of
Statement
Reference

trp9 is an enhancer of abnormal visual behavior phenotype of trpl302

NOT Enhancer of
Statement
Reference
Suppressor of
Statement
Reference

trp9 is a suppressor of visible phenotype of rdgA1

trp9 is a suppressor of abnormal neuroanatomy phenotype of CalxB

NOT Suppressor of
Statement
Reference
Other
Phenotype Manifest In
Suppressed by
Statement
Reference

trp9 has rhabdomere phenotype, suppressible by CalxB

trp9 has rhabdomere phenotype, suppressible by Arr25

Enhancer of
Statement
Reference

trp9 is an enhancer of photoreceptor neuron phenotype of trpl302

NOT Enhancer of
Suppressor of
Statement
Reference

trp9 is a suppressor of eye phenotype of rdgA1

trp9 is a suppressor of rhabdomere phenotype of CalxB

trp9 is a suppressor of phenotype of rdgA1

trp9 is a suppressor of ommatidium & microvillus phenotype of rdgA1

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

trp9 is a suppressor of ommatidium phenotype of rdgA1

trpl302/trp9 is a suppressor of ommatidium phenotype of rdgA1

NOT Suppressor of
Other
Additional Comments
Genetic Interactions
Statement
Reference

Electroretinograms of trp9, trpl302 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.

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 double mutant flies expressing any of the following: trpD621N, trpD621E or trpD621G show significant changes in their photoreceptor ionic selectivity profile (decreased permeability for Ca[2+] and Mg[2+] in particular) and alleviated channel block by Mg[2+] and ruthenium red as well as other neurophysiological defects: The flies expressing trpD621N also display decreased single channel conductance and much slower kinetics of the light response and strongly increased rate of light-induced retinal degeneration (with most rhabdomeres entirely absent or exhibiting extensive signs of disruption of the microvillar structure, the cell bodies also contained multivesicular bodies) compared to controls. The flies expressing trpD621E exhibit decreased effective pore diameter and decreased single channel conductance compared to controls. They however do not display increased rate of light-induced retinal degeneration. The flies expressing trpD621G also show much slower kinetics of the light response and decreased single channel conductance as well as altered rectification characteristics.

Flies expressing trpD626G in the trp9;trpl302 double mutant background show photoreceptor ionic selectivity profile, rectification characteristics, Mg[+] and ruthenium red channel block that are comparable to 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.

The retinal degeneration phenotype of rdgA1 flies is suppressed by trp9 (as assayed by the presence of a crisp pseudopupil in the double mutant flies).

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.

The retinal degeneration seen in both CalxB and trp9 single mutant flies when they are maintained under a 12 hour light-12 hour dark cycle is suppressed in CalxB trp9 double mutants; most ommatidia in the double mutants contain the normal number of rhabdomeres at 14 days after eclosion.

Arr25 partially suppresses the retinal degeneration seen in 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.

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.

Ommatidial appearance of rdgA1 is largely restored to wild type by mutants at the trp locus, though defects detectable at the EM level remain. These residual defects are suppressed in the triple mutant with trpl302. These anatomical rescue effects are paralleled by rescue of electrophysiological defects of rdgA1 mutants. Double rdgA1, trp mutants show age dependent retinal degeneration.

The addition of trpγhs.N.T:Hsap\MYC to trp9 flies greatly suppresses the electroretinogram (ERG) responses to light stimulus.

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.

trplunspecified; trp9 double mutant photoreceptors have no light-induced currents. The photoreceptors of trplunspecified; trp9 double mutant flies carrying trpltrp.PS show transient responses to long pulses of light. The photoreceptors of trplunspecified; trp9 double mutant flies carrying trplCBS1.trp or trplCBS2.trp show robust inward currents for the duration of the stimulus in response to long pulses of light. trp9; Cam352/Camn339 double mutant photoreceptors do not have transient light responses.

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.

In trp9 photoreceptors expressing Hsap\KCNJ2R228Q.Scer\UAS.T:Avic\GFP-EGFP channels, the PIP2 sensitive current is suppressed by a significantly greater extent than in wild-type photoreceptors.

Complementation and Rescue Data
Comments

Expression of trpninaE.T:Zzzz\SBP rescues the electroretinogram defects of trp9 flies.

trpttd4 in trans with trp9 displays complete inhibition of trplninaE.T:Avic\GFP-EGFP internalisation in the light.

Light-raised trpttd2 in trans with trp9 shows partial translocation of trplninaE.T:Avic\GFP-EGFP from the rhabdomere to the cell body.

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Mutant
Wild-type
Stocks (2)
Notes on Origin
Discoverer

Pak.

External Crossreferences and Linkouts ( 0 )
Synonyms and Secondary IDs (5)
Reported As
Symbol Synonym
Name Synonyms
Secondary FlyBase IDs
    References (72)