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.
Excised patches from rhabdomeral membranes show very small conductance values.
The small electroretinogram responses seen in trpP365/trp1 flies are not "transient" but have a maintained component that persists throughout the duration of the stimulus. In the case of trpP365/trp1 animals raised at 19oC and examined at the P15 pupal stage, a large subset of photoreceptors respond to light with smaller than normal responses (as measured by whole-cell recordings of light-induced currents). The remaining subset (43%) do not respond to light at all. In less than 1 hour old trpP365/trp1 adults, 93% of photoreceptor cells do not respond to light. trpP365/trp1 photoreceptors (in darkness) respond to voltage steps with large outward currents and significant inward currents. The properties of these currents are very similar to those of the run down current of wild-type photoreceptors, except that they are seen from the moment the recordings begin and in a normal medium. Newly eclosed trpP365/trp1 flies show virtually no signs of photoreceptor degeneration when raised at 19oC. Several hours later, the photoreceptor cells begin showing membrane shedding at the tips of some microvilli, suggesting that degeneration has begun.
When IBMX is applied to trp1 mutant flies the macroscopic response is slowed in a way that is no different to that of wild type flies exposed to IBMX.
trp1 flies raised under 12 hour light:dark conditions retain a deep pseudopupil for at least 15 days.
Flies raised at the restrictive temperature (24oC) show strong abnormalities in olfactory adaptation, requiring shorter times for half-recovery than when cultured at the permissive temperature (18oC). Files grown at the permissive temperature are indistinguishable from wild type. Temperature shift experiments indicate that trp function is required in the developing, but not the mature, antenna for normal olfactory adaptation.
The reversal potential (Erev)of the light-induced current is smaller than wild-type at both 19oC and 25oC. Erev at 25oC is significantly less than Erev at 19oC. The amplitude of the rundown current (RDC) is much smaller than wild-type at 19oC, and undetectable at 25oC.
Third instar foraging larvae show negative photobehaviour indistinguishable from the wild-type response to light. Third instar larvae show a decrease in negative phototaxis from the onset of wandering culminating in random photobehaviour indistinguishable from the response of wild-type larvae.
The 'run down current' (RDC) seen in wild-type photoreceptor preparations, due to spontaneous activation of cation channels in the plasma membrane, is absent in the mutant, suggesting it to be dependent on non-TRP channels.
Abolishes Ca2+-dependent inactivation of light-sensitive channels in photoreceptors. Abolishes Ca2+ and voltage-dependent light induced current in photoreceptors.
Shows a reduced light-induced decrease in extracellular Ca2+ concentration compared to the wild-type.
Calcium influx is reduced in photoreceptors.
The reversal potential (Erev) of the light-induced current in adult photoreceptors is significantly more negative than wild-type, and its dependence on extracellular Ca2+ is much reduced.
The retina and synapses of the ocelli in 3 week old flies appear normal.
temperature-sensitive. Rearing at 19oC (instead of 25oC) slows the rate of the decay-to-baseline of the photoreceptor potential and leads to faster initial dark recovery than occurs under non-permissive conditions. Rearing at 25oC, followed by shift of adults to 19oC, leads to more nearly normal behavior in bright light within four to six days (Minke, 1983).
trp1 has increased cell death | conditional phenotype, suppressible by Osi21die4/Osi21die4
scribsmi97B, trp1 has abnormal smell perception | dominant | female phenotype
smi28E1, trp1 has abnormal smell perception | dominant | female phenotype
scrib[+]/scribsmi97B, trp1 has abnormal smell perception | dominant | female phenotype
smi28E[+]/smi28E1, trp1 has abnormal smell perception | dominant | female phenotype
trp1, trpl302 has abnormal visual behavior phenotype
trp1 is a suppressor of retina phenotype of PldUAS.cLa, Scer\GAL4ninaE.PD
trp1 is a suppressor of ommatidium phenotype of rdgA1
trp1/trpl302 is a suppressor of ommatidium phenotype of rdgA1
trp1 is a suppressor of ommatidium phenotype of rdgBota1
trp1 is a suppressor of eye photoreceptor cell phenotype of rdgB9
trp1 is a suppressor of ommatidium phenotype of rdgB9
trp1 is a suppressor of eye photoreceptor cell phenotype of rdgBota1
trp1/trpΔ1272 is a non-suppressor of rhabdomere phenotype of rdgA1
trp1, trpl302 has photoreceptor neuron phenotype
trp1, trpl302 has photoreceptor phenotype
The retinal degeneration phenotype observed upon expression of PldScer\UAS.cLa under the control of Scer\GAL4ninaE.PD when flies are raised under continuous light for 1 day is suppressed in a trp1 mutant background.
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.
trp1 slows the initiation of deep pseudopupil loss of rdgBota1 flies and dramatically suppresses photoreceptor degeneration and ommatidial disorganisation in these flies. trp1 does not slow the initiation of deep pseudopupil loss of rdgB9 flies, but dramatically suppresses photoreceptor degeneration and ommatidial disorganisation in these flies.
Cosens, Manning.
Allele is an effective null, more so than trp2.
The trp mutation selectively abolishes one class of light-sensitive Ca2+ channel in photoreceptors.
Photolysis of the caged Ca2+ compounds DM-nitrophen and nitr-5 induces a small inward current with no detectable latency in trp1 photoreceptor cells which have been inactivated by conditioning light. Photolysis of DM-nitrophen induces a significant facilitation during the falling phase of the response, but significantly depresses the overall response during the rising phase, in trp1 photoreceptor cells which have not been inactivated.