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General Information
Symbol
Dmel\ort1
Species
D. melanogaster
Name
FlyBase ID
FBal0013284
Feature type
allele
Associated gene
Associated Insertion(s)
Carried in Construct
Also Known As
oraJK84, ora, ortJK84
Allele class
Nature of the Allele
Allele class
Mutations Mapped to the Genome
 
Type
Location
Additional Notes
References
deletion
Comment:

A deletion of 569 nucleotides containing parts of exon 2 and exon 3 and all of intron 2. Deletion corresponds to coordinates 66614-67183 of GB:AE003727.

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

Deletion of 569 nucleotides overlapping intron 2 (110bp) and 459 nucleotides of exons 2 and 3 of ort. Sequence deleted is positions 66614-67183 of AE003727. Sequence deleted encodes a substantial portion of the N-terminus extracellular domain and the first two membrane spanning segments. A frame-shift mutation is consequently introduced.

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

ort1 mutant adult males have reduced ability to orient towards and remain close to a female, compared to controls; they also lose the bias seen in controls to extend the wing closest to, rather than furthest from, the female; following of females and copulation, but not wing extensions, are significantly reduced, compared to controls.

ort1 flies do not exhibit ON and OFF transients in ERG recordings of the laminar LMC neurons at the onset and end of light stimulation.

Compared to controls, ort1 homozygous animals and ort1/ort6 mutants exhibit weaker phototaxis towards UV light.

Compared to controls, ort1/ort4 mutants exhibit weaker phototaxis towards either UV or green light, with UV phototaxis being affected the most severely in an intensity-dependent manner.

Flies combining ort1 with ort4 are largely, but not entirely, motion-blind, giving occasional small responses in head yaw and roll optomotor assays, but are entirely motion-blind when tested for optomotor yaw torque (with a fixed head position) and under low pattern contrast conditions.

Heteroallelic mutants ort1/ort4 do not exhibit optomotor responses during tethered flight in low light intensities.These mutants do not respond to front-to-back or back-to-front motion at pattern contrasts of 5%, 10% or 40%.

The temperature preference profile of ort1 homozygous adults is abnormal. There is a broader spread of temperature preferences with a significantly with fewer flies choosing the wild-type majority preference of 24-25'C and an increased preference for higher temperatures. Locomotor activity levels in these animals appear to be normal. However, when placed at 40'C, these flies are rendered unconscious at a significantly faster rate than wild-type and their recovery from a 10 minute 40'C heat shock is significantly slower than wild-type.

Mutant adults and larvae show hypersensitivity to the avermectin neurotoxins abamectin and ivermectin. Hypersensitivity manifest as reduced survival. Mutant adults show resistance to diethyl ether anaesthesia, manifest as increased survival of mutants relative to wild type. The recovery from anaesthesia times for mutants is increased relative to that of wild type controls. The difference in recovery time between males and females that is evident in Oregon R controls is abolished in the mutants. Recovery from bang-induced paralysis times is remarkably faster in Oregan R controls than ort1 mutants. Preincubation of mutant flies at 30oC has no effect on their viability or bang sensitivity.

Following eclosion, R1-R6 rhabdomeres slowly degenerate and are essentially absent after 14 days. In sev3 ort1 double mutants only R8 cells exhibit intact rhabdomeres.

Third instar foraging larvae show negative photobehaviour indistinguishable from the wild-type response to light. Third instar larvae continue to show negative phototaxis during the wandering stage, in contrast to wild-type larvae.

Extra R7 cells of rlSem do not degenerate in ort1 mutants.

Deletion of outer rhabdomeres from compund eye. Phospholipid distribution within the fly head is essentially the same as in wild type.

The hypertrophy of inner photoreceptors seen in Gap1mip-w+ homozygotes is unaffected in flies also carrying ort1.

Rhodopsin is lacking in R1-6 photoreceptors, rhabdomeres of R1-6 photoreceptors degenerate. Homozygotes exhibit only R7 and R8 cells. sevS11.T:Hsap\MYC; ort double mutants exhibit 4 small rhabdomeres per ommatidium.

The rhabdomeres of the six outer photoreceptors disappear during development. Diacylglycerol kinase activity is almost normal.

Rhodopsin levels very low in R1--R6 photoreceptors: respond poorly or not at all to light stimulus. ERG phenotype: PDA is absent, light coincident response is reduced in amplitude, transient components missing. Rhabdomeres present in young flies but rapidly degenerate.

Flies lack the outer photoreceptor cells (R1-R6).

The electroretinogram of homozygous flies is smaller in amplitude than wild-type, and lacks the prolonged depolarising afterpotential and transient components. Heterozygotes have an ERG similar to wild-type. Homozygotes have very little rhodopsin, heterozygotes have approximately 76% rhodopsin compared to wild-type levels. The R1-R6 rhabdomeres are reduced in size or absent in homozygotes.

Receptor mutant. Orientation effect is almost absent in the fixation Y-maze.

ort1 flies and sevunspecified ort1 double mutant flies show no pattern discrimination, but do show phototaxis to illuminated non-pattern targets.

rdgB9 ort1 double mutants do not show degeneration of photoreceptor cells at 18oC even after 20 days in constant light. However, at 25oC they do show degeneration after about 10 days, independent of light condition.

Electroretinogram lacks on-transient and shows either no off-transient or a delayed one, occurring 100-150 milliseconds after the light coincident photoreceptor potential is elicited. Rhodopsin levels, prolonged depolarizing afterpotentials and rhabdomere structure are normal in R1-6 photoreceptors of ort eyes, unlike the case of ninaE single or double mutants (see allele records for ort and ninaE).

External Data
Interactions
Show genetic interaction network for Enhancers & Suppressors
Phenotypic Class
Phenotype Manifest In
Additional Comments
Genetic Interactions
Statement
Reference

ort1 in a HisCl1134, ninaE1 mutant background significantly reduces the phototactic preference for ultraviolet light over green light seen in wild type and control flies.

ort1/ort4 in a HisCl1134, ninaE1 mutant background significantly reduces the phototactic preference for ultraviolet light over green light seen in wild type and control flies.

ort1/ort6 in a HisCl1134, ninaE1 mutant background significantly reduces the phototactic preference for ultraviolet light over green light seen in wild type and control flies.

Expressing ortScer\UAS.2x.T:Ivir\HA1 in Tm5c neurons in a homozygous ort1, ort1/ort4, ort1/ort6 background (with HisCl1134 and ninaE1) under the control of Scer\GAL4C1a.DBD.ort.T:Zzzz\ZipRREEL and Hsim\VP16AD.VGlut.OK371.T:Zzzz\ZipEERRL,T:SV40\nls2 enhances the preference for green light over UV seen in the mutant flies alone.

HisCl1134, ort1 double mutants fail to discriminate between wavelengths in the UV and green spectrum.

HisCl1134,ort1/HisCl1134,ort6 double mutants show weak phototaxis towards green light.

The temperature preference profile of HisCl1134, ort1 homozygous adults is abnormal. There is a broader spread of temperature preferences with a significantly with fewer flies choosing the wild-type majority preference of 24-25'C. Locomotor activity levels in these animals appear to be normal. However, when placed at 40'C, these flies are rendered unconscious at a significantly faster rate than wild-type and their recovery from a 10 minute 40'C heat shock is significantly slower than wild-type. These two phenotypes (reduced tolerance for high temperatures and slower recovery following heat shock) are both largely rescued by HisCl1+t14.3; ort+t13.3.

HisCl1134, ort1 homozygous adults have a significantly increased death rate after 6 days at 4'C compared to wild-type, but they recover more quickly from a cold induced coma. These phenotypes are largely rescued by HisCl1+t14.3; ort+t13.3.

ninaE1 ort1 flies show residual object fixation in tethered flight, but no more than 16% of the residual object fixation is accomplished with wingbeat steering (the predominant steering mechanism of normal flies). ninaE1 ort1 flies are significantly impaired in the ability to maintain their orientation towards a landmark when walking in the Buridan's paradigm assay. Their average and maximum walking speed are reduced to about one-half of the corresponding speed observed under identical conditions in wild-type flies.

Xenogenetic Interactions
Statement
Reference
Complementation and Rescue Data
Partially rescued by
Comments

Driving ortScer\UAS.cWa with Scer\GAL4NP6298 in the ort1/ort4 mutant background restores fly head yaw and roll optomotor responses to wildtype levels.

Expressing ortScer\UAS.cWa with either Scer\GAL4NP0723 or Scer\GAL4c202a in the ort1/ort4 mutant background restores optomotor responses to wildtype levels measured by fly head yaw and roll optomotor responses.

Expression of ortScer\UAS.cWa with Scer\GAL4NP6298 in the ort1/ort4 mutant background rescues optomotor yaw responses at low pattern contrast of 0.1%, but not when driven with either Scer\GAL4c202a or Scer\GAL421D. With a pattern contrast of 1%, ort1/ort4 mutants driving ortScer\UAS.cWa with Scer\GAL421D show optomotor responses only slightly reduced compared to controls, but are statistically indistinguishable from negative controls when driving with Scer\GAL4c202a.

Overexpression of ortScer\UAS.cWa with Scer\GAL421D in the ort1/ort4 mutant background rescues response to low level light intensity defects of the mutants alone, but not when expressed by Scer\GAL4c202a. However, Scer\GAL4c202a rescues this phenotype when the pattern wavelength is doubled from lambda = 18[o] to 36[o].

Expression of ortScer\UAS.cWa with Scer\GAL421D in the ort1/ort4 mutant background rescues response to front-to-back motion, but not when driven by Scer\GAL4c202a, with a pattern contrast of 5%. Rescue of back-to-front motion defects occurs when expressing with Scer\GAL4c202a at >5% pattern contrast, whilst Scer\GAL421D only rescues when the pattern contrast is 40%.

Images (0)
Mutant
Wild-type
Stocks (4)
Notes on Origin
Discoverer

Koenig.

Isolated as: Double mutant with ninaE1, called "oraJK84".

External Crossreferences and Linkouts ( 1 )
Crossreferences
GenBank Nucleotide - A collection of sequences from several sources, including GenBank, RefSeq, TPA, and PDB.
Synonyms and Secondary IDs (4)
References (34)