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.
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.
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.
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%.