A truncated, activated sevenless kinase overexpressed under the control of a duplicated sev enhancer.
sev amino acids 1865 to 2554, lacking most of the extracellular domain, encoded by cDNA are under the control of the duplicated sev enhancer and Hsp70 promoter. N-terminal signal sequence is provided by an inframe fusion with the signal peptide of Lcp3, and the protein is tagged with a Tag:MYC epitope.
The increased photoreceptor cell phenotype seen in sevS11.T:Hsap\MYC flies is suppressed when flies coexpress either S6kIIScer\UAS.T:Hsap\MYC or S6kIIK231R.Scer\UAS.T:Hsap\MYC under the control of Scer\GAL4hs.2sev.
Expression of either cdi33-077, cdi34-165 or cdi44-004 under the control of Scer\GAL4hs.2sev suppresses the rough eye phenotype of sevS11.T:Hsap\MYC flies. In the absence of the Scer\GAL4hs.2sev driver, no suppression is seen.
The addition of dosR31 almost completely suppresses the rough eye phenotype seen in sevS11.T:Hsap\MYC animals. The addition of both dosR31 and doshs.2sev does not suppress the phenotype. The addition of both dosR31 and dosR644K.R696K.hs.2sev or dosR696K.hs.2sev continues to suppress the rough eye phenotype. The addition of both dosR644K.hs.2sev partially suppresses the rough eye phenotype.
mask10.22 dominantly suppresses the ectopic R7 phenotype caused by sevS11.T:Hsap\MYC; the double mutant flies have an average of 1.8 ectopic R7 cells per ommatidium. mask5.8 dominantly suppresses the ectopic R7 phenotype caused by sevS11.T:Hsap\MYC; the double mutant flies have an average of 1.9 ectopic R7 cells per ommatidium.
When SelDk11320 is added to sevS11.T:Hsap\MYC flies, there is an increase of wild-type ommatidia from less than 10% to more than 50%. Only 7.5% of ommatidia in sevS11.T:Hsap\MYC eyes contain one R7 cell, the addition of SelDk11320 increases that to 61.2%. The addition of Catn1 also suppresses these phenotypes.
The addition of heterozygous dosR31 or dosP115 largely suppresses the sevS11.T:Hsap\MYC rough eye phenotype. The addition of doshs.T:Avic\GFP to dosR31/sevS11.T:Hsap\MYC flies restores the multiple R7 phenotype.
The extra R7 photoreceptor cells seen in flies carrying sevS11.T:Hsap\MYC are reduced to an average of 2.71 +/- 0.23 or 2.32 +/- 0.11 R7 photoreceptor cells per ommatidium if the flies are also carrying rin1 or rin2 respectively.
Ras85DV12.sev in combination with sevS11.T:Hsap\MYC results in synthetic lethality. Expression of sevS11.T:Hsap\MYC above a certain level in embryos results in lethality and this lethality is enhanced by co-expression of Ras85DV12.sev. The lethality is sensitive to the expression levels of both sevS11.T:Hsap\MYC and Ras85DV12.sev. Less than 10% of sevS11.T:Hsap\MYC Ras85DV12.sev embryos form cuticle. Those embryos that do form cuticle generally have missing or malformed anterior structures including head parts and thoracic segments, as marked by absence of denticle belts. Approximately one-third of the embryos show curling of the cuticle, possibly due to a failure in germband retraction, and approximately one-tenth of embryos have a weak dorsal closure phenotype. A small fraction of embryos have missing or fused abdominal denticle belts, swollen anterior segments or completely lack identifiable structures and form a ball of cuticle. sevS11.T:Hsap\MYC embryos show a similar range of phenotypes. sevS11.T:Hsap\MYC is not lethal in combination with phylsev.PC, rosev.PI, aopACT.sev, phylhs.sev or Ras85DN17.hs.2sev. The lethality caused by sevS11.T:Hsap\MYC in combination with Ras85DV12.sev is suppressed by Trl62, trxunspecified, Df(2L)JK12, skd2, osa2, mor1, kto1, kis1, kis2, brm1, brm2, Df(3R)red-P52, RpII140AS, RpII15V, SR3-8XS-701, SR3-8S-959, SR3-7XS-17N, SR3-7S-499, Taf1XS-2232, Taf1S-625, Su(Tpl)S-705, Su(Tpl)S-192, Taf4S-466, Taf4XS-793, Taf6XS-922, Sose4G, Ras85De1B, Ras85DE4, rlXS-2275, rlXS-2442, ksrXS-2424, ksrXS-2832, phyl2829, phyl2245, βggt-IS-2554, mamS-176, Df(3R)293γ5, Df(2L)ast2, Df(2R)nap9, Df(2R)pk78c or Df(3L)vin2. The lethality caused by sevS11.T:Hsap\MYC in combination with Ras85DV12.sev is suppressed by l(3)0624006240, l(3)0626506265, l(3)0929109291, Rpd304556, l(3)0514305143, btl00208, btl04727, frc10098, ftz-f103649, eRF105637, l(3)77CDf04521, tws02414, tws06848, l(3)0360803608, l(3)0665806658, osa04539, fray07551, l(3)0582005820, InR05545, pnt04263b, pnt07825, l(3)0307703077, l(3)0470804708, l(3)0674306743 or l(3)0673406734. The lethality caused by sevS11.T:Hsap\MYC in combination with Ras85DV12.sev is suppressed by the l(3)06948 line (l(3)06948a06948a and sr06948b), by the l(3)03745 line (tws03745a and Dl03745b) and by the l(3)04704 line (l(3)04704a04704a and l(3)04704b04704b). The lethality caused by sevS11.T:Hsap\MYC in combination with Ras85DV12.sev is not suppressed by TfIIA-SE32, ash12, Vha5515, Vha5516, mor2, osa1, sls1, skd1, Df(3R)urd, urd2, vtd3, Pc3 or Pc4.