chordotonal organ precursor cell & ventral thoracic disc, with Scer\GAL4sca-109-68
Flies expressing EgfrDN.Scer\UAS and PvrDN.Scer\UAS under the control of Scer\GAL4slbo.2.6 show differences in the migration behaviour of border cell clusters. First, a distinct front-back polarity is evident in wild-type clusters, which show spatially segregated protrusion and retraction with high protrusion velocities predominating at the front and high retraction velocities at the back. This spatial segregation is lost in clusters lacking guidance-receptor activities. Second, these double mutant clusters display overall slower protrusion and retraction velocities.
Flies expressing Rac1N17.Scer\UAS, PvrDN.Scer\UAS and EgfrDN.Scer\UAS exhibit a change in border cell migration, with changes in local protrusion and retraction behaviour that are different to those found in Rac1N17.Scer\UAS single mutants.
Flies expressing Rac1N17.Scer\UAS and EgfrDN.Scer\UAS exhibit a change in border cell migration, with changes in local protrusion and retraction behaviour that are different to those found in Rac1N17.Scer\UAS single mutants.
Downregulation of Egfr, through expression of EgfrDN.Scer\UAS, does not alter the ommatidial rotation phenotype seen in flies expressing miple1Scer\UAS.T:Ivir\HA1 under the control of Scer\GAL4hs.2sev.
Expression of EgfrDN.Scer\UAS under the control of Scer\GAL4Act.PU suppresses the increased size of Apc2g10 ApcQ8 mutant intestinal stem cell clones 7 and 14 days after clone induction (ACI). The multilayering phenotype often seen at 21 days ACI is also suppressed.
Border cell clusters show severe delays in initiating posterior migration and show strongly reduced forward speed once migratory in females co-expressing PvrDN.Scer\UAS and EgfrDN.Scer\UAS under the control of Scer\GAL4slbo.2.6. The number of cellular extensions from the front of the border cell cluster is reduced compared to wild type and an increase in side and back extensions.
Coexpression of EgfrDN.Scer\UAS with vg2.Scer\UAS under the control of Scer\GAL4Mef2.PR results in the size and number of the ectopic muscle adhesion sites being decreased compared to when vg2.Scer\UAS alone is expressed and increased compared to EgfrDN.Scer\UAS lone expression.
Coexpression of tkvQ253D.Scer\UAS.cNb with EgfrDN.Scer\UAS, under the control of Scer\GAL4e22c, not only fails to induce ectopic vein cells, but also inhibits endogenous vein formation, suggesting that activation of the dpp pathway alone is not sufficient for vein differentiation.
Coexpression of EgfrDN.Scer\UAS and PvrDN.Scer\UAS, under the control of Scer\GAL4slbo.2.6, results in a strong enhancement of the border cell misguidance phenotype seen when PvrDN.Scer\UAS is expressed alone; the penetrance of the phenotype is increased from 16 to 90%.
Coexpression of EgfrDN.Scer\UAS and CycEScer\UAS.cLa, under the control of Scer\GAL4en-e16E, show approximately double the amount of apoptosis in cells of posterior compartments relative to expressing CycEScer\UAS.cLa alone.
Co-expression of PvrDN.Scer\UAS and EgfrDN.Scer\UAS under the control of Scer\GAL4c306 results in border cell migration defects. The severity of the migration defects is enhanced if the females also express TieDN.Scer\UAS.
Coexpression of the EgfrDN.Scer\UAS and mir-7Scer\UAS.cLb transgenes, under the control of Scer\GAL4GMR.PF, results in ommatidia with ectopic photoreceptor cells. The positions of these cells suggest they are R3 and R4.
The loss of midline glial (MG) cells in EgfrDN.Scer\UAS; Scer\GAL4sli.PS embryos is suppressed by WrvX1/WrvX1. Approximately twice as many MG cells survive as in wild-type (average of 6.1 per segment n=201, compared to average = 2.8 for wild-type).
Border cells in the ovaries of EgfrDN.Scer\UAS; PvrDN.Scer\UAS; Scer\GAL4slbo.2.6 animals form lack long cellular extensions (20-40 μm) and form only very few intermediate cellular extensions (10-20 μm).
EgfrDN.Scer\UAS and PvrDN.Scer\UAS, when driven by Scer\GAL4slbo.2.6, leads to a dramatic effect on border cell migration. 90% of border cell clusters migrate less than half way towards the oocyte. In 5% of egg chambers, border cell clusters are found off the direct track to the oocyte. The combination of Pvf1EP1624, and EgfrDN.Scer\UAS (driven by Scer\GAL4slbo.2.6) leads to strong effect. Border cells are not able to reach the oocyte by stage 10, and they also show a low level of "off track" migration.
Co-expression of CblDv.Scer\UAS with EgfrDN.Scer\UAS under the control of Scer\GAL4GMR.PF suppresses the phenotypes of both mutants. Retinal development is restored although the eye is smaller than wild-type and ommatidial orientation is irregular. At 29[o]C, veins L2, L3 and L5 are completely rescued, with partial rescue of L4.
When co-expression of EgfrDN.Scer\UAS and panΔN.Scer\UAS is driven by Scer\GAL4T155 the entire tergite is transformed to pleura. When co-expression of EgfrDN.Scer\UAS and dppScer\UAS.cSa is driven by Scer\GAL4T155 the tergite is reduced to a very small patch near the dorsal midline and the lateral tergite is completely transformed to pleura. These effects are not due to reduced histoblast proliferation.
Homozygous wgl-12 larvae carrying EgfrDN.Scer\UAS which have been shifted to the restrictive temperature after 8 hours of development have denticle belts with almost exclusively large denticles of the row 5 type (although their hooks somewhat resemble the row 1-4 type) and an apparently normal strip of row 6 denticles most posteriorly. Almost all the denticles point posteriorly. Does not alter the denticle phenotype of wgl-17 larvae when expressed in embryos under the control of Scer\GAL4arm.PS.
The effect on border cell cluster migration when all border cells co-express PvrDN.Scer\UAS and EgfrDN.Scer\UAS under the control of Scer\GAL4slbo.2.6 and a single border cell expresses Egfr::Hsap\EGFRhE-E.Scer\UAS.T:Avic\GFP have been studied. In those border cell clusters where the single Egfr::Hsap\EGFRhE-E.Scer\UAS.T:Avic\GFP-expressing cell is located at the front of the cluster, the cluster on average moves forward, when the Egfr::Hsap\EGFRhE-E.Scer\UAS.T:Avic\GFP-expressing cell is in the back, the cluster on average moves relatively more backwards.
In the absence of illumination, border cells expressing EgfrDN.Scer\UAS and PvrDN.Scer\UAS under the control of Scer\GAL4slbo.2.6 and carrying Hsap\RAC1PA.Q61L.Scer\UAS.T:Disc\RFP-mCherry,T:Zzzz\PT1 fail to move forward. When Hsap\RAC1PA.Q61L.Scer\UAS.T:Disc\RFP-mCherry,T:Zzzz\PT1 is photoactivated at the rear of the border cell cluster, rearward movement is seen. When photoactivation is stopped, the border cell cluster stops moving.
Photo-inactivation of Hsap\RAC1PA.T17N.Scer\UAS.T:Disc\RFP-mCherry,T:Zzzz\PT1 at the front of border cell clusters expressing Hsap\RAC1PA.T17N.Scer\UAS.T:Disc\RFP-mCherry,T:Zzzz\PT1, EgfrDN.Scer\UAS and PvrDN.Scer\UAS under the control of Scer\GAL4slbo.2.6 results in local retraction.
The ectopic wing vein phenotype of Scer\GAL4GMR.PF>Hsap\ATN1N917.65Q.Scer\UAS flies is suppressed when EgfrDN.Scer\UAS is coexpressed. Wings of flies expressing both transgenes resemble wings that express only EgfrDN.Scer\UAS.