Expression of a single copy of zipFL.Scer\UAS.T:Avic\GFP under the control of Scer\GAL4en-e16E results in a wing vein expansion phenotype in 82% of wings. The penetrance of this phenotype is slightly decreased (to 72%) in a zip1/+ background.
Expression of zipFL.Scer\UAS.T:Avic\GFP under the control of Scer\GAL4arm.T:Hsim\VP16 results in the loss of para-segmental boundary straightness.
Embryos expressing zipFL.Scer\UAS.T:Avic\GFP under the control of Scer\GAL4mat.αTub67C.T:Hsim\VP16 do not show germ-band extension defects, and no change is observed in apical cell surface size.
In transgenic mosaic embryos in which some cells express zipFL.Scer\UAS.T:Avic\GFP under the control of Scer\GAL4e22c in a zip1/zip2 background, leading-edge cells that do not express zipFL.Scer\UAS.T:Avic\GFP cannot maintain tension and are stretched by neighbouring zipFL.Scer\UAS.T:Avic\GFP expressing cells. The length of contiguous regions of Scer\GAL4e22c>zipFL.Scer\UAS.T:Avic\GFP expressing leading-edge cells along the supracellular purse string decrease in length over time, indicative of contraction. In contrast, non zipFL.Scer\UAS.T:Avic\GFP-expressing contiguous regions fail to contract, increasing in length over time. In transgenic mosaic embryos in which some cells express zipFL.Scer\UAS.T:Avic\GFP under the control of Scer\GAL4sqh.PW in a zip1/zip2 background, Scer\GAL4sqh.PW>zipFL.Scer\UAS.T:Avic\GFP expressing leading-edge cells that contact Scer\GAL4sqh.PW>zipFL.Scer\UAS.T:Avic\GFP expressing amnioserosa cells are severely contracted, and the scalloped morphology of the early leading edge is enhanced. In contrast, when non-expressing leading-edge cells contact non-expressing amnioserosa cells the leading edge cells fail to contract and become stretched. When non-expressing leading-edge cells contact Scer\GAL4sqh.PW>zipFL.Scer\UAS.T:Avic\GFP-expressing amnioserosa cells, leading-edge cells show some contraction. Finally, Scer\GAL4sqh.PW>zipFL.Scer\UAS.T:Avic\GFP-expressing cells show some contraction when they contact non-expressing amnioserosa cells, although this is to a lesser extent than when both cell types express zipFL.Scer\UAS.T:Avic\GFP. Nonexpressing leading-edge cells fail to incorporate into the canthus and cause inward progression of the canthus to stall. These nonexpressors never get fully incorporated into the seam - instead, a small gap is formed when zipping fails and closure bypasses the nonexpressing cells to initiate a new seam. In contrast, Scer\GAL4sqh.PW>zipFL.Scer\UAS.T:Avic\GFP-expressing cells are incorporated into each canthus at a similar and nearly constant rate. In transgenic mosaic embryos in which some amnioserosa cells express zipFL.Scer\UAS.T:Avic\GFP under the control of Scer\GAL4c381 in a zip1/zip2 background, nonexpressing amnioserosa cells fail to contract apically and remain rounded. These cells do show an apical shape change at later stages but this may be due to forces generated by surrounding Scer\GAL4c381>zipFL.Scer\UAS.T:Avic\GFP-expressing amnioserosa cells and the approaching lateral-epidermis sheet. Embryos that express zipFL.Scer\UAS.T:Avic\GFP under the control of Scer\GAL4en-e16E in a zip1/zip2 background display stripe-alignment defects in 65% of cases.
Ubiquitous overexpression of zipFL.Scer\UAS.T:Avic\GFP, under the control of the Scer\GAL4sqh.PW, rescues dorsal closure in more than 84% of zip1/zip2; Dpse\l(2)gl+t12.2/Dpse\l(2)gl+t12.2 embryos. 61% of these rescued flies survive to hatch as larvae, 41% survive to pupal stages and 2.8% eclose as adults. Expression of zipFL.Scer\UAS.T:Avic\GFP in the epidermis and a few amnioserosa cells, driven by Scer\GAL4e22c, rescues the zip1/zip2; Dpse\l(2)gl+t12.2/Dpse\l(2)gl+t12.2 dorsal closure phenotype in 88% of embryos. Rescued flies survive to larval stages in 60% of cases and to pupal stages in 21% of cases, although no flies eclose. Expression of zipFL.Scer\UAS.T:Avic\GFP in the amnioserosa, driven by Scer\GAL4c381, rescues the dorsal closure phenotype of Dpse\l(2)gl+t12.2/Dpse\l(2)gl+t12.2 mutants in 82% of embryos. However, none of the rescued embryos survive to larval stages. Similarly, when zipFL.Scer\UAS.T:Avic\GFP expression is driven in the leading edge by Scer\GAL4LE, dorsal closure is rescued in 87% of embryos, but only 1% of flies survive to larval stages. zipFL.Scer\UAS.T:Avic\GFP expression in epidermal stripes, driven by Scer\GAL4en-e16E, rescues dorsal closure in only half of embryos and does not rescue lethality.
Scer\GAL4sqh.PW/zipFL.UAS.GFP partially rescues zip2/zip1
Scer\GAL4sqh.PW/zipFL.UAS.GFP partially rescues zip2/zip1
Expression of zipFL.Scer\UAS.T:Avic\GFP under the control of Scer\GAL4sqh.PW rescues the embryonic lethality of zip1/zip2 animals. 86 +/- 2% of the rescued animals survive to the pupal stage, but only 6 +/- 7% eclose as adults.
