Fig. 4. E-cadherin distribution and TAI and PVR expression in mutant egg chambers. (A,B) Expression of TAI in wild-type (A) and Pvf1^EP1624 (B) egg chambers. Border cells are indicated by the arrow. (C,D) PVR expression (red) in the follicle cells surrounding the oocyte in an egg chamber containing a large tai mutant follicle cell clone. Absence of GFP staining (green in D) marks the cells that are homozygous mutant for tai^61G1 (tai^-/-; broken line indicates the clone border). (E,F) PVR expression in wild-type (E) and tai mutant (F) border cell clusters (arrows). (G-L) Merged confocal z sections showing DE-cadherin protein expression in border cell clusters. (G) An example of a stage 9 wild-type border cell cluster undergoing migration. The polar cells (*) express highest levels of DE-cadherin, whereas the border-cell/nurse-cell junctions exhibit lower, punctate staining for DE-cadherin (arrowheads). DE-cadherin levels are high at junctions between border cells. (H) Stage 10 tai mutant border cell cluster. DE-cadherin protein levels are high throughout the cluster (compare with polar cells, *), especially at several nurse-cell/border-cell boundaries (arrows). (I,J) Stage 10 Pvf1 mutant egg chamber. DE-cadherin levels are high at a subset of border-cell/nurse-cell junctions (arrows). (J) DE-cadherin is high between border cells (compare with polar cells, *) and in one border-cell/nurse-cell junction. (K,L) Stage 10 slbo-GAL4/UAS-Pvf1 (UAS-Pvf1) border cell clusters. DE-cadherin levels are high at border-cell/nurse-cell junctions (arrows); polar cells are marked with an asterisk. Anterior is towards the left in all panels.