Fig. 5. E-Cadherin is not required for PGCs to enter nascent stem cell niches. (A) A clone of PGCs derived from a single, labeled posterior pole cell in the embryonic gonad are labeled with anti-GFP antibody (green). The PGCs are distributed widely along both anteroposterior and mediolateral axes in this late third instar larval ovary. The cells of the ovary are outlined by anti-1B1 staining (red). The dotted line traces the forming terminal filament/cap cells (TF/CpC). (B) A late third instar larval ovary containing shg-null PGCs and their wild-type siblings. All cells in the ovary are outlined by anti-1B1 antibody staining (blue). All PGCs are labeled by anti-Vasa antibody (green). The shg-null PGCs (outlined by a thick white line) show no ß-Galactosidase expression, whereas their wild-type sibling PGCs (thin white line) show elevated expression of ß-Galactosidase (red). Note that a shg-null PGC (arrow) is in contact with nascent TF/CpCs (dotted line, TF). (C,D) A late third instar larval ovary triple-labeled for E-cadherin (green), Vasa (red), and 1B1 (blue). The dotted lines in D show forming TF/CpCs. In all PGCs (arrowheads in C; red in D), either in the anterior or posterior half of the ovary, E-Cadherin is concentrated on cell surface, including at the interface between CpCs and the contacting PGCs, irrespective of whether the spectrosome in the PGCs is apposed to CpCs (PGC pointed by a black arrow) or not (PGC pointed by a white arrow). (E) The shg-null PGCs (red) and their wild-type siblings (orange) show similar distributions in the late third instar larval ovaries, except that more wild-type PGCs are in contact with the posterior somatic cells (P<0.005, t test); the biological significance of which is not understood. Note that, more shg-null than wild-type PGCs are in contact with CpCs.