Fig. 6. PGCs proliferate with random divisional orientation. (A-D) Late third instar larval ovaries containing dividing PGCs (outlined by thick dotted lines). The ovaries were double stained with anti-Vasa antibody (green) to label all PGCs, and anti-1B1 antibody (red) to visualize spectrosome orientation in PGCs and to outline somatic cells. Dividing PGCs in contact with TF/CpCs (outlined by thin dotted lines) are oriented perpendicularly (A,C) or in parallel (B), or approximately 45° (D) to the cap cell-PGC interface. PGCs in contact with posterior somatic cells also divide perpendicularly (C), or in parallel (A,B), to the soma-germline interface. (E) A quantitative comparison of the divisional orientation of PGCs contacting CpCs, of those in the anterior half but not contacting cap cells (anterior PGCs), and of those in the posterior half (posterior PGCs). The CpC-PGC interface is assigned a value of 90°. Each red dot in the diagram represents an individual sample (n=63).