Fig. 1. Related developmental timing between GSC establishment and TF/cap cell formation during ovarian development. The female gonads in A-C were labeled for Hts (red) and GFP (green). D was labeled for Bam (red) and GFP (green). E and F were labeled for lacZ (red) and GFP (green). All the images represent one confocal section and the anterior end is towards the left. (A) A bam-GFP gonad at the late third-instar larval stage showing no significant GFP expression in PGCs. The arrowhead indicates an anterior PGC and the arrow indicates a posterior PGC. (B) A bam-GFP gonad at the larval-pupal transition stage showing sporadic GFP-positive PGCs. The arrowhead indicates one anterior PGC negative for GFP, while the arrow indicates a posterior PGC positive for GFP. (C) A bam-GFP gonad at the early pupal stage showing that all posterior PGCs (arrow) are positive for GFP and anterior PGCs (arrowhead) are negative for GFP. (D) A vasa-GFP gonad at the early pupal stage showing that some of the posterior PGCs (arrow) are BamC-positive and anterior PGCs (arrowhead) are BamC-negative. vasa-GFP labels all germ cells. (E) A hh-lacZ;bam-GFP gonad at the late third instar larval stage showing TF stacks (brackets) forming in a progressive manner across the gonad and no bam-GFP expression in PGCs (arrow). The TF stack indicated by the bottom bracket has more cells than the ones indicated by the upper brackets. (F) A hh-lacZ;bam-GFP gonad at the early pupal stage showing that posterior PGCs (arrow) are bam-GFP-positive and anterior PGCs close to TFs (brackets) and cap cells (arrowhead) are bam-GFP-negative. Scale bars: 20 µm.