Figure 4.

Osa represses engrailed expression in ECs. (A–F) Germaria stained for α-spectrin (red), Armadillo (red), and En (green). (A,B) Flies were initially kept at 25 °C and then shifted to 29 °C after eclosion. (C–F) c587-gal4;;tubP-GAL80^ts was used for osa KD. (C,D) Flies were initially kept at 18 °C and then shifted to 29 °C at the EP stage. The newly born females were dissected. (E,F) Flies were initially kept at 18 °C until eclosion and then kept at 29 °C for another 14 days before dissection. The control germaria (A,C,E) exhibited specific En staining in TF and CpCs. The osa RNAi-1 germaria (B,D,F) exhibited ectopic En staining in the ECs (indicated by white arrows) in addition to CpCs. c587 > osa RNAi-2 gave a similar phenotype (not shown). (G–H’) MARCM clones stained for En (red). Clonal cells were marked by GFP (green). CpCs here are indicated by white dashed circles. The mosaic germarium with control clones (G,G’) exhibited specific En staining in TF and CpCs. The mosaic germarium with osa³⁰⁸ mutant ECs (H,H’) exhibited ectopic En staining in clonal ECs (indicated by white arrow heads) in addition to CpCs. Several compressed z-sections are shown in (A–H’). (I–L) Graph showing the percentage quantification of germaria with En ectopic expression. The scale bar is shown in (A).