Fig. 9. Noa expression in cyst cells is necessary for sperm development. Wild-type testes (A,C,E) and testes from transgenic animals carrying a PPY-Gal4-driven UAS-noa-RNAi construct (B,D,F) were analyzed by microscopy. Testis shape is altered (testis tip is indicated by a white arrowhead) and the small seminal vesicle (sv) remains empty (compare A with B). The testis shown in B represents a severe case of the variable RNAi phenotypes. (C-F) Squash preparations of testes with Hoechst 33258 (green) and TRITC-coupled phalloidin (red) staining. (D) Testes with a weak phenotype showing displaced nuclei that do not show an individualization cone even though the rest of the cyst does (arrows in D). In the wild-type sometimes nuclei are also displaced but these then also contain an individualization cone (arrowhead in C). Individualization cones of the 64 spermatids in a cyst are found dispersed after staining with TRITC-coupled phalloidin (region between the white arrowheads in F) in contrast to the synchronized individualization complexes observed in wild-type cysts (E). The testis in F represents a weak phenotype after RNAi. The expression characteristics of the PPY-driver line are demonstrated by a UAS-GFP transgene (G,H). Cysts containing early stages of spermatogenesis (e.g. spermatocytes, arrows in G,H) are stained all around proving premeiotic expression in both cyst cells by the PPY driver.