Fig. 2. Fzr is partially sufficient to induce precocious endocycles, dMyc to accelerate endocycles. Ectopic expression of fzr (hsFlp; UAS-fzr; UASGFP act<FRT-CD2-FRT<Gal4) reduces CycA and B levels, stops mitosis (A,B) and allows the formation of large nuclei (B) indicative of precocious endocycles prior to stage 6 in oogenesis. The diagram in C presents the percentage of the wild-type and mutant follicle cells that show positive staining to mitotic markers during the mitotic stage. fzr (D,F,J) and myc (E,G,K) overexpression (hsFlp; UAS-fzr or UAS-myc; UASGFP act<FRT-CD2-FRT<Gal4) generate enlarged nuclei, which is indicative of abnormal endocycles but do not affect the amplification stage because normal BrdU-incorporation pattern at stage 10B-12 (red arrows) is observed in cells overexpressing fzr (F) and myc (G). (H-K) FACS profiles of DNA content in UAS-fzr (J) and UAS-myc (K) mutant nuclei compared with these in WT nuclei (H) show the appearance of a cell population that has 32n DNA, also observed in Rbf mutants (I) (Bosco et al., 2001). Green, GFP (A,D,E), Fzr Ab (F); red, CycB (A), DAPI (D,E), BrdU (F,G); blue, DAPI (A,F,G).