Fig. 4. Replication defects delocalize and increase Dup levels in follicle cells. (A,B) Immunolabeling for Orc2 (red) indicates that it is localized to amplification foci in wild-type (A) and Mcm6^K1214 mutant (B) early-stage 10B follicle cell nuclei (TOTO-3, blue). (C-H) Immunolabeling for Dup (red). Dup is localized to chorion foci in wild-type stage 10B follicle cells (C), whereas in Mcm6^K1214 (D) Dup protein is largely dispersed and more abundant, although some nuclei had detectable concentrations of Dup protein at chorion loci (arrow). Because late-stage 10B follicle cells are shown in C and D, one focus of Dup staining at the chorion locus on the third chromosome locus predominates. The bright blue foci are heterochromatin. (E-H) Dup localization and abundance are altered in the other amplification mutant strains mus101^K451 (E), chiffon⁰²³³ (F), Orc2^fs293 (G) and dup^PA77 (H). Images are composites of confocal sections. Scale bar, 5 µm.