Centrosome duplication is not affected in futile cycle ( fue ) mutants. Centrosomes at the eight-cell stage during interphase visualized with an antibody directed against γ-tubulin (green) and nuclei labeled with 4',6-diamidino-2-phenylindole (blue) from (A) a wild-type embryo, (B) a fue embryo and (C) an embryo treated with the DNA replication inhibitor aphidicolin. (D) through (F) Enlargements of single-centrosome pairs shown in (A) through (C), respectively. Centrosomes are present and able to duplicate in all fue cells as well as the (anucleate) cells of aphidicolin-treated embryos, demonstrating that the centrosomes can duplicate independently of nuclei. Scale bars = 20 mm. Reprinted with permission .