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Fig. 1. fue embryos undergo several rounds of anucleate cleavage. Fixed
wild-type (A) and fue (B) embryos at the eight-cell stage, labelled
with DAPI to reveal nuclei (red) and fluorescein phalloidin to visualise the
actin cytoskeleton (green). (C) A wild-type embryo at the sphere stage and (D)
a living fue embryo shortly after it has arrested cleavage. In both
cases development took place for the same period of time. In most of the
fue embryos, the characteristic cleavage orientation pattern is not
perturbed, and the cells progress through several cleavage cycles, indicating
that the core cell cycle engine is not affected. (E,F) Unfertilized wild-type
and fue eggs, showing that the sperm is required to initiate cleavage
of the fue embryo as in the wild type.