Fig. 3. Timing and extent of gastrulation movements. (A) Timing of the beginning of gastrulation movements in intact embryos (light gray circles), devitellinized embryos (medium gray circles) and P₁ isolates (black circles) with respect to the length of the Ea and Ep cell cycle. The timing of gastrulation was normalized between embryos (see Materials and Methods). Black ticks along Ea/Ep lineage represent a fifth of the total cell cycle. The early lineage is shown for reference. (B,C) Quantification of P₄ and MSxx movement relative to Ea and Ep in wild-type (WT) intact, devitellinized, P₁ isolates and mom-2 P₁ isolates. The data are shown by quadrant graphs, with gray unbroken lines representing individual cases and black broken lines representing the mean for all embryos. A diagram representing the measurement method is shown above the graphs. (B) Quantification of P₄ movement relative to Ea and Ep from the time P₄ is born until MSxx is born (12 minutes). (C) Quantification of MSxx and P₄ movement relative to Ea and Ep after MSxx is born (30 minutes).