Table 1.

Numbers of embryos imaged and analyzed for each experiment. The cellular behaviors described were consistently observed in these biological and technical replicates.

Experiment	Number of embryos analyzed
Fig. 1A (movie 1)	3
Fig. 1B (movie 2)	5
Fig. 2A (movie 3)	3
Fig. 2B (movie 4)	5
Fig. 3A (movie 5)	3
Fig. 3B (movie 6)	6
Fig. 4 (movie 7)	3