Fig. 5

Fig. 5 High levels of Bmp activity are necessary for NCEZ and promote vegetal migration of mesendodermal cells. (A) Ventral view of a labeled sbn embryo at midgastrulation; note the extended cell array. (B) sbn embryo at early segmentation showing a significantly elongated labeled cell array. (C) Ventral cells migrate vegetally in WT from midto late gastrulation. The direction of their net paths was determined from three time-lapse recordings from 8.2 to 8.8 hpf (75–85% epiboly). Rose diagrams are arranged to represent the number of ventral cells taking these net paths, with all paths starting at a common origin; vegetal is represented as 90° and animal direction as 270°. (D) Ventral mesodermal cells in sbn migrate along net paths oriented in all directions. (E) The same data are represented as the percentage of cells taking each net path, in order to demonstrate the strong vegetal bias in WT and slight lateral bias in sbn. Scale bar, 100 μm.