Figure 2:

Distribution patterns of FDA-labeled clones in the neural ectoderm at the end of gastrulation (stages 12-13).

(A) At the end of gastrulation, neural ectodermal clones of FDA-injected 16-cell dorsal midline blastomeres extended from the animal pole, which is the future forebrain region, to the posterior, closing blastopore (bl). The patterns were sorted into categories according to the lateral extent of the cells, from narrow (type A) to broad (type D), as described in the Methods. Type E was only observed in embryos in which the Rmet cocktail was injected into L-D1; it distinctly did not contain cells that extended to the blastopore.

(B) The frequency of the various types of clones observed for control embryos that were injected with only FDA, i.e., without added metabolites (R-D11, L-D11) or embryos injected with metabolite cocktails at the 8-cell stage and then FDA at the 16-cell stage (Lmet-R-D11, Rmet-L-D11). Samples sizes are in parentheses.