FIG. 2.

Alterations at the node. E7.5 embryos exposed to scrambled shRNA (A, C, E, G) or to Geminin shRNA (B, D, F, H) were analyzed using SEM or Foxa2 expression in sagittal sections (E, F). Arrowheads (A–F), node; *(A–D), border of PE and DE; white arrowhead (G, H), ciliated cells of the node; black arrowheads (H), aggregate of cells at the node; f, foregut pocket; Hf, headfolds; PS, primitive streak. Anterior view in A, B; Anterior is to the left in C–F; Distal tip of the embryo toward the top in G, H (inset is posterior to anterior orientation). Scale bars=100 μm (A–D, G, H), 10 μM (inset in C), and 200 μm (E, F). PE, primitive endoderm; DE, definitive endoderm. Color images available online at www.liebertonline.com/scd