A representative transverse section taken through an HH20 chick trunk followed by immunohistochemistry for Annexin A6 (A, red, caret), the migratory neural crest cell marker HNK-1 (B, green, arrowhead), and the differentiating neuronal marker TuJ1 (C, purple, arrow), with a corresponding merge image (D). A higher magnification image of the boxed region in (D) is shown in (D′). Annexin A6 expression is present in a subset of post-mitotic neurons at the core of the developing dorsal root ganglia, indicated by TuJ1- and Annexin A6-double-positive cells (D, D′, white, #). A few of the TuJ1-positive neurons (C, gray arrow) are Annexin A6-negative (A, gray caret; D, D′, yellow, #). The neural tube (NT) still expresses Annexin A6, but the expression is confined to the lateral zone of differentiating neurons (A–D′). DAPI (blue) labels cell nuclei. Scale bar, 50μm (A–D) and 125μm (D′). Ectoderm is denoted by e.