Figure 2.

Structure of a terminal end bud. The terminal end bud is composed of multiple layers of preluminal epithelial cells encased in an outer layer of pluripotent stem cells called cap cells. The cap cells are connected through P-cadherin (P-Cad) junction, while the preluminal cells are connected through E-cadherin (E-Cad) junctions. Local interactions between netrin-1, a neural guidance cue, present on preluminal cells and neogenin, a netrin receptor, present on the cap cells help maintain the proximity of these two layers.