Fig. 8. Expression of Hoxa2 and Hoxa3 after grafting of cardiac dorsal neural tubes to the midbrain region. At HH12 (12 hours after grafting), Hoxa2 (A-C) and Hoxa3 (E-G) are expressed in the grafted dorsal neural tube and migrating neural crest cells. At HH18 (24 hours after grafting), both Hoxa2 (D) and Hoxa3 (H) are downregulated in the grafted tissue and neural crest. Arrows indicate migrating neural crest cells also immunostained with HNK-1 (red). Arrowheads indicate the midbrain region where cardiac dorsal neural tubes were grafted.