Xenbase Image ID: 146177

Figure 4. A proposed developmental pathway for outgrowth of the tailbud. (a) Drawings of cross sections through a Stage 31 Xenopus tailbud showing the location of the cnh, pw, and expression of five genes. Lfng (lime green) in the dorsal half of the tailbud and dll1/notch (blue) in the posterior wall suggests that notch signaling (hatched blue/green) could be active in the tail tip. Wnt3a (red) is present in a posterior to anterior gradient in the dorsal neural tube and evx1 (purple) in the tailbud tip. (b) Activating notch signaling in a graft in the neural plate of the trunk or anterior TFR results in an ectopic tail containing neural tube from the graft and fin from the host, and with tailbud markers expressed at the tip. If placed too far anterior, the graft fails to make a tail and is incorporated into the host neural tube. If wnt3a is added, anterior grafts also form tails, suggesting Wnt inhibition in anterior neural plate regions prevents notch from inducing tail outgrowth. Data from Beck and Slack.[27] Image published in: Beck CW (2015) Copyright © 2015. Image reproduced with permission of the Publisher, John Wiley & Sons. Larger Image Printer Friendly View

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