Formation of a “Pre-mouth Array” from the Extreme Anterior Domain Is Directed by Neural Crest and Wnt/PCP Signaling
The mouth arises from the extreme anterior domain (EAD), a region where the ectoderm and endoderm are directly juxtaposed. Here, we identify a ‘‘premouth array’’ in Xenopus that forms soon after the cranial neural crest has migrated to lie on either side of the EAD. Initially, EAD ectoderm comprises...
| Main Authors: | , , , , |
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| Other Authors: | |
| Format: | Article |
| Language: | en_US |
| Published: |
Elsevier
2017
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| Online Access: | http://hdl.handle.net/1721.1/106859 https://orcid.org/0000-0001-6631-0042 https://orcid.org/0000-0002-2634-6689 https://orcid.org/0000-0002-4890-424X |
| Summary: | The mouth arises from the extreme anterior domain (EAD), a region where the ectoderm and endoderm are directly juxtaposed. Here, we identify a ‘‘premouth array’’ in Xenopus that forms soon after the cranial neural crest has migrated to lie on either side of the EAD. Initially, EAD ectoderm comprises a wide and short epithelial mass that becomes narrow and tall with cells and nuclei changing shape, a characteristic of convergent extension. The resulting two rows of cells—the pre-mouth array—later split
down the midline to surround the mouth opening. Neural crest is essential for convergent extension and likely signals to the EAD through the Wnt/planar
cell polarity (PCP) pathway. Fzl7 receptor is locally required in EAD ectoderm, while Wnt11 ligand is required more globally. Indeed, heterologous cells expressing Wnt11 can elicit EAD convergent extension. The study reveals a precise cellular mechanism that positions and contributes to the future mouth. |
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