Xenopus, an emerging model for studying pathologies of the neural crest

Neural crest cells are a multipotent embryonic stem cell population that emerges from the lateral border of the neural plate after an epithelium-to-mesenchyme transition. These cells then migrate extensively in the embryo and generate a large variety of differentiated cell types and tissues. Alterations in almost any of the processes involved in neural crest development can cause severe congenital defects in humans. Moreover, the malignant transformation of one of the many neural crest derivatives, during childhood or in adults, can cause the development of aggressive tumors prone to metastasis such as melanoma and neuroblastoma. Collectively these diseases are called neurocristopathies. Here we review how a variety of approaches implemented using the amphibian Xenopus as an experimental model have shed light on the molecular basis of numerous neurocristopathies, and how this versatile yet underused vertebrate animal model could help accelerate discoveries in the field. Using the current framework of the neural crest gene regulatory network, we review the pathologies linked to defects at each step of neural crest formation and highlight studies that have used the Xenopus model to decipher the cellular and molecular aspects of neurocristopathies.