The neural crest is a vertebrate-specific migratory stem cell population that generates a remarkably diverse set of cell types and structures. Because many of the morphological, physiological and behavioural novelties of vertebrates are derived from neural crest cells, it is thought that the origin of this cell population was an important milestone in early vertebrate history. An outstanding question in the field of vertebrate evolutionary-developmental biology (evo-devo) is how this cell type evolved in ancestral vertebrates. In this review, we briefly summarize neural crest developmental genetics in vertebrates, focusing in particular on the gene regulatory interactions instructing their early formation within and migration from the dorsal neural tube. We then discuss how studies searching for homologues of neural crest cells in invertebrate chordates led to the discovery of neural crest-like cells in tunicates and the potential implications this has for tracing the pre-vertebrate origins of the neural crest population. Finally, we synthesize this information to propose a model to explain the origin of neural crest cells. We suggest that at least some of the regulatory components of early stages of neural crest development long pre-date vertebrate origins, perhaps dating back to the last common bilaterian ancestor. These components, originally directing neuroectodermal patterning and cell migration, served as a gene regulatory 'scaffold' upon which neural crest-like cells with limited migration and potency evolved in the last common ancestor of tunicates and vertebrates. Finally, the acquisition of regulatory programmes controlling multipotency and long-range, directed migration led to the transition from neural crest-like cells in invertebrate chordates to multipotent migratory neural crest in the first vertebrates.

中文翻译：

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脊椎动物神经嵴细胞的起源和进化。

神经嵴是脊椎动物特有的迁移干细胞群，可产生非常多样化的细胞类型和结构。由于脊椎动物的许多形态、生理和行为新颖性都源自神经嵴细胞，因此人们认为该细胞群的起源是早期脊椎动物历史上的一个重要里程碑。脊椎动物进化发育生物学（evo-devo）领域的一个突出问题是这种细胞类型如何在祖先脊椎动物中进化。在这篇综述中，我们简要总结了脊椎动物的神经嵴发育遗传学，特别关注指导神经嵴在背神经管内早期形成和迁移的基因调控相互作用。然后，我们讨论在无脊椎动物脊索动物中寻找神经嵴细胞同源物的研究如何导致在被囊动物中发现神经嵴样细胞，以及这对追踪神经嵴种群的前脊椎动物起源的潜在影响。最后，我们综合这些信息，提出一个模型来解释神经嵴细胞的起源。我们认为，至少神经嵴发育早期阶段的一些调节成分早于脊椎动物的起源，也许可以追溯到最后的共同两侧对称动物祖先。这些成分最初指导神经外胚层模式和细胞迁移，充当基因调节“支架”，在被囊动物和脊椎动物的最后共同祖先中，具有有限迁移和效力的神经嵴样细胞在其上进化。最后，控制多能和远程定向迁移的调节程序的获得导致从无脊椎动物脊索动物中的神经嵴样细胞转变为第一批脊椎动物中的多能迁移神经嵴。