小柯机器人

研究揭示神经嵴对新头进化的作用
2019-10-25 10:35

美国加州理工学院Marianne E. Bronner研究小组近日取得一项新成果。他们的研究揭示了新头通过逐步获取神经嵴调节回路来进化。该项研究成果于2019年10月23日在线发表于《自然》杂志。

为了研究神经嵴细胞的进化如何影响脊椎动物的身体发育,研究人员测试了沿着无颚脊椎动物七鳃鳗前后轴控制神经嵴发育的分子回路。基因表达分析表明,七鳃鳗的神经嵴颅亚群缺少专属于羊膜动物颅神经嵴转录回路的大部分成分,并赋予了在非颅神经嵴亚群上形成颅面软骨的能力。与此相符的是,层次聚类分析表明,七鳃鳗颅神经嵴的转录特征与羊膜动物的躯干神经嵴更为相似。值得注意的是,对小鳐鱼和斑马鱼胚胎中的颅神经嵴的分析表明,颅神经嵴特有的转录途径是通过将网络成分逐渐增加到有颌类动物的神经嵴中而出现的,随后该神经嵴被限制在头区域。

这些结果表明,在脊椎动物谱系基础上的祖先神经嵴具有躯干状的身份。研究人员认为,通过逐步装配轴向特异的调节回路来实现的颅神经嵴出现,可以使脊椎动物进化过程中新头的形成变得更加精细。

据悉,神经嵴是胚胎干细胞群体,是脊椎动物中出现的,已被认为是“新头”的关键组成部分,这种新头使脊椎动物具有掠夺性行为。

附:英文原文

Title: Evolution of the new head by gradual acquisition of neural crest regulatory circuits

Author: Megan L. Martik, Shashank Gandhi, Benjamin R. Uy, J. Andrew Gillis, Stephen A. Green, Marcos Simoes-Costa, Marianne E. Bronner

Issue&Volume: 2019-10-23

Abstract: The neural crest, an embryonic stem-cell population, is a vertebrate innovation that has been proposed to be a key component of the ‘new head’, which imbued vertebrates with predatory behaviour1,2. Here, to investigate how the evolution of neural crest cells affected the vertebrate body plan, we examined the molecular circuits that control neural crest development along the anteroposterior axis of a jawless vertebrate, the sea lamprey. Gene expression analysis showed that the cranial subpopulation of the neural crest of the lamprey lacks most components of a transcriptional circuit that is specific to the cranial neural crest in amniotes and confers the ability to form craniofacial cartilage onto non-cranial neural crest subpopulations3. Consistent with this, hierarchical clustering analysis revealed that the transcriptional profile of the lamprey cranial neural crest is more similar to the trunk neural crest of amniotes. Notably, analysis of the cranial neural crest in little skate and zebrafish embryos demonstrated that the transcriptional circuit that is specific to the cranial neural crest emerged via the gradual addition of network components to the neural crest of gnathostomes, which subsequently became restricted to the cephalic region. Our results indicate that the ancestral neural crest at the base of the vertebrate lineage possessed a trunk-like identity. We propose that the emergence of the cranial neural crest, by progressive assembly of an axial-specific regulatory circuit, allowed the elaboration of the new head during vertebrate evolution.

DOI: 10.1038/s41586-019-1691-4

Source: https://www.nature.com/articles/s41586-019-1691-4

Nature:《自然》,创刊于1869年。隶属于施普林格·自然出版集团,最新IF:69.504
官方网址:http://www.nature.com/
投稿链接:http://www.nature.com/authors/submit_manuscript.html


本期文章:《自然》:Online/在线发表

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