Anteroposterior patterning in hemichordates and the origins of the chordate nervous system
Anteroposterior patterning in hemichordates and the origins of the chordate nervous system
复制标题
DOI：
10.1016/s0092-8674(03)00469-0
复制
发表时间：
2003-06-27
期刊：
影响因子：
64.5
通讯作者：
Kirschner, M
中科院分区：
文献类型：
--
作者：
Lowe, CJ;Wu, M;Kirschner, M
脊索动物的中枢神经系统被认为起源于后口类祖先的背侧中枢神经系统、腹侧中枢神经系统或非中枢神经系统。为了解决这些问题，我们研究了半索动物Saccoglossus kowalevskii，并研究了参与脊索中枢神经系统模式化的基因的直系同源物的表达。研究的所有22个直系同源物在外胚层中以与脊索动物中发现的几乎相同的前后排列表达。域拓扑是半索动物和脊索动物之间的保守，尽管事实上，半索动物有一个分散的神经网络，而脊索动物有一个集中的系统。我们建议后口类祖先可能有一个分散的神经系统，后来集中在脊索动物谱系的进化过程中。
The chordate central nervous system has been hypothesized to originate from either a dorsal centralized, or a ventral centralized, or a noncentralized nervous system of a deuterostome ancestor. In an effort to resolve these issues, we examined the hemichordate Saccoglossus kowalevskii and studied the expression of orthologs of genes that are involved in patterning the chordate central nervous system. All 22 orthologs studied are expressed in the ectoderm in an anteroposterior arrangement nearly identical to that found in chordates. Domain topography is conserved between hemichordates and chordates despite the fact that hemichordates have a diffuse nerve net, whereas chordates have a centralized system. We propose that the deuterostome ancestor may have had a diffuse nervous system, which was later centralized during the evolution of the chordate lineage.