Hox gene expression in the hemichordate Saccoglossus kowalevskii and the evolution of deuterostome nervous systems
Hox gene expression in the hemichordate Saccoglossus kowalevskii and the evolution of deuterostome nervous systems
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DOI：
10.1093/icb/icl045
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发表时间：
2006-12-01
影响因子：
2.6
通讯作者：
Lowe, C. J.
中科院分区：
文献类型：
--
作者：
Aronowicz, J.;Lowe, C. J.
脊索动物中枢神经系统的进化起源仍不确定。从经典形态学比较和广泛的后生动物门得出的结论与来自以中枢神经系统为特征的发育模型系统的新分子遗传信息相冲突。这引发了关于祖先后口动物神经系统性质的争论。半索动物作为基础后口动物在解决有关脊索动物神经系统进化的假设方面占据着系统发育的关键地位。表征其弥散神经系统发育的分子基础，可以深入了解保守的身体模式基因在特定神经解剖学进化中的作用。我们描述了直接发育的半索动物 Saccoglossus kowalevskii 发育过程中 hox 基因的表达。这些基因在半索动物中的巢式外胚层表达表明它们在两侧对称动物外胚层的前/后区域化中发挥一般的模式作用，而不是与中枢神经系统的发育和进化唯一相关。
The evolutionary origins of the chordate central nervous system remain uncertain. Conclusions drawn from classical morphological comparisons and from a broad range of metazoan phyla conflict with the new molecular genetic information from developmental model systems characterized by central nervous systems. This has led to debate as to the nature of the ancestral deuterostome nervous system. Hemichordates as basal deuterostomes occupy a phylogenetically critical position for addressing hypotheses on the evolution of the chordate nervous system. Characterizing the molecular basis of the development of their diffuse nervous system offers insights into the role of conserved body patterning genes in the evolution of specific neural anatomies. We present a description of hox gene expression during the development of the direct-developing hemichordate Saccoglossus kowalevskii. The nested ectodermal expression of these genes in a hemichordate suggest that they play a general patterning role in the anterior/posterior regionalization of the ectoderm of bilaterians rather than being uniquely associated with the development and evolution of central nervous systems.