Comparative molecular embryology of arthropods:: the expression of Hox genes in the spider Cupiennius salei
Comparative molecular embryology of arthropods:: the expression of Hox genes in the spider Cupiennius salei
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DOI：
10.1080/07924259.1999.9652701
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发表时间：
1999-09-01
影响因子：
0.8
通讯作者：
Tautz, D
中科院分区：
文献类型：
--
作者：
Damen, WGM;Tautz, D
为了更好地了解发育过程的进化，我们研究了蜘蛛中分节基因的表达。蜘蛛所属的螯肢类是一个基底节肢动物类群。因此，螯肢类和昆虫之间共有的胚胎学特征可能代表了节肢动物的祖先特征。昆虫和蜘蛛的比较分子胚胎学将向我们展示节肢动物发育过程的保守或分歧程度。蜘蛛和昆虫之间共享的分子机制可能最终使我们能够定义节肢动物门的分子原型。这本身就是比较不同门的必要条件。我们在这里提出的数据是在蜘蛛Cupiennius salei的Hox基因的分析。螯形动物的Hox复合体大概由9个Hox基因组成。除了在昆虫中识别的八个Hox基因的直向同源物之外，蜘蛛还具有脊索动物Hox 3基因的直向同源物。这可能是最直接的证据表明，祖先节肢动物Hox复合体由9个Hox基因。前Hox基因的表达模式的分析揭示了一个保守的模式，在节肢动物的头部分割。这与传统的观点相矛盾，即后脑节在螯肢动物中缺失。保守的前表达边界的Hox基因表明，在蜘蛛和昆虫中发现的Hox基因表达寄存器可能反映了在很大程度上的祖先模式的节段细分节肢动物。这加强了节肢动物单系性的论点。
In order to get a better understanding in the evolution of developmental processes, we have studied the expression of segmentation genes in a spider. The chelicerates, to which the spiders belong, form a basal arthropod group. Shared embryological features between chelicerates and insects therefore presumably represent ancestral characters for the arthropods. The comparative molecular embryology of insects and spiders will show us the degree of conservation or divergence of the processes underlying arthropod development. Shared molecular mechanisms between spiders and insects may eventually allow us to define a molecular archetype for the phylum Arthropoda. This in itself will be a necessity for comparing different phyla. The data we present here are an analysis of Hox genes in the spider Cupiennius salei. The Hox complex of chelicerates presumably consists of nine Hox genes. In addition to orthologues for the eight Hox genes as recognized in insects, the spider possesses an orthologue for the chordate Hox3 gene. This is probably the most direct evidence that the ancestral arthropod Hox-complex consisted of nine Hox-genes. Analysis of the expression patterns of the anterior Hox genes revealed a conserved mode of head segmentation in arthropods. This contradicts the traditional view that the deuterocerebral segment is missing in chelicerates. The conserved anterior expression borders for the Hox genes suggest that the Hox gene expression register as found in spiders and in insects may reflect to a great extent the ancestral mode of segmental subdivision in arthropods. This strengthens the argument for a monophyly of the arthropods.