Expression pattern of Brachyury and Not in the sea urchin: comparative implications for the origins of mesoderm in the basal deuterostomes.
Expression pattern of Brachyury and Not in the sea urchin: comparative implications for the origins of mesoderm in the basal deuterostomes.
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海胆中 Brachyury 和 Not 的表达模式：对基底后口动物中胚层起源的比较意义。
DOI：
10.1006/dbio.1998.9177
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发表时间：
1999
期刊：
影响因子：
--
通讯作者：
Davidson,EH
中科院分区：
文献类型：
--
作者：
Peterson,KJ;Harada,Y;Cameron,RA;Davidson,EH
本研究关注了两个转录因子在海胆发育过程中的表达：SpNot（脊椎动物Not基因的同源物）和SpBra（脊椎动物Brachyury基因的同源物）。SpNot转录本在间质-囊胚阶段通过原位杂交在植物板中检测。随后，该基因在次级间质中表达，但在原肠胚形成后不再表达。SpNot在幼虫发育过程中被上调，在成虫雏形的内陷前庭中。在一些幼虫特异性组织中也发现了转录本，包括肩章、囊胚孔细胞和色素细胞。SpBra也表现出不连续的表达模式。与SpNot相似，该基因在胚胎发生过程中在胚胎植物板和次级间充质建立细胞中表达，然后表达消失。该基因在一周后的喂食幼虫中，在成虫的前庭中被上调。与SpNot不同的是，SpBra在左右水冷体的中胚层中也有表达，并且在任何幼虫特异性组织中都不表达。我们将本研究中确定的空间表达谱与间接发育的半足动物（后口动物中棘皮动物姐妹群的代表）中同源Brachyury基因的空间表达谱进行了比较。这些观察结果阐明了基础后口动物最大间接发育过程的遗传基础。最后，Brachyury似乎是海胆胚胎中预留细胞后代的一个极好的标记。
This work concerns the expression of two transcription factors during the development of the sea urchin Strongylocentrotus purpuratus: SpNot, the orthologue of the vertebrate Not gene, and SpBra, the orthologue of the vertebrate Brachyury gene. SpNot transcripts are detected by in situ hybridization in the vegetal plate at the mesenchyme–blastula stage. Later the gene is expressed in the secondary mesenchyme, but expression is no longer detectable after gastrulation. SpNot is upregulated during larval development, in the invaginating vestibule of the adult rudiment. Transcripts are also found in several larva-specific tissues, including the epaulets, blastocoelar cells, and pigment cells. SpBra also displays a discontinuous pattern of expression. Much like SpNot, this gene is expressed during embryogenesis in the embryonic vegetal plate and secondary mesenchyme founder cells, and expression is then extinguished. The gene is upregulated over a week later in the feeding larva, in the vestibule of the adult rudiment. In contrast to SpNot, SpBra is also expressed in the mesoderm of both left and right hydrocoels, and it is not expressed in any larva-specific tissues. We compare the spatial expression profile determined in this study with that of the orthologous Brachyury gene in an indirectly developing enteropneust hemichordate, a representative of the sister group to the echinoderms within the deuterostomes. These observations illuminate the genetic basis underlying the process of maximal indirect development in basal deuterostomes. Finally, Brachyury appears to be an excellent marker for the progeny of the set-aside cells of the sea urchin embryo.