Evolutionary origins of the vertebrate heart:: Specification of the cardiac lineage in Ciona intestinalis
Evolutionary origins of the vertebrate heart:: Specification of the cardiac lineage in Ciona intestinalis
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DOI：
10.1073/pnas.1634991100
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发表时间：
2003-09-30
影响因子：
11.1
通讯作者：
Levine, M
中科院分区：
文献类型：
--
作者：
Davidson, B;Levine, M
在这里，我们利用广泛的细胞谱系信息和流线型基因组的海鞘，Ciona肠子，研究心脏发育的基础脊索动物。分析了几个心脏基因，包括果蝇tinman基因的唯一的乔纳同源基因，并分离了一些基因的组织特异性增强子。这些增强子中的保守序列基序促进了Ciona hand样基因心脏增强子的分离。总之，这些研究为心脏中胚层的分化提供了一个调控框架，从110个细胞阶段开始，一直延伸到尾伸长期间的心脏祖细胞融合。心脏谱系与生殖系有共同的起源，只有在64细胞阶段与生殖系分离后，才在心脏祖细胞中首次检测到合子转录。我们提出，生殖系决定因素通过抑制非心脏中胚层谱系发育所需的诱导信号，以及提供心脏发育所需的Wnt-5和其他信号的局部来源，影响心脏中胚层的规范。我们讨论了生殖系也影响脊椎动物心脏发育的可能性。
Here we exploit the extensive cell lineage information and streamlined genome of the ascidian, Ciona intestinalis, to investigate heart development in a basal chordate. Several cardiac genes were analyzed, including the sole Ciona ortholog of the Drosophila tinman gene, and tissue-specific enhancers were isolated for some of the genes. Conserved sequence motifs within these enhancers facilitated the isolation of a heart enhancer for the Ciona Hand-like gene. Altogether, these studies provide a regulatory framework for the differentiation of the cardiac mesoderm, beginning at the 110-cell stage, and extending through the fusion of cardiac progenitors during tail elongation. The cardiac lineage shares a common origin with the germ line, and zygotic transcription is first detected in the heart progenitors only after its separation from the germ line at the 64-cell stage. We propose that germ-line determinants influence the specification of the cardiac mesoderm, both by inhibiting inductive signals required for the development of noncardiac mesoderm lineages, and by providing a localized source of Wnt-5 and other signals required for heart development. We discuss the possibility that the germ line also influences the specification of the vertebrate heart.