Atrial myocardium derives from the posterior region of the second heart field, which acquires left-right identity as Pitx2c is expressed
Atrial myocardium derives from the posterior region of the second heart field, which acquires left-right identity as Pitx2c is expressed
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DOI：
10.1242/dev.014563
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发表时间：
2008-03-15
期刊：
影响因子：
4.6
通讯作者：
Buckingham, Margaret E.
中科院分区：
文献类型：
--
作者：
Galli, Daniela;Dominguez, Jorge N.;Buckingham, Margaret E.
在小鼠胚胎中，被描述为第二心脏区域（SHF）的内脏中胚层以Islet 1表达为标志。该区域的前部表达许多标记物，包括Fgf 10，并且已经确定了这些细胞对流出道和右心室心肌的贡献。我们现在表明，后部区域也有心肌潜力，特别是引起分化的心房细胞。这一结论是基于使用内源和转基因标记的外植体实验和Dil标记，然后进行胚培养。右或左后SHF中的祖细胞分别贡献于右或左共同心房。用转基因胚胎（其中转基因标记右心房）进行的外植体实验表明，心房祖细胞在Pitx 2c首次表达时在4-和6-体节阶段之间获得左右身份。通过获得和丧失功能对Pitx 2c的操纵表明，它抑制了右心房身份的转基因标记。在左静脉窦和后SHF左侧的培养外植体中也观察到对细胞增殖的抑制作用。本报告提供了新的见解SHF的贡献心房心肌和Pitx 2c的左心房的形成的影响。
Splanchnic mesoderm in the region described as the second heart field (SHF) is marked by Islet1 expression in the mouse embryo. The anterior part of this region expresses a number of markers, including Fgf10, and the contribution of these cells to outflow tract and right ventricular myocardium has been established. We now show that the posterior region also has myocardial potential, giving rise specifically to differentiated cells of the atria. This conclusion is based on explant experiments using endogenous and transgenic markers and on Dil labelling, followed by embryo culture. Progenitor cells in the right or left posterior SHF contribute to the right or left common atrium, respectively. Explant experiments with transgenic embryos, in which the transgene marks the right atrium, show that atrial progenitor cells acquire right-left identity between the 4- and 6-somite stages, at the time when Pitx2c is first expressed. Manipulation of Pitx2c, by gain- and loss-of-function, shows that it represses the transgenic marker of right atrial identity. A repressive effect is also seen on the proliferation of cells in the left sinus venosus and in cultured explants from the left side of the posterior SHF. This report provides new insights into the contribution of the SHF to atrial myocardium and the effect of Pitx2c on the formation of the left atrium.