Departamento de Biología del Desarrollo Cardiovascular, Centro Nacional de Investigaciones Cardiovasculares Carlos III, Madrid, Spain.
Evol Dev. 2010 Nov-Dec;12(6):552-67. doi: 10.1111/j.1525-142X.2010.00441.x.
In chick and mouse embryogenesis, a population of cells described as the secondary heart field (SHF) adds both myocardium and smooth muscle to the developing cardiac outflow tract (OFT). Following this addition, at approximately HH stage 22 in chick embryos, for example, the SHF can be identified architecturally by an overlapping seam at the arterial pole, where beating myocardium forms a junction with the smooth muscle of the arterial system. Previously, using either immunohistochemistry or nitric oxide indicators such as diaminofluorescein 2-diacetate, we have shown that a similar overlapping architecture also exists in the arterial pole of zebrafish and some shark species. However, although recent work suggests that development of the zebrafish OFT may also proceed by addition of a SHF-like population of cells, the presence of a true SHF in zebrafish and in many other developmental biological models remains an open question. We performed a comprehensive morphological study of the OFT of a wide range of vertebrates. Our data suggest that all vertebrates possess three fundamental OFT components: a proximal myocardial component, a distal smooth muscle component, and a middle component that contains overlapping myocardium and smooth muscle surrounding and supporting the outflow valves. Because the middle OFT component of avians and mammals is derived from the SHF, our observations suggest that a SHF may be an evolutionarily conserved theme in vertebrate embryogenesis.
在鸡和鼠胚胎发生过程中，一个被描述为次级心脏场（SHF）的细胞群体为心脏流出道（OFT）的发育添加了心肌和平滑肌。在此添加之后，例如，在鸡胚的 HH 阶段 22 左右，SHF 可以通过动脉极的重叠接缝在结构上被识别，在那里跳动的心肌与动脉系统的平滑肌形成连接。以前，我们使用免疫组织化学或一氧化氮指示剂（如二氨基荧光素 2-乙酸酯）表明，类似的重叠结构也存在于斑马鱼和一些鲨鱼物种的动脉极中。然而，尽管最近的工作表明斑马鱼 OFT 的发育也可能通过添加类似于 SHF 的细胞群体来进行，但在斑马鱼和许多其他发育生物学模型中是否存在真正的 SHF 仍然是一个悬而未决的问题。我们对广泛的脊椎动物的 OFT 进行了全面的形态学研究。我们的数据表明，所有脊椎动物都具有三个基本的 OFT 成分：近端心肌成分、远端平滑肌成分和中间成分，其中包含围绕和支撑流出瓣膜的重叠心肌和平滑肌。由于禽类和哺乳动物的中间 OFT 成分源自 SHF，我们的观察表明 SHF 可能是脊椎动物胚胎发生中的一个进化保守主题。
