Molecular and cellular mechanisms of second heart field development in zebrafish.

生物学中的一个基本问题是器官如何发育并呈现出成熟的成人形态。心脏尤其如此，在生长和发育过程中，心脏必须继续保持发育中的胚胎的血液流动。一个令人惊讶的发现是，心脏的大部分发育是通过在已经跳动的心管中增加细胞来实现的。一组被称为“次级心场”(SHF)的细胞迁移到心脏中，形成了成熟心脏的很大一部分，包括右室、流出道、大部分心房和分隔四个心腔的隔膜。SHF增加发生在小鼠身上，这种模型通常用于研究心脏发育，此时胚胎正在子宫内发育，这使得详细观察这一关键过程变得非常困难。由于其光学清晰度、快速的外部发育和对遗传方法的适应性，斑马鱼已成为研究心脏如何发育的有力工具。我的团队最近发现，斑马鱼心脏的发育还包括增加一个类似SHF的细胞群。由于可以在斑马鱼胚胎中实时观察心脏发育，我们现在可以用一种迄今为止在小鼠模型中不可能实现的方式来检查SHF。

A fundamental question in biology is how organs develop and assume their mature, adult form. This is especially true for the heart, which must continue to maintain blood flow in the developing embryo while growing and developing. A surprising finding has been that much of heart development occurs by addition of cells to the already beating heart tube. A group of cells termed the "secondary heart field" (SHF) migrates into the heart and forms a large portion of the mature heart, including the right ventricle, outflow tract, much of the atria and septa that separate the 4 chambers. SHF addition occurs in mice, the model typically used to study heart development, at at time when the embryo is developing in the uterus, making detailed observation of this key process very difficult. Due to its optical clarity, rapid external development and amenability to genetic approaches, the zebrafish has become a powerful tool to study how heart development. My group has recently found that development of the zebrafish heart also involves addition of a SHF-like population of cells. As heart development can be visualized in real-time in the zebrafish embryo, we are now positioned to examine the SHF in a way not possible in the mouse model used to date.