ABSTRACT
The mammalian heart is a complex multi-chambered pump consisting of two ventricles, two atria, outfl ow and infl ow tracts, conduction system, valves, endocardium, and coronary vessels. Proper functioning of the heart requires a highly coordinated process of assembly and integration of all these components. It has long been believed that the identity of each heart chamber is determined in each segment at the linear heart tube stage. However, this classical segmental prespecifi cation view of cardiogenesis has been challenged by the identifi cation of the second heart fi eld (SHF). The cardiac progenitors in this SHF are delineated by the expression of Isl1, a LIM homeodomain transcription factor that plays a key role during cardiogenesis in vertebrates and non-vertebrates (Cai et al. 2003; Dodou et al. 2004; Lin et al. 2006; Lin et al. 2007; Mann et al. 2009; Moretti et al. 2006; Sun et al. 2007). In this chapter, we will review the current understanding of the biology of Isl1+ cardiac progenitors and their potential application to cardiac regenerative medicine.
