Cardiac-cell specific enhancer elements and uses thereof

The invention relates to reagents and methods for expressing gene products in cardiac cells or precursors to cardiac cells in vitro and in vivo. The invention features cardiac cell-specific enhancer elements derived from Csx/Nkx2.5 regulatory regions. These enhancer elements are useful, for example, for (i) regulating gene expression in cardiac cells, (ii) inducing stem cells (e.g., embryonic stem cells or bone marrow stem cells) to differentiate as cardiomyocytes, and (iii) identifying factors that induce the differentiation of stem cells as cardiomyocytes.