In the current reporting period, we have worked on the generation of human embryonic stem cell derived marker cell lines for different steps of cardiomyocyte differentiation. The cell lines are designed to express fluorescent proteins under the control of gene promoters that mark cardiac progenitor cells, cardiomyocytes, or cardiac conduction system cells.
We tested several HUES cell lines for this purpose and chose cell lines that can differentiate into cardiomyocytes efficiently but are easy to expand and appear stable over several passages in culture. We generated several BAC transgenic cell lines that specifically express green fluorescent protein in cardiomyocytes. Further cell lines are being generated. The cell lines will be used in high-throughput screens to identify molecules and mechanisms that direct the efficient in vitro differentiation into different cardiac cells.