Generation of a TPM1 homozygous knockout embryonic stem cell line by CRISPR/Cas9 editing.

Alpha-Tropomyosin (TPM1) plays a crucial role in actin regulation and stability and contributes fundamental functions to heart development: without TPM1 expressing, mice embryos will die early in embryogenesis. To further identify the role of TPM1 in human cardiac development, here we generated a homozygous TPM1 knockout (TPM1-/-) human embryonic stem cell (hESC) line using CRISPR/Cas9-based genome editing system. The generated TPM1-/- hESC line maintained normal karyotype, highly expressed pluripotency markers and was able to differentiate into all three germ layers in vivo. This cell line provides a powerful tool to investigate the role of TPM1 in heart development in future.