ABSTRACT
AIM: To study cellular and molecular mechanisms of cardiac development associated genes ex- pression and its function during early stage cardiomyogenesis. METHODS: (1 ) Mouse embryonic stem cells (ESC) line D3 culture. (2) Inductive culals of ESC differentiated into cardiac myocytes in vitro.(3) Identification of ESC -derived cardiac myocytes: RNA isolation; synthesis of specific primer and RT - PCR; Label of RT - PCR products with [? - 32P] dATP as probes, purifyed by sephadex G - 50 columns, determined the yield of DNA. RNA dot hy- bridization. RESULTS: 80% of ESC differentiated into cardiomyocytes by improved conditional medium. Cardiomy- ocytes contraCted in a synchronous manner. The results of RT - PCR and RNA blot showed that cardiac genes were expressed abundantly and specifically during the early cardiomyogenesis. CONCLUSIONS: ESC were able to be dif- ferentiate into cardiomyocytes. Different concentrations and components of RA, DMSO and FCS affected ESC car- diomyogenesis in de. The optimal result obtained was from the conditional medium, a mixturce of 2 nmol/L retinoic acid (RA), 0.6% dimethyl sulfoxide (DMSO) and 20% fend calf serum (FCS).