Fig. 1.
Gene networks underlying cardiac development and reprogramming. (A) A brief overview of a subset of transcription factor interactions that drive the specification of the first heart field (red), second heart field (blue) and ventricular chamber. Transcription factors colored in purple represent regulators of both heart fields. Arrows indicate transcriptional activation; dashed lines indicate functional interdependency. LA, left atrium; LV, left ventricle; OFT, outflow tract; RA, right atrium; RV, right ventricle. (B) Fibroblasts with forced expression of GATA4, MEF2C and TBX5 (GMT) with or without HAND2 are reprogrammed into induced cardiomyocytes (iCMs) both in vitro and in vivo. Addition of AKT1 and ZNF281 to the reprogramming cocktail further increases reprogramming efficiency.