Krüppel-like factor 1 is a core cardiomyogenic trigger in zebrafish

Repairing the fish heart Although humans show minimal regenerative capability, zebrafish can regenerate their hearts through a mechanism whereby heart muscle cells (cardiomyocytes) revert to a less mature state and then proliferate to replace the damaged tissue. Ogawa et al. show that Krüppel-like factor 1 (Klf1/Eklf), a transcription factor well known for its role in red blood cell development, is an essential factor for heart regeneration in zebrafish. Klf1 is specifically expressed in cardiomyocytes after injury, and its activation is sufficient to stimulate new cardiomyocyte production without injury. This potent effect is achieved through reprogramming of gene networks regulating cardiomyocyte differentiation and mitochondrial metabolism. Science , this issue p. 201