Heart ventricle regeneration in the lizard Eublepharis macularius, the leopard gecko

Cardiac cryoinjury induced localized cardiac cell death, followed by an increase in cell proliferation by injury-adjacent cardiomyocytes and non-cardiomyocytes. By 100 days, the histology of the ventricular myocardium was near-completely restored. Echocardiography and invasive hemodynamic monitoring demonstrated that global cardiac function is restored within this timeframe, verifying functional replacement of the myocardium.

To explore the molecular basis, we performed bulk RNA sequencing of the injury-adjacent tissue and found that many of the molecular mechanisms common to other cardiac regenerating species, including genes involved in heart development, glycolysis, and extracellular matrix deposition, are also conserved in geckos. Taken together, this work expands the comparative framework of heart regeneration to include reptiles and indicates that the ability to replace missing or damaged cardiomyocytes is shared across more than 350 million years of evolution.