Adult sox10+ Cardiomyocytes Contribute to Myocardial Regeneration in the Zebrafish

Abstract

Summary: During heart regeneration in the zebrafish, fibrotic tissue is replaced by newly formed cardiomyocytes derived from preexisting ones. It is unclear whether the heart is composed of several cardiomyocyte populations bearing different capacity to replace lost myocardium. Here, using sox10 genetic fate mapping, we identify a subset of preexistent cardiomyocytes in the adult zebrafish heart with a distinct gene expression profile that expanded after cryoinjury. Genetic ablation of sox10+ cardiomyocytes impairs cardiac regeneration, revealing that these cells play a role in heart regeneration. : Unlike adult mammals, zebrafish regenerate their heart after injury through proliferation of preexistent cardiomyocytes. Sande-Melón et al. identify a subset of sox10-positive cardiomyocytes within the uninjured heart with a high capacity to contribute to the new myocardium. Ablation of these cardiomyocytes confirms that they play an essential role during heart regeneration. Keywords: heart regeneration, sox10, zebrafish, cardiomyocyte proliferation