Understanding the molecular basis for cardiomyocyte cell cycle regulation: new insights in cardiac regeneration after injury?

Author for correspondence: Center for Regenerative Medicine in Barcelona, Dr. Aiguader, 88, 08003, Barcelona, Spain and Gene Expression Laboratory, The Salk Institute for Biological Studies, 10010 North Torrey Pines Road, La Jolla, CA 93027, USA Tel.: +1 858 453 4100 Fax: +1 858 453 2573 [email protected] [email protected] 20% of the ventricle. To directly identify the source of newly formed cardiomyocytes during zebrafish heart regeneration, our group and others established a genetic strategy to lineage-trace cardiomyocytes in the adult fish, based on the cre/lox system widely used in the mouse [10,11]. Using this approach, both groups found that heart regeneration in zebrafish is driven by preexisting cardiomyocytes, rather than by progenitor cells.