Towards deciphering variations of heart regeneration in fish

Among adult vertebrates, the zebrafish presents the rather exceptional capacity to efficiently regenerate its heart after injury. This bony fish has thus become a leading genetic model organism to elucidate the natural mechanisms of successful cardiac restoration. Given its potential biomedical significance, parallel analyses between zebrafish and mammals are aiming at the identification of the permissive and restrictive factors modulating the underlying cardiomyocyte proliferation. The recent discovery that some other bony fish species have a lower regenerative competence than zebrafish opens new opportunities for comparative studies within a framework of similar animal physiology and organ structure. Here, we review recently identified modulators of cardiomyocyte proliferation in zebrafish and highlight the results obtained by this comparative approach.