Two back-to-back papers came to the same conclusion that "a population of cardiomyocytes – heart muscle cells - on the periphery of the injury site becomes activated. Then, those heart muscle cells near the injury site begin to divide and integrate into the gap to build a new wall of heart muscle."
Nature Editor Summary: These two groups used genetic fate-mapping approaches to identify which population of cardiomyocytes contribute prominently to cardiac muscle regeneration after an injury approximating myocardial infarction. They show that cardiac muscle regenerates through activation and expansion of existing cardiomyocytes, and does not involve activation of a stem cell population.
Primary contribution to zebrafish heart regeneration by gata4+ cardiomyocytes
Zebrafish are able to replace lost heart muscle efficiently, and are used as a model to understand why natural heart regeneration — after a heart attack, for instance — is blocked in mammals. Here, and in an accompanying paper, genetic fate-mapping approaches reveal which cell population contributes prominently to cardiac muscle regeneration after an injury approximating myocardial infarction. The results show that cardiac muscle regenerates through activation and expansion of existing cardiomyocytes, without involving a stem-cell population.
Kazu Kikuchi, Jennifer E. Holdway, Andreas A. Werdich, Ryan M. Anderson, Yi Fang, Gregory F. Egnaczyk, Todd Evans, Calum A. MacRae, Didier Y. R. Stainier & Kenneth D. Poss
Zebrafish heart regeneration occurs by cardiomyocyte dedifferentiation and proliferation
Zebrafish are able to replace lost heart muscle efficiently, and are used as a model to understand why natural heart regeneration — after a heart attack, for instance — is blocked in mammals. Here, and in an accompanying paper, genetic fate-mapping approaches reveal which cell population contributes prominently to cardiac muscle regeneration after an injury approximating myocardial infarction. The results show that cardiac muscle regenerates through activation and expansion of existing cardiomyocytes, without involving a stem-cell population.
Chris Jopling, Eduard Sleep, Marina Raya, Mercè Martí, Angel Raya & Juan Carlos Izpisúa Belmonte
De novo is not always the best way.
OMG, someone in TM lab did this too. They showed me the data during my interview. He'll be so pissed