Fig. 1.

Fig. 1.

Cardiac slices retain characteristics of the regenerating heart. (A) Schematic representation of workflow. (B) Immunolabeling on 5 dpi whole hearts, 5 dpi cardiac slices after 1 day culture and 5 dpi cardiac slices after 3 day culture from a Tg(nppa:mCitrine) transgenic line. Trabecular cardiomyocytes are marked with mCitrine (green) and embryonic myosin is marked with N2.261 (magenta). Scale bars: 200 µm (overview); 50 µm (zoom). (C) Immunolabeling on 5 dpi whole hearts, 5 dpi cardiac slices after 1 day culture and 5 dpi cardiac slices after 3 day culture from a Tg(nppa:mCitrine) transgenic line. Cardiomyocyte nuclei are marked with MEF2 (green) and proliferating nuclei are marked with PCNA (magenta). Scale bars: 200 µm (overview) or 10 µm (zoom). (D) Quantification of MEF2⁺/PCNA⁺ cells in the border zone of injured hearts/cardiac slices and remote zone of uninjured hearts/cardiac slices. Each dot represents a result from one heart or cardiac slice. Data are mean±s.d. *P<0.05, ***P<0.001, ****P<0.0001.