Fig. 1: Adult nkx2.5−/− fish have structurally normal hearts.
From: Activation of Nkx2.5 transcriptional program is required for adult myocardial repair
A Schematic of the experimental design and genotype identification. B–D Representative images of hearts stained for Tropomyosin (green) and DAPI (blue) indicate cardiac muscle and nuclei, respectively, in wild-type (WT0) (n = 11) (B), Tg(hsp70l:nkx2.5-EGFP) (TG0) (n = 6) (C), and nkx2.5−/− (MT0) (n = 7) (D) adult hearts. Scale bar, 100 μm. E–G The same sections in the top panels are stained with Acid Fuchsin-Orange G (AFOG) to indicate fibrin (red), myocardium (orange), and collagen (blue) in non-transgenic wild-type (WT0) (n = 11) (E), transgenic wild-type (TG0) (n = 6) (F), and nkx2.5−/− (MT0) (n = 7) (G) adult hearts. Scale bar, 100 μm. H–M In situ hybridization for vmhc (H–J) and amhc (K–M) in non-transgenic wild-type (WT0) (n = 11) (H, K), transgenic wild-type (TG0) (n = 6) (I, L), and nkx2.5−/− (MT0) (n = 7) (J, M) adult hearts. In nkx2.5−/−hearts, amhc is expressed ectopically in the ventricle (arrows) (n = 7/7). N–P Tropomyosin immunostaining elucidates well-organized z-disks in non-transgenic wild-type (WT0) (n = 11) (N), transgenic wild-type (TG0) (n = 6) (O), and nkx2.5−/− (MT0) (n = 7) (P) ventricular myocardium. Scale bar, 10 μm. Q, R Morphometric evaluation of trabecular myocardium in non-transgenic wild-type (WT0) (n = 5), transgenic wild-type (TG0) (n = 5), and nkx2.5−/− (MT0) (n = 5) adult hearts and ventricular volume in non-transgenic wild-type (WT0) (n = 8), transgenic wild-type (TG0) (n = 8), and nkx2.5−/− (MT0) (n = 7) adult hearts. Mean and standard error of each data set are shown. Unpaired, two-tailed t-test demonstrates no statistically significant differences between WT0 and TG0 (p = 0.1428) and WT0 and MT0 (p = 0.8124) in Q. Unpaired, two-tailed t-test illustrates no statistically significant difference between WT0 and TG0 (p = 0.2770) and statistically significant difference between WT0 and MT0 (p = 0.0490) in R. S Swim endurance assessed in non-transgenic wild-type (WT0) (n = 6), transgenic wild-type (TG0) (n = 6), and nkx2.5−/− (MT0) (n = 6) fish at maximal water speed. Mean and standard error of each data set are shown. Unpaired, two-tailed t-test shows no statistically significant differences between WT0 and TG0 (p = 0.3866) and WT0 and MT0 (p = 0.3409). Source data are provided as a Source Data file.
