Fig. 2: Lifespan and cardiac phenotype of the Lmna^F/F:mcm mice.

A The median lifespan of the Lmna^F/F:mcm mice was 27 days after a single Tmx injection (****P < 0.0001; Log-rank (Mantel–Cox) test). B Lmna^F/F:mcm mice develop kyphosis (red arrow) by 21 days after injection. C PCR detected the floxed (deleted) Lmna gene (red arrowhead) only in whole heart tissue after Tmx induction and neither in other tissues or when Tmx was not injected. Assays were performed once with the number of animals as indicated in the graph. DNA marker in bp (D) LaminA/C levels were quantified by Western analysis of whole heart lysates 21 days after Tmx induction. A significant reduction in A-type Lamin protein was detected. Lamin C levels were not reduced as much in the Lmna^F/F:mcm hearts compared to Lmna^F/F:mcm controls (****P < 0.0001; unpaired two-tailed T-test, data presented as mean ± SD). Quantitative analysis was performed at 21 days post-Tmx induction (right panel). The presence of the LoxP sites in the WT-Lmna gene (Lmna^F/F) results in a reduction in Lmna transcript levels compared to Lmna^Wt/Wt levels. However, this had no overt effect on longevity or postnatal growth/viability. Markers in kDA (E, F) LaminA/C protein, detected by immunofluorescence, was reduced/absent in CM nuclei in both (E) isolated CMs (Scale bar 10 μm) and (F) heart sections (red arrows) with CM nuclei detected by PCM-1 staining, 21 days after Tmx induction. Nuclei are in blue. The images shown are representative of three independently performed experiments. Scale bar 10 μm. Source data are provided as a Source Data file.