Fig 1: Expression of mitochondrial dynamics regulatory proteins in Sigmar1-/- mouse hearts at 6 months of age. A, Representative Western blot and (B) densitometric quantification of the expression of mitochondrial dynamic regulatory proteins in the whole-cell fraction of Wt and Sigmar1-/- hearts: pDrp1 Ser637, pDrp1 Ser616, Drp1, and OPA1. C, Representative Western blot and (D) densitometric quantification of the expression of mitochondrial dynamic regulatory proteins in the mitochondrial fraction of Wt and Sigmar1-/- hearts: Drp1 and OPA1. Drp1-overexpressing HEK293 cells were used as a positive control for Drp1, and ß-actin was used on the same membrane. The cytosol fraction was used as a positive control to confirm GAPDH detection. COXIV was used on the same membrane, confirming the mitochondrial extracts. Ponceau S protein staining of the transfer membrane confirmed approximately equal loading and transfer across the gel (n=5-6 mice per group). P values were determined by Tukey post hoc test. Boxes represent interquartile ranges, lines represent medians, whiskers represent ranges, and P values were determined by a Kruskal-Wallis test. NS indicates not significant; Wt, wild type.