FIG 1.

Generation of transgenic mice with skeletal-muscle-specific NCX1 overexpression. (A) Western blotting for endogenous NCX1 expression at different ages in quadriceps muscles of WT and Sgcd^−/− mice. GAPDH is a loading control. (B) Histological immunofluorescence images (×200 magnification) of NCX1 expression (red) and DAPI (blue) from quadriceps of Sgcd^−/− and WT mice at 3 months of age. (C) Western blotting for endogenous NCX1 during a time course of regeneration at 3, 7, and 14 days (d) after cardiotoxin (CTX) injection into skeletal muscle. (D) Schematic of the human skeletal α-actin (HSA) promoter upstream of the canine NCX1 cDNA used to make TG mice. (E) Western blotting in quadriceps (Quad.) and diaphragm (Diaph.) of NCX1 TG and NTG mice at 8 weeks of age for NCX1, SERCA1, and NKA (Pan). The asterisks indicate differences between the quadriceps and diaphragm in baseline SERCA1 and NKA expression. (F) Immunofluorescence image (×200 magnification) of NCX1 (red) versus membranes stained with wheat germ agglutinin (WGA, green stained)) from histological sections of quadriceps muscle from NTG and NCX1 TG mice. (G) Immunocytochemical staining (×600 magnification) of NCX1 (red) and NKAα2 (green) in isolated myofibers from NCX1 TG and NTG mice.