Fig. 1.

Genetically engineered mouse model lacking two C-zone repeats in titin. a Titin spans from Z-disk (Z) to M-band (M) in the sarcomere. Top, domain structure of A-band segment of titin highlighting the C-zone and the two deleted C-repeats in the Ttn ^ΔC1-2 mouse model (additionally, showing binding sites of the titin antibodies used in this study). b Titin exon usage in myocardial tissue from 8-week-old WT and Ttn ^ΔC1-2 male mice (n = 8 each). c Top, agarose protein gel of titin in left ventricular (LV) myocardium and extensor digitorum longus (EDL) skeletal muscle. Bottom, western blots using Z1Z2 and M8-9 antibodies. 1–4 Cardiac titin (1 N2BA (WT), 2 N2B (WT), 3 N2BA (Ttn ^ΔC1-2), and 4 N2B (Ttn ^ΔC1-2)); 5–6 EDL muscle titin (5 N2A (WT) and 6 N2A (Ttn ^ΔC1-2)). d Superresolution microscopy using T12 and M8-9 antibodies. Scale bars, 1 μm