(A) BIN1 and DNM2 protein domains; corresponding exons and isoforms are shown. N-BAR, N-terminal amphipathic helix and Bin-amphiphysin-Rvs domain; PI, phosphoinositide-binding domain; CBD, clathrin-binding domain; MBD, MYC-binding domain; SH3, Src homology domain; PH, pleckstrin homology domain; GED, GTPase effector domain. Region targeted by exon 20 Bin1–/– mice is indicated. Position of peptides encoded by alternative exons 11 and 12B indicated (not to scale). Predominant BIN1 isoforms are depicted on the right. Iso1 (brain), Iso8 (skeletal muscle), Iso9 (ubiquitous), Iso10 (ubiquitous, cardiac muscle) (adapted from ref. 24). (B) Immunofluorescence staining of primary myotubes (differentiated for 8 days [8d]) and murine muscles at embryonic day 18.5 (E18.5) and in adult (12 weeks) from WT mice. E18.5 muscles have longitudinal (predominant in this image) or transversal triads. DNM2 (upper panel, green in merge) and BIN1 (middle panel, red in merge) immunolabeling is shown. Scale bars: 10 μm. (C) Immunofluorescence staining of semi-thin (200 μm) sections from WT mice, DHPR (upper panel, red in merge), and BIN1 (middle panel, green in merge). Scale bar: 10 μm. (D) Intensity scans spanning 1 complete sarcomere from the above images.