Proteins implicated in triad organization in skeletal muscle. (a) Electron microscopic image showing ferrocyanate-treated muscle from wild-type mouse. (b) Electron microscopic image showing ferrocyanate-treated muscle from Cav3 (caveolin 3)-mutant mouse. Note the altered appearance and orientation of T-tubules (from ; ©2001 The American Society for Biochemistry and Molecular Biology). (c) Electron microscopic image from Drosophila normal muscle. Note that dyads are localized in proximity to the Z-line (similar to vertebrate). (d through f) Electron microscopic images from Bin1 (amphiphysin)-null Drosophila showing alteration of T-tubules resulting in (d) mislocalized, (e) longitudinal and (f) dilated tubules (from ; ©2001 Cold Spring Harbor Laboatory Press). (g through j) Electron microscopic images of ferrocyanate-treated muscles from (g and h) wild-type and (i and j) MG29 (mitsugumin)-knockout mice demonstrating the alterations in T-tubule organization. Note the absence of (i) T-tubule or (j) longitudinal orientation (from ; ©1999 The Rockefeller University Press. The Journal of Cell Biology, 2002, 159:695-705). (k and l) Electron microscopic images from (k) wild-type and (l) JPH1 (junctophilin)-knockout skeletal muscles from neonate mice showing the altered triads with swollen SR (reprinted from ; ©2002 with permission from Elsevier). (m and n) Electron microscopic images of ferrocyanate-treated muscles from (m) wild-type and (n) Dysf (dysferlin)-knockout mice showing an abnormal shape of the T-tubule system (from ; ©2010 John Wiley and Sons). (o and p) Electron microscopic images of ferrocyanate-treated muscles from (o) wild-type and (p) Mtm1 (myotubularin)-knockout mice revealing a severe alteration in T-tubule organization. Note the absence (arrowhead) or the longitudinally oriented (arrow) T-tubules (from ; ©2009 National Academy of Sciences, USA).