Fig 3.

Cryo-ET of FIB-milled toadfish swimbladder muscle.¹³ A. X-Y slices through the tomogram determined for the triad shown in Fig. 2B (section thickness ~100 nm). Slices are 1 nm thick, spaced at 10 nm intervals along Z. B. Manually segmented model in the region of the triad junction. Green, T-tubule; blue, density containing ryanodine receptors; yellow, SR membrane; purple, unidentified mass density in lumen of T-tubule. C. View onto RyR-bearing surface of SR (from upper SR in B) showing 4-6 RyRs (numbered), which are not clearly resolved from one another. Parts of A adapted from reference.¹³