Volume 8 issue 1 January 2007
Patients with a non-dysferlin Miyoshi Myopathy have a novel membrane repair defect
Jyoti K. Jaiswal, Gareth Marlow, Gillian Summerill, Ibrahim Mahjneh, Sebastian Mueller, Maria Hill, Katsuya Miyake, Hannelore Haase, Louise V.B. Anderson, Isabelle Richard, Sari Kiuru-Enari, Paul L. McNeil, Sanford M. Simon and Rumaisa Bashir

Video 1: Lysosomal exocytosis in control cells. Lysosomes of control fibroblasts growing on glass coverslip were labeled with FITC-dextran. Cells were imaged by TIR-FM using 60X 1.45 NA objective and 488nm laser excitation. Video shows a single cell imaged at 6 frames per second and the elapsed time is shown at the top right corner of the video. During imaging cells were treated with 10µM ionomycin, which resulted in exocytosis of lysosomes. Each exocytic event appears as the flash of FITC dextran fluorescence, which is caused by diffusion of the FITC dextran in the extracellular space away from the site of fusion.

Video 1 (.mpg)

Video 2: Lysosomal exocytosis in cells from patient 1. Lysosomes in fibroblasts of patient 1 were labeled with FITC-dextran and imaged by TIR-FM as for the control fibroblasts. Video shows a single cell imaged at 5 frames per second and the elapsed time is shown at the top left corner of the video. During imaging cells were treated with 10µM ionomycin causing lysosomes to exocytose. Individual exocytic event appears as a flash of FITC dextran fluorescence, which is due to the diffusion of the FITC dextran in the extracellular space away from the site of fusion.

Video 2 (.mpg)

Video 3: Lysosomal exocytosis in cells from patient 2. Lysosomes in fibroblasts of patient 2 were labeled with FITC-dextran and imaged by TIR-FM as for the control fibroblasts. Video shows a single cell imaged at 5 frames per second and the elapsed time is shown at the top right corner of the video. Lysosomal exocytosis was triggered during imaging by treating cells with 10µM ionomycin. Each exocytic event appears as a flash of FITC dextran fluorescence, which is due to the diffusion of the FITC dextran in the extracellular space away from the site of fusion.

Video 3 (.mpg)