title: Inner membrane dynamics in mitochondria.
abstract: Combining the use of cells with sparse cristae marked with IMP-EGFP and short pulsed sub-saturating fluorescence excitation (non-saturation fluorescence microscopy/NSFM) revealed inhomogeneous fluorescence distribution along mitochondria in living cells. Also the matrix located TMRE was distributed non-uniformly and at least in part filling the gaps between the IMP-EGFP fluorescence: fluorescence intensities are modulated in space and time in part in an antidromic manner. The spatial modulations can be interpreted to represent cristae/matrix distributions. The temporal fluctuations of fluorescence vary within 0.3-3s. Because most peak positions of IMP fluorescence remain stationary up to at least several minutes, temporal intensity modulations may result from varying emissions related to the degree of excitation and/or represent wobbling of cristae, i.e. lateral movements, bending or size changes. Modulations by noise and non-saturated excitation have been reduced by 3 steps of deconvolution followed by averaging 4 images. This allowed a final temporal resolution of 150ms. Disappearance of cristae or formation of new ones takes place within a few seconds, but these are rare events. Thus position of cristae seems to be rather stable, but they regularly disassemble close to fission sites. Treatment with oligomycin strongly reduces "wobbling" activity.
authors.affiliation: Kinematic Cell Research Group, Institute for Cell Biology and Neurosciences, Goethe University Frankfurt, Max-von-Laue Strasse 13, 60438 Frankfurt am Main, Germany; Mitochondrial Biology Group, Buchmann Institute for Molecular Life Sciences, Goethe University Frankfurt, Max-von-Laue Strasse 15, 60438 Frankfurt am Main, Germany.
authors.forename: Daniel
authors.initials: D
authors.lastname: Dikov
authors.affiliation: Kinematic Cell Research Group, Institute for Cell Biology and Neurosciences, Goethe University Frankfurt, Max-von-Laue Strasse 13, 60438 Frankfurt am Main, Germany. Electronic address: Bereiter-Hahn@bio.uni-frankfurt.de.
authors.forename: Juergen
authors.initials: J
authors.lastname: Bereiter-Hahn
mesh_terms: D005456:Fluorescent Dyes / Q000737:chemistry / Q000378:metabolism; D049452:Green Fluorescent Proteins / Q000378:metabolism; D006367:HeLa Cells; D061307:Human Umbilical Vein Endothelial Cells / Q000648:ultrastructure*; D006801:Humans; D008856:Microscopy, Fluorescence; D063154:Mitochondrial Dynamics; D051336:Mitochondrial Membranes / Q000187:drug effects / Q000648:ultrastructure*; D009840:Oligomycins / Q000494:pharmacology; D053140:Organelle Shape; D009942:Organometallic Compounds / Q000737:chemistry / Q000378:metabolism
chemical_list: D005456:Fluorescent Dyes; D009840:Oligomycins; D009942:Organometallic Compounds; C110932:tetramethyl rhodamine ethyl ester; D049452:Green Fluorescent Proteins
keywords: Cristae dynamics; Cristae – matrix visualization; FPALM; GFP; IMM; IMP; Mitochondria; NSFM; Non-saturation fluorescence microscopy (NSFM); OMM; ROS; SOFI; STED; TMRE; fluorescence photoactivation localization microscopy; green fluorescent protein; inner mitochondrial membrane; inner mitochondrial membrane protein; mitochondrial membrane potential; non-saturation fluorescence microscopy; outer mitochondrial membrane; pixel; px; reactive oxygen species; stimulated emission depletion – microscopy; super-resolution optical fluctuation imaging; tetramethylrhodamine ethylester; Δψ