title: Electron tomographic analysis reveals ultrastructural features of mitochondrial cristae architecture which reflect energetic state and aging.
abstract: Within mitochondria, the ability to produce energy relies upon the architectural hallmarks of double membranes and cristae invaginations. Herein, we describe novel features of mitochondrial cristae structure, which correspond to the energetic state of the organelle. In concordance with high-energy demand, mitochondria of Drosophila indirect flight muscle exhibited extensive intra-mitochondrial membrane switches between densely packed lamellar cristae that resulted in a spiral-like cristae network and allowed for bidirectional matrix confluency. This highly interconnected architecture is expected to allow rapid equilibration of membrane potential and biomolecules across integrated regions. In addition, mutant flies with mtDNA replication defect and an accelerated aging phenotype accumulated mitochondria that contained subsections of swirling membrane alongside normal cristae. The swirling membrane had impaired energy production capacity as measured by protein composition and function. Furthermore, mitochondrial fusion and fission dynamics were affected in the prematurely aged flies. Interestingly, the normal cristae that remained in the mitochondria with swirling membranes maintained acceptable function that camouflaged them from quality control elimination. Overall, structural features of mitochondrial cristae were described in three-dimension from serial section electron tomographic analysis which reflect energetic state and mtDNA-mediated aging.
authors.affiliation: Institute of Cellular and Organismic Biology, Academia Sinica, Taipei, Taiwan.|Graduate Institute of Molecular and Comparative Pathobiology, School of Veterinary Medicine, National Taiwan University, Taipei, Taiwan.
authors.forename: Yi-Fan
authors.initials: YF
authors.lastname: Jiang
authors.affiliation: Institute of Cellular and Organismic Biology, Academia Sinica, Taipei, Taiwan.
authors.forename: Shao-Syuan
authors.initials: SS
authors.lastname: Lin
authors.affiliation: Institute of Cellular and Organismic Biology, Academia Sinica, Taipei, Taiwan.
authors.forename: Jing-Min
authors.initials: JM
authors.lastname: Chen
authors.affiliation: Institute of Cellular and Organismic Biology, Academia Sinica, Taipei, Taiwan.
authors.forename: Han-Zen
authors.initials: HZ
authors.lastname: Tsai
authors.affiliation: Institute of Cellular and Organismic Biology, Academia Sinica, Taipei, Taiwan.
authors.forename: Tao-Shih
authors.initials: TS
authors.lastname: Hsieh
authors.affiliation: Institute of Cellular and Organismic Biology, Academia Sinica, Taipei, Taiwan.
authors.forename: Chi-Yu
authors.initials: CY
authors.lastname: Fu
mesh_terms: D000375:Aging; D000818:Animals; D004264:DNA Topoisomerases, Type I / Q000235:genetics / Q000378:metabolism; D004272:DNA, Mitochondrial / Q000378:metabolism; D004330:Drosophila; D055032:Electron Microscope Tomography; D003576:Electron Transport Complex IV / Q000378:metabolism; D004734:Energy Metabolism / Q000502:physiology*; D063154:Mitochondrial Dynamics; D051336:Mitochondrial Membranes / Q000737:chemistry / Q000378:metabolism / Q000648:ultrastructure*
chemical_list: D004272:DNA, Mitochondrial; D003576:Electron Transport Complex IV; D004264:DNA Topoisomerases, Type I