Structure of Mitochondria and Vacuoles of Candida utilis and Schizosaccharomyces pombe Studied by Electron Microscopy of Serial Thin Sections and Model Building

Abstract

The structure of mitochondria and of vacuoles in Candida utilis and Schizosaccharomyces pombe has been studied by electron microscopy of serial thin sections and subsequent model building. The models of the two cells of C. utilis which were studied confirmed our earlier findings, made by high voltage electron microscopy of thick sections, that there is a single, branched and continuous mitochondrial network in the cell (Davison & Garland, 1975). A model of a S. pombe cell showed that the mitochondrial structure was far more continuous than expected from inspection of thin sections, there being but two large and two small mitochondria. The models demonstrated that the few large vacuoles in C. utilis were interconnected into a single cluster, whereas in S. pombe there were two separate complexes of interconnected vacuoles towards each pole of the cell.

Whole Cell Cryo-Electron Tomography Suggests Mitochondria Divide by Budding

“…1-4). Consistent with previous observations by EM of serial thin sections (Davison & Garland, 1977) and by fluorescence microscopy (Benard & Karbowski, 2009), we also observed large portions of the mitochondrial network, confirming its presence. However, it was impractical to perform a montage of cryoelectron tomography due to the radiation damage caused by overexposure in the overlapping areas.…”

“…In addition, understanding how binary fission occurs is challenged by the complexity of mitochondrial morphology and dynamics. It is well known that the majority of mitochondria in a cell form a huge interconnected network (Davison & Garland, 1977), which is highly dynamic (Lewis & Lewis, 1914) and undergoes continuous and frequent fission and fusion (Chan, 2006; Hoppins et al, 2007; Westermann, 2010; Youle & van der Blick, 2012). One of the potential challenges is to understand how this very large interconnected mitochondrial network accommodates binary fission, as binary fission would require the mitochondrial network to double in size before it divides into two equally sized daughter mitochondria.…”

Growth and Respiration Characteristics of Candida albicans

“…This tendency also occurs during germ tube formation. However, while Tanaka et al have reported the occurrence of cell-cycle associated fusion and fragmentation of mitochondria in C. albieans [114], similar to other Candida species, e.g., C. utilis [23] and C. tropiealis [32], a recent fluorescence micrographic study by Ito-Kuwa et al does not demonstrate cell-cyle related morphological changes [45]. Rather it suggests that the form and number of mitochondria of C. albieans are primarily influenced by the physiological state of growth.…”

Three-dimensional reconstruction of a pathogenic yeastExophiala dermatitidiscell by freeze-substitution and serial sectioning electron microscopy

“…Three‐dimensional reconstruction of cells from serial sections has been used for studying the complex architecture and dynamics of organelles in various species of yeast cells [1–8]. A single giant mitochondrion was reported in Saccharomyces cerevisiae [2], but other studies have shown multiple mitochondria and changes in the number and morphology at different stages of the cell cycle and under various growth conditions [3,5–8].…”