Effects of growth conditions on mitochondrial morphology inSaccharomyces cerevisiae

Abstract

Effects of growth conditions on mitochondrial morphology were studied in living Saccharomyces cerevisiae cells by vital staining with the fluorescent dye dimethyl-aminostyryl-methylpyridinium iodine (DASPMI), fluorescence microscopy, and confocal-scanning laser microscopy. Cells from respiratory, ethanol-grown batch cultures contained a large number of small mitochondria. Conversely, cells from glucose-grown batch cultures, in which metabolism was respiro-fermentative, contained small numbers of large, branched mitochondria. These changes did not significantly affect the fraction of the cellular volume occupied by the mitochondria. Similar differences in mitochondrial morphology were observed in glucose-limited chemostat cultures. In aerobic chemostat cultures, glucose metabolism was strictly respiratory and cells contained a large number of small mitochondria. Anaerobic, fermentative chemostat cultivation resulted in the large, branched mitochondrial structures also seen in glucose-grown batch cultures. Upon aeration of a previously anaerobic chemostat culture, the maximum respiratory capacity increased from 10 to 70 mumole.min-1.g dry weight-1 within 10 h. This transition resulted in drastic changes of mitochondrial number, morphology and, consequently, mitochondrial surface area. These changes continued for several hours after the respiratory capacity had reached its maximum. Cyanide-insensitive oxygen consumption contributed ca. 50% of the total respiratory capacity in anaerobic cultures, but was virtually absent in aerobic cultures. The response of aerobic cultures to oxygen deprivation was qualitatively the reverse of the response of anaerobic cultures to aeration. The results indicate that mitochondrial morphology in S. cerevisiae is closely linked to the metabolic activity of this yeast: conditions that result in repression of respiratory enzymes generally lead to the mitochondrial morphology observed in anaerobically grown, fermenting cells.

Fast 100-nm resolution three-dimensional microscope reveals structural plasticity of mitochondria in live yeast

“…The strain BY4743 (24) used in this study exhibits relatively simple mitochondrial networks on fermentable carbon sources like glucose, whereas on nonfermentable sources such as glycerol, the network is branched and more elaborate. Although straindependent differences have been reported (25), this appears to be a typical behavior.…”

“…To demonstrate its continuous reticular structure, Nunnari et al (30) have gained 3D images of the mitochondrial compartment by means of epifluorescence microscopy combined with image restoration. This method, as well as confocal fluorescence microscopy (25), allowed a distinction of glycerol-and glucosegrown yeast cell populations. However, in both cases, the limited spatial resolution rendered an equilateral 3D representation of the mitochondrial compartment impossible.…”

Different carbon sources affect lifespan and protein redox state during Saccharomyces cerevisiae chronological ageing

“…During ageing in CR and SCG the mitochondria appear progressively more numerous and present a clear spherical shape. Even the mitochondria morphology of SCD grown cells tends to become similar to the one in CR and SCG by passing to the derepressed state characteristic of low glucose level [32], although some cells tend to Research Article 937 retain mitochondria with filamentous morphology. It is interesting to note that the number of GFP-labelled yeast cells drastically decreased during ageing in SCD compared to the other two conditions (Fig.…”

“…This increase was related to the mitochondria state [38,39]. During the exponential phase and even more so during ageing, cells grown in CR or SCG displayed small and numerous mitochondria; these differences were previously analysed by Visser [32], who shows that the reticular morphology is associated with a repressed condition typical of growth in high glucose medium or oxygen absence, whereas yeast cells growing on non-fermentable carbon sources display a large number of small mitochondria. This situation is not reproducible in mammalian cells.…”

Origin of Nuclear Mitochondrial Pseudogenes (Numts)

“…This yeast dramatically regulates the shape, size, and number of its mitochondria during cell growth [3]. It was found that the number of mitochondria increases when cells of Saccharomyces cerevisiae are under glucose-limiting conditions [4].…”