11/15/2010
Monitoring Cell Size and Organelle Volumes in Yeasts
The Science
p>Cell size is a key factor in initiating cell division in yeasts, and the number and volume of organelles have a profound impact on the function and viability of a cell. Soft X-ray tomography at the Advanced Light Source was used to characterize these parameters in strains of Saccharomyces cerevisiae at each of the key stages in the cell cycle and to determine relationships between cellular and organelle volumes. Results showed that growth of the major organelles—with the notable exception of vacuoles—is strictly regulated in accordance with cell size. Similar ratios were found to be maintained in Schizosaccharomyces pombe and Candida albicans. These experiments will undoubtedly improve our understanding of how cells control their size and that of their component organelles.
Summary
Specimens are imaged in a near-native state, and relatively large numbers of cells can be readily analysed. In this study, we characterized haploid and diploid strains of Saccharomyces cerevisiae at each of the key stages in the cell cycle and determined the relationships that exist cellular and organelle volumes. Researchers then compared these results with SXT data obtained from Schizosaccharomyces pombe, the three main phenotypes displayed by the opportunistic yeast pathogen Candida albicans and from a coff1-22 mutant strain of S. cerevisiae. This comparison revealed that volumetric ratios were invariant, irrespective of yeast strain, ploidy or morphology, leading to the conclusion these volumetric ratios are common in all yeasts.
Principal Investigator
Carolyn A. Larabell
University of California–San Francisco
References
Uchida, M., Y. Sun, G. McDermott, C. Knoechel, M. A. Le Gros, D. Parkinson, D. G. Drubin, and C. A. Larabelll. 2011. “Quantitative Analysis of Yeast Internal Architecture Using Soft
X-Ray Tomography,” Yeast 28, 227–36. DOI:10.1002/yea.1834.