Evaluation of image processing programs for accurate measurement of budding and fission yeast morphology
To study the cellular functions of gene products, various yeast morphological mutants have been investigated. To describe yeast morphology objectively, we have developed image processing programs for budding and fission yeast. The programs, named CalMorph for budding yeast and F-CalMorph for fission yeast, directly process microscopic images and generate quantitative data about yeast cell shape, nuclear shape and location, and actin distribution. Using CalMorph, we can easily and quickly obtain various quantitative data reproducibly. To study the utility and reliability of CalMorph, we evaluated its data in three ways: (1) The programs extracted three-dimensional bud information from two-dimensional digital images with a low error rate (<1%). (2) The absolute values of the diameters of manufactured fluorescent beads calculated with CalMorph were very close to those given in the manufacturer’s data sheet. (3) The programs generated reproducible data consistent with that obtained by hand. Based on these results, we determined that CalMorph could monitor yeast morphological changes accompanied by the progression of the cell cycle. We discuss the potential of the CalMorph series as a novel tool for the analysis of yeast cell morphology.
KeywordsSaccharomyces cerevisiae Schizosaccharomyces pombe Image processing Cell shape Actin Cell cycle
We thank Tamao Goto, Yuka Kitamura, and Emi Shimoi for technical assistance and the members of the Ohya and Morishita groups at the University of Tokyo for stimulating discussions. This work was supported by the Institute for Bioinformatics and Research and Development of the Japan Science and Technology Corporation.
- Hirata D, Kishimoto N, Suda M, Sogabe Y, Nakagawa S, Yoshida Y, Sakai K, Mizunuma M, Miyakawa T, Ishiguro J, Toda T (2002) Fission yeast Mor2/Cps12, a protein similar to Drosophila Furry, is essential for cell morphogenesis and its mutation induces Wee1-dependent G(2) delay. EMBO J 21:4863–4874PubMedCrossRefGoogle Scholar