Effect of a selectable marker ura4+ gene on survival of stationary-phase cells of the fission yeast cultured in a synthetic defined medium.

Takanori Senoo, Naoya Katayama, Atori Nakamura, Shinji Kawano, and Shogo Ikeda

The chronological lifespan (CLS) in yeast is defined as the survival time of non-dividing cells such as cells in the stationary phase during growth. Deletion mutants of the fission yeast (Schizosaccharomyces pombe) have been constructed by replacement of target gene with a selectable marker such as the ura4+gene. During CLS assays of various mutants, we noticed that the ura4+ marker might have affected the survival of stationary-phase cells when mutant cells were cultured in a synthetic defined (SD) medium. In this study, we compared the CLS of ura4+ strains with that of several ura4– mutants and show that the ura4+ gene may reduce the survival of stationary-phase cells cultured in SD medium. The shortened CLS phenotype of the ura4+ strain was not observed when cells were cultured in a rich medium YES. Although the reason for this phenomenon is unclear, caution must be taken when the CLS of deletion mutants carrying the ura4+ marker is measured in SD medium.

The Bulletin of Okayama University of Science

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