Yeast on a Chip - Single-cell Analyses of MAPK Signaling Pathways in Saccharomyces Cerevisiae using Cell Chips

The mitogen-activated protein kinase (MAPK) signaling pathways are essential for cell growth, cell differentiation and survival in eukaryotes. The MAPK signaling pathways transmit signals from the cell surface to nucleus. The mating and high osmolarity responses in the budding yeast, Saccharomyces cerevisiae, depend on the MAPK signaling pathways. Here we analyzed the mating and high osmolarity responses in the budding yeast, S. cerevisiae at single-cell level using cell chips. The cell chip analyses of the mating and high osmolarity responses were performed using fluorescent proteins fused to genes whose transcription is specifically upregulated by each signaling. Using the technique, we have determined the real-time gene expression patterns of the mating and high osmolarity responses at single-cell level. In this study, we observed that the mating and high osmolarity MAPK signaling showed a non-uniform, fluctuating flux in the population of yeast cells analyzed.