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We have visualized redox and structural changes in the mitochondria of yeast Saccharomyces cerevisiae as a eukaryotic cell model using a genetically encoded yellow fluorescent protein (Y1-Yellow) and conventional fluorescence microscopy. Y1-Yellow originating from a yellow emitting luminous bacterium Aliivibrio sifiae Y1 was fused with a mitochondria-targeted sequence (mt-sequence). Y1-Yellow fluorescence arising only from the mitochondrial site and the color of yellow fluorescence could be easily differentiated from cellular autofluorescence and from that of conventional probes. Y1-Yellow expressing S. cerevisiae made the yellow fluorescence conspicuous at the mitochondrial site in response to reactive oxygen species (ROS) transiently derived in the wake of pretreatment with hydrogen peroxide. Based on our observation with Y1-Yellow fluorescence, we also showed that mitochondria rearrange to form a cluster structure surrounding chromosomal DNA via respiratory inhibition by cyanide, followed by the generation of ROS. In contrast, uptake of an uncoupler of oxidative phosphorylation is not responsible for mitochondrial rearrangement. These results indicate the utility of Y1-Yellow for visualization of mitochondrial vitality and morphology in living cells.

CuInS2 crystals were successfully grown by the Hot-Press method at 700 °C for 1 h under high pressure in Cu-rich region. The In-rich samples were found to contain a small amount of secondary phase (CuIn5S8). Crystalline grain sizes in the In-rich region increased with increasing Cu/In ratio, whereas they remained constant in the Cu-rich region. All samples exhibited a low Sulfur concentration. This indicated that Cu atoms on In sites and In interstitials, and/or S vacancies might lead to an enhancement in electrical conductivity in both p- and n-type material.