Δint6 cells are sensitive to caffeine. The
wild-type strain (A, C, and E) or Δint6 (B, D, and F)
were grown under the following conditions; YEA medium (A and B), YEA +
10 mM caffeine (C to F). A to D were examined under a fluorescence
microscope, while E and F were examined by conventional light
microscopy.