Fig. 2. Cytosolic pH change and patterning. (A,B) Cells were grown in atmospheric oxygen or (C,D) 100 % O₂. (A,C) Fluorescence intensity obtained by confocal microscopy; excitation at 488 nm and 510-550 nm band pass filter. (B,D) Transmitted light. (E,F) Fluorescence intensity averaged over the vertical direction in the indicated boxes. Low fluorescence intensity in the inner-zone cells suggests acidification of their cytosolic pH.