Figure 3
Characteristic patterns of intracellular pH (pH i ). CFDA staining, SIM, S9 to S10B, A, B, C: representative grey-scale images, A´, B´, C´: corresponding pseudocolour images. Alkaline pHi is indicated by strong, acidic pHi by weak fluorescence intensity (see scale bar). D: schematic drawings of characteristic pHi-patterns; alkaline regions are shown in blue (staining in Ooc is not considered). Between S9 and S10B, an anteroposterior pHi-gradient develops within the NC group, the NC adjacent to the anterodorsal region of the Ooc (asterisk) being most acidic. Usually, an anteroposterior pHi-gradient was observed within the FC epithelium, the cFC being most acidic. Also the migrating BC are characterized through an acidic pHi. Near the posterior oolemma (Ool), the Ooc is alkaline compared to the remaining regions. For abbreviations, see Figure 1.