Fig. 4. Effects of nutritional shifts on pHi. Phluorin-expressing
wild-type cells were grown to early logarithmic phase in EMM(glutamine) pH 5.5
(left) or EMM(proline) pH 5.5 (right) and mounted in the same media in the
flow chamber. After a 30-60 minute equilibration time the perfusion medium was
switched (t=0) to EMM(proline) pH 5.5 (left) or EMM(glutamine) pH 5.5 (right).
The top panels show the mean internal pH of 20-40 cells plotted as a function
of time. Error bars indicate s.d. Lower panels are scatter plots of internal
pH as a function of cell length at the indicated times. Open diamonds indicate
binucleate cells whereas closed diamonds indicate uni-nucleates.
