(a) Wild-type yeast cultured in S(-NC) for 4 h. PtdIns(3) P was labelled intensely in the EF of autophagosomal membranes. A lower but still significant amount of labelling was also seen in the PF of autophagosome membranes as well as in the EF of the vacuolar membrane. Scale bar, 0.5 μm. 