Cytological parameters of N-resupplied cells. A and B, Size distribution (A) and cell count (B) of the PL and cht7 cells at different times (h) following N resupply. C, Relative DNA content of the PL and cht7 following N resupply. 1C and 2C, one copy and two copies of chromatin content. Five independent biological repeats were examined for (A–C), all showing a similar pattern with one representative result depicted. Results shown here in A and B are from the same experiment. D, Per cell FA content for total lipid and TAG following N resupply of the PL. Averages (n = 3) and sd are indicated. E to H, Transmission electron micrographs showing an overview of wild-type CC-125 cells at the indicated time points (h) during N resupply (NR). The darkly stained vacuole bodies are marked by yellow arrows. I to L, Closer details of subcellular organization of NR12 CC-125 cells. Physical contact of lipid droplets with the chloroplast outer envelope (I); small lipid droplet fused with the vacuole (J); space between thylakoid membranes (K); internal degradation of the unknown vacuole body (L). The scale bar is indicated in each panel. ES, Eyespot; LD, lipid droplet; OE, chloroplast outer envelope; P, pyranoid; SG, starch granule; V, vacuole.