Effect of the SQDG-defect on the cell size or Chl content. Wild-type cells were normally cultured whereas SD1 cells precultured with supplementation of SQDG were transferred to SQDG-replete or -deprived conditions for 3 days. In individual cells of the wild type or SD1, forward light scattering or Chl fluorescence was measured with a flow cytometer, as described under Materials and Methods. Shown are the results representative of three independent experiments. (A) Wild-type cells. (B) SD1 cells replete of SQDG. (C) SD1 cells defective in SQDG.