Fig. 5

Indirect immunofluorescence microscopy showing successive stages of embryogenesis in T. socialis. Each column shows a DIC image (top row), a fluorescence image labeled with anti-SAS-6 antibody (green) and DAPI (blue) (second row), a merged DIC and fluorescence image of anti-SAS-6 antibody and DAPI (third row), and a fluorescence image labeled with anti-tubulin α antibody (magenta) of the same embryo. Positions of nuclei (letter n), chloroplasts (letter c), and basal bodies labeled with anti-SAS-6 antibody (arrowheads) are shown. Scale bars: 5 μm. a Prior to embryogenesis. b Two-celled stage. c Early 4-celled stage. The angles of the longitudinal axes of daughter protoplasts, which are indicated by basal bodies and chloroplasts, did not change during successive cell divisions (a–c). d Late 4-celled stage showing emitted flagella (arrows). The angles of longitudinal axes of daughter protoplasts did not change after successive cell divisions, though a pair of diagonally opposed daughter protoplasts shifted slightly toward the anterior of the embryo (“A” in Fig. 3c, e). e After hatching. The basal bodies of four cells are arranged in a square shape in the same plane