Fig. 7. smp is involved in cell proliferation from MBT onwards. Clonal injections with either control MOs (smpMOIC and smpMOIIC) or specific MOs (smpMOI and smpMOII), coupled with carboxyfluorescein (-F) or lissamine (-L), respectively. (A-H) Injected embryos observed at early gastrula (A,D), mid gastrula (B,E) or late gastrula (C,F) stages. (A,B) Animal and dorsal views of control-injected embryos. (D,E) Animal and dorsal views of smpMO-injected embryos, showing smp-morphant cells that derived from the injected blastomere. Some of them remain aggregated during gastrulation (white dotted lines indicate the margin of the blastoderm). (C,F) At late gastrula stage, smpMO-containing cells are excluded from the embryonic axis (white dotted lines delimit both sides of the body axes). (G) Number of fluorescent cells per embryo, at early gastrula stage, within a single experiment (n, number of embryos). The average number of fluorescent cells is 67.3±4.3 for control embryos and 42.2±9.8 for smpMO-injected embryos. These values are significantly different (P<0.02). (H) Half of the smpMOII-L-injected embryos display a reduced number of isolated fluorescent cells (<50), always associated with a single cluster of cells. (I-N) Confocal microscope observation of flat mounts of early gastrula embryos after clonal injection with smpMOIIC-L (I-K, n=3) or smpMOII-L (L-N, n=5). The nuclear morphology of smpMO-containing cells (red) was analyzed by DAPI staining (blue). Control-injected cells showed normal mitotic (arrowhead) and interphasic (arrow and inset) nuclei (I-K). By contrast, smpMOII-L-injected blastomeres have descendants with abnormally large nuclei (L-N, arrows and inset).