Morpholino oligonucleotides and GFP-CAAX RNA (150 pg) were coinjected into one dorsal blastomere of four-cell embryos. Gastrocoel roof plate (GRP) was dissected at stage 17 and stained with anti-GFP and anti-acetylated tubulin antibodies. Arrowheads (red channel only) indicate GRP cilia. The midline (M) is shown by a dashed line. Merged images are shown on the left. Div-MO, but not Co-MO, inhibited cilia formation in the GRP. (A) Control MO, 40 ng. (B) Diversin MO, DivMO, 40 ng. (C) Effects of DiVMO on GRP cilia. The number of GRP cilia was scored in the area of 1900 μm2 (adjacent to the midline), which was randomly selected in morpholino-injected embryos. The area on the contra-lateral side was used as an additional control. DivMO drastically reduced cilia number.