Fig. 1: Halved H. pulcherrimus embryos undergo unique developmental process.

a Schematic image of experiment and question of this research. Eggs were fertilized, then 2-cell stage embryos were divided into half after removing fertilization envelope. b–t Developmental processes of halved embryos (b–e, j–o) and the corresponding intact embryos (f–i, p–t). Developmental stages specific to halved embryos were named as flat, cup and sphere. (l’, m’) Magnified images of cup opening site in (l, m). Images shown are representative of nine independent experiments performed with similar results. Orange dashed lines, outline of edge of the cup shape embryos. Scare bars, 50 µm (full images), 20 µm (l’, m’).