Fig. 10. Early embryonic lethality in epi-1 mutants. A homozygous epi-1(rh199) embryo inside of the heterozygous parent shows cells (asterisks) that are separated and detached from the tissues. The detachment of cells during embryonic development and the failure of organogenesis cause embryonic lethality in predicted epi-1 null mutants. The eggshell (arrows) is slightly shrunk owing to the fixation. Scale bar: 5 µm.