Homozygous germline clones in the ovaries are viable, and can produce mature ovarioles. Over 50% of eggs deposited by females with homozygous germline clones are unfertilised. Heterozygous Syx1A^L266 embryos derived from females with homozygous Syx1A^L266 germline clones are viable and develop normally. Syx1A^L266/Syx1A^L371 embryos derived from females with homozygous Syx1A^L266 germline clones arrest very early, usually before germ band extension. Homozygous or Syx1A^L266/Syx1A^L371 mitotic cycle 14 embryos derived from females with homozygous Syx1A^L266 germline clones have large acellular patches. Within these patches the actin cytoskeleton is completely absent and the nuclei are disorganised and begin to fall away from the surface of the embryo.