No mutation has been detected in the coding region.
Most extreme eggs are spindle shaped without dorsal appendages. Other eggs have fused dorsal appendages or of normal morphology but remain unfertilized.
Eggs derived from homozygous females form a syncytial blastoderm and many embryos begin to cellularise. Variable cellularisation defects are seen. Gastrulation takes place but is usually very abnormal. The embryos form cuticle with holes, variable head defects and segment fusions.