Eggs derived from homozygous females form a syncytial blastoderm and many embryos begin to cellularise. Cellularisation is irregular. Gastrulation takes place but is usually very abnormal. The embryos form pieces of cuticle. sie3 also causes considerable embryonic lethality when the mother is heterozygous for sie3.
semidominant effect, causing 60-80% embryonic lethality when mother heterozygous.