Absence of posterior pole plasm, polar granules and pole cells.

Embryos lack pole cells. Large amounts of vas protein are expressed in early stages of oogenesis. Perinuclear localization is reduced in favour of additional protein in the cytoplasm: vas protein fails to distribute asymmetrically. Cleavage embryos have uniform vas protein distribution, the protein disappears by early gastrulation.

stau³/stau⁴ transheterozygous embryos derived from homozygous females have no polar granules, fail to form pole cells and have deletions of abdominal structures. Posterior localization of vas and CycB transcripts is completely abolished.