During embryogenesis, the pushing force generated by ectoderm convergent extension is impaired or lacking. Germ band extension is desynchronized from mesoderm and endoderm invaginations.

Approximately 50% of homozygous embryos die before the cellular blastoderm stage, and the remainder die later in embryogenesis. Approximately 15% of embryos derived from Pu^rWE75/+ females die before the cellular blastoderm stage. These embryos have irregularly distributed nuclei, show asynchronous nuclear division, have abnormally diffuse chromosomes and sometimes have chromatin bridges between nuclei.

Embryos have completely unpigmented and weak cuticles. A portion of the homozygous embryos die before blastoderm formation with a defect in nuclear division (fewer nuclei that are misshapen, asynchronous and unevenly distributed), homozygous embryos that develop after have a segmentation defect (segment fusions and deletions). Eye colour: wild-type. Catecholamine functions normal.