Heterozygous females deposit normal numbers of normal looking eggs. The eggs are normally fertilised as revealed by the presence of a sperm tail in the egg cytoplasm. As in wild type, the nuclei are well contoured in newly deposited eggs, suggesting compact nuclei. The four haploid nuclei appear compact in unfertilised eggs laid by virgin heterozygous females. A bundle of microtubules is seen between the two inner haploid nuclei and is most likely the central spindle pole body that persists following the second meiotic division (this phenotype is never seen in wild-type eggs). Severe defects appear 6-7 minutes after fertilisation when the female and male pronuclei become juxtaposed; the male and female pronuclei are poorly contoured suggesting nuclear envelope defects. Generally, disorganised masses of microtubules (MTs) form instead of the gonomeric spindle. The MT mass appears as a prominent sperm aster and persists for several minutes. The centrosome replicates, however, the daughter centrosomes cannot separate. The chromosomes fail to segregate and disintegrate in minutes. The centrosomes may replicate 2 or 3 times but instead of separating they organise rudimentary asters of MTs along with a general decay of the egg cytoplasm. About 1% of eggs derived from Fs(2)Ket² Dp(2;Y)G females turn brown, indicating the progression of embryogenesis to the stage of cuticle formation. In addition a small number of adult offspring are produced.

Heterozygous females are fully viable and fertile. Mutant phenotype may be 'cured' by increasing the normal gene product ratio.

About 50% of the eggs from heterozygous females appear unfertilised. The remainder can undergo cleavage divisions up to the syncytial blastoderm stage.