60.7% of eggs laid by homozygous females are resistant to a 2 minute incubation in 50% bleach, compared to over 90% of control eggs, suggesting that vitelline membrane crosslinking occurs in the mutant eggs, but might be incomplete or delayed relative to wild type.

Most 0-1 hour fertilised eggs (embryos) laid by heterozygous females undergo embryonic mitotic divisions. In contrast, no embryos laid by wisp⁴¹/Df(1)RA47 females enter a normal zygotic mitosis. Instead, they are arrested at an aberrant metaphase-like stage with very few (usually five or less) spindles. The chromosomes associated with the spindle structures are condensed and appear to have entered a division cycle. The aberrant spindles are generally not associated with microtubule-organising centers (MTOCs). However, in some of these fertilised eggs, one spindle can be seen deep inside the embryo, with two aster structures.

Analysis of 5-15 minute embryos derived from wisp⁴¹/Df(1)RA47 females indicates that all stages of female meiosis are seen in the mutant embryos, although they show reduced α-tubulin staining of the acentriolar MTOC between the two linked meiotic spindles in metaphase II and telophase II. In embryos from the mutant females, the paternal chromosomes decondense to form a male pronucleus, as in control embryos, but none of the female meiotic products migrate towards the male pronucleus, and thus there is no pronuclear apposition.

The four maternally derived nuclei in unfertilised eggs from wisp⁴¹/Df(1)RA47 females (these eggs have been generated by mating the females to spermless males) become associated with spindles that resemble meiotic spindles (in control unfertilised eggs, a polar body rosette structure forms normally). In some cases, the four haploid nuclei fuse to associate with an irregular-sized spindle, but no rosette-shaped structure can be seen.