The timing of the appearance of the first spindle microtubules after nuclear envelope breakdown shows only a marginal difference between wild type and wac^Δ12 mutant oocytes.

wac^Δ12 mutant oocytes have a significantly increased frequency of spindles with missing or weak spindle poles compared to wild type.

Homozygous or hemizygous (over Df(3L)BSC125) wac^Δ12 mutants are viable. Adults exhibit a few morphological defects such as rough eyes, missing bristles, or abdominal cuticle defects, indicating few cell division failures in imaginal tissues.

Chromosome condensation appears to be generally higher in wac^Δ12 mutants, although overcondensation is rarely observed. the frequency of mitosis is significantly higher and the frequency of anaphases among mitotic cells is significantly lower in the mutant, although only a low level of aneuploid cells is found. These results indicate that mitotic progression is delyed but not blocked before anaphase onset and that chromosomes are properly segregated in general.

wac^Δ12 homozygous spermatids exhibit a wild-type distribution of nuclear size at the postmeiotic onion stage. Approximately 7% of sex chromosomes mis-segregate. compared to 0.5% in controls.

wac^Δ12 mutants are male fertile but female sterile. Mutant adult females develop fully matured ovaries and lay eggs that fail to hatch.

Chromosomal positioning is disrupted within the bipolar spindle in the majority of wac^Δ12 oocytes (~57%). Meiotic chromosomes are often spread and/or stretched along the spindle in wac^Δ12 mutants rather than being clustered together at the equator region as seen in wild-type.