Mitotic cells from the brains of homozygous adults show several defects. From prophase to anaphase condensing chromatin appears fuzzy. In addition mant prometaphase and metaphase figures do not show well-defined sister chromatids. Most cells in anaphase show abnormally condensed chromatin and contained chromatin bridges and some chromosome fragmentation. Over half of anaphase figures show chromatin bridges during telophase. About 9/10 of prophases or metaphases show abnormal condensation. About 4/5 of glu^k06821a/glu^k08819 anaphase or telophase figures show chromatin bridges, those bridges that persist to telophase also show abnormal decondensation. Mutant brains are smaller and show higher levels of apoptosis than wild-type. 3% of cells in glu^k06821a homozygous brains are apoptotic and 2.5% in glu^k06821a/glu^k08819 brains (compared to 0.5% in wild-type). Mean chromosome lengths in either glu^k08819 homozygous or glu^k06821a/glu^k08819 brains that have been incubated in colchicine do not differ from wild-type.

Lethality is during the late larval stage. Neuroblasts show distinct abnormalities during chromosome segregation. A large proportion of anaphase or telophase cells fail to resolve sister chromatids, thus forming chromatin bridges that occasionally result in chromosome breakage and polyploidy. Mutant cells take longer to exit mitosis than wild type.