Unfertilized eggs have either no nuclei or a small number of large nuclei, free centrosomes and independent arrays of microtubules. Fertilized eggs from homozygous asp females have this phenotype and embryos that undergo varying degrees of aberrant morphogenesis. The embryos have free centrosomes, abnormal arrays of microtubules and have large areas that are devoid of or have a reduced number of nuclei. Brain neuroblasts of homozygous asp larvae have a high mitotic index and have condensed chromosomes as if blocked at metaphase. Immunostaining reveals that many cells have a single centrosome connected to the metaphase chromosomes by microtubules connected in a hemi-spindle-like structure.
