Basal bodies are present in asl¹/Df(3R)ED5177 spermatocytes, but more than one-third of the cells show a loss of basal bodies and the basal bodies are smaller than normal. The recruitment of pericentriolar material (PCM) by centrioles is impaired in asl¹/Df(3R)ED5177 spermatocytes, but the PCM is able to assemble in mitosis in mutant spermatogonia.

The centrosomes are severely perturbed in asl¹ spermatocytes, with most spermatocytes containing a single cluster of up to four centrioles. Aster nucleation is very reduced and defects in meiotic spindle assembly are seen. In some cases microtubule organisation is anastral and chaotic, while the main spindle type seen in the mutant spermatocytes is monastral.

In embryos derived from asl¹/Df(3R)ED5177 mothers, female meiosis proceeds normally; distinct polar bodies and female pronuclei are seen, sperm entry takes place and upon fertilisation, all five nuclei are present and arranged in a seemingly normal configuration. However, assembly of the sperm aster, centrosome duplication and pronuclear fusion do not occur in these embryos. Instead, nonfunctional, anastral spindle-shaped structures are formed around the female-derived chromosomes and chromosome segregation is never seen.

asl²/asl¹ and asl³/asl¹ animals are viable. Onion stage spermatids from homozygous males have nuclei and nebenkern of various sizes. Homozygous, asl²/asl¹ and asl³/asl¹ spermatocytes are completely devoid of asters. Homozygous spermatocytes have morphologically normal centrioles. However, centriole separation is abnormal; some nebenkern are associated with two centrioles instead of one as in wild-type. Prometaphase I, metaphase I and early anaphase I appear to last longer in homozygous testes than in wild-type.

Primary spermatocytes of homozygous males are devoid of spindle asters. This defect is restricted to meiotic cell division.

Primary spermatocytes in meiotic prophase are devoid of spindle asters in homozygous males. Nonetheless, chromosome segregation does occur, and a central spindle forms as the chromosomes migrate to the poles. The anaphase poles are very broad, sister chromatids separate during the first meiotic division, non-disjunction is frequent and cytokinesis does not occur. Spermatid cysts contain a myriad of micronuclei associated with large nebenkern. Mitosis in larval neuroblasts is normal, suggesting that asl⁺ function is specifically required for the formation of the meiotic centrosome.