sauZ2217 homozygous adults present heat sensitive paralysis (38[o]C), unlike heterozygotes and wild-type controls. These mutants exhibit normal wing posture.
Most spermatids in sauZ2217/Df(2L)Exel7010 males testes are multinucleate, indicating cytokinesis failure.
The majority of sauZ2217 mutant spermatids have one large nebenkern with four nuclei of normal size, indicating a cytokinetic failure in both meiotic divisions. A very small proportion (<1%) have two nuclei and a large nebenkern, indicating failure of only one of the meiotic divisions. An equally small proportion have three nuclei, indicating failure of cytokinesis in the first meiotic division, followed by budding off of only one daughter cell in the second meiotic division. A proportion of spermatids (<3%) have over four nuclei, which may result from defects in the mitotic divisions preceding mitosis. Spermatocytes of sauZ2217 mutants lack an organized central spindle and an F-actin ring throughout ana-telophase. The equatorial anillin band is present but fails to constrict properly.