Mature oocytes show cytological defects (reduced distances between homologous centromeres) but no defects in somatic mitosis of larval CNS or in male meiosis. Oocyte spindles are bipolar as normal, but are shorter and denser than wild type. In contrast to wild type, where homologous centromeres are located at opposite ends, homologous centromeres are located closely together in 45% of mutant oocytes. Unlike controls, mutant oocytes have asymmetric kinetochores at late stages which are not corrected and are stably maintained - homologous kinetochores are seen to attach to microtubules from the same pole (monopolar attachment). Kinetochore-microtubule attachments are formed precociously in mutant oocytes and kinetochores are much less mobile.