Meiosis I proceeds to metaphase and, rarely, anaphase in mutant males. In most cysts in division, bivalents with the centromeres directed towards opposite poles are seen. Undivided co-oriented bivalents move polewards in anaphase spindles. This movement is irregular, resulting in many cases with more than 32 nuclei per cyst and many micronuclei. Many cysts do not undergo meiosis at all, and instead all their chromosomes are found in projected nuclear pockets. First division spindles are tetrapolar, but the two daughter asters are found close to each other at the spindle poles, forming in effect two parallel spindles.