Meiotic entry is blocked, meiotic spindles do not form.
The testes of homozygous males contain only premeiotic germ cell stages.
In homozygotes, spermatocytes form but fail to undergo meiotic divisions. 64-cell spermatid cysts are absent. BrdU labeling shows that mitotic and premeiotic S phases occur as in wild-type, and meiotic prophase is normal. Subsequent stages of meiosis are aberrant. Chromosomes remain at the nuclear periphery, and centrosome separation occurs but the centrosomes do not reach the poles and do not nucleate asters. The nuclear lamina fails to break down. Spermiogenesis continues to a limited extent. Mitochondria begin to form nebenkern in tetraploid spermatids. Hemizygous males show minor but reproducible defects in spermatogenesis.
Some 16-cell cysts resemble those of pelo, with no meiosis and abnormally large Nebenkern in late spermatocytes; others contain multiple nuclei as well as large Nebenkern.
bol1 has abnormal meiotic cell cycle | male phenotype, suppressible by tweβTub85D.PM
bol1 has spindle | male phenotype, suppressible by tweβTub85D.PM
A. Spradling.