Semilethal: 30% of viability.
The divisions of the gonial cells are not completed in hemizygous males. Many primary spermatocyte cysts contain less than 16 cells. The spermatocyte nuclei are fenestrated in some areas, the nucleolus is large and the endoplasmic reticulum is closely associated with the nuclear envelope which is irregular. No normal mitochondrial derivatives are seen. Complete axonemes are seen in cells approximating stage 6, but the axonemes are not associated with normal membranes or mitochondria. Gametes degenerate in the spermatid stage.
Mutation blocks gene functions that are critical to the development of both reproductive and non-reproductive tissues. Genetic lesions evident prior to meiosis in the male gametes.
viable male-sterile