topiZ3-2139/topiZ3-0707 heterozygote males show morphological defects of the nuclear lamina in stage S4-S6 spermatocytes (the lamina has more ballon-like shape, largely lacking the deformations that correlate with chromosome distribution seen in wild-type), while in stage S3 the lamina is of wild-type appearance.
topiZ3-2139/topiZ3-0707 mutant spermatocytes exhibit meiotic arrest and other defects, including bivalent chromosomes condensing to spherical shapes away from the nuclear periphery, and failure of the nucleolus to fully break down.
Chromosomes in mutant primary spermatocytes are partially condensed and are not close to the nuclear envelope (in contrast to wild-type primary spermatocytes where they are decondensed and adjacent to the nuclear envelop).
The testes of topiZ3-2139/topiZ3-2139 adult males contain germ cell cysts up to and including mature primary spermatocytes, but lack germ-cells in meiotic division or spermatid differentiation stages. Degenerating primary spermatocytes are present in the distal region of the testis.