Males homozygous for the tw8 haplotype are sterile. As those studies describe, testes from tw8/tw8 males have many degenerating seminiferous tubules that are devoid of germ cells. Other tubules undergo grossly normal spermatogenesis; however, many spermatids have abnormally shaped heads and dumbbell-shaped nuclei. Some tubules also seem to be less organized than in wild type, having germ cells of apparently different stages within the same section of the tubule. The manchettes show subtle defects, mostly appearing less uniform than manchettes in wild type. Some manchettes appear to bundle around the caudal end of the nucleus with fewer numbers of microtubules extending into the cytoplasm. ventolin inhalers
There also appear to be aggregates of ectopic microtubules that are unrelated to manchette formation. As in wild type, the manchettes are disassembled in step 15 spermatids SPNR staining in tw8 homozygotes appeared nonuniform, being highly localized to the caudal end of the nucleus and exhibiting less staining as the manchette extended into the cytoplasm (tw8 panel, Fig. 1). SPNR-positive microtubule aggregates were also evident (arrow, tw8 panel,Fig. 1). SPNR could also be seen in the cytoplasm of some elongating spermatids, as well as in a Sertoli cell at the basal lamina, apparently from the phagocytosis of an elongating spermatid (arrowhead tw8 panel, Fig. 1). Confocal micrographs of SPNR and tubulin in early-stage spermatids show that the two proteins colocalized with one another (Fig 4, A-C). As the spermatids elongated, SPNR (Fig. 4D) and tubulin (Fig. 4E) staining became patchy and discontinuous (Fig. 4F, merged image).
FIG. 4. Confocal micrographs of SPNR and tubulin immunolocalization in tiva/jw,a (A-F) and tw2/tw2 (G-L) testes. Testis sections were treated with rabbit polyclonal affinity-purified anti-SPNR and/or mouse monoclonal anti-a-tubulin primary antibodies. Sections were then treated with an antirabbit FITC-conjugated and/or anti-mouse Texas red-conjugated secondary antibody. A, D, G, J) SPNR; B, E, H, K) tubulin; C, F, I, L) merged SPNR and tubulin staining. F) Arrow points to ”patchy” staining pattern. I and L) Arrow points to ectopic manchette.