Spermatogenic defects in <i>Katnal2</i>^GCKO/GCKO mice.

<p>(<b>a</b>) Testis weight in <i>Katnal2</i>^FLOX/FLOX (white triangles) and <i>Katnal2</i>^GCKO/GCKO (black triangles) mice (n = 3/group). (<b>b</b>) Daily sperm output (DSP) in the testes of <i>Katnal2</i>^FLOX/FLOX (white triangles; n = 3) and <i>Katnal2</i>^GCKO/GCKO (black triangles; n = 4) mice. (<b>c</b>) Total epididymal sperm content of <i>Katnal2</i>^FLOX/FLOX (white triangles) and <i>Katnal2</i>^GCKO/GCKO (black triangles) mice (n = 3/group). Total epididymal sperm content was reduced by 94.1% in <i>Katnal2</i>^GCKO/GCKO mice compared to <i>Katnal2</i>^FLOX/FLOX mice. In <b>a</b>–<b>c</b> lines represent mean ± SD, ** p<0.01 compared to <i>Katnal2</i>^FLOX/FLOX. Periodic acid Schiff’s (PAS) stained testis sections from <i>Katnal2</i>^FLOX/FLOX and <i>Katnal2</i>^GCKO/GCKOO mice (<b>d</b>–<b>i</b> and <b>p-q</b>). Low magnification view of seminiferous tubules in <i>Katnal2</i>^FLOX/FLOX (<b>d</b>) and <i>Katnal2</i>^GCKO/GCKO (<b>e</b>) mice. Multinucleated symplasts (arrowhead) were frequently observed in the <i>Katnal2</i>^GCKO/GCKO seminiferous epithelium. Elongating spermatids in <i>Katnal2</i>^FLOX/FLOX (<b>f</b>) versus <i>Katnal2</i>^GCKO/GCKO (<b>g</b>) mice. Abnormal nuclear morphology of spermatids (arrowheads) was frequently observed in <i>Katnal2</i>^GCKO/GCKO mice. Spermiation in <i>Katnal2</i>^FLOX/FLOX (<b>h</b>) versus <i>Katnal2</i>^GCKO/GCKO (<b>i</b>) mice. Retained elongated spermatids (arrowheads) were often observed in stage IX tubules of <i>Katnal2</i>^GCKO/GCKO mice but were rarely observed in <i>Katnal2</i>^FLOX/FLOX mice. Acetylated tubulin immunolabelling as a marker for sperm tail presence in <i>Katnal2</i>^FLOX/FLOX (<b>j</b>) and <i>Katnal2</i>^GCKO/GCKO (<b>k</b>) testis sections. Sperm tail content was markedly reduced in <i>Katnal2</i>^GCKO/GCKO (<b>k</b>) versus <i>Katnal2</i>^WT/WT (<b>j</b>) mice. Scale bars in <b>d</b>–<b>k</b> = 10 μm. Electron microscopy of stage VIII tubulobulbar complexes (asterisks) in <i>Katnal2</i>^FLOX/FLOX (<b>l</b>) versus <i>Katnal2</i>^GCKO/GCKO (<b>m</b>) mice. Tubulobulbar complex formation was normal in <i>Katnal2</i>^GCKO/GCKO mice. Scale bars in <b>l</b>–<b>m</b> = 2 μm. Immunostaining of seminiferous tubules for the tubulobulbar complex marker ARP2 in <i>Katnal2</i>^FLOX/FLOX (<b>n</b>) versus <i>Katnal2</i>^GCKO/GCKO (<b>o</b>) mice further confirmed the presence of tubulobulbar complexes from <i>Katnal2</i>^GCKO/GCKO spermatids. Residual body (arrowheads) formation in <i>Katnal2</i>^FLOX/FLOX (<b>p</b>) versus <i>Katnal2</i>^GCKO/GCKO (<b>q</b>) mice. Residual body formation appeared normal in <i>Katnal2</i>^GCKO/GCKO mice. Scale bars in <b>n</b>–<b>q</b> = 10 μm. Primary antibody negative controls for (<b>j</b>–<b>k</b>) and (<b>n</b>–<b>o</b>) are included in <a href="http://www.plosgenetics.org/article/info:doi/10.1371/journal.pgen.1007078#pgen.1007078.s009" target="_blank">S7 Fig</a>.