Immunostaining of CDC42 and IFT74 in spermatozoa from mice and humans. (A) Immunostaining of CDC42 (red) and α-tubulin (green) in spermatozoa from Iqcn^+/+ and Iqcn^−/− male mice. Scale bars, 10 μm. (B) Immunostaining of IFT74 (red) and α-tubulin staining (green) in spermatozoa from Iqcn^+/+ and Iqcn^−/− male mice. Scale bars, 10 μm. (C) Immunostaining of CDC42 (red) and α-tubulin staining (green) in spermatozoa from normal controls and affected individuals. Scale bars, 5 μm. (D) Immunostaining of IFT74 (red) and α-tubulin staining (green) in spermatozoa from normal controls and affected individuals. Scale bars, 5 μm. IQCN, IQ motif-containing N; CDC42, cell division cycle 42; IFT74, intraflagellar transport 74.