FIGURE 2.

DNAH2 deficiency in mice recapitulates multiple morphological abnormalities of the flagella in humans. (A) Confocal images of DNAH2 in WT and Dnah2^Δ/Δ sperm. DNAH2 were immunodetected from WT sperm but not from Dnah2^Δ/Δ sperm. Sperm heads were counterstained with Hoechst. Shown images are confocal images merged to the corresponding DIC images. H, head; MP, midpiece; PP, principal piece. (B) Testicular and epididymal histology of Dnah2^Δ/Δ mouse testis and epididymis. H/E stained sections show Dnah2^Δ/Δ males produce less sperm with elongated tails in the lumen of seminiferous tubule in testis (top), resulting in fewer sperm cells in the epididymis (bottom, corpus). (C,D) Multiple morphological defects in epididymal Dnah2^Δ/Δ sperm. (C) Morphology of Dnah2^+/Δ (left) and Dnah2^Δ/Δ (right) sperm. Sperm from heterozygous males are morphologically normal. Dnah2^Δ/Δ sperm, however, present MMAF-like phenotypes, such as absent, short, coiled, and irregular-caliber flagella (from left top, clockwise direction). Sperm heads were Hoechst-stained (blue). Fluorescence confocal and corresponding DIC images are merged. (D) Proportions of sperm with defective flagellar morphologies. Sperm with absent, short, bent, coiled, and irregular-caliber flagella were quantified from WT (gray) and Dnah2^Δ/Δ (red) male mice (N = 3, each). Sperm proportions of each pattern were statistically compared between WT and Dnah2^Δ/Δ males. Data is represented as mean ± SEM. *p < 0.05; **p < 0.01; ***p < 0.001.