Figure 5.

Sperm Morphology and Ultrastructure Analyses for Dnah8-KO Male Mice

(A) H&E staining of the spermatozoa obtained from mouse cauda epididymis. The spermatozoa from heterozygous mutated (Dnah8^wt/em1) male mice showed normal morphology. In contrast, Dnah8-KO (Dnah8^em1/em1) male mice manifested aberrantflagellar morphologies, which were consistent with the clinical phenotypes in the MMAF-affected men. Scale bar: 5 μm.

(B) TEM of cross-sections of the spermatozoa from Dnah8-KO male mice. Cross-sections of the mid-piece (i) and principal piece (iii) of the sperm flagella in heterozygous mutated male mice are shown as controls. (ii) Cross-sections of the mid-piece of the sperm flagella in Dnah8-KO male mice revealed disorganization of mitochondrial sheaths, outer dense fibers, and microtubules. (iv) Cross-sections of the principal piece of the sperm flagella in Dnah8-KO male mice showed disorganization of fibrous sheaths, outer dense fibers, and microtubules. White arrows indicate mitochondrial sheath, orange arrows indicate fibrous sheaths, yellow arrows indicate outer dense fibers, blue arrows indicate peripheral microtubule doublets, and red arrows indicate the central pair of microtubules. Scale bars: 200 nm.