TEM of sperm from Eno4Gt/Gt and WT mice. Sperm collected from cauda epididymis were fixed, sectioned, and examined by TEM. Cross sections (A–C) and sagittal section (D) of sperm flagellum are shown. A, B, and D) Sperm from Eno4Gt/Gt mouse. C) Sperm from WT mouse. LC, longitudinal column; AN, annulus. Bars = 0.2 μm.