Figure 3: TEM analysis of CCDC103 p.His154Pro spermatozoa revealed the absence of DAs. Representative TEM micrographs showing cross-sections of end piece (first line), middle principal piece (middle line), and longitudinal surface (bottom line) of sperm flagella from a fertile control (left part) and two patients (middle part IV:1 and right part IV:7). Scale bars = 2 μm. Red arrow indicates the normal DAs in control and the DA-absent place in patients. TEM: transmission electron microscopy; CCDC103: coiled-coil domain-containing 103; DA: dynein arm.