Figure 3
Ultra-structural analysis of the spermatozoa from male Gykl1 and Gk2 mutant mice. (a–d) The spermatozoa were collected from various mice and analyzed by transmission electron microscopy (TEM) coupled with Electron Tomography, which enabled detailed 3D imaging of the midpiece and tail regions. For each group, the middle slice of the electron tomogram is shown on the left, the annotation model on the right, and superimposed tomogram with the annotation model in the middle. Purple indicates the outer cell membrane of the spermatozoa, green the outer membrane of the mitochondria, cyan the doublet microtubule or central microtubule, and yellow the outer dense fibers. White arrows, swollen and misarranged mitochondria. Black arrows, midpiece that lacks mitochondria. Green arrows, gaps between outer dense fibers. Red arrows, gaps between the mitochondrial sheath and outer dense fibers. Yellow arrows, branched or fragile axoneme. Scale bar, 200 nm. (e and f) The length of the mitochondria short axis (e) and the gaps among outer dense fibers (f) in the spermatozoa from wild-type and mutant mice were measured and plotted. Over 300 spermatozoa were counted for each group. Error bars represent s.d. Significance was determined by ANOVA. *P<0.05.
