Fig. 4

Morn2 knockout causes abnormal mitochondrial morphology in sperm. A TEM analysis of spermatozoa from epididymis in Morn2^+/– and Morn2^–/– mice. The flagellum mid-piece from Morn2^–/– spermatozoa showed hypertrophy and swelling of the mitochondria and disarrangement and hyperplasia of the outer dense fibers. Red arrow: outer dense fiber; White arrow: mitochondrial sheath. The test was replicated three times using distinct biological samples. The scale bar is shown in the figure. B SEM analysis of spermatozoa from the epididymis of Morn2^+/– and Morn2^–/– mice. The test was replicated three times using distinct biological samples. The scale bar is shown in the figure. C TEM showed that the spermatozoa from Morn2^–/– mice had axonemal disorganization. The test was replicated three times using distinct biological samples. The scale bar is shown in the figure. D TEM showed that the mid-piece of the axoneme from Morn2^–/– mice showed hyperplasia of the outer dense fiber, and the arrangement of the mitochondrial sheath was severely disrupted. Red arrow: outer dense fiber; Blue arrow: radial spoke; Yellow arrow: mitochondrial sheath; 1: microtubules doublet; 2: microtubule central pair. The test was replicated three times using distinct biological samples. The scale bar is shown in the figure