Fig. 2

Sperm Morphology and Ultrastructure Analyses for Men Harboring ARMC2 Variants. A Light microscopy analysis of spermatozoa from the control and men harboring ARMC2 variants. Most spermatozoa from men harboring ARMC2 variants have flagella that are short, coiled, or of irregular caliber. The spermatozoa from subjects P1 and P2 are given as examples of typical MMAF phenotypes observed in men harboring ARMC2 variants. Scale bars: 10 μm. B TEM analyses of sperm cells from a fertile control and two men harboring ARMC2 variants. The control individual shows the typical ‘‘9 + 2’’ microtubule structure, including nine peripheral microtubule doublets paired with nine outer dense fibers and the central pair of microtubules, surrounded by the organized mitochondrial sheath or fibrous sheath. The ultrastructure observed in cross-sections of the flagella in men harboring ARMC2 variants indicates the misarranged outer dense fibers and disorganization of the peripheral microtubules with a lack of the central pair of microtubules. Scale bars: 500 nm. Abbreviations: MS, mitochondrial sheath (yellow arrows); CP, central pair of microtubules (orange arrows); MD, microtubules doublet (green arrows); ODF, outer dense fiber (blue arrows). C In the lung window, P2-I demonstrated bilateral lower lung bronchiectasis with characteristic imaging features, including the signet ring sign (red arrows). In the mediastinal window, P2-II displayed normal anatomical positioning of the liver (blue arrows), spleen (yellow arrows), and stomach (green arrows), with no evidence of situs inversus