Fig. 2.

Transmission electron microscopy analysis of sperm cells from CFAP43 and CFAP44 patients shows a severe axonemal disorganization. (Left panel) Longitudinal sections (scale bar = 500 nm) and cross-sections (scale bars, 100 nm) of sperm flagellum from control. (Central panel) Longitudinal sections (scale bars, 500 nm) and cross-sections (scale bars, 100 nm) of sperm flagellum from CFAP43-mutated patient (P₄₃-8). We can notice a short short tail corresponding to a cytoplasmic mass containing the different components of the flagellum, all unorganized. In CFAP43 upper cross-section, the CPC is not aligned with DMTs 3 and 8 (red line) and is rotated by 90°. We can observe the absence of central pair of microtubules in other cross-sections. (Right panel) Ultrastructure of CFAP44-mutated sperm (P₄₄-3) longitudinal sections (scale bars = 500 nm) show similar ultrastructure of short tail (cytoplasmic mass). In CFAP44 upper cross-section, the central pair is disassembled and displaced (red arrow). We can observe the absence of central pair of microtubules in other cross-sections. Scales bars for cross-sections = 100 nm