Figure 2.

Sperm Morphology and Ultrastructure Analyses for Men Harboring TTC29 Mutations

(A) Light microscopy analysis of spermatozoa from the control (i) and men harboring TTC29 mutations (ii–v). Most spermatozoa from men harboring TTC29 mutations have flagella that are absent (ii), short (iii), coiled (iv), or of irregular caliber (v). The spermatozoa from subject A038 IV-1 are given as examples of typical MMAF phenotypes observed in men harboring TTC29 mutations. Scale bars: 5 μm

(B) TEM analyses of sperm cells from a fertile control and two men harboring TTC29 mutations. Cross-sections of the mid-piece (i) and principal piece (iv) of the flagella in a control man show 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 TTC29 mutations indicates the misarranged outer dense fibers (ii) and disorganization of the peripheral microtubules with lack of the central pair of microtubules (iii, v, and vi). Scale bars: 200 nm. Abbreviations: CP, central pair of microtubules (green arrows); MT, peripheral microtubule doublet (blue arrows); ODF, outer dense fiber (purple arrows).