1. An ultrastructural and immunocytochemical study of a rare genetic sperm tail defect that causes infertility in humans 
Baccio Baccetti, M.D., Emanuele Bruni, Ph.D., Laura Gambera, Ph.D., Elena Moretti, Ph.D., Paola Piomboni, Ph.D. 
Fertility and Sterility 
Volume 82, Issue 2, Pages (August 2004)
DOI: /j.fertnstert

2. FIGURE 1
Transmission electron microscopy micrographs of longitudinal and cross-sections of ejaculated spermatozoa. (a) A spermatozoon shows well-shaped acrosome (A) and nucleus (N) with condensed chromatin, whereas abnormal length of the midpiece region (M) is evident. (b) Bundles of axonemes (Ax) with incomplete microtubular set, enveloped in the same membrane. (c) The peculiar sperm tail defect is absence of the fibrous sheath at the principal-piece level, where the axonemal pattern and the accessory fibers are regularly assembled. (d) Fibrous sheath remnants (FSR) embedded in residual bodies released in the ejaculate. Original magnification, ×11,000 for A; ×60,000 for B; ×109,500 for C; ×10,000 for D.
Baccetti. Rare human flagellar cytoskeletal defect. Fertil Steril 2004.
Fertility and Sterility  , DOI: ( /j.fertnstert )

3. FIGURE 2
Ultraviolet and blue-light micrographs of ejaculated spermatozoa and cryofixed testicular tissue. (a, b) Staining with monoclonal anti-tubulin antibody highlights bundles of axonemes emerging at the end of the midpiece. (c, d) A disorganized network of microtubular structures emerging randomly at any level of the flagellum. (e, f) Double-staining performed with anti-tubulin antibody and fluorescence (MitoTracker FM), respectively, shows very short tail (arrows), tail with disorganized network of microtubular structures (arrowheads), and an increased length of mitochondrial helix. (g, h) Immunocytochemical labeling with anti-AKAP 82 monoclonal antibody of sperm from another patient affected by fibrous sheath dysplasia; fluorescence staining highlights the disorganization or the reduced presence of AKAP4 protein at the tail level. Labeling with the same antibody was regularly present at the principal-piece level of sperm from proven-fertile individuals (i). (j, k) Cryofixed testicular tissue is labeled with anti-AKAP 82 monoclonal antibody (J) and anti-tubulin monoclonal antibody (k). (j) The presence of AKAP4 protein is diffuse in the testicular tubule. (k) Abnormally numerous organized microtubular structures localized all over in the seminiferous epithelium, from the basal to the adluminal region. Original magnification, × 570 for A, B; ×450 for C, D; ×450 for e; ×400 for F–H; ×520 for I; ×800 for J; ×400 for K.
Baccetti. Rare human flagellar cytoskeletal defect. Fertil Steril 2004.
Fertility and Sterility  , DOI: ( /j.fertnstert )

4. FIGURE 3
Transmission electron microscopy micrographs of longitudinal sections of testicular spermatids. Acrosomes (A) surround nuclei (N) with evidently immature chromatin. (a, b) An emerging, well-developed, centriolar adjunct (CA) is evident. (b) A peculiar abundance of mitochondria (M), assembled around a rolled-up or doubled axoneme at the midpiece level and spread in the upper region of cytoplasmic residue (CR). Fibrous sheath remnants (FSR) are present in the cytoplasm of spermatids, but they are never organized around the principal piece (PP), emerging at the lower region of cytoplasm. (c) A large cromatoid body (CB) envelopes the distal centriole. (d) The ring-shaped annulus (An) surrounding the axoneme (AX) and the accessory fibers. (e) Bundle of axoneme (AX) with complete microtubular set enveloped in the same membrane. (f) Longitudinal section of spermatid with acrosome (A) surrounding a regularly shaped nucleus (N) with almost condensed chromatin and a cross-section of the principal piece (arrow) with well-organized axoneme and accessory fibers but completely lacking in fibrous sheath. Original magnification, ×7000 for A; ×6500 for B; ×9500 for C; ×16,000 for D; ×34,000 for E; ×20,000 for F.
Baccetti. Rare human flagellar cytoskeletal defect. Fertil Steril 2004.
Fertility and Sterility  , DOI: ( /j.fertnstert )