'Round head' sperm defect. Ultrastructural and meiotic segregation study

The sperm 'round head' defect, also known as globozoospermia, is an uncommon alteration of sperm morphology generally characterised by 100% round headed sperm totally lacking an acrosome. This alteration is a genetic sperm defect as demonstrated by analysing the incidence of these alterations in a population of infertile men showing a history of consanguinity and cases belonging to the same family. Ultrastructural characteristics and meiotic segregation in spermatozoa from two patients affected by 'round head' sperm defect were investigated. The sperm quality was examined by light and transmission electron microscopy (TEM) and fluorescence in situ hybridization (FISH) analysis was performed in order to investigate the meiotic behavior of chromosomes namely gonosomes and chromosome 18. TEM analysis, mathematically elaborated, clearly diagnosed the 'round head' genetic sperm defect and highlighted at the same time the presence of other phenotypic alterations belonging to pathologies such as immaturity, apoptosis and necrosis. It is possible to hypothesize that round headed sperm could be a 'weak phenotype' allowing the sperm pathologies to overlap with a sperm defect of genetic origin, further compromising fertilizing potential. FISH analysis revealed a positive correlation between globozoospermia and higher disomies of sex chromosomes and diploidies suggesting a higher risk of creating an aneuploid embryo after intracytoplasmic sperm injection.     

Gene deletions in an infertile man with sperm fibrous sheath dysplasia

BACKGROUND: Asthenozoospermia may sometimes be related to geneticstructural defects of the sperm tail detectable by transmissionelectron microscopy. Dysplasia of the fibrous sheath (DFS) isa genetic sperm defect, characterized by dysplastic developmentof the axonemal and periaxonemal cytoskeleton. We report thecase of an infertile man with normal sperm count and total spermimmotility in which dysplasia of the fibrous sheath, Akap3,Akap4 gene deletions, meiotic segregation of chromosomes 18,X and Y and Y microdeletions were investigated. METHODS: A 32-year-oldman with a 3-year history of primary infertility presented atour Regional Referral Center for Male Infertility. Family medicalhistory, lymphocyte karyotype, PCR analysis, physical examination,hormone assays and semen analysis were performed. RESULTS: Ultrastructuralsperm evaluation showed dysplasia of the fibrous sheath. Immunostainingof AKAP4 protein was negative in sperm tails. PCR analysis revealedintragenic deletions of the Akap3 and Akap4 genes. Fluorescencein situ hybridization on sperm showed a high frequency of XYdisomy. CONCLUSION: In this infertile patient, our results suggesta possible relationship between dysplasia of the fibrous sheath,partial deletions in the Akap3 and Akap4 genes and absence ofAKAP4 protein in the fibrous sheath. These findings, however,were not detected in another four patients with dysplasia ofthe fibrous sheath. Our results require future confirmatorymolecular analyses.     

10, 15 reciprocal translocation in an infertile man: ultrastructural and fluorescence in-situ hybridization sperm study: case report

BACKGROUND: Peculiar sperm defects are described in a sterile man heterozygous for a balanced translocation t(10;15) (q26;q12). As this structural reorganization was absent in the parents, the translocation must have appeared de novo in the present patient. METHODS: Spermatozoa were analysed under light and transmission electron microscopy (TEM). Fluorescence in-situ hybridization (FISH) was performed on the lymphocyte karyotype. Aneuploidy frequencies of chromosomes 18, X and Y in sperm nuclei, not involved in the translocation, were investigated using three-colour FISH. Dual- colour FISH was used to evaluate segregation of chromosomes 10, 15 in decondensed sperm nuclei. Moreover, three-colour FISH, using telomeric probes for chromosomes 10, 15 was performed in order to distinguish balanced and unbalanced gametes. RESULTS AND CONCLUSIONS: Overall, structural characteristics indicate general immaturity of the germinal cells. FISH sperm analysis detected an increase in chromosome 18 disomy (0.81%) suggesting an interchromosomal effect. A high frequency of diploidies, particularly 18,18,X,X and 18,18,X,Y, was also found. FISH segregation analysis for chromosomes 10, 15 indicated that 32.8% were balanced gametes, whereas 68.2% were unbalanced. Taken together, these data demonstrate in a male carrier of a reciprocal translocation t(10;15) the presence of diffuse ultrastructural sperm alterations and a high frequency of sperm aneuploidies. The existence of a correlation among these factors is proposed.     

Ultrastructural pathology of the sperm flagellum: association between flagellar pathology and fertility prognosis in severely asthenozoospermic men

An ultrastructural study of spermatozoa in a series of 247 severely asthenozoospermic patients disclosed two kinds of anomalies. The first was dysplasia of the fibrous sheath, a primary defect of spermatozoa with hypertrophy and hyperplasia of the fibrous sheath, associated axonemal anomalies, familial incidence and chronic respiratory disease. The patients could be divided into two subgroups: the complete form (all spermatozoa affected) and the incomplete form (alterations in 70- 80% spermatozoa). There were no spontaneous or in-vitro fertilization (IVF) pregnancies. Intracytoplasmic sperm injection (ICSI) in six patients resulted in successful fertilizations, but only two pregnancies were obtained. These features configure a phenotype that suggests a genetic origin. The second anomaly was non-specific flagellar anomaly (NSFA), random secondary flagellar alterations affecting variable numbers of spermatozoa, without respiratory disease or familial incidence. 54 men with NSFA were followed for 2-6 years. Of these, 18 achieved conception, either spontaneous or by means of assisted fertilization, followed by 14 pregnancies and 12 live births. Their sperm motility significantly increased during the follow-up period. In the remaining 36 men motility did not change during the follow-up period and there were no fertilizations or pregnancies. We conclude that in severe asthenozoospermia, ultrastructural examination of spermatozoa has an effective prognostic value, identifying two syndromes with very different flagellar alterations and fertility potentials.      

Successful intracytoplasmic sperm injection with spermatozoa from a patient with dysplasia of the fibrous sheath and chronic respiratory disease

The present report describes a successful intracytoplasmic sperm injection (ICSI) procedure performed with immotile spermatozoa from a young man with a combination of dysplasia of the fibrous sheath and dynein deficiency, a recently described variant of the immotile cilia syndrome. This methodology provides the only suitable solution for these patients in whom all other assisted fertilization technologies have previously failed, and opens the possibilities for treatment of male infertility due to severe, irreversible sperm defects such as the one reported here.      

Incidence of tail structure distortions associated with dysplasia of the fibrous sheath in human spermatozoa

Dysplasia of the fibrous sheath (DFS) is an anomaly found in spermatozoa of severe asthenozoospermic patients. Marked hypertrophy and hyperplasia of the fibrous sheath is the common characteristic. Immunocytochemistry allowed us to visualize the distortions and incidence of tail structure abnormalities associated with this phenotype in six patients; four with a complete form and two with an incomplete form of this pathology previously diagnosed and studied by electron microscopy. Microtubules and fibrous sheaths were studied using monoclonal antibodies against alpha-acetylated tubulin and anti-FSC1 (the major protein component of the fibrous sheath). Mitochondrial sheaths were visualized using the mitochondrion-specific vital dye MitoTracker green FM(TM). Phase contrast and fluorescent microscopy of semen samples showed large numbers of spermatozoa with short, rigid, thick and irregular tails. As expected, anomalous and completely distorted fibrous sheaths, severe alterations of the axonemal microtubules and different patterns of mitochondrial sheath configurations were found. While ultrastructural studies of thin sections allow an in-depth knowledge of the internal organization of the sperm tail, fluorescence labelling of selected sperm components affords a unique view of the whole flagellum including topographical relationships of various organelles. The combination of these different approaches is essential for a comprehensive understanding of this particular pathology.     

Genetic sperm defects and consanguinity.

BACKGROUND: The existence of a genetic component to human infertility has been suggested, although neither the specific abnormalities involved, nor their genetic mechanism of transmission, are currently defined. We have examined, by transmission electron microscopy (TEM), ejaculate from 1600 males with fertility problems. Among the subjects studied, we focused on a group of patients whose family histories revealed different degrees of consanguinity, in order to evaluate the relationship between consanguinity and particular sperm alterations. METHODS AND RESULTS: A total of 64 consanguineous individuals were identified. In this group, excluding two azoospermic patients, 17 patients (27%) were found to have well recognized genetic ultrastructural defects affecting their entire sperm population: eight subjects had spermatozoa with "stunted tails", four "detached tail" spermatozoa, two "Kartagener's syndrome", two "miniacrosome" and one "round headed" spermatozoa. Since these alterations affect the total sperm population and do not respond to medical treatment, they are suspected of having a genetic origin. The remaining group of 1506 non-consanguineous patients suffered from the same genetic defects in only 15 cases (<1%). CONCLUSIONS: From the data presented, it appears that some very peculiar and rare sperm defects may have a genetic basis since they occur more frequently in consanguineous patients, and are related to different degrees of consanguinity. Since the ejaculate of the remaining patients, both consanguineous and not, showed diverse types of ultrastructural sperm anomalies that did not affect the entire sperm population, they might represent pathologies lacking a genetic basis.     

Knockout mouse models of sperm flagellum anomalies

To date, 21 knockout mouse models are known to bear specific anomalies of the sperm flagellum structures leading to motility disorders. In addition, genes responsible for flagellar defects of two well-known spontaneous mutant mice have recently been identified. These models reveal genetic factors, which are required for the proper assembly of the axoneme, the annulus, the mitochondrial sheath and the fibrous sheath. Many of these genetic factors follow unexpected cellular pathways to act on sperm flagellum morphogenesis. These mouse models may bear anomalies which are restricted to the spermatozoa or display more complex phenotypes that often include neuropathies and/or cilia-related diseases. In human, several structural disorders of the sperm flagellum found in brothers or consanguineous men probably have a genetic origin, but the genes involved have not yet been identified. The mutant mice we present in this review are invaluable models, which can be used to identify potential candidate genes for infertile men with specific sperm flagellum anomalies.     

Value of transmission electron microscopy for primary ciliary dyskinesia diagnosis in the era of molecular medicine: Genetic defects with normal and non-diagnostic ciliary ultrastructure

ABSTRACT

Primary ciliary dyskinesia (PCD) is a genetic disorder causing chronic oto-sino-pulmonary disease. No single diagnostic test will detect all PCD cases. Transmission electron microscopy (TEM) of respiratory cilia was previously considered the gold standard diagnostic test for PCD, but 30% of all PCD cases have either normal ciliary ultrastructure or subtle changes which are non-diagnostic. These cases are identified through alternate diagnostic tests, including nasal nitric oxide measurement, high-speed videomicroscopy analysis, immunofluorescent staining of axonemal proteins, and/or mutation analysis of various PCD causing genes. Autosomal recessive mutations in DNAH11 and HYDIN produce normal TEM ciliary ultrastructure, while mutations in genes encoding for radial spoke head proteins result in some cross-sections with non-diagnostic alterations in the central apparatus interspersed with normal ciliary cross-sections. Mutations in nexin link and dynein regulatory complex genes lead to a collection of different ciliary ultrastructures; mutations in CCDC65, CCDC164, and GAS8 produce normal ciliary ultrastructure, while mutations in CCDC39 and CCDC40 cause absent inner dynein arms and microtubule disorganization in some ciliary cross-sections. Mutations in CCNO and MCIDAS cause near complete absence of respiratory cilia due to defects in generation of multiple cellular basal bodies; however, the scant cilia generated may have normal ultrastructure. Lastly, a syndromic form of PCD with retinal degeneration results in normal ciliary ultrastructure through mutations in the RPGR gene. Clinicians must be aware of these genetic causes of PCD resulting in non-diagnostic TEM ciliary ultrastructure and refrain from using TEM of respiratory cilia as a test to rule out PCD.     

Efficacy of the swim-up method in eliminating sperm with diminished maturity and aneuploidy

BACKGROUND: We have previously shown that after 80% Percoll centrifugation there is an overall 2.7-fold reduction of sperm with chromosomal disomies and diploidies (3.2-fold and 2.0-fold respectively), and of sperm with diminished maturity as detected by cytoplasmic retention. The relationship between disomies and immature sperm was r = 0.7, suggesting that disomy primarily originates in immature sperm. In the present work we studied the efficacy of the swim-up method in elimination of sperm with diminished maturity and with chromosomal aberrations in the swim-up sperm fractions of 10 patients (sperm concentration: 20 +/- 3.9 x 10(6)/ml, range 8.9-45.5; sperm motility: 45.2 +/- 2.4, all mean +/- SEM). METHODS: The validity of the study was enhanced by assessing each sperm fraction with three-colour (X, Y and 17; 5000 sperm) and two-colour (10 and 11; 5000 sperm) chromosome probes using fluorescence in-situ hybridization (FISH). Thus, in each sample 10 000 sperm were evaluated. The incidence of diminished maturity sperm was assessed with creatine kinase immunocytochemistry. RESULTS: In the swim-up fractions there was a reduction in the frequencies of disomic sperm, whether considering the sex chromosomes (1.4-fold) or the three autosomal chromosomes (1.5-fold based on the aggregate frequencies of disomy 10, 11 and 17). There was also a 1.5-fold reduction in diminished maturity sperm, indicating a relationship between the proportion of immature sperm and chromosomal aneuploidies (r = 0.46, P < 0.05, n = 20). Diploid sperm were reduced at a 2.7-fold rate, whether assessed with two- or three-colour FISH. There was a slight increase in the X/Y ratios. CONCLUSIONS: Swim-up reduces the proportion of sperm with chromosomal aberrations and of sperm with diminished maturity. When compared with the results of the previous study with gradient centrifugation performed on semen samples with similar quality, the efficacy after swim-up is lower for disomies and higher for diploidies than that of gradient centrifugation.     

A pathology of the sperm centriole responsible for defective sperm aster formation,syngamy and cleavage

BACKGROUND: In the present report we analyse the structural and functional features of sperm from a patient with severe asthenoteratozoospermia and failure of cleavage after ICSI. METHODS: Sperm were studied by phase contrast and transmission electron microscopy and microinjected into bovine oocytes to examine aster formation using antibodies against acetylated alpha- and beta-tubulins. RESULTS: Acephalic sperm, headless tails and abnormal alignments of the head-tail junction were observed. Flagella evidenced the features of dysplasia of the fibrous sheath. Bovine oocytes injected with patient's sperm showed male and female pronuclei but a faulty development of microtubules from the sperm-derived centrosome. The first ICSI attempt using conventional sperm selection methods resulted in fertilized two pronuclei zygotes, but no syngamy or cleavage. Three more ICSI attempts were performed, carefully avoiding sperm with obvious anomalies of the connecting piece. Fertilization and cleavage took place in all cycles, and in two of them positive betahCG plasma levels were detected but preclinical abortions ensued. CONCLUSIONS: We propose that the alterations in the head-tail junction and attachment, responsible for the observed sperm phenotype, result from centriolar dysfunctions that cause insufficient sperm aster formation, lack of syngamy and cleavage or defective embryos leading to early abortions.     

Human sperm tail fibrous sheath undergoes phosphorylation during its development.

The phosphorylation of the human sperm tail fibrous sheath as a maturational step during its development is reported for the first time. This was demonstrated using GDA-J/F3 and RT97 monoclonal antibodies (MoAb) which recognize the fibrous sheath. In indirect immunofluorescence microscopy of frozen sections of human adult testes, the two antibodies reacted with the assembled fibrous sheath only, but the numbers of sperm tails stained with RT97 were consistently lower than those treated with GDA-J/F3. Furthermore, by using double indirect immunofluorescence, although the majority of spermatozoa were doubly stained with the two MoAbs, some GDA-J/F3-positive sperm tails were negative with RT97. In epididymal and ejaculated spermatozoa, the two antibodies stained all the tails. This indicated that the ontogenic appearance of the GDA-J/F3 epitope precedes that of RT97. In Western blotting and/or indirect immunofluorescence of spermatozoa, treatment of samples with alkaline phosphatase abolished the reactivity of RT97 while that of GDA-J/F3 MoAb was not affected. This finding indicated that the RT97 but not the GDA-J/F3 epitope was phosphorylated. Together, these results therefore reveal that during tail morphogenesis, the fibrous sheath undergoes phosphorylation as part of its structural maturation. Screening of sperm cell precursors recovered from oligozoospermic donors showed reaction of some abnormal germ cells with GDA-J/F3 MoAb but not with RT97, suggesting the possible failure of phosphorylation of the fibrous sheath protein in these cells. The significance of these findings is discussed together with the biological importance of phosphorylation to the fibrous sheath.     

Clinical and genetic aspects of primary ciliary dyskinesia/Kartagener syndrome

Primary ciliary dyskinesia is a genetically heterogeneous disorder of motile cilia. Most of the disease-causing mutations identified to date involve the heavy (dynein axonemal heavy chain 5) or intermediate (dynein axonemal intermediate chain 1) chain dynein genes in ciliary outer dynein arms, although a few mutations have been noted in other genes. Clinical molecular genetic testing for primary ciliary dyskinesia is available for the most common mutations. The respiratory manifestations of primary ciliary dyskinesia (chronic bronchitis leading to bronchiectasis, chronic rhino-sinusitis, and chronic otitis media) reflect impaired mucociliary clearance owing to defective axonemal structure. Ciliary ultrastructural analysis in most patients (>80%) reveals defective dynein arms, although defects in other axonemal components have also been observed. Approximately 50% of patients with primary ciliary dyskinesia have laterality defects (including situs inversus totalis and, less commonly, heterotaxy, and congenital heart disease), reflecting dysfunction of embryological nodal cilia. Male infertility is common and reflects defects in sperm tail axonemes. Most patients with primary ciliary dyskinesia have a history of neonatal respiratory distress, suggesting that motile cilia play a role in fluid clearance during the transition from a fetal to neonatal lung. Ciliopathies involving sensory cilia, including autosomal dominant or recessive polycystic kidney disease, Bardet-Biedl syndrome, and Alstrom syndrome, may have chronic respiratory symptoms and even bronchiectasis suggesting clinical overlap with primary ciliary dyskinesia.     

Sperm ubiquitination in patients with dysplasia of the fibrous sheath

BACKGROUND: Human sperm with structural abnormalities display an increased content of the cellular proteolytic marker peptide, ubiquitin. We investigated whether dysplasia of the fibrous sheath (DFS), a severe structural anomaly found in the sperm of some asthenozoospermic patients, is accompanied by (i) increased ubiquitination of the sperm surface and (ii) by increased ubiquitination of the sperm mitochondria. METHODS AND RESULTS: Five DFS patients and eight fertile donors were studied by immunocytochemistry with anti-ubiquitin antibodies. Increased cross-reactivity of the ubiquitinated mitochondrial epitopes was seen in 32-50% of DFS sperm, but only 2-4.1% of sperm from fertile donors. Sperm surface ubiquitination assessed by sperm-ubiquitin tag immunoassay (SUTI) and immunofluorescence demonstrated an increased sperm ubiquitination in all DFS patients. The average median value of ubiquitin-induced fluorescence in DFS patients was 25.8 counts (range 19.8-37.9), as opposed to 13.4 counts range (9.3-16.6) in fertile men. Sperm with 'stump tails', coiled tails, twin and triplet sperm, and clusters of immature spermatogenic cells were common. CONCLUSIONS: DFS sperm have increased cross-reactivity to anti-ubiquitin antibodies, a finding consistent with the ubiquitination of defective sperm shown in animal models. These results justify the use of ubiquitin-based assays for objective semen analysis in infertile men with heritable defects.     

Investigation of chromosome 21 aneuploidies in breast fibroadenomas by fluorescence in situ hybridisation

Abstract Fibroadenoma (FA) is a benign breast tumour that occurs in about 25% of women. Cytogenetic studies suggest that numerical chromosomal aberrations may contribute to tumorigenesis, but chromosomal instability is still poorly characterised in breast cancer. The aim of this study was to investigate numerical alterations of chromosome 21 in 15 breast FAs. All samples were analysed by classical cytogenetics and by fluorescence in situ hybridisation (FISH) for chromosome 21 DNA sequences. Classical cytogenetics analysis showed that all cells were diploidies with modal number varying between 43 and 47 chromosomes, and clonal chromosome alterations in 46.7% of tumours. Clonal numerical alterations involved, preferentially, chromosomes 8, 10, 12, 16 and 21. FISH analysis showed a statistically significant difference for chromosome 21 monosomy between seven samples and control group. This monosomy varied from 24.5% to 43.5% of analysed cells. The presence of chromosomal alterations in FAs may be a consequence of the proliferation process and is probably not related to the aetiology of this type of lesion. The study of benign proliferations and comparison with chromosome alterations in their malignant counterparts should result in an understanding of the genes acting in cell proliferation alone and those that cause these cells to both undergo malignant transformation and become invasive.     

AJ-FSI monoclonal antibody detects a novel group of non-glycostlated antigens within the human sperm tail fibrous sheath

AJ-FS1 is one of a new series of monoclonal antibodies (MoAbs)raised by immunizing mice with isolated human sperm tail fibroussheath. Usinjg indirect immunofluorescence (IIF), the AJ-FS1MoAb didnot react with the surface antigens of viable sperm,but didstain the falgellar principal piece of sperm dried ontoslides or those demenbranated with 1% Triton X-100. The specificityof the antibody for the fibrous sheatht was confirmed by immunogoldelectron microscopy which showed the distrobution of gold particleson the outer fibrous sheath surface, and its reaction with theWestern blots of purified fibrous sheath preparations wheremultiple protein bands with mol. wt ranging between 97 and 28kDa were identified. The same peptides were alsod detected inurea-dithiothreitol (DTT) fraction of sequentially extractedspermatozoa but not in Triton or Triton-DTT sperm lysates. Thefailure of sodium metaperiodate to abrogate the antobody reactionin both Western blotting and IIf indicated on the non-glycosylatednature of the antigens. IIF screening of human testicular cryosatatsections with AJ-FS1 MoAb showed its reactivity with the assembledfibrous sheath of maturing sperm tails only; thus indicatingthe late apperance of the antigens during spermatogensis. Theanti-body did not react with skin, oesophagus, tongue, liver,kidney, placenta, uterus, cervix or their blood vessels. Thesignificance of these results is discussedtogether with theimportnce of AJ-FS1 MoAb as a specific probe for the characterizationof the fibrous sheath antigens in both normal and abnormal falgella.     

Ciliary Ultrastructure in Primary Ciliary Dyskinesia and Other Chronic Respiratory Conditions: The Relevance of Microtubular Abnormalities

Twenty-eight subjects with chronic respiratory disease were investigated for clinical data, ciliary beat frequency of nasal mucosa (10 cases), and ciliary ultrastructure. The cases were divided into two groups: those considered compatible with primary ciliary dyskinesia (genetic), and those not fitting into this category (others). A case was defined as genetic if one or more of the following were present: dextrocardia, ciliary beat frequency less than 10 Hz, or an average dynein arm count (outer, inner, or both) of less than two per ciliary cross-section. In each of the genetic cases at least two of these parameters were present. The percentage of malformed microtubules was calculated from the total number of evaluated cross-sections for each case. Ciliary microtubular abnormalities of any kind were no more frequent in cases of primary ciliary dyskinesia than in other cases. The same was true for transposition and radial spoke defects.     

Numerical and structural chromosomal abnormalities detected in human sperm with a combination of multicolor FISH assays

A pair of multicolor FISH assays (X-Y-21 and A-M-16) was developed for human sperm to simultaneously measure sex ratios; aneuploidies involving chromosomes 1, 16, 21, X, and Y; meiotic diploidies; and structural aberrations involving chromosome 1p. Sex ratios in sperm were not significantly different from unity among healthy men. Baseline frequencies of disomic sperm for chromosomes 1, 8, and 21 were similar (6.7 per 10(4) sperm, 95% CI of 5.6-8.1), suggesting that among these three chromosomes, chromosome 21 was not especially prone to nondisjunction. Frequencies of disomy 16 sperm were significantly lower, however (3.5 per 10(4) sperm, 95% CI of 2.0-6.2; P < 0.02). The baseline frequencies of sperm disomy by FISH for chromosomes 16 and 21 were validated against aneuploidy data obtained by the hamster-egg technique for human sperm cytogenetics. The frequencies of X-X, Y-Y, X-Y ("Klinefelter") sperm and sex-null ("Turner") sperm were 5.5, 5.1, 5.5, and 7.8 per 10(4) sperm, respectively. For chromosomes 16 and 21, the frequencies of nullisomic and disomic sperm were similar, suggesting that gain and loss events occurred symmetrically. However, more gain than loss was reported for chromosomes 1, X, and Y. The frequency of MI and MII diploid sperm (with flagella) was approximately 12 per 10(4) (range 8.3-16.7 per 10(4) sperm). Based on flagella data, the frequency of somatic cells in the semen was estimated to be approximately 1.8 per 10(4) sperm. Loss or gain of a portion of chromosome-arm 1p occurred in 5.5 per 10(4) sperm, and the percentage of sperm carrying structural aberrations within the haploid genome as calculated from FISH (1.4%), was similar to that obtained with the hamster-egg technique. These complementary sperm FISH assays have promising applications in studies of chromosomally abnormal sperm after exposure to occupational, medical, and environmental toxicants.     

'9 + 0' axoneme in spermatozoa and some nasal cilia of a patient with totally immotile spermatozoa associated with thickened sheath and short midpiece

A patient is described with 100% immotile spermatozoa. The sperm cells lack the central pair of microtubules or the complete axoneme. This defect is associated with a thickened fibrous sheath and a shortened midpiece containing defective mitochondria. Fifteen per cent of the nasal cilia of this patient lack the central pair of microtubules. Eighteen similar cases have been described in the literature suggesting that this association of ultrastructural defects may be considered a syndrome.