Hum. Reprod. Advance Access originally published online on January 5, 2007
Human Reproduction 2007 22(4):1052-1059; doi:10.1093/humrep/del481
| ||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||
Ultrastructural nuclear defects and increased chromosome aneuploidies in spermatozoa with elongated heads
1 Department of Genetic and Reproduction, APHP, INSERM U782, Paris 11 University, Antoine Béclère Hospital, Clamart, France 2 Department of Andrology 3 Department of Hormonology and Molecular Biology, APHP, Kremlin Bicêtre Hospital, Kremlin Bicêtre, France
4 To whom correspondence should be addressed at: Unité d'Andrologie, APHP, INSERM U782, Service de Biologie et Génétique de la Reproduction, Hôpital du Kremlin Bicêtre, 63 rue Gabriel Peri, 94276 Le Kremlin Bicêtre, France. Tel.: +33 1 45 21 26 44; Fax: +33 1 45 21 23 21; E-mail: nprisant{at}yahoo.com
 |
Abstract |
|---|
 Top Abstract IntroductionMaterials and methodsResultsDiscussionReferences |
|---|
BACKGROUND: Cellular and molecular mechanisms leading to elongated sperm heads are not known. We have analysed the nuclear status of spermatozoa with elongated heads.
METHODS: Fourteen men with at least 30% of spermatozoa with an elongated nucleus were studied and compared with five fertile men as controls. Sperm morphology was analysed by a quantitative ultrastructural analysis. Sperm chromosomal content was assessed by three-colour fluorescence in-situ hybridization (chromosomes X, Y, 18). Y chromosome microdeletion and karyotype were analysed.
RESULTS: Elongated sperm head rates of the patients were 46.9% (30–75 versus 0–2% in the control group) by light microscopy and 34.4% by electron microscopy. In all patients, the chromatin was poorly condensed in elongated sperm heads (50% of elongated nuclei). No anomalies of sperm biochemical markers were found. All the men showed normal karyotype (46,XY) and absence of Y chromosome microdeletion. Aneuploidy rates of gonosomes and chromosome 18 were significantly increased in patients (1.64- and 3.6-fold, P = 0.006 and 0.026, respectively).
CONCLUSIONS: This study demonstrates that impaired chromatin compaction and slightly increased chromosome aneuploidies are found in spermatozoa with an elongated head, suggesting possible mechanisms such as meiotic non-disjunctions or spermiogenesis anomalies.
Key words: chromosome abnormalities/electron microscopy/elongated sperm head/fluorescence in-situ hybridization/male infertility
|
Introduction |
|---|
|
TopAbstractIntroductionMaterials and methodsResultsDiscussionReferences |
|---|
The normal shape of the head of the human spermatozoon is oval, with a length of 5–6 µm and width of 2.5–3.5 µm. Long-headed sperm can have a 1-fold increased overall head length, whereas the width is slightly reduced (Dadoune et al., 1980
). Consequently, the acrosome covers only 30% of the sperm head (Dadoune et al., 1980). The increased sperm head length results from an abnormally elongated nucleus that also presents particular membranous layers between the outer and inner leaves of the nuclear envelope (Rouy and Sentein, 1977). These sperm nuclear anomalies are associated with anomalies of the neck region and the persistence of a cytoplasmic droplet (Rousso et al., 2002). Most frequently, in routine analysis, spermatozoa with an elongated nucleus are recorded considering the head shape characteristics, such as tapered head (Auger et al., 1990; Urry et al., 1990) and pyriform or pear-shaped head (Kubo-Irie et al., 2005; Rousso et al., 2002), without reference to the increase in nuclear length. This type of sperm morphological anomaly never affects the whole sperm population and is present in variable proportions in the semen of the same subject (Jagoe et al., 1986). Thus, elongated-head sperm cells are present in human semen at a mean of 5.9% in fertile men (Schwartz et al., 1984) and at a mean of 22% in subfertile men (Rousso et al., 2002). A low fertilization rate has been found in men with severely elongated sperm heads (Osawa et al., 1999). The incidence of spermatozoa with an elongated head is also increased in infertile men with varicocele (Portuondo et al., 1983; Naftulin et al., 1991), with urogenital infections (Menkveld and Kruger, 1998) and in the case of workers in a reinforced plastic production (Jelnes, 1988).
The mechanisms that lead to the aberrant nuclear elongation have not been elucidated. Although an increased size of the nucleus as a whole, in addition to the increased length, has been described (Katz et al., 1982), this type of teratospermia has not been investigated at the level of the sperm chromosomal content. Other types of morphologically abnormal human spermatozoa have been found to present chromosomal anomalies. For example, the macronuclear spermatozoa are affected by a high level of hyperploidy (Yurov et al., 1996; Vicari et al., 2003) and particularly tetraploidy (Benzacken et al., 2001; Devillard et al., 2002; Lewis-Jones et al., 2003; Mateu et al., 2006). Whether anomalies of the chromosomal numerical content or any other molecular mechanism, such as alteration of the chromatin compaction, are responsible for the increased nuclear volume of elongated spermatozoa is questioned. We report the ultrastructural and cytogenetic studies of a series of 14 patients with semen containing spermatozoa with elongated heads.
|
Materials and methods |
|---|
|
TopAbstractIntroductionMaterials and methodsResultsDiscussionReferences |
|---|
Patients and controls
The patients were referred to the Laboratory of Andrology because of a history of infertility. They were retained on the criterion of at least 30% of elongated sperm heads in two successive routine analyses. Five fertile men were included as controls. History of genitourinary infections or previous testicular injury, family infertility and personal habit (occupational hazards, drug, tobacco and alcohol intake) were recorded. They had undergone neither medical nor surgical treatment during the 3 months prior to semen examination. They had normal secondary sex characteristics with no gynecomastia. Scrotal examination was performed to confirm that testes were bilaterally descended, of normal size and of soft consistency. The patients were informed of the exact nature and the goal of the investigations performed and provided written informed consent according to French law.
Semen parameters
Semen samples were collected by masturbation into a sterile plastic cup after at least 2–7 days of ejaculatory abstinence (4 days on average). Only completely collected semen samples were included. Semen samples were allowed to liquefy for 30 min up to 1 h and were then evaluated under light microscopy, according to World Health Organization (WHO) guidelines (WHO, 1999). The recorded variables taken into consideration were volume of the ejaculate (ml), sperm concentration (x106 ml–1), total sperm count (x106), percentage of progressive sperm cells (a + b), sperm viability (%) and percentage of morphologically normal spermatozoa. Sperm heads were considered as elongated when the head showed an increase of at least 20% of their length, including pear-shaped spermatozoa. Tapered spermatozoa with a reduced width and a normal length were not considered. Morphological examination consisted in the analysis of 100 consecutive May-Grünwald–Giemsa stained spermatozoa. Sperm viability was assessed by eosin–negrosin staining. Bacteriological cultures and a leukocyte count were carried out on semen samples (LeucoscreenTM, Fertipro, Beernem, Belgium).
Biochemical markers were assessed on seminal plasma obtained by centrifugation at 600 g for 20 min, and deproteinization was achieved on a centrifugal filter device Ultrafree-0.5 (Millipore Corp, Bedford, MA, USA). Markers of epididymis function were carnitine (nM) and 
-1-4 glucosidase (mU). Markers of the prostate secretions were citric acid (µM), prostatic acid phosphatase (U) and zinc (µM). Marker of seminal vesicles was fructose (µM).
Electron microscopy analysis
The samples were centrifuged at 350 g for 10 min and the supernatant was discarded. The sperm pellet was fixed in a solution of 2.5% glutaraldehyde (Agar Scientific Ltd, Cambridge, UK) and 0.1 mol ml–1 sodium cacodylate/HCl/phosphate buffer pH 7.2–7.4. After centrifugation, the sample was suspended in 0.2 M sodium cacodylate buffer. Secondary fixation was performed using 1% osmium tetraoxide (Agar Scientific), after which spermatozoa were dehydrated in graded alcohol and embedded in Epon resin (Polysciences Inc., Warrington, PA, USA). Semi-thin sections were stained with toluidine blue-Azur II and examined on a Zeiss Axioscope photomicroscope (Carl Zeiss S.A.S., Oberkochen, Germany). Ultra-thin sections (90 nm) were cut with a Reichert OmU2 ultra-microtome (Reichert-Jung AG, Wien, Austria) using a diamond knife, mounted on nickel grids, stained with uranyl acetate and lead citrate, and examined using a JEOL JEM 100CX II electron microscope (Jeol Ltd, Tokyo, Japan) operated at 80 kV. Photographs were taken on Kodak electron microscopy film. Negatives were scanned using an Epson Perfection 3200 photo flat bed scanner with a transparency attachment (Seiko Epson Corporation, Nagano, Japan). Digitized images were processed using Adobe Photoshop software programme (Adobe System Inc., San Jose, CA, USA). For each patient, the quantitative analysis in electron microscopy was performed on 25–30 longitudinal sections of the sperm head (including the basal plate) and on at least 50 transverse sections of the principal piece of the flagellum. The rates of chromatin condensation anomalies have been estimated, first considering the total population of sperm heads of each patient and, second, considering only the elongated sperm heads of each patient. The rate of chromatin condensation anomalies was compared with the mean value (under 22%) in normal sperm (Escalier 1983a, 1990).
Genetic analyses
The constitutional blood karyotype of the patients was performed on cultured lymphocytes, according to standard techniques. Microdeletion analysis of the Y chromosome used a sequence tagged sites (STS)-PCR technique. Nineteen STS corresponding to the three distinct AZF loci were selected. The STS tested were sY84, sY95, sY124, sY143, sY130, sY134, sY136, sY152, sY240, sY148, sY232, sY249, sY156, sY204, sY208, sY254, sY269, sY158 and sY160.
Fluorescence in-situ hybridization
A three-colour fluorescence in-situ hybridization (FISH) analysis was performed, using probes specific for chromosomes 18, X and Y. Semen from fertile patients was used as controls. After liquefaction at room temperature for 60 min, 1 ml of neat semen was diluted in 1 ml of FerticultTM (Fertipro). After centrifugation at 500 g, the pellets were fixed on slides with freshly prepared Carnoy's fixative solution (methanozl–acetic acid, 3:1). Sperm nuclei were decondensed using NaOH solution (1 mol L–1) for 2 min at room temperature. Slides were then dehydrated through an ethanol series (70, 90, and 100%) and air-dried. Five microlitres of DNA probe mixture were deposited on the sperm nuclei preparation, covered with a coverslip and sealed with rubber cement. We used the commercial kit AneuvysionTM (Vysis, Downers Grove, IL, USA) with DNA probes specific for chromosome 18 (CEP 18 spectrumAquaTM 18p11.1–q11.1), for X chromosome (CEP X SpectrumGreenTM Xp11.1–q11.1) and for Y chromosome (CEP Y SpectrumOrangeTM Yp11.1–q11.1). Denaturation was performed at 73°C for 3 min. Hybridization was performed by overnight incubation in a dark, moist chamber. After hybridization, the coverslips were removed and slides were washed for 2 min in 0.4x saline sodium citrate (SSC) 0.3% Nonidet P40 (NP40) solution at 73°C, followed by 30 s wash in 2.0x SSC 0.1% NP40 solution at room temperature. Slides were then counterstained with 4',6-diaminidino-2-phenylindol dihydrochloride (DAPI; Sigma-Aldrich, Saint Quentin Fallavier, France) and mounted in antifading solution (Vectashield, Vector Laboratories, Burlingame, CA). Fluorescent signals were evaluated in 1000 spermatozoa for each sample and for each probe. FISH slides were screened using an X-100 objective on a Zeiss epifluorescent microscope equipped with aqua, fluorescein isothiocyanate and rhodamine single band pass filters. Only individual and well-delineated sperm nuclei were scored. We used the Martin and Rademaker scoring criteria (Martin and Rademaker, 1995). A spermatozoon was scored as disomic if it showed two hybridization signals of the same colour, size and intensity. Two spots separated by less than the diameter of one hybridization domain were scored as a single signal. The absence of hybridization signal for a single chromosome was scored as nullisomy for this chromosome only if the other probed chromosome gave a signal. No FISH signals in a spermatozoa head showing DAPI stain were considered a case of no hybridization. Sperm aneuploidy rates were determined by the sum of nullisomy and disomy rates.
The Student's t-test, the Mann–Whitney nonparametric test and the Pearson correlation coefficient were used for statistical analyses. Differences were considered to be significant when P-value was <0.05.
|
Results |
|---|
|
TopAbstractIntroductionMaterials and methodsResultsDiscussionReferences |
|---|
Clinical characteristics of the patients
Among the 14 patients, 8 patients consulted for primary infertility (patients 1, 3, 5, 7, 8, 10, 12 and 13), and 5 patients for secondary infertility (patients 2, 4, 6, 9 and 14) or tertiary infertility (patient 11). Patient 10 had diabetes and asthma. Cryptorchidy of the right testis (patient 12), varicocele (patients 9 and 12) and inguinal hernia (patient 14) were treated previously by surgery. Testes of patient 6 were injured when he was a teenager. Eight patients (patients 2, 3, 4, 5, 7, 8, 9 and 13) were smokers (>20 cigarettes per day), patient 14 was a frequent bicycle user and patient 8 presented with an occupational hazard (solvent exposure). No patient presented with heat exposure, history of genitourinary infections and neither drug nor alcohol intake. Patients 7 and 14 were from consanguineous parents.
Semen parameters
Semen parameters for each patient and control are detailed in Table I. Semen parameters of the patients group when compared with the control group were as follows (mean ± SD): total sperm count (103.3 Mo ± 106.3 versus 419.4 Mo ± 472.0, respectively), percentage of progressive sperm cells (21.3% ± 10.8 versus 21.0% ± 15.5, respectively), sperm viability (65.8% ± 19 versus 67.6% ± 22.8, respectively) and percentage of normal spermatozoa (4.8% ± 4.7 versus 33.2% ± 5.4, respectively). The patients presented a ‘polymorphic teratozoospermia’, where a majority of spermatozoa displayed more than one type of abnormality. Elongated sperm head rates were ranged between 30 and 75% (mean, 46.9%) in the patient group, and between 0 and 2% in the control group.
|
Semen biochemical markers in the patient group were found within normal range as follows (mean ± SD): carnitine (855.2 ± 555.6 nM),
-1-4 glucosidase (75.5 ± 47.7 mU), citric acid (84.8 ± 52.6 µM), prostatic acid phosphatase (104.8 ± 74.4 U), zinc (5.6 ± 3.9 µM), and fructose (62.7 ± 30.6 µM). The semen's bacteriological cultures were negative for all patients.
Ultrastructural analysis of the sperm head characteristics of the patients
Depending on the patients, and when compared with normally elongated sperm heads (Figure 1A), 15–56% of the spermatozoa (patient 12 and 2, respectively) showed an increased nuclear length (Table II) (Figure 1B–H). Sperm heads with an increase of their length and width (Figure 1B) or both their length and thickness (Figure 1C) were considered as ‘large elongated’ sperm heads. These latter spermatozoa represented 6–31% of the whole sperm population, depending on the patients.
|
|
The nuclear content was either normally condensed (Figure 1A) or insufficiently condensed, with a granular aspect (Figure 1B and C). Considering the entire population of spermatozoa of each patient, a poorly condensed chromatin reached 32–60% (i.e. greater than the mean value for normal sperm of 22%) of the sperm heads in 8 out of the 14 patients (mean 44%) (Table II). These percentages were increased when compared with normal sperm (mean, 22%) (see Materials and methods). An insufficient chromatin condensation could be found in nuclei with a normal length (Figure 1D), but was more frequent in elongated sperm heads (Table II). Indeed, all the studied patients presented an incomplete chromatin condensation in the elongated sperm heads and at a mean of 50% (range 27–71%) (Table II). Nuclear lacunae devoid of chromatin were present in the nuclei with a normally condensed chromatin (Figure 1A) and those with granular chromatin (Figure 1B). In elongated sperm heads, the posterior region of the nucleus showed a characteristic membranous proliferation of the nuclear envelope (Figure 1B, C and E), often more developed on one nuclear side (Figure 1B).
Binucleated sperm cells were present in 11 out of the 14 patients at various percentages (range 5–27%), depending on the patients (Table II) and most of them appeared immature and in a large cytoplasm. Chromatin of these double nuclei was frequently poorly condensed (Figure 1E). Biflagellated spermatozoa were less frequent (not shown).
At the flagellum level, the patients presented with a mitochondrial sheath misassembly (all patients, range 43–89%), an absence of axonemal doublets (11 patients, range 33–58%) and various anomalies of the disposition of the ribs or of the longitudinal columns of the fibrous sheath (12 patients, range 23–77%) (data not shown).
Genetic and FISH analyses
All the men showed a normal karyotype (46,XY) and an absence of Y chromosome microdeletion. Sperm FISH results, including disomy and nullisomy rates, are indicated in Table I. The aneuploidy rates for chromosome 18 varied from 0 to 1.6% in the patient group (mean, 0.93%) and from 0.1 to 0.5% in the control group (mean, 0.26%). The aneuploidy rates for gonosomes varied from 0.6 to 3.4% in the patient group (mean, 1.78%) and from 1.1 to 1.3% in the control group (mean, 1.08%). Aneuploidy rates of gonosomes and chromosome 18 were significantly higher in patients with elongated sperm heads when compared with the values of control sperms (1.64- and 3.6-fold increase, P = 0.006 and P = 0.026, respectively). Mean diploidy rates were 0.26% in the patient group and 0.20% in the control group and not significantly different between the two groups.
Spearman analyses between gonosomes or chromosome 18 aneuploidy rates, and sperm parameters (total sperm count, percentage of progressive sperm cells, sperm viability and percentage of normal spermatozoa) yielded no significant correlations. As well, there was no correlation between sperm aneuploidy rates and tobacco intake (data not shown).
|
Discussion |
|---|
|
TopAbstractIntroductionMaterials and methodsResultsDiscussionReferences |
|---|
This study shows that spermatozoa with elongated sperm heads are associated with an insufficiently condensed chromatin and an increase of the sperm chromosomal aneuploidy rate.
Our study shows discrepancies in the percentages of elongated sperm heads, as estimated by light and electron microscopy. These differences could be related to the very fact that the posterior region of the nucleus is often engulfed in a cytoplasm containing the redundant nuclear envelope. This hidden nuclear posterior region does not allow the estimation of the real extension of the nucleus of spermatozoa, as observed by light microscopy. Conversely, electron microscopy did not allow the estimation of the whole nuclear shape since the ultra-thin sections allow the observation of only 2D of the sperm nuclei (i.e. the length and either the width or the thickness).
Most frequently, in routine analysis by using light microscopy, spermatozoa with an elongated nucleus are recorded considering the head shape characteristics, such as tapered head (Auger et al., 1990; Urry et al., 1990) and pyriform or pear-shaped head (Rousso et al., 2002; Kubo-Irie et al., 2005), but without reference to any increased nuclear length. Only two publications studied elongated-head spermatozoa by using electron microscopy (Rouy and Sentein, 1977; Dadoune et al., 1980). Using scanning electron microscopy, Dadoune et al. (1980) differentiated thin and elongated sperm head (long-headed sperm). This study showed that the acrosome accounted for 30% of the elongated sperm head, the post-acrosomal cap, the posterior nuclear space, for 9 and 6%, respectively, and the posterior part of the head covered with a voluminous cytoplasmic sheath for 56%. Rouy and Sentein (1977) performed a study by transmission electron microscopy of elongated spermatozoa both in semen and in a testicular biopsy. They found particular membranous layers between the outer and inner leaves of the nuclear envelope in the posterior nuclear region that formed during the spermiogenesis. All these morphological anomalies were present in the elongated spermatozoa of our study. Also a coiled flagellum is frequently present in spermatozoa with an elongated sperm head that could be explained by anomalies of the localization or size of the basal plate as a result of the membranous proliferation. It is worth noting that the percentage of progressive spermatozoa is low in all the studied patients. The associated anomalies of the sperm head and flagellum should contribute to the motility defects. A previous study showed that morphologically normal spermatozoa swam faster and straighter and exhibited higher beat frequencies than did morphologically abnormal sperm and that the differences were most pronounced for spermatozoa with elongated or pyriform tapering heads (Katz et al., 1982). Importantly, the chromatin was poorly compacted in a high percentage of elongated sperm heads, suggesting that the last step of chromatin maturity is impaired. Immaturity of the chromatin in elongated sperm heads has been already described by using aniline blue staining (Auger et al., 1990). Also, we observed no anomalies in semen zinc or fructose levels, which are considered by several authors (Kvist et al., 1987; Bjorndahl and Kvist, 1990) as a possible mechanism involved in chromatin condensation. The rate of elongated sperm heads with anomalies of chromatin condensation is close to that of macronuclear spermatozoa (Escalier, 1983b).
In our study, aneuploidy rates, assessed by FISH, were statistically higher in patients with elongated sperm heads than in controls. Percentages of aneuploid sperm are higher in cases of impaired sperm parameters: oligozoospermia (Gianaroli et al., 2005; Nagvenkar et al., 2005; Pang et al., 2005; Rives, 2005), asthenospermia (Bernardini et al., 2005; Templado et al., 2005) and teratospermia (Machev et al., 2005; Templado et al., 2005), including structural flagellar anomalies (Carrell et al., 2004; Rives et al., 2005). Only two types of spermatozoa with anomalies of the nucleus have been investigated by FISH. In the case of round headed spermatozoa (also called globozoospermia), anomalies of the chromosome content have been found at various degrees, depending on the patients (Carrell et al., 1999, 2001; Martin et al., 2003; Morel et al., 2004; Ditzel et al., 2005). The macronuclear spermatozoa have been found to present with a high level of hyperploidy (Yurov et al., 1996; Vicari et al., 2003), particularly tetraploidy (Benzacken et al., 2001; Devillard et al., 2002; Lewis-Jones et al., 2003; Mateu et al., 2006). A report on FISH analysis of men with either large or elongated sperm nuclei (only a published abstract available) indicated a hyperploidy reaching 23.4% (Fedorova, 2003). This high level of hyperploidy suggests that the patients analysed shared a particular sperm phenotype such as elongated sperm head originating from germ cells with impaired meiotic divisions (i.e. macrocephalic). In our study, the increased rates of aneuploidy were in the same range as those found in men with either oligospermia, or teratospermia, or asthenospermia (Gianaroli et al., 2005; Nagvenkar et al., 2005; Pang et al., 2005; Rives, 2005). Nevertheless, it should be noted that the rates of aneuploidy concern a low number of the sperm cells in all these spermatogenesis disturbances. Moreover, we did not find any statistical relationship between the aneuploidy rates and any sperm parameter for each of our patients. In our study, nullisomy rates were lower than disomy rates in patients and controls. These results were also observed in studies indicating disomy and nullisomy rates in sperm (Callogero et al., 2001; Strassburger et al., 2006).
The finding of both elongated sperm heads and aneuploidies in spermatozoa could be due to abnormal testis environment leading to an increased rate of non-disjunction and to the production of nucleus anomalies. A disturbance of the germinal cell epithelium is supported by the case of varicocele. In varicocele patients, the percentage of ‘tapered’ sperm heads is variably estimated to reach 20 (Portuondo et al., 1983) or 36% (Naftulin et al., 1991), and these patients present an increase in sperm numerical chromosome anomalies (Baccetti et al., 2006). In our study, patients 9 and 12 had a previously cured varicocele. Their sperm numerations were normal and both showed a rate of aneuploidy in the mean range of the studied patients (Table I).
The mechanisms leading to an excessive elongation of the sperm nucleus are poorly understood. Only testes from cases with varicocele and elongated sperm heads have been investigated. The scrotal temperature was found to be higher in infertile men with a varicocele (Ali et al., 1990; Naughton et al., 2001), and Sertoli cells were found to be injured (Terquem and Dadoune, 1981). Spermatids were found wrongly positioned to Sertoli cells and Sertoli–germ cell junction complexes structurally abnormal (Cameron et al., 1980). Besides, it is interesting to note that elongated sperm heads have been found associated to an abnormally narrow shaped spermatid microtubular manchette (Rouy and Sentein, 1977), as also previously observed in the azh/azh mutant mouse model (Cole et al., 1988). This suggests that the manchette could exert an excessive pressure on the nucleus before its condensation and could explain why elongated sperm heads frequently present an elongated and tapered nucleus.
Interestingly, rat testes with an experimental varicocele present with a diminution of the expression of Fas (but not of FasL) (Celik-Ozenci et al. 2006) and of Notch-1 and -2 (Sahin et al., 2005). Fas has been found in cytoplasmic extrusions of elongated spermatids and it was suggested that Fas might be necessary for normal spermiogenesis, especially for normal sperm head morphology (Celik-Ozenci et al., 2006). Notch signalling is known to control cell fate through local cell interactions. Notch-1 is expressed in elongated spermatids and may be related to their maturation (Sahin et al., 2005). Moreover, men with varicocele have been found to have an ectopic nuclear localization of the C3 subunit of the 20S proteasome in their spermatozoa (Ziemba et al., 2002). These recent data open the door towards interesting investigations in order to define which nuclear molecular factor(s) could be involved in the abnormal sperm nuclear elongation and meiotic division errors.
In conclusion, our study demonstrates that the chromatin compaction is altered in spermatozoa with an elongated head and that the numerical chromosome content is slightly, but significantly, disturbed. These data should lead further studies to identify the mechanisms behind the meiotic errors and chromatin compaction impairment in patients with elongated sperm heads.
|
References |
|---|
|
TopAbstractIntroductionMaterials and methodsResultsDiscussionReferences |
|---|
Ali JI, Weaver DJ, Weinstein SH, Grimes EM. (1990) Scrotal temperature and semen quality in men with and without varicocele. Arch Androl 24:2215–219.[Web of Science][Medline]
Auger J, Mesbah M, Huber C, Dadoune JP. (1990) Aniline blue staining as a marker of sperm chromatin defects associated with different semen characteristics discriminates between proven fertile and suspected infertile men. Int J Androl 13:6452–462.[Web of Science][Medline]
Baccetti BM, Bruni E, Capitani S, Collodel G, Mancini S, Piomboni P, Moretti E. (2006) Studies on varicocele III: ultrastructural sperm evaluation and 18, X and Y aneuploidies. J Androl 27:194–101.
Benzacken B, Gavelle FM, Martin-Pont B, Dupuy O, Lievre N, Hugues JN, Wolf JP. (2001) Familial sperm polyploidy induced by genetic spermatogenesis failure: case report. Hum Reprod 16:122646–2651.
Bernardini LM, Calogero AE, Bottazzi C, Lanteri S, Venturini PL, Burrello N, De Palma A, Conte N, Ragni N. (2005) Low total normal motile count values are associated with increased sperm disomy and diploidy rates in infertile patients. Int J Androl 28:6328–336.[CrossRef][Web of Science][Medline]
Bjorndahl L and Kvist U. (1990) Influence of seminal vesicular fluid on the zinc content of human sperm chromatin. Int J Androl 13:3232–237.[Web of Science][Medline]
Calogero AE, De Palma A, Grazioso C, Barone N, Romeo R, Rappazzo G, D'Agata R. (2001) Aneuploidy rate in spermatozoa of selected men with abnormal semen parameters. Hum Reprod 16:61172–1179.
Cameron DF, Snydle FE, Ross MH, Drylie DM. (1980) Ultrastructural alterations in the adluminal testicular compartment in men with varicocele. Fertil Steril 33:5526–533.[Web of Science][Medline]
Carrell DT, Emery BR, Liu L. (1999) Characterization of aneuploidy rates, protamine levels, ultrastructure, and functional ability of round-headed sperm from two siblings and implications for intracytoplasmic sperm injection. Fertil Steril 71:3511–516.[CrossRef][Web of Science][Medline]
Carrell DT, Wilcox AL, Udoff LC, Thorp C, Campbell B. (2001) Chromosome 15 aneuploidy in the sperm and conceptus of a sibling with variable familial expression of round-headed sperm syndrome. Fertil Steril 76:61258–1260.[CrossRef][Web of Science][Medline]
Carrell DT, Emery BR, Wilcox AL, Campbell B, Erickson L, Hatasaka HH, Jones KP, Peterson CM. (2004) Sperm chromosome aneuploidy as related to male factor infertility and some ultrastructure defects. Arch Androl 50:3181–185.[CrossRef][Web of Science][Medline]
Celik-Ozenci C, Sahin Z, Ustunel I, Akkoyunlu G, Erdogru T, Korgun ET, Baykara M, Demir R. (2006) The Fas system may have a role in male reproduction. Fertil Steril 85:Suppl 1, 1168–1178.[CrossRef][Web of Science][Medline]
Cole A, Meistrich ML, Cherry LM, Trostle-Weige PK. (1988) Nuclear and manchette development in spermatids of normal and azh/azh mutant mice. Biol Reprod 38:2385–401.[Abstract]
Dadoune JP, Fain-Maurel MA, Guillaumin M, Guillaumin D. (1980) Scanning electron microscopic morphometry of a discriminated population of elongated human spermatozoa. Int J Fertil 25:118–27.[Web of Science][Medline]
Devillard F, Metzler-Guillemain C, Pelletier R, DeRobertis C, Bergues U, Hennebicq S, Guichaoua M, Sele B, Rousseaux S. (2002) Polyploidy in large-headed sperm: FISH study of three cases. Hum Reprod 17:51292–1298.
Ditzel N, El-Danasouri I, Just W, Sterzik K. (2005) Higher aneuploidy rates of chromosomes 13, 16, and 21 in a patient with globozoospermia. Fertil Steril 84:1217–218.[Medline]
Escalier D. (1983a) Cryobiologie du spermatozoïde humain: Localisation et quantification des lésions cellulaires. PhD(Paris XI, Paris).
Escalier D. (1983b) Human spermatozoa with large heads and multiple flagella: a quantitative ultrastructural study of 6 cases. Biol Cell 48:165–74.[Web of Science][Medline]
Escalier D. (1990) Failure of differentiation of the nuclear–perinuclear skeletal complex in the round-headed human spermatozoa. Int J Dev Biol 34:2287–297.[Medline]
Fedorova KTI, Baranov V, Rybouchkin A, Van der Elst J, Dhont M. (2003) A cytogenetic analysis of spermatozoa with abnormal head morphologies injected in mouse oocytes. Ann Genet 46:3183.
Gianaroli L, Magli MC, Cavallini G, Crippa A, Nadalini M, Bernardini L, Menchini Fabris GF, Voliani S, Ferraretti AP. (2005) Frequency of aneuploidy in sperm from patients with extremely severe male factor infertility. Hum Reprod 20:82140–2152.
Jagoe JR, Washbrook NP, Hudson EA. (1986) Morphometry of spermatozoa using semiautomatic image analysis. J Clin Pathol 39:121347–1352.
Jelnes JE. (1988) Semen quality in workers producing reinforced plastic. Reprod Toxicol 2:3–4209–212.[CrossRef][Medline]
Katz DF, Diel L, Overstreet JW. (1982) Differences in the movement of morphologically normal and abnormal human seminal spermatozoa. Biol Reprod 26:4566–570.[Abstract]
Kubo-Irie M, Matsumiya K, Iwamoto T, Kaneko S, Ishijima S. (2005) Morphological abnormalities in the spermatozoa of fertile and infertile men. Mol Reprod Dev 70:170–81.[CrossRef][Web of Science][Medline]
Kvist U, Bjorndahl L, Kjellberg S. (1987) Sperm nuclear zinc, chromatin stability, and male fertility. Scanning Microsc 1:31241–1247.[Web of Science][Medline]
Lewis-Jones I, Aziz N, Seshadri S, Douglas A, Howard P. (2003) Sperm chromosomal abnormalities are linked to sperm morphologic deformities. Fertil Steril 79:1212–215.[CrossRef][Web of Science][Medline]
Machev N, Gosset P, Viville S. (2005) Chromosome abnormalities in sperm from infertile men with normal somatic karyotypes: teratozoospermia. Cytogenet Genome Res 111:3–4352–357.[CrossRef][Web of Science][Medline]
Martin RH and Rademaker A. (1995) Reliability of aneuploidy estimates in human sperm: results of fluorescence in situ hybridization studies using two different scoring criteria. Mol Reprod Dev 42:189–93.[CrossRef][Web of Science][Medline]
Martin RH, Greene C, Rademaker AW. (2003) Sperm chromosome aneuploidy analysis in a man with globozoospermia. Fertil Steril 79:Suppl 3, 1662–1664.[CrossRef][Web of Science][Medline]
Mateu E, Rodrigo L, Prados N, Gil-Salom M, Remohi J, Pellicer A, Rubio C. (2006) High incidence of chromosomal abnormalities in large-headed and multiple-tailed spermatozoa. J Androl 27:16–10.
Menkveld R and Kruger TF. (1998) Sperm morphology and male urogenital infections. Andrologia 30:Suppl 1, 49–53.[Web of Science][Medline]
Morel F, Douet-Guilbert N, Moerman A, Duban B, Marchetti C, Delobel B, Le Bris MJ, Amice V, De Braekeleer M. (2004) Chromosome aneuploidy in the spermatozoa of two men with globozoospermia. Mol Hum Reprod 10:11835–838.
Naftulin BN, Samuels SJ, Hellstrom WJ, Lewis EL, Overstreet JW. (1991) Semen quality in varicocele patients is characterized by tapered sperm cells. Fertil Steril 56:1149–151.[Web of Science][Medline]
Nagvenkar P, Zaveri K, Hinduja I. (2005) Comparison of the sperm aneuploidy rate in severe oligozoospermic and oligozoospermic men and its relation to intracytoplasmic sperm injection outcome. Fertil Steril 84:4925–931.[CrossRef][Web of Science][Medline]
Naughton CK, Nangia AK, Agarwal A. (2001) Pathophysiology of varicoceles in male infertility. Hum Reprod Update 7:5473–481.
Osawa Y, Sueoka K, Iwata S, Shinohara M, Kobayashi N, Kuji N, Yoshimura Y. (1999) Assessment of the dominant abnormal form is useful for predicting the outcome of intracytoplasmic sperm injection in the case of severe teratozoospermia. J Assist Reprod Genet 16:8436–442.[CrossRef][Web of Science][Medline]
Pang MG, Kim YJ, Lee SH, Kim CK. (2005) The high incidence of meiotic errors increases with decreased sperm count in severe male factor infertilities. Hum Reprod 20:61688–1694.
Portuondo JA, Calabozo M, Echanojauregui AD. (1983) Morphology of spermatozoa in infertile men with and without varicocele. J Androl 4:5312–315.
Rives NM. (2005) Chromosome abnormalities in sperm from infertile men with normal somatic karyotypes: asthenozoospermia. Cytogenet Genome Res 111:3–4358–362.[CrossRef][Web of Science][Medline]
Rives N, Mousset-Simeon N, Mazurier S, Mace B. (2005) Primary flagellar abnormality is associated with an increased rate of spermatozoa aneuploidy. J Androl 26:161–69.
Rousso D, Kourtis A, Mavromatidis G, Gkoutzioulis F, Makedos G, Panidis D. (2002) Pyriform head: a frequent but little-studied morphological abnormality of sperm. Arch Androl 48:4267–272.[CrossRef][Web of Science][Medline]
Rouy S and Sentein P. (1977) Ultrastructural characteristics of human spermatozoa with elongated head (author's trans.). Pathol Biol (Paris) 25:10691–697.[Medline]
Sahin Z, Bayram Z, Celik-Ozenci C, Akkoyunlu G, Seval Y, Erdogru T, Ustunel I, Baykara M, Demir R. (2005) Effect of experimental varicocele on the expressions of Notch 1, 2, and 3 in rat testes: an immunohistochemical study. Fertil Steril 83:186–94.[CrossRef][Web of Science][Medline]
Schwartz D, Mayaux MJ, Guihard-Moscato ML, Spira A, Jouannet P, Czyglik F, David G. (1984) Study of sperm morphologic characteristics in a group of 833 fertile men. Andrologia 16:5423–428.[Web of Science][Medline]
Strassburger D, Reichart M, Kaufman S, Kasterstein E, Komarovsky D, Bern O, Friedler S, Schachter M, Ron-El R, Raziel A. (2007) Morphology assessment and fluorescence in situ hybridization of the same spermatozoon using a computerized cell-scanning system. Hum Reprod 22:1201–209.
Templado C, Bosch M, Benet J. (2005) Frequency and distribution of chromosome abnormalities in human spermatozoa. Cytogenet Genome Res 111:3–4199–205.[CrossRef][Web of Science][Medline]
Terquem A and Dadoune JP. (1981) Morphological findings in varicocele: an ultrastructural study of 30 bilateral testicular biopsies. Int J Androl 4:5515–531.[Web of Science][Medline]
Urry RL, Heaton JB, Moore M, Middleton RG. (1990) A fifteen-year study of alterations in semen quality occurring after vasectomy reversal. Fertil Steril 53:2341–345.[Web of Science][Medline]
Vicari E, de Palma A, Burrello N, Longo G, Grazioso C, Barone N, Zahi M, D'Agata R, Calogero AE. (2003) Absolute polymorphic teratozoospermia in patients with oligoasthenozoospermia is associated with an elevated sperm aneuploidy rate. J Androl 24:4598–603.
WHO. (1999) Laboratory Manual for the Examination of Human Semen and Sperm-Cervical Mucus Interaction(Cambridge University Press, Cambridge, UK).
Yurov YB, Saias MJ, Vorsanova SG, Erny R, Soloviev IV, Sharonin VO, Guichaoua MR, Luciani JM. (1996) Rapid chromosomal analysis of germ-line cells by FISH: an investigation of an infertile male with large-headed spermatozoa. Mol Hum Reprod 2:9665–668.
Ziemba H, Bialy LP, Fracki S, Bablok L, Wojcik C. (2002) Proteasome localization and ultrastructure of spermatozoa from patients with varicocele—immunoelectron microscopic study. Folia Histochem Cytobiol 40:2169–170.[Medline]
Submitted on July 27, 2006; resubmitted on October 5, 2006; accepted on November 29, 2006.
CiteULike 
Connotea 
Del.icio.us What's this?
This article has been cited by other articles:
|
|
 |
|
  G. Cavallini, A. Crippa, M. C. Magli, N. Cavallini, A. P. Ferraretti, and L. Gianaroli A Study to Sustain the Hypothesis of the Multiple Genesis of Oligoasthenoteratospermia in Human Idiopathic Infertile Males Biol Reprod, October 1, 2008; 79(4): 667 - 673. [Abstract] [Full Text] [PDF]
|
|
| ||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||