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Rosario D'Agata

Publications and source records attributed to Rosario D'Agata.

10 recordsLinked to original sources

Gene expression in mouse spermatogenesis during ontogenesis.

In this study, we evaluated the expression of genes probably involved in spermatogenesis in the mouse. We examined cytosolic chaperonin theta subunit (CCTtheta), Ngg1 interacting factor 3 like 1 binding protein 1 (NIF3L1 BP1) and apolipoprotein H (ApoH) expression during mouse onto-geny using RT-PCR. Testicular tissue was obtained from mice 3, 6, 8, 10, 12, 14, 18, 20 and 40 (adult) days after birth. For each mouse, one testis was used for histological examination, whereas RNA was extracted from the controlateral testis for expression analysis. RT-PCR analysis showed that CCTtheta gene expression was low until day 10, but increased drastically afterwards. At this age, spermatocytes started to be present in the mouse testis. Therefore, CCT protein could be involved in chromatin packaging and remodeling during spermiogenesis, as also suggested by other studies. NIF3L1 BP1 expression increased steadily during ontogenesis reaching maximum levels in the adult mouse when all germ cell stages are present. This finding suggests that NIF3L1 BP1 is a gene not expressed by a specific germ cell type. ApoH expression was very low or absent during prepuberal stages, whereas it was detectable in the adult testis when spermatogenesis was completed. This suggests that ApoH may be involved in clearing apoptotic bodies during spermatogenesis since apoptotic events increase during spermatogenesis. This study contributes to understanding the role played by genes important for spermatogenesis.

Animals↗

Quantitative evaluation of partial deletions of the DAZ gene cluster.

Partial deletions of the DAZ gene cluster are thought to cause spermatogenesis impairment. The presence of homologous copies of this gene in the Y chromosome does not allow PCR to be used for the identification of this abnormality. Hence, sequence family variants (SFV), following amplification of sY581, sY587 and sY586 and subsequent enzymatic digestion with Sau3A, DraI and TaqI, respectively, and the dual fiber fluorescence in situ hybridization (FISH) have been used to this aim. However, SFV is not always able to identify single DAZ gene copy deletions. We report a quantitative real-time PCR application to evaluate partial deletions of the DAZ gene cluster. To accomplish this, we designed a probe on exon 6 of the DAZ gene which is repeated 3 times in DAZ1, once in DAZ2 and DAZ3 and twice in DAZ4. Five normozoospermic healthy men (C1-C5) having 4 DAZ gene copies by SFV were selected. Fiber-FISH confirmed this outcome in C1-C4, but not in C5 who had an incomplete DAZ gene cluster. The men underwent then quantitative real-time PCR and C1 was arbitrarily selected as calibrator for the calculation of the DAZ gene signals because of the lowest variation in the threshold cycles. Real-time PCR identified 7.2+/-0.05 signals in C2-C4 and 5.4+/-0.05 signals in C5. The overall coefficient of variation was 1.4+/-0.2%. The loss of two signals in this subject may relate to a deletion of both DAZ2 and DAZ3 or of DAZ4 gene. Since SFV showed clearly the presence of DAZ2, it may be hypothesized that C5 lacks DAZ4. In conclusion, these data suggested that quantitative real-time PCR seems to be an effective and reproducible technique that can be used to study the DAZ gene cluster. In addition, the probe chosen for this approach may give indication on the DAZ gene copy deleted.

Adult↗

Patients with abnormal sperm parameters have an increased sex chromosome aneuploidy rate in peripheral leukocytes.

BACKGROUND: Patients with oligoasthenoteratozoospermia (OAT) and normal karyotypes have an increased sperm aneuploidy rate. This may be due to an altered intratesticular environment that affects the chromosomal segregation mechanism(s). Alternatively, it may be due to a generalized meiotic and mitotic abnormality. In this case, patients with abnormal spermatogenesis should also have an increased somatic cell aneuploidy rate. To test this hypothesis, we evaluated peripheral leukocyte aneuploidy rate in patients with spermatogenic impairment. METHODS: In all, 38 patients were enrolled, of whom 20 had OAT, 15 non-obstructive azoospermia and three Y chromosome (Yq) microdeletions (AZF). Eight healthy normozoospermic men with proven fertility were recruited as controls. Conventional karyotype analysis, AZF microdeletion evaluation and triple-colour FISH for chromosomes X, Y and 12 were conducted in all patients and controls. A total of 1000 lymphocytes were scored for each patient and control. RESULTS: All patients and controls had a normal karyotype. Sex chromosome aneuploidy rates in peripheral lymphocytes was significantly higher in patients with OAT (0.74+/-0.09%), azoospermia (1.15+/-0.15%) or Yq microdeleted (1.54+/-0.40%), compared with controls (0.15+/-0.03%) (P <0.05). CONCLUSIONS: Patients with OAT, azoospermia or Yq microdeletions had a slight, but significant, increase of sex chromosome aneuploidy rate in lymphocytes, suggesting the presence of a generalized defective cell division mechanism. In contrast with recent observations, Yq microdeletions do not seem to predispose to a higher number of malsegregation events in somatic cells compared with patients with azoospermia.

Adult↗

Morphologically normal spermatozoa of patients with secretory oligo-astheno-teratozoospermia have an increased aneuploidy rate.

BACKGROUND: Normal morphology is a major criterion for selecting spermatozoa to be injected. Given that teratozoospermia is one of the most critical parameters associated with sperm aneuploidy, the purpose of this study was to evaluate the aneuploidy rate of morphologically normal spermatozoa of patients with oligo-astheno-teratozoospermia (OAT). METHODS: Ten patients with secretory OAT and six age-matched normozoospermic men with a normal karyotype were enrolled. After assignment to normal or abnormal category, the location of each spermatozoon was recorded using an electronic microstage locator. Slides were then subjected to triple-colour fluorescence in situ hybridization for chromosomes X, Y and 12. RESULTS: OAT patients had a lower number of morphologically normal and abnormal spermatozoa carrying the X chromosome, compared with normozoospermic men. They also exhibited increased XY and XX disomy rates. Morphologically abnormal spermatozoa from normozoospermic men also had an increased XX disomy rate compared with normally shaped spermatozoa obtained from the same men. The total sperm aneuploidy rate of morphologically abnormal spermatozoa of normozoospermic men was 4.4-fold higher than that of spermatozoa with normal morphology. The total aneuploidy rates of spermatozoa with normal or abnormal head shape from OAT patients were similar to each other and to that of abnormally shaped spermatozoa from normozoospermic men, but they were higher than the rate found in normally shaped spermatozoa of normal men. CONCLUSIONS: Normally shaped spermatozoa of OAT patients have an increased aneuploidy rate.

Adult↗

Human follicular fluid stimulates the sperm acrosome reaction by interacting with the gamma-aminobutyric acid receptors.

OBJECTIVE: To evaluate whether gamma-aminobutyric acid receptors are involved in human sperm acrosome reaction induced by the follicular fluid (FF). DESIGN: Random selection of normal sperm samples. SETTING: Normal men in an university clinic of andrology. PATIENT(S): Men with normal sperm analysis parameters. INTERVENTION(S): None. MAIN OUTCOME MEASURE(S): Acrosome reaction on motile spermatozoa. RESULT(S): Follicular fluid stimulated the acrosome reaction dose-dependently. The effect of a maximally effective concentration of FF (30%, vol/vol) was significantly suppressed by bicuculline, a GABAA receptor antagonist, and saclofen, a GABAB receptor antagonist, added concomitantly. Each of the two antagonists used alone was devoid of effect. Because the GABAA receptor is linked to the chloride channel, we tested whether picrotoxin, a blocker of this channel, could modulate the effects of the FF. Picrotoxin alone did not have any effect on the acrosome reaction induced by the FF, whereas it had a significant suppressive effect if coincubated with saclofen. The acrosome reaction induced by the FF was also inhibited by picrotoxin plus verapamil, a calcium channel blocker, whereas verapamil alone had no significant effect. This suggested that both chloride and calcium ions mediated the acrosome reaction induced by the FF. CONCLUSION(S): The simultaneous blockade of GABAA and GABAB receptors suppressed the acrosome reaction induced by the FF. This finding suggested that GABA receptors play a physiologic role in sperm activation and shed further light on the mechanism of FF action on human sperm acrosome reaction.

Acrosome Reaction↗

Inhibition of oocyte fertilization by assisted reproductive techniques and increased sperm DNA fragmentation in the presence of Candida albicans: a case report.

The effects of Candida albicans on sperm parameters and the outcome of infertility treatment are unclear. This report describes a lack of fertilization after assisted reproductive techniques and increased sperm DNA fragmentation in an infertile patient with male accessory gland infection due to Candida albicans. He had normal sperm parameters and, therefore, underwent conventional IVF for a female factor of infertility. No spermatozoa or only one spermatozoon per oocyte were found attached to the zona pellucida of the six mature oocytes retrieved. A new semen sample was then requested from the patient to perform intracytoplasmic sperm injection (ICSI) on the same oocytes, but again no fertilization resulted. Candida albicans was detected in the medium where spermatozoa were co-incubated with oocytes and subsequently in the urethral swabs. It did not have any detrimental effect on sperm parameters soon after ejaculation or following separation of motile spermatozoa by swim-up technique. Fertilization failure after assisted reproduction treatment was associated with an increased percentage of motile spermatozoa having chromatin packaging abnormalities, externalization of phosphatidylserine and DNA fragmentation. In conclusion, Candida albicans did not affect sperm parameters, but increased sperm chromatin packaging damage and apoptosis that might have caused fertilization failure after assisted reproduction treatment in this couple.

Adult↗

Lower sperm aneuploidy frequency is associated with high pregnancy rates in ICSI programmes.

BACKGROUND: A large proportion of patients undergoing ICSI have been shown to have an increased sperm aneuploidy rate. This study was undertaken to evaluate the impact of sperm aneuploidy on ICSI outcome. METHODS: To accomplish this, 48 consecutive unselected male patients (median age 34 years) had their sperm aneuploidy rate evaluated in the same swim-up preparation used for ICSI. Chromosomes 8, 12, 18, X and Y were evaluated by fluorescence in-situ hybridization. Patients were divided into two groups (A and B) based on the sperm aneuploidy frequency in their sperm. Group A had values below and group B above the upper limit of normal [1.55%, determined in 14 healthy men (median age 25 years) with normal semen parameters by WHO 1999 criteria (control group)]. RESULTS: Group A consisted of 12 patients (25%) whose sperm aneuploidy rates fell below the cut-off value of the control group (median 1.25%; range 0.85-1.52). Group B consisted of the remaining 36 patients (75%), who had an elevated sperm aneuploidy rate (median 3.25%; range 1.64-23.60). Fertilization (93 versus 85%) and cleavage (100 versus 98%) rates were similar for both groups. Group A had significantly higher clinical pregnancy (75 versus 34%; P < 0.001) and implantation (34 versus 13%; P < 0.001) rates compared with group B. In addition, group A had a lower overall miscarriage rate (11.1 versus 38.9%). Other factors that affect pregnancy and implantation, such as patient age and conventional semen parameters, were similar for both groups. CONCLUSION: This study showed that chromosomally abnormal sperm have a negative impact on ICSI outcome.

Abortion, Spontaneous↗

Chromosome analysis of epididymal and testicular spermatozoa in patients with azoospermia.

Azoospermic patients can now father children once spermatozoa have been retrieved from the epididymis or the testis. However, there are concerns about the risk of chromosomal abnormalities since an increase in sperm aneuploidy rate has been reported in samples from patients with abnormal sperm parameters. The purpose of this study was therefore to evaluate the sperm aneuploidy and diploidy rates for chromosomes 8, 12, 18, X and Y in spermatozoa extracted from the epididymes (n=10) or the testes (n=6) of patients with azoospermia. Ejaculated spermatozoa of healthy men (n=14) served as control. Epididymal and testicular spermatozoa had an aneuploidy rate significantly higher than that found in ejaculated spermatozoa. The aneuploidy and diploidy rates of testicular spermatozoa were higher, but not significantly different, than those found in epididymal spermatozoa. This study has shown that azoospermic patients have an increased sperm aneuploidy rate. They should therefore be given appropriate genetic counselling before entering in-vitro fertilisation programs.

Adult↗

Globozoospermia is associated with chromatin structure abnormalities: case report.

A recent study has shown normal sperm chromatin structure in a patient with globozoospermia. However, the poor success rate following intracytoplasmic sperm injection (ICSI) with the use of this sperm suggests that sperm nuclear abnormalities may be present. We report here a study of the sperm DNA integrity and chromosome aneuploidy and diploidy rates of a patient with 100% round-headed sperm. The sperm chromatin packaging quality was assessed by using flow cytometry after staining the DNA with propidium iodide. DNA fragmentation, possibly indicative of apoptosis, was evaluated by flow cytometry using the terminal deoxynucleotidyl transferase-mediated fluorescein-dUTP nick-end labelling (TUNEL) assay. The sperm chromosome aneuploidy and diploidy rates were evaluated by fluorescence in-situ hybridization using alpha-centromeric probes for chromosomes 8, 12, 18, X and Y. The patient with globozoospermia had a significantly higher number of sperm with chromatin decondensation (35 +/- 1.1%) and positive for the TUNEL assay (37 +/- 1.7%) compared with that found in four normal controls (4.7 +/- 0.4 and 22.5 +/- 1.2% respectively). In contrast, the total sperm aneuploidy (0.16%) and diploidy (0.05%) rates for the chromosomes studied were within the range found in 14 normozoospermic men. To the best of our knowledge, this is the first case report of round-headed sperm that has shown an elevated number of sperm with abnormal chromatin structure and DNA strand breaks.

Adult↗

Absolute polymorphic teratozoospermia in patients with oligo-asthenozoospermia is associated with an elevated sperm aneuploidy rate.

Infertile patients with abnormal sperm parameters have an increased sperm aneuploidy rate, despite a normal blood karyotype. The evaluation of sperm chromosome aberrations in patients with teratozoospermia only has shown a rate similar to that found in patients exhibiting oligo-astheno-teratozoospermia, which suggests that teratozoospermia is the critical parameter associated with aneuploidy. However, it is not known which alteration of the sperm morphology is associated with chromosome aberrations. The few cases reported so far have shown an association with the presence of abnormal head morphology and particularly with enlarged heads. We report the sperm aneuploidy rate of 3 patients with oligo-asthenozoospermia who have absolute teratozoospermia (100% abnormal forms) and a different percentage of sperm head abnormalities. Fourteen healthy men with normozoospermia served as control subjects. Sperm aneuploidy and diploidy rates were calculated by using triple-color fluorescence in situ hybridization (FISH) for chromosomes 12, X, and Y, and double-color FISH was used for chromosomes 8 and 18. Patient K53, who had the highest number of spermatozoa with enlarged heads (54.3%), also had the highest aneuploidy and diploidy rates. The other 2 patients, K56 and K61, had sperm aneuploidy and diploidy rates lower than those of patient K53 but still well above the range found in normal men. Sperm chromosome abnormalities were intermediate in patient K61 and lower in patient K56, who had the lowest rate of spermatozoa with enlarged heads (18.9%). These data add further evidence that patients with teratozoospermia have an increased sperm aneuploidy rate and that this is particularly high in presence of an elevated percentage of spermatozoa with enlarged heads. For this reason, germ cells exhibiting this abnormality should not be used in in vitro fertilization programs.

Adult↗