Meiotic chromosome abnormalities in fertile men: are they increasing?

Uroz, Laia; Rajmil, Osvaldo; Templado, C.

doi:10.1016/j.fertnstert.2010.06.042

Cited by 10 publications

(7 citation statements)

References 45 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…Chromosome 21, the smallest one in the karyotype, and the sex chromosomes, whose pairing is limited to the pseudoautosomal region, appear frequently as two separated univalents. In accordance with our results, other meiotic studies in fertile male donors reported G-group and sex chromosomes as the most susceptible to having no chiasmata at MI (Skakkebaek et al, 1973;Uroz et al, 2011) or no recombination foci at pachytene (Sun et al, 2006) (reviewed by Tempest, 2011). The absence of chiasmata has been correlated with an abnormal chromosome segregation in meiosis I both in trisomic 21 (Savage et al, 1998;Oliver et al, 2009) and 47,XXY conceptuses (Hassold et al, 1991;Lorda-Sanchez et al, 1992;Thomas et al, 2000).…”

Section: Low Chiasma Count In Human Spermatocytes Isupporting

confidence: 90%

“…Studies at these meiotic stages are scarce, owing to the difficulty of obtaining testicular tissue. Meiotic analyses carried out on fertile and infertile men described abnormal chiasma count and numerical chromosome abnormalities (Skakkebaek et al, 1973;Chandley et al, 1976;Koulischer et al, 1982;Egozcue et al, 1983;Laurie et al, 1985;Guichaoua et al, 1986;Uroz et al, 2009Uroz et al, , 2011 but they were not focused on studying non-disjunction mechanisms.…”

Section: Introductionmentioning

confidence: 99%

See 1 more Smart Citation

Meiotic non-disjunction mechanisms in human fertile males

Uroz

Templado

2012

Human Reproduction

View full text Add to dashboard Cite

background: In humans, little is known about the mechanisms of non-disjunction working in male meiosis, although considerable attention has been given to these mechanisms in female meiosis. The present study explores the origin of meiotic non-disjunction during human spermatogenesis and the chromosomes most commonly involved in this process. methods:We used Multiplex fluorescence in situ hybridization to carry out meiotic analyses in metaphase I (MI) and metaphase II (MII) spermatocytes from three fertile donors. Testicular biopsy was obtained during a vasectomy procedure.results: We examined a total of 317 MI and 248 MII spermatocytes. The frequency of numerical chromosome abnormalities at MII (14.5%) was 5.5 times higher than at MI (2.5%). We observed 88 (27.7%) spermatocytes I with chromosome bivalents with a low chiasma count, usually small chromosomes displaying two separated univalents. Chromosomes X, Y and 21 were the most commonly found as achiasmate chromosomes at MI and the most frequently involved in disomy at MII. Hyperploidy frequency in spermatocytes II (disomy) was significantly higher (P , 0.001) than that found in spermatocytes I (trisomy).conclusions: Achiasmate non-disjunction and premature separation of sister chromatids appear to be the two main non-disjunction mechanisms during the first meiotic division in human spermatogenesis, and both mechanisms contribute equally to the genesis of aneuploidy. The elevated frequencies of disomy detected in spermatocytes II are significantly higher than those previously described in human spermatozoa, suggesting the existence of a postmeiotic checkpoint monitoring numerical abnormalities.

show abstract

Section: Low Chiasma Count In Human Spermatocytes Isupporting

confidence: 90%

Section: Introductionmentioning

confidence: 99%

Meiotic non-disjunction mechanisms in human fertile males

Uroz

Templado

2012

Human Reproduction

View full text Add to dashboard Cite

show abstract

“…15,[18][19][20][21] and metaphase I spermatocytes. 31 Acentric fragments can either acquire a neocentromere and be rescued, or be lost. 32 This could explain the excess of duplications detected in spermatozoa with respect to the rate of subtelomeric duplications in subjects with a clinical phenotype The higher rate of duplications could be explained by a mitotic origin rather than a meiotic origin for some of these de novo abnormalities.…”

Section: Discussionmentioning

confidence: 99%

Advanced age increases chromosome structural abnormalities in human spermatozoa

et al. 2010

Self Cite

View full text Add to dashboard Cite

This study explores the relationship between sperm structural aberrations and age by using a multicolor multichromosome FISH strategy that provides information on the incidence of duplications and deletions on all the autosomes. ToTelvysion kit (Abbott Molecular, Abbott Park, IL, USA) with telomere-specific probes was used. We investigated the sperm of 10 male donors aged from 23 to 74 years old. The donors were divided into two groups according to age, a cohort of five individuals younger than 40 and a cohort of five individuals older than 60 years. The goal of this study was to determine (1) the relationship between donor age and frequency and type of chromosome structural abnormalities and (2) chromosomes more frequently involved in sperm structural aberrations. We found that the older patients had a higher rate of structural abnormalities (6.6%) compared with the younger cohort (4.9%). Although both duplications and deletions were seen more frequently in older men, our findings demonstrate the presence of an excess of duplications versus deletions in both groups at a ratio of 2 to 1. We demonstrate that the distribution of duplications and deletions was not linear along the chromosomes, although a trend toward a higher rate of abnormalities in larger chromosomes was observed. This work is the first study addressing the frequencies of sperm chromosome structural aberrations of all autosomes in a single assay thus making a contribution to the clarification of the amount and origin of damage present in human spermatozoa and in relation to age.

show abstract

“…Environmental factors may either damage critical genes or alter gene expression by interfering with the epigenetic programming. 46 The genetic damages may also be revealed by the increasing frequency of meiotic abnormalities in fertile men in recent decades 47 or by models of germ cell cultures with toxic presence. Meiosis is thus shown to be severely impaired by low concentrations of hexavalent chromium.…”

Section: Contribution Of Environmental Factorsmentioning

confidence: 99%

Decline of semen quality among 10 932 males consulting for couple infertility over a 20-year period in Marseille, France

Geoffroy-Siraudin¹,

Loundou²,

Romain³

et al. 2012

Asian J Androl

View full text Add to dashboard Cite

Semen from 10 932 male partners of infertile couples was analysed and sperm parameter trends were evaluated at the Reproduction Biology Laboratory of the University Hospital of Marseille (France) between 1988 and 2007. After 3-6 days of abstinence, semen samples were collected. Measurements of seminal fluid volume, pH, sperm concentration, total sperm count, motility and detailed morphology of spermatozoa were performed. Sperm parameters were analysed on the entire population and in men with normal total numeration (o40 million per ejaculate). The whole population demonstrated declining trends in sperm concentration (1.5% per year), total sperm count (1.6% per year), total motility (0.4% per year), rapid motility (5.5% per year) and normal morphology (2.2% per year). In the group of selected samples with total normal sperm count, the same trends of sperm quality deterioration with time were observed. Our results clearly indicate that the quality of semen decreased in this population over the study period. Keywords: environment; male infertility; regional differences; semen quality; sperm parameters INTRODUCTION Numerous studies suggest a decline in semen quality in some parts of the world. 1-8 By contrast, other studies have shown no evidence of deteriorating semen quality. 9-16 Some studies concern infertile couples, while others analyse normal sperm parameters. Thus, a worldwide decreasing trend in semen parameter values can be neither confirmed nor rejected. 17 It was recently reported that fecundity is affected by this decrease. 18,19 It was speculated that decreasing sperm parameters are in response to adverse environmental factors. Nevertheless, the observed discrepancies between studies suggest regional differences in semen quality. [20][21][22] Variations in environmental factors, industrial pollution and/or lifestyle could explain these discrepancies. A large number of environmental factors can pollute air, drinking water and food. This can directly alter the male gonad by blood-testis barrier disruption and cellular toxicity, or disrupt androgen biosynthesis and action. Among these environmental factors, oestrogenic or anti-androgenic endocrine disrupting compounds inhibit critical cellular process controlling steroidogenesis in Leydig cells and androgen binding to the androgen receptor. 23 It has been hypothesized that endocrine disrupting compounds play a major role in the aetiology of increased incidence of testicular dysgenesis syndrome which gathers decreased quality of semen, cryptorchidism, hypospadias and testicular cancer. 24 Chemicals with hormone-like activity can also

show abstract

Meiotic chromosome abnormalities in fertile men: are they increasing?

Cited by 10 publications

References 45 publications

Meiotic non-disjunction mechanisms in human fertile males

Meiotic non-disjunction mechanisms in human fertile males

Advanced age increases chromosome structural abnormalities in human spermatozoa

Decline of semen quality among 10 932 males consulting for couple infertility over a 20-year period in Marseille, France

Contact Info

Product

Resources

About