Figure 2 - available from: Molecular Cytogenetics
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Sex chromosome pairing and recombination in the 47, XYY patient. Representative pachytene spermatocytes immunostained for CREST (Blue), SYCP3 (Red) and MLH1 (Green). a Two Y chromosomes partially paired and associated with X chromosome. There is no recombination on the sex chromosomes. c Two Y chromosomes partially paired and associated with chromosome X. Notably there is a recombination focus on the short arm of Y bivalent. e Two Y chromosomes completely paired and associated with X chromosome at the end of short arms. Notably there is no recombination on the sex chromosomes. g Two Y chromosomes completely paired and associated with chromosome X. Notably there is a recombination focus on the short arm of Y bivalent. b, d, f and h are the schematic configurations of the sex chromosomes from the cell shown in a, c, e and g, respectively
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Back ground
Men with 47, XYY syndrome are presented with varying physical attributes and degrees of infertility. Little information has been documented regarding the meiotic progression in patients with extra Y chromosome along with the synapses and recombination between the two Y chromosomes.
Spermatocyte spreading and immunostaining were applied...
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... lymphocytes revealed a karyotype of 47, XYY in all the 100 studied cells of the patient. FISH using a DNA probe specific to human Y chromosome on spermatocyte spreads indicated that all the 71 analyzed pachytene spermatocytes had a XYY constitution (Fig. 1). Table 1). Notably, in none of the studied pachytene cells, X was found to pair with Y ( Fig. 2; Table ...
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... in pachytene spermatocytes of the patient. All the 65 spermatocytes with partial or complete YY synapsis were analyzed. Recombination between two the Y chromo- somes was observed in 27 out of 65 or 41.5 % cells. In spermatocytes with partial YY synapsis, recombination was observed to occur between the two Yp in 21 out of 47 (or 44.7 %) cells ( Fig. 2; Table 2), while in those with complete YY synapsis, recombination between the two Yp was seen as expected but at a lower frequency (4 out of 18, or 22.2 %, Table 2). More interestingly, recombin- ation between the two Yq was also observed in 2 out of 18 (or 11.1 %) spermatocytes with complete YY synapsis ( Fig. 4; Table 2). It was ...
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... was also observed in 2 out of 18 (or 11.1 %) spermatocytes with complete YY synapsis ( Fig. 4; Table 2). It was noted that the frequency of recom- bination between Yp arms was higher when two Y chro- mosomes were partially synapsed. More strikingly, MLH1 foci were not detected on remaining 38 cells although the two Y chromosomes were synapsed ( Fig. 2; Table ...
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... and secondary spermatocyte or spermatid We have observed abnormal pair and synapsis of sex chromosomes in our 47,XYY patient. A predominant pair and synapsis pattern observed was a partially or completely paired and synapsed YY bivalent associated with X chromosome, which forming a trivalent in 45 of 71, or 63.4 % of studied spermatocytes ( Figs. 2 and 3; Tables 1 and 3). The minor pair and synapsis pattern was an YY bivalent and a univalent X in 26 of 71, or 36.6 % of the studied cells, while in none of the studied cells, X and Y were found associated with each other ( Figs. 2 and 3; Tables 1 and 3). Several other studies on pachytene cells have also reported that the two Y- ...
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... bivalent associated with X chromosome, which forming a trivalent in 45 of 71, or 63.4 % of studied spermatocytes ( Figs. 2 and 3; Tables 1 and 3). The minor pair and synapsis pattern was an YY bivalent and a univalent X in 26 of 71, or 36.6 % of the studied cells, while in none of the studied cells, X and Y were found associated with each other ( Figs. 2 and 3; Tables 1 and 3). Several other studies on pachytene cells have also reported that the two Y- chromosomes preferentially pair and synapsis [2,22,23]. Solari and Valzacchi [23] had found a complete absence of normal XY pachytene spermatocytes and 86 % sper- matocytes showed Y-Y bivalent plus a univalent X in their XYY patient. We thus ...
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... 25 spermatocytes showed recombination between two Yp arms while 2 showed recombination between two Yq arms. This indicates at least that long arm of Y chromo- some also has the property to pair, synapse and recombine between each other during meiosis. MLH1 foci were not detected on remaining 38 cells although the two Y chro- mosomes were paired ( Fig. 2; Table 2), the reason for this remains unknown. To our surprise, the number of MLHI foci on autosomes were also significantly reduced in our 47,XYY patient when compared to the controls (Table 2), which indicates presence of an inter-chromosomal effect (ICE). This ICE was probably due to activation of pachy- tene checkpoint that delays ...
Citations
... It has diverse causes, including genetic and environmental factors (4,5) with dozens of molecular and cytogenetic factors being identified associated with male and/or female infertility. Mainly, male infertility is caused by chromosomal abnormalities including an abnormal number or structure of sex chromosomes or autosomes (6,7). Other than such gross chromosomal changes, single-gene mutations have recently received attention as a cause of infertility (8)(9)(10)(11). ...
... These errors may make the cells susceptible to meiotic arrest and increase the levels of aneuploidy within spermatozoa. [30][31][32] If spermatozoa is present, studies have reported a majority of pachytene cells (58%-100%) in the ejaculate of patients that contain the extra Y chromosome. [8] Thus in theory, there is a significant risk of fetal demise and transmission of a SCA in future offspring, at frequency of 50%. ...
The aim of this study is to evaluate the pregnancy outcomes of males with a 47, XYY karyotype following assisted reproductive treatment.
A retrospective study was performed using data from infertile men with 47, XYY at a center for reproductive medicine in 2004 to 2017. Of the 19,842 infertile males treated, a total of 21 showed the 47, XYY karyotype and were included in the present study. Clinical variables were collected. Three men were under treatment with their partner before either in vitro fertilization (IVF) or intracytoplasmic sperm injection (ICSI).
The incidence of 47, XYY in infertile men is 1/945 (21/19842). Most men are azoospermic or severely oligospermic. Three men and their partners underwent IVF or ICSI treatment with fresh ejaculate samples. The fertilization rate was 52.94% to 83.33%. The embryo cleavage rate was 50% to 90%. One man had abnormal sex hormonal levels and his partner had no clinical pregnancy. The other 2 couples had healthy baby boys.
Live spermatozoa can be gathered and fertility is possible for infertile males with 47, XYY syndrome when IVF or ICSI treatment is used. It is recommended that genetic counseling is provided in such cases.
... Although the 47,XYY condition is one of the most frequent chromosomal aneuploidies in human males, scarce analytic results have been reported in the literature on the presence of the extra Y chromosome and its meiotic behaviour (reviewed in Kim et al., 2013). Recently, Wu et al. (2016) reported that all of the 71 analysed spermatocytes from testicular tissue were 47,XYY, with the X + YY configuration being the most frequent one, as previously described by other authors (Speed et al., 1991;Solari and Rey Valzacchi, 1997). ...
Although most XYY men have normal sperm counts and are fertile (supposedly due to the loss of the extra Y before meiosis), there is a minority who are infertile. In these cases, the XYY spermatocytes are able to enter meiosis and form different synaptic configurations. With regard to mosaics, there is scarce well-defined information on the presence of the second Y and its meiotic behaviour. In this study, the chromosome constitution and the synaptic behaviour of pachytene spermatocytes from an azoospermic man with testicular hypotrophy and non-mosaic 47,XYY karyotype were analysed. Furthermore, we determined the chromosome constitution of the somatic Sertoli cells. Five karyotypically normal men with obstructive azoospermia, but having complete spermatogenesis, were included as controls. Immuno-FISH using specific protein markers of synapsis and recombination (SYCP3, SYCP1, BRCA1, MLH1, CREST) and a specific Yq12 DNA probe were used. In addition, we used the newly developed Super-Resolution Structured Illumination Microscopy (SR-SIM) to clearly define the synaptic configurations. FISH analysis was also performed on Sertoli cells. The histopathological analysis showed variable degrees of spermatogenesis development in the testicular tissue of the propositus. Immuno-FISH analysis showed that most of the primary spermatocytes were euploid 46, XY. The use of SR-SIM confirmed the existence of this euploidy. Only a few pachytene spermatocytes showed an aneuploid X + YY constitution. Sertoli cells showed two different populations with one or two Y chromosomes, in similar proportions. Thus an abnormal niche of sex-trisomic Sertoli cells should be also considered when searching for the origin of spermatogenesis failure in XYY men.
... Sertoli cell-only syndrome (SCO) and maturation arrest (MA) are common testicular biopsy findings [26]. There is an increased incidence of chromosomally abnormal spermatozoa in the semen of men with 47,XYY syndrome, especially sex chromosome disomies [27,28]. ...
While 7 % of the men are infertile, currently, a genetic etiology is identified in less than 25 % of those men, and 30 % of the infertile men lack a definitive diagnosis, falling in the “idiopathic infertility” category. Advances in genetics and epigenetics have led to several proposed mechanisms for male infertility. These advances may result in new diagnostic tools, treatment approaches, and better counseling with regard to treatment options and prognosis. In this review, we focus on clinical aspects of male infertility and the role of genetics in elucidating etiologies and the potential of treatments.
Hypertension is one of the long term medical problems in world leading to mortality of 18% globally. Epigenetic modifications like gene regulation, DNA histone modification and methylation patterns are mostly affected during Hypertension condition and need to be carefully monitored. So, metosartan is the one of the antihypertensive drug used to study its effects on genome especially in In-vivo condition. Metosartan doesn't affect the chromatin integrity in hypertensive rats but reduces the sperm count drastically and reaches up to zero at 1.25mg/ml concentration. Majorly the drug affects the sperm count but not the maturation of sperm. In hypertension condition the sperms are aggregated in to complex where as in metosartan treated group In-vitro lead to severe looping of sperms and resulted in formation of apoptotic bodies. In normal rats excessive DNA fragmentation is seen in metosartan treated group and treatment with RNase A along with metosartan in-vitro restored the chromatin integrity but failed to give promisive results in In-vivo condition. So, study of genome integrity in hypertensive patients treated with metosartan is compulsory as it affects chromatin integrity adversely in In-vitro condition in normal rats.
