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Genetic dosage and position effect of small supernumerary marker chromosome (sSMC) in human sperm nuclei in infertile male patient.

Olszewska M, Wanowska E, Kishore A, Huleyuk N, Georgiadis AP, Yatsenko AN, Mikula M, Zastavna D, Wiland E, Kurpisz M - Sci Rep (2015)

Bottom Line: The molecular cytogenetic characteristics of sSMC delineated the karyotype as 47,XY,+der(15)(pter->p11.2::q11.1->q11.2::p11.2->pter)mat.Importantly, we found significant repositioning of chromosomes X and Y towards the nuclear periphery, where both chromosomes were localized in close proximity to the sSMC.This suggests the possible influence of sSMC/XY colocalization on meiotic chromosome division, resulting in abnormal chromosome segregation, and leading to male infertility in the patient.

View Article: PubMed Central - PubMed

Affiliation: Institute of Human Genetics, Polish Academy of Sciences, Department of Reproductive Biology and Stem Cells, Strzeszynska 32, 60-479 Poznan, Poland.

ABSTRACT
Chromosomes occupy specific distinct areas in the nucleus of the sperm cell that may be altered in males with disrupted spermatogenesis. Here, we present alterations in the positioning of the human chromosomes 15, 18, X and Y between spermatozoa with the small supernumerary marker chromosome (sSMC; sSMC(+)) and spermatozoa with normal chromosome complement (sSMC(-)), for the first time described in the same ejaculate of an infertile, phenotypically normal male patient. Using classical and confocal fluorescent microscopy, the nuclear colocalization of chromosomes 15 and sSMC was analyzed. The molecular cytogenetic characteristics of sSMC delineated the karyotype as 47,XY,+der(15)(pter->p11.2::q11.1->q11.2::p11.2->pter)mat. Analysis of meiotic segregation showed a 1:1 ratio of sSMC(+) to sSMC(-) spermatozoa, while evaluation of sperm aneuploidy status indicated an increased level of chromosome 13, 18, 21 and 22 disomy, up to 7 × (2.7 - 15.1). Sperm chromatin integrity assessment did not reveal any increase in deprotamination in the patient's sperm chromatin. Importantly, we found significant repositioning of chromosomes X and Y towards the nuclear periphery, where both chromosomes were localized in close proximity to the sSMC. This suggests the possible influence of sSMC/XY colocalization on meiotic chromosome division, resulting in abnormal chromosome segregation, and leading to male infertility in the patient.

No MeSH data available.


Related in: MedlinePlus

Schematic representation of the radial analysis of the localization of chromosome 15, 18, X, Y and sSMC centromeres, according to the results from Table 2.(a) Comparison of the centromere positioning of individual chromosomes in sSMC+ and sSMC− spermatozoa. The arrows indicate the directions of statistically significant shifts of the centromeres. (b) Comparison of the suggested chromosome 15 territory localization according to SMAD6 (15q22.31) gene positioning (grey color for sSMC+ spermatozoa and yellow for sSMC−). (c) Spatial nuclear area encompassing the positions of all the evaluated chromosomes in fragments of chromocenter(s) in sSMC+ gametes (red areas) and sSMC− spermatozoa (grey areas). (d) Fragments of possible chromocenter(s) with a perspective of the whole sperm nucleus. Solid lines represent the observed areas, while dotted lines show their mirror-images. (e) Dendrogram classification of centromere clusters in sSMC+ and sSMC− spermatozoa according to both positioning criteria. In the sSMC+ gametes, chromosomes X and Y were clustered together with the sSMC, while in the sSMC− gametes there were two groups of chromosomes: 15/18 and X/Y, as in (c) part of the figure. (f) Examples of sperm FISH phenotypes following hybridization with centromere-specific probes for chromosomes 15, 18, X and Y and a gene-specific probe for SMAD6.
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f2: Schematic representation of the radial analysis of the localization of chromosome 15, 18, X, Y and sSMC centromeres, according to the results from Table 2.(a) Comparison of the centromere positioning of individual chromosomes in sSMC+ and sSMC− spermatozoa. The arrows indicate the directions of statistically significant shifts of the centromeres. (b) Comparison of the suggested chromosome 15 territory localization according to SMAD6 (15q22.31) gene positioning (grey color for sSMC+ spermatozoa and yellow for sSMC−). (c) Spatial nuclear area encompassing the positions of all the evaluated chromosomes in fragments of chromocenter(s) in sSMC+ gametes (red areas) and sSMC− spermatozoa (grey areas). (d) Fragments of possible chromocenter(s) with a perspective of the whole sperm nucleus. Solid lines represent the observed areas, while dotted lines show their mirror-images. (e) Dendrogram classification of centromere clusters in sSMC+ and sSMC− spermatozoa according to both positioning criteria. In the sSMC+ gametes, chromosomes X and Y were clustered together with the sSMC, while in the sSMC− gametes there were two groups of chromosomes: 15/18 and X/Y, as in (c) part of the figure. (f) Examples of sperm FISH phenotypes following hybridization with centromere-specific probes for chromosomes 15, 18, X and Y and a gene-specific probe for SMAD6.

Mentions: The determined radial positioning (2D) of the centromeres of chromosomes 15, 18, X, Y and sSMC in the sperm cell nucleus are shown in Table 2 and Fig. 2. When comparing sSMC+ and sSMC− spermatozoa, statistically significant differences (P < 0.01) were found only in the case of sex chromosomes, according to the criterion of the nucleus depth (‘center-periphery’; H/L values). It was found that, in sSMC+ gametes, the X and Y centromeres were strongly repositioned towards the nucleus periphery (X: H/L = 0.201; Y: H/L = 0.212) when collating with sSMC− spermatozoa (X: H/L = 0.109; Y: H/L = 0.100) (X and Y: P < 0.0001) (Fig. 2a). Moreover, when collating the localization of sSMC vs. the sex chromosomes in sSMC+ gametes, similar positioning was noted (P > 0.01) (Fig. 2a). In case of chromosome 15 vs. sSMC, it was found that, in sSMC+ gametes, centromere 15 was localized deep in the nucleus of the spermatozoa, while sSMC had a position near the nuclear periphery (P < 0.0001) (Table 2, Fig. 2a). No statistical differences (P > 0.01) in centromere positioning were observed for chromosomes 15 and 18 when collating sSMC+ vs. sSMC− spermatozoa (Fig. 2a). Similarly, the results of positioning the SMAD6 locus (15q22.31) show that the topology of the gene had unaltered positions (P > 0.01) both in sSMC+ (D/L = 0.575; H/L = 0.134) and sSMC− (D/L = 0.557; H/L = 0.123) spermatozoa (Table 2, Fig. 2b).


Genetic dosage and position effect of small supernumerary marker chromosome (sSMC) in human sperm nuclei in infertile male patient.

Olszewska M, Wanowska E, Kishore A, Huleyuk N, Georgiadis AP, Yatsenko AN, Mikula M, Zastavna D, Wiland E, Kurpisz M - Sci Rep (2015)

Schematic representation of the radial analysis of the localization of chromosome 15, 18, X, Y and sSMC centromeres, according to the results from Table 2.(a) Comparison of the centromere positioning of individual chromosomes in sSMC+ and sSMC− spermatozoa. The arrows indicate the directions of statistically significant shifts of the centromeres. (b) Comparison of the suggested chromosome 15 territory localization according to SMAD6 (15q22.31) gene positioning (grey color for sSMC+ spermatozoa and yellow for sSMC−). (c) Spatial nuclear area encompassing the positions of all the evaluated chromosomes in fragments of chromocenter(s) in sSMC+ gametes (red areas) and sSMC− spermatozoa (grey areas). (d) Fragments of possible chromocenter(s) with a perspective of the whole sperm nucleus. Solid lines represent the observed areas, while dotted lines show their mirror-images. (e) Dendrogram classification of centromere clusters in sSMC+ and sSMC− spermatozoa according to both positioning criteria. In the sSMC+ gametes, chromosomes X and Y were clustered together with the sSMC, while in the sSMC− gametes there were two groups of chromosomes: 15/18 and X/Y, as in (c) part of the figure. (f) Examples of sperm FISH phenotypes following hybridization with centromere-specific probes for chromosomes 15, 18, X and Y and a gene-specific probe for SMAD6.
© Copyright Policy - open-access
Related In: Results  -  Collection

License
Show All Figures
getmorefigures.php?uid=PMC4663790&req=5

f2: Schematic representation of the radial analysis of the localization of chromosome 15, 18, X, Y and sSMC centromeres, according to the results from Table 2.(a) Comparison of the centromere positioning of individual chromosomes in sSMC+ and sSMC− spermatozoa. The arrows indicate the directions of statistically significant shifts of the centromeres. (b) Comparison of the suggested chromosome 15 territory localization according to SMAD6 (15q22.31) gene positioning (grey color for sSMC+ spermatozoa and yellow for sSMC−). (c) Spatial nuclear area encompassing the positions of all the evaluated chromosomes in fragments of chromocenter(s) in sSMC+ gametes (red areas) and sSMC− spermatozoa (grey areas). (d) Fragments of possible chromocenter(s) with a perspective of the whole sperm nucleus. Solid lines represent the observed areas, while dotted lines show their mirror-images. (e) Dendrogram classification of centromere clusters in sSMC+ and sSMC− spermatozoa according to both positioning criteria. In the sSMC+ gametes, chromosomes X and Y were clustered together with the sSMC, while in the sSMC− gametes there were two groups of chromosomes: 15/18 and X/Y, as in (c) part of the figure. (f) Examples of sperm FISH phenotypes following hybridization with centromere-specific probes for chromosomes 15, 18, X and Y and a gene-specific probe for SMAD6.
Mentions: The determined radial positioning (2D) of the centromeres of chromosomes 15, 18, X, Y and sSMC in the sperm cell nucleus are shown in Table 2 and Fig. 2. When comparing sSMC+ and sSMC− spermatozoa, statistically significant differences (P < 0.01) were found only in the case of sex chromosomes, according to the criterion of the nucleus depth (‘center-periphery’; H/L values). It was found that, in sSMC+ gametes, the X and Y centromeres were strongly repositioned towards the nucleus periphery (X: H/L = 0.201; Y: H/L = 0.212) when collating with sSMC− spermatozoa (X: H/L = 0.109; Y: H/L = 0.100) (X and Y: P < 0.0001) (Fig. 2a). Moreover, when collating the localization of sSMC vs. the sex chromosomes in sSMC+ gametes, similar positioning was noted (P > 0.01) (Fig. 2a). In case of chromosome 15 vs. sSMC, it was found that, in sSMC+ gametes, centromere 15 was localized deep in the nucleus of the spermatozoa, while sSMC had a position near the nuclear periphery (P < 0.0001) (Table 2, Fig. 2a). No statistical differences (P > 0.01) in centromere positioning were observed for chromosomes 15 and 18 when collating sSMC+ vs. sSMC− spermatozoa (Fig. 2a). Similarly, the results of positioning the SMAD6 locus (15q22.31) show that the topology of the gene had unaltered positions (P > 0.01) both in sSMC+ (D/L = 0.575; H/L = 0.134) and sSMC− (D/L = 0.557; H/L = 0.123) spermatozoa (Table 2, Fig. 2b).

Bottom Line: The molecular cytogenetic characteristics of sSMC delineated the karyotype as 47,XY,+der(15)(pter->p11.2::q11.1->q11.2::p11.2->pter)mat.Importantly, we found significant repositioning of chromosomes X and Y towards the nuclear periphery, where both chromosomes were localized in close proximity to the sSMC.This suggests the possible influence of sSMC/XY colocalization on meiotic chromosome division, resulting in abnormal chromosome segregation, and leading to male infertility in the patient.

View Article: PubMed Central - PubMed

Affiliation: Institute of Human Genetics, Polish Academy of Sciences, Department of Reproductive Biology and Stem Cells, Strzeszynska 32, 60-479 Poznan, Poland.

ABSTRACT
Chromosomes occupy specific distinct areas in the nucleus of the sperm cell that may be altered in males with disrupted spermatogenesis. Here, we present alterations in the positioning of the human chromosomes 15, 18, X and Y between spermatozoa with the small supernumerary marker chromosome (sSMC; sSMC(+)) and spermatozoa with normal chromosome complement (sSMC(-)), for the first time described in the same ejaculate of an infertile, phenotypically normal male patient. Using classical and confocal fluorescent microscopy, the nuclear colocalization of chromosomes 15 and sSMC was analyzed. The molecular cytogenetic characteristics of sSMC delineated the karyotype as 47,XY,+der(15)(pter->p11.2::q11.1->q11.2::p11.2->pter)mat. Analysis of meiotic segregation showed a 1:1 ratio of sSMC(+) to sSMC(-) spermatozoa, while evaluation of sperm aneuploidy status indicated an increased level of chromosome 13, 18, 21 and 22 disomy, up to 7 × (2.7 - 15.1). Sperm chromatin integrity assessment did not reveal any increase in deprotamination in the patient's sperm chromatin. Importantly, we found significant repositioning of chromosomes X and Y towards the nuclear periphery, where both chromosomes were localized in close proximity to the sSMC. This suggests the possible influence of sSMC/XY colocalization on meiotic chromosome division, resulting in abnormal chromosome segregation, and leading to male infertility in the patient.

No MeSH data available.


Related in: MedlinePlus