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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

Chromosome staining results: characteristics of the sSMC.(a) Ideograms of chromosome 15 and the observed sSMC. (b) GTG banding. (c) FISH with probes for chromosome 15: centromere-specific (red) and subtelomeric (green), pointing to a lack of subtelomere region in the sSMC. (d) FISH with whole chromosome painting probes for chromosomes: 15 (green) and Y (red) (e) FISH with centromere-specific probe for chromosome 15 (red) and gene-specific probe for SMAD6 (15q22.31; green). (f) Acro-p FISH result showing two NOR regions on both ends of the sSMC. Displaying modes: inverted DAPI with the whole view of the metaphase plate and DAPI with close-up of chromosomes 15 and sSMC. (g) mFISH analysis showing that sSMC was structured from only chromosome 15 material. (h) aCGH image showing a 15q11.1-q11.2 gain of ~2323 Kb size with a log ratio of 0.547, indicating a one-copy amplification in the region, which indicates the content of the sSMC.
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f1: Chromosome staining results: characteristics of the sSMC.(a) Ideograms of chromosome 15 and the observed sSMC. (b) GTG banding. (c) FISH with probes for chromosome 15: centromere-specific (red) and subtelomeric (green), pointing to a lack of subtelomere region in the sSMC. (d) FISH with whole chromosome painting probes for chromosomes: 15 (green) and Y (red) (e) FISH with centromere-specific probe for chromosome 15 (red) and gene-specific probe for SMAD6 (15q22.31; green). (f) Acro-p FISH result showing two NOR regions on both ends of the sSMC. Displaying modes: inverted DAPI with the whole view of the metaphase plate and DAPI with close-up of chromosomes 15 and sSMC. (g) mFISH analysis showing that sSMC was structured from only chromosome 15 material. (h) aCGH image showing a 15q11.1-q11.2 gain of ~2323 Kb size with a log ratio of 0.547, indicating a one-copy amplification in the region, which indicates the content of the sSMC.

Mentions: The characteristics of the analyzed sSMC are presented in Fig. 1. The use of wcp-FISH on the metaphase lymphocytes identified sSMC as being derived from chromosome 15 in 100% of the tested cells. mFISH analysis excluded the addition of any other chromosomal component to sSMC. FISH using centromeric probe for chromosome 15 and subtelomeric probe for 15q showed no subtelomere 15q presence in sSMC and at least a twice as small size for the sSMC centromere when compared to the centromere of chromosome 15. The presence of a small slice of centromeric region found in sSMC, was then confirmed by aCGH. Acro-p FISH showed the presence of nucleolar organizing regions at two ends of the analyzed sSMC. To confirm the FISH findings and to identify the size of the sSMC material, we performed a 400 K aCGH experiment. The aCGH analysis resulted in 5 copy number variations (CNVs) consisting of one small deletion and 4 amplifications (see Supplementary Fig. S1, and Supplementary Tab. S2 online). Three amplifications and a deletion had already been reported as polymorphic genomic variants in the DGV database, and one small amplification involving C7orf50 was intronic. They were thus not considered pathogenic. One large genomic region of ~2323 kb on chromosome 15 showed a gain with a log ratio of 0.547, indicating an extra copy gain in the 15q11.1-q11.2 region. The DGV database shows smaller polymorphic gains and losses in this region, but none comparable to this detected one, suggesting that this region is included in the sSMC genomic material. The amplified region includes 15 known genes based on human genome build hg19, HERC2P3, GOLGA6L6, GOLGA8C, BCL8, POTEB, NF1P1, LOC646214, CXADRP2, LOC727924, OR4M2, OR4N4, OR4N3P, REREP3, GOLGA8DP, GOLGA6L1 (see Supplementary Fig. S1 and Supplementary Tab. S3 online). The karyotype of the sSMC carrier based on FISH and CGH is: 47,XY,+der(15)(pter->p11.2::q11.1->q11.2::p11.2->pter)mat.ish der(15)(wcp15+,D15Z4+,acro-pNOR++,qter−,SMAD6−).arr[hg19] 15q11.1q11.2(20,432,851–22,756,709)×3.


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)

Chromosome staining results: characteristics of the sSMC.(a) Ideograms of chromosome 15 and the observed sSMC. (b) GTG banding. (c) FISH with probes for chromosome 15: centromere-specific (red) and subtelomeric (green), pointing to a lack of subtelomere region in the sSMC. (d) FISH with whole chromosome painting probes for chromosomes: 15 (green) and Y (red) (e) FISH with centromere-specific probe for chromosome 15 (red) and gene-specific probe for SMAD6 (15q22.31; green). (f) Acro-p FISH result showing two NOR regions on both ends of the sSMC. Displaying modes: inverted DAPI with the whole view of the metaphase plate and DAPI with close-up of chromosomes 15 and sSMC. (g) mFISH analysis showing that sSMC was structured from only chromosome 15 material. (h) aCGH image showing a 15q11.1-q11.2 gain of ~2323 Kb size with a log ratio of 0.547, indicating a one-copy amplification in the region, which indicates the content of the sSMC.
© Copyright Policy - open-access
Related In: Results  -  Collection

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

f1: Chromosome staining results: characteristics of the sSMC.(a) Ideograms of chromosome 15 and the observed sSMC. (b) GTG banding. (c) FISH with probes for chromosome 15: centromere-specific (red) and subtelomeric (green), pointing to a lack of subtelomere region in the sSMC. (d) FISH with whole chromosome painting probes for chromosomes: 15 (green) and Y (red) (e) FISH with centromere-specific probe for chromosome 15 (red) and gene-specific probe for SMAD6 (15q22.31; green). (f) Acro-p FISH result showing two NOR regions on both ends of the sSMC. Displaying modes: inverted DAPI with the whole view of the metaphase plate and DAPI with close-up of chromosomes 15 and sSMC. (g) mFISH analysis showing that sSMC was structured from only chromosome 15 material. (h) aCGH image showing a 15q11.1-q11.2 gain of ~2323 Kb size with a log ratio of 0.547, indicating a one-copy amplification in the region, which indicates the content of the sSMC.
Mentions: The characteristics of the analyzed sSMC are presented in Fig. 1. The use of wcp-FISH on the metaphase lymphocytes identified sSMC as being derived from chromosome 15 in 100% of the tested cells. mFISH analysis excluded the addition of any other chromosomal component to sSMC. FISH using centromeric probe for chromosome 15 and subtelomeric probe for 15q showed no subtelomere 15q presence in sSMC and at least a twice as small size for the sSMC centromere when compared to the centromere of chromosome 15. The presence of a small slice of centromeric region found in sSMC, was then confirmed by aCGH. Acro-p FISH showed the presence of nucleolar organizing regions at two ends of the analyzed sSMC. To confirm the FISH findings and to identify the size of the sSMC material, we performed a 400 K aCGH experiment. The aCGH analysis resulted in 5 copy number variations (CNVs) consisting of one small deletion and 4 amplifications (see Supplementary Fig. S1, and Supplementary Tab. S2 online). Three amplifications and a deletion had already been reported as polymorphic genomic variants in the DGV database, and one small amplification involving C7orf50 was intronic. They were thus not considered pathogenic. One large genomic region of ~2323 kb on chromosome 15 showed a gain with a log ratio of 0.547, indicating an extra copy gain in the 15q11.1-q11.2 region. The DGV database shows smaller polymorphic gains and losses in this region, but none comparable to this detected one, suggesting that this region is included in the sSMC genomic material. The amplified region includes 15 known genes based on human genome build hg19, HERC2P3, GOLGA6L6, GOLGA8C, BCL8, POTEB, NF1P1, LOC646214, CXADRP2, LOC727924, OR4M2, OR4N4, OR4N3P, REREP3, GOLGA8DP, GOLGA6L1 (see Supplementary Fig. S1 and Supplementary Tab. S3 online). The karyotype of the sSMC carrier based on FISH and CGH is: 47,XY,+der(15)(pter->p11.2::q11.1->q11.2::p11.2->pter)mat.ish der(15)(wcp15+,D15Z4+,acro-pNOR++,qter−,SMAD6−).arr[hg19] 15q11.1q11.2(20,432,851–22,756,709)×3.

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