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At least 1,207 records · Page 67Linked to original sources
PubMed2001

Detection of microdeletions in the short arm of the X chromosome by chromosome stretching.

The present study was focused on the resolution of "chromosome stretching". In order to determine if this method can be used for the detection of microdeletions, the p-arms of 13 normal X chromosomes were stretched as well as of those with three different deletions of known size within the DMD/BMD region in Xp21 (case A: 0.42-0.45 Mb, case B: 2.3-2.9 Mb and case C: 3.0-3.5 Mb). The process of band splitting was recorded on a video-tape and the resulting banding pattern analyzed. Stretching of the normal Xp-arms led to a splitting on a maximum band level of 1400 and showed in all cases an identical banding pattern with 13 Giemsa-dark subbands. All new Giemsa-dark and -light subbands were derived from the three initial Giemsa-dark bands at the 400 band level according to ISCN (1995): five subbands from Xp21, four subbands from Xp11.3 and Xp22.2, respectively. The origin of these subbands is partly in contrast to the high resolution ISCN (1995) ideograms: subband Xp11.22 does not originate from the Giemsa-light band Xp11.2, but from the Giemsa-dark band Xp11.3; Xp22.12 originates from Xp21; Xp22.32 from Xp22.2. Stretching of the chromosomes containing deletions showed in cases A and B no differences in banding patterns and splitting order compared to normal X chromosomes. Only in patient C was a significant difference with the normal pattern visible due to the absence of one dark subband. In this case only four Giemsa-dark subbands derived from band Xp21. Thus, at least in the DMD/BMD region, the minimal size of a deletion detected by chromosome-stretching-generated high-resolution ideograms is about 3.0-3.5 Mb.

Azure Stains↗
PubMed2002

Establishment of an R-banded rabbit karyotype nomenclature by FISH localization of 23 chromosome-specific genes on both G- and R-banded chromosomes.

Direct detection of fluorescent in situ hybridization signals on R-banded chromosomes stained with propidium iodide is a rapid and efficient method for constructing cytogenetic maps for species with R-banded standard karyotypes. In this paper, our aim is to establish an R-banded rabbit karyotype nomenclature that is in total agreement with the 1981 G-banded standard nomenclature. For this purpose, we have produced new GTG- and RBG-banded mid-metaphase karyotypes and an updated version of ideograms of R-banded rabbit chromosomes. In addition, to confirm correlations between G- and R-banded chromosomes, we have defined a set of 23 rabbit BAC clones, each containing a specific gene, one marker gene per rabbit chromosome, and we have localized precisely each BAC clone by FISH on both G- and R-banded chromosomes.

Animals↗
PubMed2004

Chromosomal constitution of embryos derived from tripronuclear zygotes studied by fluorescence in situ hybridization using probes for chromosomes 4, 13, 18, 21, X, and Y.

This study was designed to assess the chromosomal constitution and segregation patterns of cleaving embryos derived from tripronuclear zygotes. Thirty-two embryos obtained from 19 conventional IVF patients were analyzed by fluorescence in situ hybridization (FISH) using probes for chromosomes 4, 13, 18, 21, X, and Y. Sixteen embryos (50.0%) exhibited uniform, non-mosaic patterns. These embryos showed pure triploid (n = 7), pure diploid (n = 7), or pure haploid (n = 2). The remaining 16 embryos showed mosaic patterns; 1 was triploid-diploid mosaics, 9 were diploid-haploid, and 4 were haploid only. Autosomal aneuploidy occurred in 2 embryos showing a triploid complement. The sex chromosomal constituent XXX:XXY:XYY was 3:4:2 in embryos showing a pure triploid complement (including 2 embryos with aneuploidy). This ratio was not significantly different from the expected 1:2:1 (p = 0.96). Pure triploid was found in 41.7% of 2-cell embryos, but no triploid complement was found in 3-cell embryos. The present study also supports the diandric origin of tripronuclear zygotes in the conventional IVF, and, to our knowledge, is the first study to use simultaneous six-color FISH for chromosomes 4, 13, 18, 21, X, and Y in human embryos. However, no additive information was obtained about chromosome 4.

Chromosome Aberrations↗
PubMed1977

Regional assignment of seven genes on chromosome 1 of man by use of man-Chinese hamster somatic cell hybrids. II. Results obtained after induction of breaks in chromosome 1 by X-irradiation.

The position of genes coding for PGD, PPH1, UGPP, GuK1, PGM1, Pep-C, and FH on human chromosome 1 was investigated by analysis of karyotype and enzyme phenotypes in man-Chinese hamster somatic cell hybrids carrying aberrations involving chromosome 1. Suitable hybrid cell lines were obtained by X-irradiation of hybrid cells carrying an intact chromosome 1 and by fusion of human cells from a clonal population carrying a translocation involving chromosome 1 with Chinese hamster cells. The latter human cell population had been isolated following X-irradiation of primary Lesch-Nyhan fibroblasts. In addition, products of de novo chromosome breakage in the investigated hybrid lines were utilized. By integrating the results of these analyses with earlier findings in our laboratory, the following positions of genes are deduced: PGD and PPH1 in 1p36 leads to 1p34; PGM1 in 1p32; UGPP in 1q21 leads to 1q23; GuK1 in 1q31 leads to 1q42; Pep-C in 1q42; and FH in 1qter leads to 1q42.

Animals↗
PubMed1981

Conserved autosomal syntenic group on mouse (MMU) chromosome 15 and human (HSA) chromosome 22: assignment of a gene for arylsulfatase A to MMU 15 and regional mapping of DIA1, ARSA, and ACO2 on HSA 22.

We have utilized a panel of Chinese hamster x mouse somatic cell hybrids segregating mouse chromosomes to assign a gene for arylsulfatase A (ARSA) to mouse chromosome 15. Considering our previous assignment of a gene for diaphorase-1 (DIA1) to the same mouse chromosome, we have evidence for another syntenic relationship that has been conserved, since the homologous loci for human ARSA and DIA1 are both located on human chromosome 22. Because MMU 15 and HSA 22 are quite dissimilar in size and banding patterns, we have attempted to identify the conserved portion by regional mapping of human DIA1 and ARSA using somatic cell hybrids segregating a human chromosome translocation t(15;22)(q14;q13.31). The results assign human DIA1 and ARSA to the distal sub-band of 22q13 (region 22q13.31 leads to qter). The locus for mitochondrial aconitase (ACO2) has been separated by the breakpoint from DIA1 and ARSA and is located more proximally.

Aconitate Hydratase↗
PubMed1991

Chromosome condensation from prophase to late metaphase: relationship to chromosome bands and their replication time.

As chromosomes condense during early mitosis, their subbands fuse in a highly coordinated fashion. Subband fusion occurs when two large subbands flanking one minor subband come together to form one band, which takes on the cytological characteristics of the original flanking subbands. Using four different banding techniques--GTG (G-bands obtained with trypsin and Giemsa), GBG (G-bands obtained with BrdU and Giemsa), RHG (R-bands obtained by heating and Giemsa), and RBG (R-bands obtained with BrdU and Giemsa)--we studied subband fusion from prophase (1,250 bands per haploid set) to late metaphase (300 bands). To quantify the condensation process, a fusion index was established. We found that chromosomes contain preferential zones of condensation. From prophase to late metaphase, the early replicating subbands (R-subbands) fuse more readily with each other than do the late-replicating subbands (G-subbands). R-bands usually replicate early and condense late independently of the adjacent G-bands, which replicate late but condense early. Therefore, chromosome bands can undergo DNA replication and chromatin condensation relatively autonomously. Our data suggest that (1) chromosome replication and condensation are closely connected in time, (2) the metaphase bands represent independent units of chromatin condensation, and (3) the condensation process is an important feature of chromosome organization.

Cells, Cultured↗
PubMed1994

Regional localization of 56 new human chromosome 18-specific yeast artificial chromosomes.

Fifty-six chromosome 18-specific yeast artificial chromosomes (YAC) were isolated from a human monochromosomal somatic cell hybrid DNA library. Fluorescence in situ hybridization revealed that the clones were evenly distributed throughout the chromosome. The clones, with an average insert size of 250 kb, cover about 18% of the euchromatic part of chromosome 18. Of 90 STS markers tested, 17 were represented in this YAC collection. Together with our previously reported set of unique chromosome 18-specific YACs, we now have available 111 regionally mapped, essentially nonchimeric, clones that provide more than 30% coverage and form a framework for the complete physical map.

Animals↗
PubMedDate not supplied

Search for the chromosomal location of autosomal dominant cerebellar ataxia from Holguin, Cuba: exclusion from candidate regions on chromosome 4 and 11q.

A gene locus for autosomal dominant cerebellar ataxia (ADCA) has been found on chromosome 6p and named spinocerebellar ataxia 1. However, linkage exclusion from chromosome 6p and thus locus heterogeneity has been proven in Cuban ADCA, the largest known collective of ADCA patients, probably due to a founder effect. Two chromosomal regions were analyzed for linkage to Cuban ADCA: chromosome 4, since a pericentromeric inversion has been reported in a member of a European ADCA family, and chromosome 11q22-23, since it is known to contain the gene locus for ataxia telangiectasia, the main autosomal recessive disorder of cerebellar degeneration. In neither region was evidence for linkage found.

Cerebellar Ataxia↗
PubMed2024

Prenatal diagnosis and molecular cytogenetic analysis of pure chromosome 10p15.3 microdeletion using chromosomal microarray analysis.

BACKGROUND: The literature contains exceedingly limited reports on chromosome 10p15.3 microdeletions. In the present study, two cases of fetuses with pure terminal 10p15.3 microdeletion syndrome in a Chinese population were examined, with the objective of enhancing understanding of the genotype-phenotype correlation associated with 10p15.3 microdeletions. METHODS: Two fetuses with chromosome 10p15.3 microdeletion were identified from a cohort of 5,258 cases undergoing amniocentesis. Karyotyping and chromosomal microarray analysis (CMA) was conducted to assess chromosomal abnormalities and detect copy number variations (CNVs) within the families, respectively. RESULTS: In Family 1, the fetus exhibited a 556.2-Kb deletion in the 10p15.3 region, encompassing OMIM genes such as DIP2C and ZMYND11, and presented with increased nuchal translucency on prenatal ultrasound examination. Parental CMA analysis revealed that the 10p15.3 microdeletion was inherited from the father, who displayed mild language impairment. In Family 2, a comparable 10p15.3 microdeletion was identified in a fetus presenting with asymmetric butterfly vertebrae at T10 and T12, along with mild scoliosis of the spine. Family 1 elected to terminate the pregnancy, while Family 2 chose to continue. At a follow-up conducted at one year and eight months, the child demonstrated delays in both speech and motor development. CONCLUSION: The present study is the first to report two cases of pure terminal chromosome 10p15.3 microdeletion syndrome in fetuses, offering valuable insights for the prenatal diagnosis of 10p15.3 microdeletion syndrome. Further, it is the first to describe mild clinical features, specifically limited to language impairment, in a patient with 10p15.3 microdeletion syndrome.

Female↗
PubMedDate not supplied

Application of FISH and Q-PCR techniques in breakpoint diagnostics in three cases of marker chromosomes derived from chromosome 15.

BACKGROUND: The goal of the study was a search for effective methods of diagnosing additional marker chromosomes. MATERIAL AND METHODS: Three cases of extra structurally abnormal chromosomes (ESACs) were diagnosed, the ESACs having been derived from chromosome 15 by cytogenetic techniques, the fluorescence in situ hybridisation (FISH) technique and the quantitative--polymerase chain reaction (Q-PCR). An application of a set of commercially available probes, specific for the 15q11.2-q12 regions (PWACR-Prader-Willi/Angelman Critical Region) allowed for a description of the breaking points. RESULTS: The presence of PWACR region was confirmed in one case and excluded in the other two. It was also attempted to apply the Q-PCR technique for a more accurate determination of the size of the region involved in chromosomal aberration, what would allow for a more reliable prognosing of the clinical outcome. In one of the patients, the breaking point was localized as distal to D15S144 locus, while it was proximal to D15S11 locus in the two remaining cases. CONCLUSIONS: The obtained results demonstrate a possibility of using the Q-PCR method in diagnosing unbalanced chromosome aberrations.

Adult↗
PubMedDate not supplied

[Genomic organization and chromosomal localization of a new repeat MS7, specific for heterochromatin of sex chromosomes in Microtus species voles of the arvalis group].

The tandemly arranged MS4 repeat with monomeric units of 4.1 kb is species-specifically distributed in heterochromatin of sex chromosomes of four common vole species of genus Microtus, group arvalis [1, 2]. In this work, we studied the genomic organization of the MS4 homolog in euchromatin of the X chromosome of M. arvalis. It has been shown by analyzing the phage genomic clones that one MS4 copy makes a part of a monomeric unit exceeding 8.5 kb that also includes a new MS7 repeat and, possibly, LINE fragments. MS7 is located together with MS4 in heterochromatin of common vole sex chromosomes, but in a substantially lesser amount. Probably, as a result of an evolutionary transition of an original repeat from euchromatin of the X chromosome to heterochromatin of the Y chromosome, MS4 underwent multiple amplification, and MS7 spread throughout heterochromatin, being surrounded by the MS4 tandem arrays.

Animals↗
PubMed1992

Influence of chromosome condensation and preparative chromosome methods on chromatid volume.

Human metaphase chromosomes 1 and 2 were examined by electron microscopy. Volumetric determinations were calculated on non-treated isolated chromosomes and spread metaphases treated with ammoniacal silver carbonate (ASC). Chromatid volume increased from early-metaphase to late-metaphase and this increase was statistically significant. A similar relationship was found when chromosomes with differentially condensed sister chromatids were studied. The more condensed chromatid volume was greater than its less condensed sister chromatid. ASC treatment produced structural changes in chromosomes which caused an increase of volume in relation to the isolated chromosomes.

Cells, Cultured↗
PubMed1991

[Cytogenetic analysis of the chromosomal region containing the radiosensitivity genes of Drosophila. Influence of pericentromeric heterochromatin on mutagenesis in the 44-45 region of chromosome 2].

Formation of radiation-induced mutations in the 44-45 region of Drosophila melanogaster chromosome 2 carrying the In(2)G50 inversion which juxtaposes the material of this region towards the centromeric heterochromatin was studied. 14 gamma-induced rearrangements in the inverted chromosome having a new breakpoint in the 44-45 region were selected. Four of them are deletions, seven are translocations and three are transpositions. 10 of these aberrations have a second breakpoint located in the heterochromatin regions of chromosomes 2 and 3. It was shown that the frequency of deletions in the region studied is tenfold higher within the inverted chromosomes as compared with the structurally normal one. Anyway, it is essentially lower than the frequency determined in analogous experiments for the other region of the chromosome. Thus, the peculiar characteristics of radiation mutagenesis in the 44-45 region, such as the prevalence of heterochromatic aberrations in the rearrangement spectrum and the relatively low deficiency frequency are still retained after inversional shift of this region to the pericentromeric heterochromatin.

Animals↗
PubMed1991

[Chromosomal control of chiasma distribution in house mice. Analysis of chiasma distribution in homo- and heterozygotes by inversion in chromosome 1].

Examination of chiasma distribution in the chromosome 1 in male mice homo- and heterozygous for distal inversion In(1)12Rk and in normal mice was carried out. No differences in chiasma distribution was found between homozygotes for the inversion and homozygotes for normal chromosome 1. A drastic change in this trait was revealed in heterozygous animals. In heterozygotes, the telomeric segments of SC were asynapsed and unavailable for recombination. This leads to significant decrease in the frequency of bivalents bearing chiasmata in pretelomeric region. In turn, it produced chiasma redistribution in proximal noninverted portion of the bivalent 1. These results could be interpreted as evidence for chromosomal control of chiasma distribution pattern: the distance of certain part of the chromosome from telomere and interference (which also operates at the chromosomal level) are more important for determination of the chiasmata frequency in the given region, than its genetic content.

Animals↗
PubMed1989

Chromosomes in myelodysplastic syndrome: structural abnormalities of chromosome 11. Czechoslovak MDS Cooperative Group.

In a series of 121 consecutive patients with a myelodysplastic syndrome (MDS), studied in two laboratories, of which 87 (71.9%) had abnormal karyotypes, twelve had a structural abnormality of the long arm of chromosome 11 (13.8%). There were six deletions, one ring chromosome and five reciprocal translocations, all involving a chromosome band 11q23. Of these twelve patients, five had a refractory anemia (RA) and seven a refractory anemia with excess of blasts (RAEB). RA was associated more frequently with 11q deletions as the sole abnormality, while translocations or multiple chromosome abnormalities were commonly associated with RAEB. The study shows that the 11q aberrations represent frequent structural chromosome rearrangements in MDS.

Bone Marrow↗
PubMed1978

Missing X chromosome and ring chromosome 21 in a case of acute myelomonocytic leukemia.

The karyotypic picture of a female patient with acute myelomonocytic leukemia (A.M.M.L.) consisted in the loss of a sex chromosome and a ring chromosome 21. It is suggested that in A.M.M.L. the loss of sex chromosome may represent an early event, the monosomic cells being the object of further chromosome rearrangements, which involve more frequently a chromosome 21.

Adult↗
PubMed1987

Tandem duplication chromosome 21 in the offspring of a ring chromosome 21 carrier.

A direct tandem duplication chromosome 21 was found in a boy with Down's syndrome. The proband's mother and grandmother both carried a ring chromosome 21. The observed duplication chromosome in the child may be explained either by recombination between the maternal ring and the mother's normal chromosome 21 or by break of a double-sized ring chromosome 21.

Child, Preschool↗
PubMed1988

Detection of chromosome aneuploidy in interphase nuclei from human primary breast tumors using chromosome-specific repetitive DNA probes.

We have used in situ hybridization with chromosome specific repetitive DNA sequences as a probe to reveal particular chromosomes as distinct spots or clusters of signal within interphase nuclei. Using karyotypically defined cells and cell lines, we show that the number of signals obtained per nucleus correlates with the number of particular chromosomes present in that nucleus. Further, admixtures of karyotypically different cell lines could be detected. In situ hybridization of nuclei and metaphase spreads derived from the breast cancer cell line MCF-7 shows that a deviant number of spots/nucleus indicates a numerical and/or structural chromosomal aberration. In seven primary breast tumors studied, we detected numerical aberrations of the target sites of chromosomes 1 and/or 18. Although all had a single peak in DNA flow measurements, six of the cases appeared to be heterogeneous with respect to their spots/nucleus content.

Aneuploidy↗