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PubMed1995

Comparative genome map of human and cattle.

Chromosomal homologies between individual human chromosomes and the bovine karyotype have been established by using a new approach termed Zoo-FISH. Labeled DNA libraries from flow-sorted human chromosomes were used as probes for fluorescence in situ hybridization on cattle chromosomes. All human DNA libraries, except the Y chromosome library, hybridized to one or more cattle chromosomes, identifying and delineating 50 segments of homology, most of them corresponding to the regions of homology as identified by the previous mapping of individual conserved loci. However, Zoo-FISH refines the comparative maps constructed by molecular gene mapping of individual loci by providing information on the boundaries of conserved regions in the absence of obvious cytogenetic homologies of human and bovine chromosomes. It allows study of karyotypic evolution and opens new avenues for genomic analysis by facilitating the extrapolation of results from the human genome initiative.

Animals↗
PubMed2002

Genetic imbalances in progressed B-cell chronic lymphocytic leukemia and transformed large-cell lymphoma (Richter's syndrome).

Chromosomal imbalances were examined by comparative genomic hybridization in 30 cases of B-cell chronic lymphocytic leukemia (CLL) at diagnosis, in sequential samples from 17 of these patients, and in 6 large B-cell lymphomas transformed from CLL [Richter's syndrome (RS)] with no available previous sample. The most common imbalances in CLL at diagnosis were gains in chromosome 12 (30%), and losses in chromosomes 13 (17%), 17p (17%), 8p (7%), 11q (7%), and 14q (7%). The analysis of sequential samples showed an increased number of chromosomal imbalances in 6 of 10 (60%) patients with clinical progression and in 2 patients with stable stage C disease. No karyotypic evolution was observed in four cases with stable stage A disease and in one RS clonally unrelated to the previous CLL. Gains of 2pter, and 7pter, and losses of 8p, 11q, and 17p were recurrent alterations associated with karyotype progression. RS showed a higher number of gains, losses, total alterations, and losses of 8p and chromosome 9 than CLL at diagnosis. 17p losses were associated with p53 gene mutations and with a significantly higher number of chromosomal imbalances than tumors with normal chromosome 17 profile. However, no relationship was observed between 9p deletions and p16(INK4a) gene alterations. Losses of 17p and an increased number of losses at diagnosis were significantly associated with a shorter survival. These findings indicate that CLL has frequent chromosomal imbalances, which may increase during the progression of the disease and transformation into large cell lymphoma. Genetic alterations detected by comparative genomic hybridization may also be of prognostic significance.

Chromosome Aberrations↗
PubMed1993

Chromosome aberrations and cytogenetic intratumor heterogeneity in chondrosarcomas.

Clonal chromosome aberrations identified after short-term culture are presented for 13 chondrosarcomas; in 5 cases both the primary tumors and local recurrences were studied. The stemline chromosome number was hypodiploid or hyperhaploid in 9 tumors. The most frequent numerical anomalies were, in falling order of frequency, loss of chromosomes Y, 10, 13, and 6, and gain of chromosomes 7 and 20. No recurrent structural rearrangement was found, but chromosome bands 5q13, 1q21, 7p11, and 20q11 were each involved in three different rearrangements. Karyotypic heterogeneity was assessed in two different ways: as the presence of more than one clone in one sample and as the presence of different clones in different samples from the same surgical specimen. Clonal karyotypic evolution was demonstrated in 6 of the 7 cases in which two or more samples could be investigated. All 6 showed intersample heterogeneity. Intrasample heterogeneity was found in only 5 of the 28 samples with aberrations. By comparing the incidences of the nonrandomly occurring aberrations in stemlines and sidelines in the heterogeneous tumors, it was possible to conclude that loss of chromosome 13 and rearrangement of band 5q13 were early events in the clonal evolution.

Adult↗
PubMed2007

Cytogenetic evolution patterns in CML post-SCT.

The cytogenetic evolution patterns in chronic myeloid leukemia (CML) after allogeneic (allo) stem cell transplantation (SCT) are different from the ones observed in non-transplanted patients, a phenomenon suggested to be caused by the conditioning regime. We reviewed 131 CMLs displaying karyotypic evolution after SCT (122 allo, nine autologous (auto)), treated at Lund University Hospital or reported in the literature. Major route abnormalities (i.e., +8, +Ph, i(17q), +19, +21, +17 and -7) were seen in 14%, balanced aberrations in 61%, hyperdiploidy in 19%, pseudodiploidy in 79%, divergent clones in 14%, and Ph-negative clones in 21%. The breakpoints involved in secondary structural rearrangements clustered at 1q21, 1q32, 7q22, 9q34, 11q13, 11q23, 12q24, 13q14, 17q10 and 22q11. Cytogenetic abnormalities common in AML after genotoxic exposure, that is, der(1;7)(q10;p10), del(3p), -5, del(5q), -7, -17, der(17p), -18, and -21, were only rarely seen post-SCT. Comparing the cytogenetic features in relation to type of SCT revealed that balanced aberrations were significantly more common after allo than after auto SCT (64 and 22%, respectively, P=0.03). In addition, there was a trend as regards hyperdiploidy being more common after auto (P=0.07) and pseudodiploidy being more frequent after allo SCT (P=0.09). Possible reasons for these differences are discussed.

Adolescent↗
PubMed1984

Ph1-positive and Ph1-negative abnormal cell lines in a child with lymphoblastic lymphoma.

A 7-year-old Japanese boy with Ph1-positive-lymphoblastic lymphoma is described. The diagnosis was based on biopsied tonsils which were enlarged at the time of admission. On the eighth day after admission an enlarged mediastinal mass was detected on a chest X-ray film. The lymphoblasts which appeared in the peripheral blood and bone marrow proved to be T-cells. Chromosome studies on the bone marrow cells revealed two abnormal cell lines; one had a 7;11 translocation and the other a 7;11 translocation and a 9;22 translocation, forming the Ph1-chromosome. The latter line with the Ph1-chromosome was considered to have been derived from the former line without the Ph1. Our findings show that the Ph1-chromosome may be a secondary change in the course of karyotypic evolution.

Bone Marrow↗
PubMed1994

Regional assignment of the human immunoglobulin processed pseudogene C epsilon 3 (IGHEP2) to 9p24.2-->p24.1 by fluorescence in situ hybridization.

The human immunoglobulin processed pseudogene C epsilon 3 (IGHEP2), which was assigned to chromosome 9 by somatic cell hybrid analysis, has not been regionally localized as yet. In this study, using fluorescence in situ hybridization (FISH) combined with conventional QFQ-, RBG- or GTG-banding, IGHEP2 was assigned to the p terminus region of chromosome 9, at band 9p24.2-->p24.1. This result suggests that the C epsilon 3 gene is a novel telomeric DNA marker useful not only for constructing the physical map of human chromosome 9 but also for cytogenetic analyses such as cryptic translocations. In addition, comparative mapping of this gene in other catarrhine primates would contribute to investigations of human and other primate karyotype evolution.

Cells, Cultured↗
PubMed1990

Long arm deletion of chromosome 7 unrelated to original karyotype in recurrent t(8;21) acute myeloblastic leukemia.

We describe a chromosomal abnormality, 7q-, unrelated to the original karyotype in a patient with recurrent t(8;21) acute myeloblastic leukemia. The 7q-, del(7)(q22q34), was seen in otherwise karyotypically normal cells. Cyclophosphamide was administered for 5 months during the maintenance therapy. Our observations indicate that unrelated karyotypes, besides karyotypic evolution, may be implicated in tumor cell heterogeneity and may support the previous documentation of a possibly causal relationship between chemotherapy and development of 7q-. A larger study will be required to elucidate the biologic significance, if any, of the unrelated karyotypes.

Adult↗
PubMed2003

B chromosomes of the Podisma sapporensis Shir. (Orthoptera, Acrididae) analysed by chromosome microdissection and FISH.

The analysis of the distribution of repetitive DNA of the B chromosomes of Podisma sapporensis in the A and B chromosomes of the natural populations and in A chromosomes of three other species of the Podismini grasshoppers were made. DNA-libraries of the B chromosome and the euchromatic segment of the A chromosome of P. sapporensis were generated by meiotic chromosome microdissection followed by degenerated oligonucleotide primed polymerase chain reaction (DOP-PCR). Paints based on these DNA-libraries were used for FISH analysis to detect localization of homologous sequences in A and B chromosomes of P. sapporensis from different natural populations. On the basis of the FISH analysis the authors suggest that evolution of the B chromosomes in Podisma sapporensis was associated mainly with the insertions of "alien DNA sequences" into ancestral A chromosome and their further amplification. The number of initial sites of amplifications differed in the different Bs, the distance between these sites also varying. Karyotype evolution in P. sapporensis was associated partly with the insertion of "alien DNA sequences" into pericentromeric chromosomal regions. Insertion into the small short arms of the acrocentric chromosomes followed, with the DNA amplification leading to the formation of the additional C-heterochromatic arms or euchromatic-like regions of different size.

Animals↗
PubMed1987

Chromosomal analysis of bladder cancer. III. Nonrandom alterations.

Chromosome analysis using G- and C-banding was performed on 13 primary transitional cell carcinomas of the bladder. The chromosome preparations were obtained by a direct method. In eight tumors with a (near) diploid modal chromosome number, the most frequently observed chromosome aberrations were: (partial) monosomy 9 in four cases, deletion of 10q in two cases, and partial trisomy 1 in two cases. In five tumors with a modal chromosome number in the triploid or tetraploid range the chromosomes #1, #3, #7, #9, #11, and #17 were numerically and or structurally abnormal in at least four cases. In three out of ten males, the Y chromosome was missing. These findings suggest that the loss of chromosome #9, and possibly also loss of 10q is a primary event in the karyotypic evolution of transitional cell carcinoma of the bladder.

Carcinoma, Transitional Cell↗
PubMed1987

Chromosomal progression of malignant human gliomas from biopsy to establishment as permanent lines in vitro.

Karyotypes of four malignant human gliomas were followed from direct preparation and/or short-term culture through their establishment in vitro to determine whether the cultured cells maintained the original karyotypes, or were the products of selection, progression, or alteration in vitro. The karyotypes of these four human glioma-derived cell lines showed the same evolutionary pattern consisting of a doubling of the stem line or a closely related population; one line changed ploidy again to near-pentaploid. Marker types seen originally were generally retained, but new markers were acquired in the later passages. We concluded that the eventual chromosomal compositions of these four human glioma-derived cell lines were the products of karyotypic evolution, rather than simple selection of a minor population of polyploid cells.

Cell Line↗
PubMed2006

Evolutionary movement of centromeres in horse, donkey, and zebra.

Centromere repositioning (CR) is a recently discovered biological phenomenon consisting of the emergence of a new centromere along a chromosome and the inactivation of the old one. After a CR, the primary constriction and the centromeric function are localized in a new position while the order of physical markers on the chromosome remains unchanged. These events profoundly affect chromosomal architecture. Since horses, asses, and zebras, whose evolutionary divergence is relatively recent, show remarkable morphological similarity and capacity to interbreed despite their chromosomes differing considerably, we investigated the role of CR in the karyotype evolution of the genus Equus. Using appropriate panels of BAC clones in FISH experiments, we compared the centromere position and marker order arrangement among orthologous chromosomes of Burchelli's zebra (Equus burchelli), donkey (Equus asinus), and horse (Equus caballus). Surprisingly, at least eight CRs took place during the evolution of this genus. Even more surprisingly, five cases of CR have occurred in the donkey after its divergence from zebra, that is, in a very short evolutionary time (approximately 1 million years). These findings suggest that in some species the CR phenomenon could have played an important role in karyotype shaping, with potential consequences on population dynamics and speciation.

Animals↗
PubMed2006

Chromosome localization of microsatellite markers in the shrews of the Sorex araneus group.

The extremely high rate of karyotypic evolution that characterizes the shrews of the Sorex araneus group makes this group an exceptionally interesting model for population genetics and evolutionary studies. Here, we attempted to map 46 microsatellite markers at the chromosome arm level using flow-sorted chromosomes from three karyotypically different taxa of the Sorex araneus group (S. granarius and the chromosome races Cordon and Novosibirsk of S. araneus). The most likely localizations were provided for 35 markers, among which 25 were each unambiguously mapped to a single locus on the corresponding chromosomes in the three taxa, covering the three sexual chromosomes (XY1Y2) and nine of the 18 autosomal arms of the S. araneus group. The results provide further evidence for a high degree of conservation in genome organization in the S. araneus group despite the presence of numerous Robertsonian rearrangements. These markers can therefore be used to compare the genetic structure among taxa of the S. araneus group at the chromosome level and to study the role of chromosomal rearrangements in the genetic diversification and speciation process of this group.

Animals↗
PubMed2002

Comparative karyological analysis of three species of Bothriocephalus Rudolphi 1808 (Cestoda: Pseudophyllidea).

The diploid complements of mitotic metaphase plates of three species of Botriocephaluswere studied using conventional Giemsa staining and karyometric analysis. Botriocephalus claviceps and Botriocephalus gregarius showed a karyotype with 2n=14 chromosomes. All chromosomes of B. claviceps were biarmed, metacentric or meta-submetacentric. The two first pairs of homologues were markedly larger than the remaining elements and represented 48.62% of the total chromosome length. The karyotype of B. gregarius had similar metric values for the chromosomes, but clearly differed in the chromosome morphology of pairs 5, 6 and 7, which had terminally located centromeres. The diploid number 2n=12 was found in Botriocephalus scorpii. The karyotype consists of five pairs of metacentric and one pair of submeta-metacentric chromosomes. The possible pathways of karyotype evolution within Bothriocephalus spp. and their phylogenetic relations with the other karyologically studied groups in the order Pseudophyllidea are discussed.

Anguilla↗
PubMed2005

The loss of a single telomere can result in instability of multiple chromosomes in a human tumor cell line.

Spontaneous telomere loss has been proposed as an important mechanism for initiating the chromosome instability commonly found in cancer cells. We have previously shown that spontaneous telomere loss in a human cancer cell line initiates breakage/fusion/bridge (B/F/B) cycles that continue for many cell generations, resulting in DNA amplification and translocations on the chromosome that lost its telomere. We have now extended these studies to determine the effect of the loss of a single telomere on the stability of other chromosomes. Our study showed that telomere acquisition during B/F/B cycles occurred mainly through translocations involving either the nonreciprocal transfer or duplication of the arms of other chromosomes. Telomere acquisition also occurred through small duplications involving the subtelomeric region of the other end of the same chromosome. Although all of these mechanisms stabilized the chromosome that lost its telomere, they differed in their consequences for the stability of the genome as a whole. Telomere acquisition involving nonreciprocal translocations resulted in the loss of a telomere on the donor chromosome, which consequently underwent additional translocations, isochromosome formation, or complete loss. In contrast, telomere acquisition involving duplications stabilized the genome, although the large duplications created substantial allelic imbalances. Thus, the loss of a single telomere can generate a variety of chromosome alterations commonly associated with human cancer, not only on a chromosome that loses its telomere but also on other chromosomes. Factors promoting telomere loss are therefore likely to have an important role in generating the karyotype evolution associated with human cancer.

Alleles↗
PubMed2003

Heterochromatin polymorphism associated with 18S rDNA: a differential pathway among Hoplias malabaricus fish populations.

The distribution of constitutive heterochromatin has showed a relevant association with karyotypic evolution in several animal groups. In the present paper, a polymorphic condition for a heterochromatic segment overlapping a nucleolar organizer region in the fish species Hoplias malabaricus from the Iguaçu river, Southern Brazil, was analyzed. In accordance with previous studies, this population belongs to cytotype A, showing 2n = 42 meta-submetacentric chromosomes, without differentiation of sex chromosomes. Three phenotypes were established with regard to the heterochromatin located near the centromere of chromosome pair 16, and named rr for homomorphic reduced bands, dd for homomorphic duplicated bands and rd for the heteromorphic condition. The rr phenotype was predominant (70.6%), followed by rd (23.5%) and dd (5.9%), showing Hardy-Weinberg equilibrium in the population. In addition, the 18S rDNA sites also show the polymorphic condition. A possible role for this NOR/heterochromatin segment in the evolution of sex chromosomes in other H. malabaricus cytotypes is discussed.

Animals↗
PubMed2006

High-density comparative BAC mapping in the black muntjac (Muntiacus crinifrons): molecular cytogenetic dissection of the origin of MCR 1p+4 in the X1X2Y1Y2Y3 sex chromosome system.

The black muntjac (Muntiacus crinifrons, 2n = 8[female symbol]/9[male symbol]) is a critically endangered mammalian species that is confined to a narrow region of southeastern China. Male black muntjacs have an astonishing X1X2Y1Y2Y3 sex chromosome system, unparalleled in eutherian mammals, involving approximately half of the entire genome. A high-resolution comparative map between the black muntjac (M. crinifrons) and the Chinese muntjac (M. reevesi, 2n = 46) has been constructed based on the chromosomal localization of 304 clones from a genomic BAC (bacterial artificial chromosome) library of the Indian muntjac (M. muntjak vaginalis, 2n = 6[female symbol]/7[male symbol]). In addition to validating the chromosomal homologies between M. reevesi and M. crinifrons defined previously by chromosome painting, the comparative BAC map demonstrates that all tandem fusions that have occurred in the karyotypic evolution of M. crinifrons are centromere-telomere fusions. The map also allows for a more detailed reconstruction of the chromosomal rearrangements leading to this unique and complex sex chromosome system. Furthermore, we have identified 46 BAC clones that could be used to study the molecular evolution of the unique sex chromosomes of the male black muntjacs.

Animals↗
PubMed2002

Characterization of diploid, tetraploid and hexaploid Helianthus species by chromosome banding and FISH with 45S rDNA probe.

Comparative karyotype analyses of five diploid, two tetraploid, and three hexaploid species of Helianthus were performed using Feulgen staining, Giemsa C and CMA3 (C-CMA) staining, and FISH with 45S rDNA probe. The karyotypes are composed by a basic number of x = 17 with a predominance of meta- and submetacentric chromosome types. A polyploid series is associated with the basic number. Giemsa C- and C-CMA banding revealed terminal or interstitial heterochromatin according to the species, suggesting the existence of a mechanism that may be acting in the dispersion of heterochromatic segments in Helianthus. The nucleolar organizer regions were located at terminal chromosome positions by FISH with 45S rDNA probe. Diploid species presented four, six, and eight rDNA sites, tetraploid species showed eight sites and hexaploid species presented 12 rDNA sites. Karyomorphological differences include variation in number, size and chromosome morphology, suggesting that rearrangements involving small heterochromatic and rDNA segments played a major role in karyotype evolution.

Chromosome Banding↗
PubMed1990

Alpha interferon dose-dependent suppression of secondary clones in a patient with Philadelphia-positive chronic myelogenous leukemia.

A patient whose chronic myelogenous leukemia (CML) was treated with interferon alpha (IFN-alpha) is described. The disease showed karyotypic evolution during the chronic phase and the later myeloid acceleration. Both of these secondary clonal phenomena responded to IFN-alpha dose escalation. The case illustrates the dose dependence of CML responses to IFN-alpha. The phenomenon of clonal evolution is discussed in the context of this patient's disease.

Clone Cells↗