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PubMed2005

Assessment by M-FISH of karyotypic complexity and cytogenetic evolution in bladder cancer in vitro.

We carried out multiplex fluorescence in situ hybridization (M-FISH) and follow-up FISH studies on a large series of transitional cell carcinoma (TCC) cell lines and 2 normal urothelium-derived cell lines, several of which have not had karyotypes reported previously. M-FISH analysis, with appropriate follow-up, complements conventional cytogenetic analysis and array CGH studies, allowing a more accurate definition of karyotype. The detailed karyotypic data obtained will assist in choosing suitable cell lines for functional studies and identifies common losses, gains, breakpoints and potential fusion gene sites in TCC. We have shown changes in cell lines RT112 and DSH1 following prolonged culture, and differences in karyotype, between RT112 cultures obtained from different sources. We propose a model for the evolutionary changes leading to these differences. A comparison with the literature found other examples of differences in cell-line karyotypes between different sources. Nevertheless, several karyotypic changes were preserved between different sources of the same cell line and were also seen in more than one cell line. These may be the most important changes and include -8p, +20, 4q-, 10p-, 16p- and breaks in 8p21. We carried out a more detailed follow-up of some regions, which showed involvement of 8p breaks and losses in 15 of 16 TCC cell lines but in neither of the normal urothelium-derived cell lines. Some changes represented distal loss, whereas others were small deletions. Further study of this region is warranted.

Carcinoma, Transitional Cell↗
PubMed2000

Apparently unrelated clones shown by spectral karyotyping to represent clonal evolution of cryptic t(10;11)(p13;q23) in a patient with acute monoblastic leukemia.

The accurate genetic classification of acute leukemia is of the utmost clinical importance for treatment stratification. In the present study, we report on a young girl with aggressive acute monoblastic leukemia (AML) (M5b) with skin, lymph node, and bone marrow involvement, in whom cytogenetic analysis revealed three clones with different secondary chromosomal changes. Two clones had the secondary +8 and del(9q) aberrations, with the der(11)t(1;11) in the second one; the third clone was apparently unrelated to the others, and had add(7)(p?21),-13,+22. Using the spectral karyotyping (SKY) technique, we found that all three clones originated from a common clone that harbored the hidden primary t(10;11)(p13;q23) or its derivatives, suggesting clonal evolution. The first clone had the balanced t(10;11), the second had its derivative, der(10)t(10;11), and the third had the other derivative, der(11)t(10;11). On fluorescence in situ hybridization (FISH), MLL gene splitting, with translocation of its centromeric portion to 10p, and deletion of its telomeric portion, was demonstrated. In conclusion, the detection of the very poor prognostic t(10;11) aberration in AML, was possible by complementing the traditional cytogenetic analysis with SKY and FISH.

Bone Marrow Cells↗
PubMed2004

Resolution and evolution of the duck-billed platypus karyotype with an X1Y1X2Y2X3Y3X4Y4X5Y5 male sex chromosome constitution.

The platypus (2n = 52) has a complex karyotype that has been controversial over the last three decades. The presence of unpaired chromosomes and an unknown sex-determining system especially has defied attempts at conventional analysis. This article reports on the preparation of chromosome-specific probes from flow-sorted chromosomes and their application in the identification and classification of all platypus chromosomes. This work reveals that the male karyotype has 21 pairs of chromosomes and 10 unpaired chromosomes (E1-E10), which are linked by short regions of homology to form a multivalent chain in meiosis. The female karyotype differs in that five of these unpaired elements (E1, E3, E5, E7, and E9) are each present in duplicate, whereas the remaining five unpaired elements (E2, E4, E6, E8, and E10) are absent. This finding indicates that sex is determined by the alternate segregation of the chain of 10 during spermatogenesis so that equal numbers of sperm bear either one of the two groups of five elements, i.e., five X and five Y chromosomes. Chromosome painting reveals that these X and Y chromosomes contain pairing (XY shared) and differential (X- or Y-specific) segments. Y differential regions must contain male-determining genes, and X differential regions should be dosage-compensated in the female. Two models for the evolution of the sex-determining system are presented. The resolution of the longstanding debate over the platypus karyotype is an important step toward the understanding of mechanisms of sex determination, dosage compensation, and karyotype evolution.

Animals↗
PubMed1993

[The independent variability of different karyotypic characteristics during the spontaneous neoplastic evolution of mouse embryo fibroblasts].

The dynamics of some karyotype characteristics throughout the spontaneous neoplastic evolution of embryonal fibroblasts of different mouse strains was studied using a differential staining of chromosomes. The independent variability of chromosome modal numbers, the number of polyploid cells in the cell line, the number of chromosomal rearrangements within one cell, the activity of formation of different types of chromosomal rearrangements and the activity of interactions of the homologous chromosomes in 15 studied cell lines were revealed. Possible levels of variability regulations of different karyotype characteristics are discussed.

Animals↗
PubMed1990

Spontaneous phenotypic and karyotypic progression in the SV40 transfected cell line SVG during prolonged passage in vitro.

Transfection of primary cultures of human cells with origin of replication deficient SV40 DNA has been carried out by others to generate in vitro models of malignant transformation in vivo. The present work describes progressive alterations in karyotype and phenotype in one such transfected (neuroglial) cell line (SVG). After repeated passage, recognisable marker chromosomes evolved. These may be related to karyotypic anomalies found in human glial tumors. Accompanying the evolution in karyotype were changes in phenotype. Although presaging malignant transformation, these stopped short of actual tumorigenicity.

Animals↗
PubMedDate not supplied

The selfish karyotype. An analysis of the biological basis of morals.

An analysis is made of the kin-selection/group-selection debate on the issue of the biological basis of morals. The kin-selection view sees altruism, and morals in the case of humans, as resting solely on genetic factors; in fact, on this view, evolution itself is to take place only through genetic change -- a position which cannot be reconciled with our knowledge that species evolution involves karyotypic change. Morality is thought to stem from a particular gene which at one time was completely absent from the human population but which later entered and spread through it. On the generally accepted conception of kin selection, this 'altruistic' gene is to be responsible not only for apparently altruistic behaviour towards near relatives, but also for parental care. Thus this view, among other things, has the absurd consequence that there was a period directly after humans first came into existence during which we did not care for our young. In contrast, the group-selection view, as developed here, sees morality as stemming from the species' karyotype, and to be passed on karyotypically from species to species through evolution. As suggested by Darwin, morality is thus derived from our social instincts, and is fundamentally directed to members of one's tribe or community, not to members of one's family. In keeping with this perspective, it is suggested here that the biological basis of morals does not concern the continuation of each individual's gene line, but the continuing existence of the individual's community, and thus, indirectly, the survival of the human species, through supporting the continuing instantiation of its karyotype.

Altruism↗
PubMed2004

Acquired Robertsonian translocations are not rare events in acute leukemia and lymphoma.

Robertsonian translocations are the most common constitutional structural abnormalities but are rarely reported as acquired aberrations in hematologic malignancies. The nonhomologous acrocentric rearrangements are designated as Robertsonian translocations, whereas the homologous acrocentric rearrangements are referred to as isochromosomes. Robertsonian rearrangements have the highest mutation rates of structural chromosome rearrangements based on surveys of newborns and spontaneous abortions. It would be expected that Robertsonian recombinations would be more common than suggested by the literature. A survey of the cytogenetics database from a single institution found 17 patients with acquired Robertsonian rearrangement and hematologic malignancies. This is combined with data from the literature for a total of 237 patients. All of the possible types of Robertsonian rearrangements have been reported in hematologic malignancies, with the i(13q), i(14q), and i(21q) accounting for nearly 60%. Complex karyotypic changes are seen in the majority of cases, corresponding with disease evolution. These karyotypes consistently show loss of chromosomes 5 and/or 7 in the myelocytic disorders, nonacrocentric isochromosomes, and centromeric breakage and reunion. However, nearly 25% of the acquired rearrangements were found as the sole abnormality or in addition to an established cytogenetic aberration. Most of these were the i(14q) with the myelodysplasia subtypes refractory anemia and chronic myelomonocytic leukemia.

Acute Disease↗
PubMed1989

Cytogenetic studies of 103 patients with acute myelogenous leukemia in relapse.

In order to investigate the cytogenetic patterns in relapsed acute myelogenous leukemia (AML), a clinical and cytogenetic follow-up of patients newly diagnosed for the Fourth International Workshop on Chromosomes in Leukemia (4IWCL) was evaluated at the 6IWCL. Information was received on 103 patients in relapse who were then classified into seven groups according to the diagnostic karyotype. These groups were: normal, t(8;21), t(15;17), +8, a single specific abnormality either numerical or structural other than those already listed, a single nonrandom or miscellaneous abnormality again either numerical or structural, and complex abnormalities. The patient's age, diagnostic FAB type, the number of relapses, the total survival time, and the karyotype in relapse were considered in each of these cytogenetic groups. The remission and survival rates were comparable in all groups except the +8 group, where patients relapsed earlier and had a shorter survival time. Multiple relapses occurred most frequently in the t(8;21) group, whereas none of the patients with t(15;17) relapsed more than once, although the total survival time was similar to the two groups. Thirty-nine percent of the patients relapsed with the same karyotype as at diagnosis. A more complex karyotype showing evolution was found in 53%, and 8% showed either a less-complicated karyotype or appeared to have reverted to normal. Numerical abnormalities in relapse frequently involved trisomy of chromosomes 8 and/or 21. There was a nonrandom development of 9q- with relapse in patients with t(8;21). A pericentric inversion of chromosome 4, and abnormality infrequently reported at diagnosis, was found in relapse in association with t(15;17), t(8;21), and +8 karyotypes. Changes considered to be typically secondary in nature involving 5q, 7q, and 12p were seen in only seven cases. Twenty-one patients who had an apparently normal karyotype at diagnosis remained normal in relapse, indicating that absence of clonal chromosome abnormality is a real observation in AML rather than a failure of detection.

Adolescent↗
PubMed1978

Cytogenetic aspects of phylogeny in the Bovidae. I. G-banding.

An extensive G-banding study of karyotypes of 12 species of Bovidae has been undertaken in an attempt to trace homologies and patterns of evolution of karyotype phenotypes throughout the family. G-banding profiles revealed a considerable degree of chromosome-arm homology throughout the group, which also extended into the related superfamilies, the Giraffoidea and Cervoidea. The conservation of banding patterns in chromosome arms strongly indicates that Robertsonian translocation type rearrangements have provided the major source of interspecies karyotype differences, with inversions and reciprocal and tandem translocations providing relatively minor contributions. Examples of individuals carrying newly arisen Robertsonian translocations are not infrequent, and in one instance there was evidence that two similar rearrangements had arisen independently in two species. Despite the extensive changes in karyotype organization, subfamilies within the Bovidae were characterized by the presence of common rearrangements, and those involving autosomal pairs 11 and 12 of the ox, as well as the X chromosome, separate the Bovinae from the Caprinae and Hippotraginae.

Animals↗
PubMed1994

Increasing complexity of the karyotype in 50 human gliomas. Progressive evolution and de novo occurrence of cytogenetic alterations.

We studied the karyotypes of eight differentiated gliomas, 19 anaplastic gliomas, and 23 glioblastomas (GBM). Normal stemlines were present in 70% of the differentiated and anaplastic gliomas; abnormalities were mostly characterized by loss of sex chromosomes. In GBM, on the contrary, only 13% of the stemlines were normal and three groups, 45,XO, near-diploid, and near tetraploid, could be identified. The most frequent alterations among GBM were: total or partial loss of chromosome 10 in nine cases, structural abnormalities of chromosome 9 in seven cases, and loss of the Y chromosome in stemline clones of seven cases. Less frequent abnormalities included chromosomes 7, 1, 3, and 19. Our data support the cytogenetic model of gliomas as multi-stage tumors. GBM, in particular, can originate from the evolution of astrocytomas but can also develop de novo. In both cases loss of genetic material on chromosome 10 seems to play a crucial role.

Adult↗
PubMed1999

Comparative painting reveals strong chromosome homology over 80 million years of bird evolution.

Chickens and the great flightless emu belong to two distantly related orders of birds in the carinate and ratite subclasses that diverged at least 80 million years ago. In the first ZOO-FISH study between bird species, we hybridized single chromosome paints from the chicken (Gallus domesticus) onto the emu chromosomes. We found that the nine macrochromosomes show remarkable homology between the two species, indicating strong conservation of karyotype through evolution. One chicken macrochromosome (4) was represented by a macro- and a microchromosome in the emu, suggesting that microchromosomes and macrochromosomes are interconvertible. The chicken Z chromosome paint hybridized to the emu Z and most of the W, confirming that ratite sex chromosomes are largely homologous; the centromeric region of the W which hybridized weakly may represent the location of the sex determining gene(s).

Animals↗
PubMed1994

Inverted repeat structure and homologous sequences in the LD1 amplicons of Leishmania spp.

In the parasitic trypanosomatids of the genus Leishmania, novel circular (CD) and linear (LD) multicopy genetic elements arise de novo either spontaneously or as a result of drug selection. We report that the LD1 minichromosomes of L. donovani, L. major and L. mexicana (ranging in size from 180 to 230 kb) have an inverted repeat structure and contain homologous sequences located at similar distances from the telomere; one half of the chromosome being the mirror image of the other. They must therefore have originated from a unique conserved source chromosome; the size polymorphism being generated by the point at which inversion occurs. The circular CD1 elements appear to be circularised segments of the LD1 elements. These observations lead to a unified concept of how minichromosomes LD1 and circular CD1 genetic elements emerge within the Leishmania and contribute to evolution of karyotype.

Animals↗
PubMed1988

Existence of two distinct processes of chromosomal evolution in near-diploid colorectal tumors.

The comparison of all the karyotypes established in each of 18 near-diploid colorectal tumors made it possible to reconstruct a clonal evolution and to distinguish between early and late chromosomal aberrations. Because no abnormalities were observed in all tumors, and as even the most frequent changes, i.e., monosomy 17p and monosomy 18, may be present in mosaic, no chromosomal change can be regarded as a common primary event in the carcinogenetic process. However, the repeated occurrence of several changes favors the hypothesis of two karyotypic evolutionary processes. In most tumors, monosomy 17p and 18 were found, and the karyotypic evolution involved mainly several additional monosomies due to unbalanced rearrangements or losses that affect, by order of decreasing frequency, chromosomes 1p, 4, 14, 5q, 6q, 2p, and 11q, as well as gains of chromosomes 20, 8q, 13, 17q, and X. In this group of tumors, the mean number of chromosomes remains close to 46. In the other tumors, either only a monosomy 17p or a monosomy 18 was found and the karyotypic evolution involved essentially trisomies, resulting from gains with, by order of decreasing frequency, a preferential involvement of chromosomes 7, 8q, 13, 17q, 20, X, 2p, 5, and 16, the only additional recurrent deletion affecting chromosome 1p. In these tumors, the mean chromosome number is close to 51. Ten out of 11 polyploid sidelines emerged from monosomic-type tumors.

Chromosome Aberrations↗
PubMed2006

Karyology of the Antarctic scallop Adamussium colbecki, with some comments on the karyological evolution of pectinids.

Karyotype, location of the nucleolar organiser region (NOR) and heterochromatin presence and composition were studied in the Antarctic scallop Adamussium colbecki Smith, 1902. The karyotype exhibits 2n = 38 chromosomes with 11 pairs of metacentrics, 5 of submetacentrics, one subtelocentric and two telocentrics. Ag-NOR, CMA(3), DA/MM and NOR-FISH evidenced paracentromeric NORs on the short arm of 2nd pair chromosomes. Digestion with three restriction endonucleases followed by sequential staining with Giemsa, CMA(3) and DAPI evidenced on all chromosomes centromeric heterochromatin positive for both DAPI and CMA(3). In situ hybridisation analysis showed the presence of an AT-rich satellite DNA in the centromeric heterochromatin of several chromosomes. A mosaicism was detected in the germinal cell lines of one specimen, as in six of the 20 plates examined the set had 37 chromosomes with a missing pair of telocentrics and an unpaired metacentric. Comparison of the chromosome sets of all the pectinids studied to date and comparison with a phyletic tree obtained from molecular mitochondrial genes studies yielded good agreement between karyotype morphology and taxonomic classification.

Animals↗
PubMed1988

Karyotypic stability in chronic B-cell leukemia.

Twenty-one patients with B-cell chronic lymphocytic leukemia (B-CLL) have been followed for more than 2 years with serial cytogenetic studies, including 11 cases for more than 5 years and three others for more than 10 years. A chromosomally abnormal clone was present at the time of initial study in 10 of these patients, and neither these nor the 11 individuals with a normal karyotype had any cytogenetic evolution during the follow-up period, although clinical progression, requiring therapy, was observed in 13 cases. In an additional 12 B-CLL patients who had repeat chromosome studies but were followed for less than 2 years, two patients with advanced disease and multiple cytogenetic abnormalities developed minor additional karyotypic changes and died within 18 months, and two patients with a normal karyotype developed rapidly progressive disease associated with an emerging chromosomally abnormal clone and survived only 1 year. These results demonstrate that karyotypic evolution is rare in B-CLL. Its occurrence indicates a poor prognosis, but its rarity suggests that clinical progression in this disease is usually more dependent on other factors.

Adult↗