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PubMed1977

Chromosomes and causation of human cancer and leukemia. XXVI. Binding studies in acute lymphoblastic leukemia (ALL).

Chromosomes were studied in the bone marrow cells of 101 patients with acute lymphoblastic leukemia (ALL) hospitalized at or attending the clinics of Roswell Park Memorial Institute (RPMI) between January, 1968, and December, 1976. Aneuploidy was observed in about 50% (54/101) of the cases. Two cases were hypodiploid and the remaining were either pseudo or hyperdiploid. The frequency of abnormalities and the chromosomal numbers were similar to those of 106 cases studied in our laboratory prior to 1968. Of 50 recently unselected cases of ALL in whom Q- and G-banded karyotypes were attempted, 31 were successfully analyzed with these techniques. The banding patterns revealed 16 cases to have chromosome abnormalities and four of these to have a similar abnormality, i.e., partial deletion of the long arm of chromosome no. 6: two cases had a 6q- with additional abnormalities and two had 6q- as the sole karyotypic abnormality. The breakpoint in chromosome no. 6 seemed to involve a segment from q21 to q25. An isochromosome of the long arm of no. 7, i(7q), was observed in two cases, two additional no. 21 chromosomes were observed in five cases and, except for the Y, all other chromosomes participated in the karyotypic changes encountered in the 16 cases in which banding analyses were performed. Banding analysis has afforded the first reliable approach towards ascertaining karyotypic evolution in ALL, which was achieved in eight cases of the present study. The chromosomes contributing to this karyotypic evolution were distributed widely. Thus, all chromosomes except the Y participated in numerical and/or structural karyotypic changes. Even though nonrandom chromosome changes may occur early in ALL, the pristine prototypic picture of the karyotypes in ALL is often obfuscated by successive chromosomal changes and hyperdiploidy by the time the karyotypes are analyzed in this condition. Further cytogenetic studies are required, with special attention to karyotypic evolution, in order to uncover the significance of chromosomal changes in early and late ALL.

Adolescent↗
PubMed2006

Karyotype relationships of six bat species (Chiroptera, Vespertilionidae) from China revealed by chromosome painting and G-banding comparison.

The Vespertilionidae is the largest family in the order Chiroptera and has a worldwide distribution in the temperate and tropical regions. In order to further clarify the karyotype relationships at the lower taxonomic level in Vespertilionidae, genome-wide comparative maps have been constructed between Myotis myotis (MMY, 2n = 44) and six vesper bats from China: Myotis altarium (MAL, 2n = 44), Hypsugo pulveratus (HPU, 2n = 44), Nyctalus velutinus (NVE, 2n = 36), Tylonycteris robustula (TRO, 2n = 32), Tylonycteris sp. (TSP, 2n = 30)and Miniopterus fuliginosus (MFU, 2n = 46) by cross-species chromosome painting with a set of painting probes derived from flow-sorted chromosomes of Myotis myotis. Each Myotis myotis autosomal probe detected a single homologous chromosomal segment in the genomes of these six vesper bats except for MMY chromosome 3/4 paint which hybridized onto two chromosomes in the genome of M. fuliginosus. Our results show that Robertsonian translocation is the main mode of karyotype evolution in Vespertilionidae and that the addition of heterochromatic material also plays an important role in the karyotypic evolution of the genera Tylonycteris and Nyctalus. Two conserved syntenic associations (MMY9 + 23 and 18 + 19) could be the synapomorphic features for the genus Tylonycteris. The integration of our maps with the published maps has enabled us to deduce chromosomal homologies between human and these six vesper bats and provided new insight into the karyotype evolution of the family Vespertilionidae.

Animals↗
PubMed2025

Subgenomic divergence and functional innovation following whole-genome duplication in Maleae species of Rosaceae.

Whole-genome duplication (WGD) drives plant evolution by inducing karyotype rearrangements and gene loss through subgenome fractionation. In this study, we investigate post-WGD evolutionary dynamics in Rosaceae, focusing on Maleae species, which uniquely experienced an additional WGD. Using phylogenetic and synteny analyses, we reveal that chromosomal breakpoints act as hotspots for localized fractionation, contributing to blurred homoeologous origins and influencing gene retention patterns. Here, we reconstruct karyotype evolution across Rosaceae subfamilies, highlighting chromosome reductions and lineage-specific rearrangements in Dryadoideae, Rosoideae, and Amygdaloideae. We also identify a bias for retaining transcription factors and hormone-related genes from older WGDs in subsequent polyploidy events. Transcriptome analysis classifies WGD-derived genes in Maleae species, such as apple and loquat, into three expression groups, with hormone-enriched genes playing roles in lignification and fruit-related innovations. These findings demonstrate the interplay between chromosomal breakpoints, biased retention, and functional divergence, revealing their contributions to genomic and phenotypic evolution in Maleae and their adaptive success within Rosaceae.

Genome, Plant↗
PubMed2002

Interstitial telomeric sites and NORs in Hartmann's zebra (Equus zebra hartmannae) chromosomes.

Interstitial telomeric sites (ITSs) are considered as signatures of chromosomal rearrangements that take place during karyotype evolution. Understanding that equids have undergone rapid karyotype evolution compared with the average in other mammals, a search of these signatures was carried out in the Hartmann's mountain zebra (Equus zebra hartmannae; EZH) chromosomes. Six consistent ITSs were identified on five of the zebra chromosomes (EZH1p, 1q, 2q, 5q, 6q and 11q). The location of these ITSs coincided with fusion points of some of the evolutionarily conserved human-Hartmann's zebra chromosomal segments suggesting that the sequences are remnants of fusion events between ancestral chromosomes. Incidentally, three of the ITSs also matched with the presence of constitutive heterochromatin. Further, ribosomal gene clusters were localized on five zebra chromosomes and the data were compared with those in other equid species. The findings offer preliminary evidence on the likely evolution of some of the Hartmann's zebra chromosomes and add to the current search for clues that lead to the ancestral chromosomal configuration in equids.

Animals↗
PubMed2004

Wilms tumors develop through two distinct karyotypic pathways.

Wilms tumor is an embryonic neoplasm characterized by a large variation in histologic patterns. Cytogenetic investigations have identified nonrandom chromosomal changes characteristic for this tumor type, of which numerical changes, mostly trisomies for chromosomes 7, 8, and 12, are particularly frequent. Despite the abundance of cytogenetic information, with more than 350 published karyotypes, very little is known about the mode of karyotypic evolution. In this investigation, we have used 355 karyotypes of Wilms tumor to identify frequent imbalances. The most frequent were +1q, +6, +7q, +8, +12, +13, -11, and -16. Tumor cases were then classified with respect to the presence or absence of these imbalances and statistically analyzed to assess the order of appearance of chromosomal imbalances, as well as possible karyotypic pathways. We show that Wilms tumors develop through one major mode of karyotypic evolution, common to both low- and high-complex tumors, and that polyploid cases are relatively rare. We also establish a temporal order by which the different imbalances occur and show that at least two cytogenetic pathways exist, one dominated by gains and another by losses. We also show that these pathways are well separated and do not share a common set of late imbalances.

Biological Evolution↗
PubMed1976

[New data on non-parallel evolution of karyotype and morphology in Phyllotinae (Rodents, Cricetidae)].

The non-concordance of the morphological and chromosomal evolution in the Phyllotinae is discussed in the light of the latest karyological data concerning the genus Zygodontomys: individual specimens of this genus from French Guiana present a new chromosomal formula with a high number 2 N; their karyotypical and morphological peculiarities are sufficient to warrant creating a new species Z. reigi. The great variability of the karyotypes appearing in this genus permits one to think that the various groups could represent successive aspects of the same chromosomal evolution, an increase of the number 2 N preceding an eventual decrease.

Animals↗
PubMed1984

Evolution of karyotype in haploid cell lines of Drosophila melanogaster.

Seven continuous cell lines have been established in vitro from lethal embryos produced by the female sterile mutant mh 1182 of Drosophila melanogaster. Six lines show haploid metaphases. Karyotype analysis revealed a high level of aneuploid cells with frequent chromosome fragments. In three lines, haploid cells were quickly overgrown by diploid cells. Two lines were more stable but the proportion of haploid cells decreased with time. One line was stable, showing 80-90% of haploid cells for over 1 000 cell generations. Stable haploid clones have been isolated from two lines. Crossing of mh 1182/mh 1182 females with males bearing a ring X chromosome shows that the haploid genome retained in the cells is of maternal origin and that the diploid cells derive from pre-existing haploid cells. The appearance of the diploid cells and the conditions of karyotypic stability are analysed.

Animals↗
PubMed2005

Breakpoint analysis of the pericentric inversion distinguishing human chromosome 4 from the homologous chromosome in the chimpanzee (Pan troglodytes).

The study of breakpoints that occurred during primate evolution promises to yield valuable insights into the mechanisms underlying chromosome rearrangements in both evolution and pathology. Karyotypic differences between humans and chimpanzees include nine pericentric inversions, which may have potentiated the parapatric speciation of hominids and chimpanzees 5-6 million years ago. Detailed analysis of the respective chromosomal breakpoints is a prerequisite for any assessment of the genetic consequences of these inversions. The breakpoints of the inversion that distinguishes human chromosome 4 (HSA4) from its chimpanzee counterpart were identified by fluorescence in situ hybridization (FISH) and comparative sequence analysis. These breakpoints, at HSA4p14 and 4q21.3, do not disrupt the protein coding region of a gene, although they occur in regions with an abundance of LINE and LTR-elements. At 30 kb proximal to the breakpoint in 4q21.3, we identified an as yet unannotated gene, C4orf12, that lacks an homologous counterpart in rodents and is expressed at a 33-fold higher level in human fibroblasts as compared to chimpanzee. Seven out of 11 genes that mapped to the breakpoint regions have been previously analyzed using oligonucleotide-microarrays. One of these genes, WDFY3, exhibits a three-fold difference in expression between human and chimpanzee. To investigate whether the genomic architecture might have facilitated the inversion, comparative sequence analysis was used to identify an approximately 5-kb inverted repeat in the breakpoint regions. This inverted repeat is inexact and comprises six subrepeats with 78 to 98% complementarity. (TA)-rich repeats were also noted at the breakpoints. These findings imply that genomic architecture, and specifically high-copy repetitive elements, may have made a significant contribution to hominoid karyotype evolution, predisposing specific genomic regions to rearrangements.

Animals↗
PubMed1988

Comparative study of G- and C-banded chromosomes of five species of Microtidae: a chromosomal evolution analysis.

G-banded karyotypes were compared in the following species of Microtidae: Microtus nivalis, M. cabrerae, M. arvalis, and Arvicola sapidus. Previous observations on A. sapidus and A. terrestris were also incorporated in this study. The results show that Robertsonian translocations and pericentric inversions are common mechanisms involved in the karyotypic evolution of this group. Interspecific differences on the G-banding patterns were also analysed, and an attempt was made to establish a presumptive phylogenetic tree.

Animals↗
PubMedDate not supplied

Liver metastasis of a human colorectal cancer containing two actively growing subclones.

A common pattern of karyotype evolution between clones involves gradual changes of one or only a few chromosomes. Karyotypes of one day-old cultures derived from a tumor nodule of colorectal cancer liver metastasis were studied by GTG chromosome banding. Two karyotypically distinct aneuploid CC-9-a and CC-9-b clones were found respectively, at about 1:3 ratio. Both clones showed common karyotype characteristics with the same number of copies for 13 normal and four marker chromosomes, indicating their common genetic origin. However, CC-9-b differed from CC-9-a by the loss of one copy each of eight normal and four common marker chromosomes. This mode of gross single-chromosome losses is also seen in established cell lines, and probably plays an important role in the drastic chromosome changes associated with the duplication-reduction cycle of karyotype evolution.

Cell Division↗
PubMed1985

Double nondisjunction during karyotypic progression of chemically induced Syrian hamster cell lines.

The karyotypic evolution of three chemically induced cell lines of Syrian hamster embryo in culture are described. The only karyotypic alteration of one clone was a trisomy of chromosome #11, which presumably arose by nondisjunction after carcinogen treatment. A pure population of cells with the trisomy was observed repeatedly upon karyotyping of cells at the first three passages after cloning. However, at a late passage, apparently normal diploid cells appeared in the culture, which we propose resulted from a second nondisjunction of one chromosome #11, reverting the cells from trisomy 11 to disomy 11. The karyotypic evolution of two other cell lines also involved double nondisjunction, which resulted in duplication of a translocated chromosome and concurrent loss of the normal nonrearranged chromosome. Taken together with the reported findings of others, the results indicate that double nondisjunction is a mechanism in karyotypic progression during neoplastic development.

Animals↗
PubMed2006

Phylogenomics of several deer species revealed by comparative chromosome painting with Chinese muntjac paints.

A set of Chinese muntjac (Muntiacus reevesi) chromosome-specific paints has been hybridized onto the metaphases of sika deer (Cervus nippon, CNI, 2n = 66), red deer (Cervus elaphus, CEL, 2n = 62) and tufted deer (Elaphodus cephalophus, ECE, 2n = 47). Thirty-three homologous autosomal segments were detected in genomes of sika deer and red deer, while 31 autosomal homologous segments were delineated in genome of tufted deer. The Chinese muntjac chromosome X probe painted to the whole X chromosome, and the chromosome Y probe gave signals on the Y chromosome as well as distal region of the X chromosome of each species. Our results confirmed that exclusive Robertsonian translocations have contributed to the karyotypic evolution of sika deer and red deer. In addition to Robertsonian translocation, tandem fusions have played a more important role in the karyotypic evolution of tufted deer. Different types of chromosomal rearrangements have led to great differences in the genome organization between cervinae and muntiacinae species. Our analysis testified that six chromosomal fissions in the proposed 2n = 58 ancestral pecoran karyotype led to the formation of 2n = 70 ancestral cervid karyotype and the deer karyotypes is more derived compare with those of bovid species. Combining previous cytogenetic and molecular systematic studies, we analyzed the genome phylogeny for 11 cervid species.

Animals↗
PubMed1994

Karyotypic analysis of a heterogeneous human transitional cell carcinoma of the bladder.

The UCRU-BL-17 (BL-17) series of xenografts, tissue culture sublines, and cloned cell lines (Fig. 1) shows a range of heterogeneous growth characteristics both in vitro and in vivo (Table 1) and represents a model of human bladder cancer heterogeneity. Cytogenetic analysis was undertaken to determine if specific chromosome changes correlated with particular aspects of the heterogeneous phenotypes. The BL-17 sublines and cloned cell lines shared many common chromosome abnormalities. Indeed, the cloned cell lines showed nearly identical karyotypes despite their marked differences in growth characteristics. Karyotypic evolution with passage through the nude mice was apparent, however. This evolution occurred at the specific chromosome regions of 1p12, 3cen-3p21, and 6cen-6q21. Whether the heterogeneity of karyotype between the BL-17 cell lines resulted from the existence of multiple clones in the original patient tumor or from karyotypic instability through passage in nude mice is uncertain, but in either case the specificity of karyotypic evolution observed suggests that 1p12, 3cen-3p21, and 6cen-6q21 are hotspots for rearrangement in the BL-17 tumor. No specific correlations between chromosome abnormalities and biologic characteristics could be made, but several unique karyotypic features arose in the progression to two of the sublines, BL-17/23 alpha and BL-17/0/X2A, coinciding with a loss of anchorage-independent growth by BL-17/23 alpha and a change in growth in vivo from a solid tumor to a fluid-filled tumor by BL-17/0/X2A.

Aged↗
PubMed1992

Clonal evolution in primary 5q-syndrome.

Primary 5q-syndrome is a type of myelodysplastic syndrome characterized by refractory anemia, thrombocytosis, and hypolobulated megakaryocytes. The risk of leukemic transformation is low. A case of 5q- syndrome that occurred in a 42-year-old woman and was complicated by leukemic transformation 7 years after the initial diagnosis is reported. An additional clonal karyotypic anomaly, del(7q), was seen in the leukemic cells. The literature on leukemic and karyotypic evolution of primary 5q- syndrome is reviewed and the implication of karyotypic evolution is discussed.

Acute Disease↗
PubMed2005

Statistical behavior of complex cancer karyotypes.

Epithelial tumors commonly show complex and variable karyotypes that obscure the identification of general patterns of the karyotypic evolution. To overcome some of these problems, we previously systematically analyzed the accumulated cytogenetic data from individual tumor types by using various statistical means. In the present study, we compare previous results obtained for nine tumor types and perform several meta-analyses of data obtained from a number of epithelial tumors, including head and neck, kidney, bladder, breast, colorectal, ovarian, and lung cancer, as well as from malignant melanoma and Wilms tumor, with the specific aim of discovering common patterns of karyotypic evolution. We show that these tumors frequently develop through a hypo- or a hyperdiploid pathway and progress by an increasing number of alternative imbalances through at least two karyotypic phases, Phases I and II, and possibly through a third, Phase III. During Phase I, the karyotypes exhibited a power law distribution of both the number of changes per tumor and the frequency distribution at which bands were involved in breaks. At the transition from Phase I to Phase II/III, the observed power law distributions were lost, indicating a transition from an ordered and highly structured process to a disordered and chaotic pattern. The change in karyotypic orderliness at the transition from Phase I to Phase II/III was also shown by a drastic difference in karyotypic entropy.

Biological Evolution↗
PubMed1997

Segmental homology among cattle (Bos taurus), Indian muntjac (Muntiacus muntjak vaginalis), and Chinese muntjac (M. reevesi) karyotypes.

In an attempt to examine homologies between Indian and Chinese muntjac karyotypes at a subchromosomal level, five bovine cosmids were comparatively mapped by heterologous fluorescence in situ hybridization (FISH). In the Indian muntjac (2n = 6) all cosmids mapped to chromosome 1, whereas in the Chinese muntjac (2n = 46) two cosmids mapped to chromosome 3 and one cosmid each mapped to chromosomes 1, 7, and 17. These markers have maintained their intrachromosomal position relative to a centromere/telomere axis in cattle and in Chinese and Indian muntjac chromosomal arms. Our results corroborate the tandem-fusion hypothesis for muntjac karyotypic evolution and establish orientational homology between the involved Chinese muntjac chromosomes and the discrete segments on Indian muntjac chromosome 1. Furthermore, our data disclose regional homologies between cattle and muntjac genomes and demonstrate the validity of intergeneric cosmid-FISH for investigations on karyotype evolution.

Animals↗
PubMed2006

Karyotype variation, evolution and phylogeny in Borago (Boraginaceae), with emphasis on subgenus Buglossites in the Corso-Sardinian system.

BACKGROUND AND AIMS: Karyological variation in the Mediterranean genus Borago and cytogeography of subgenus Buglossites in Corsica, Sardinia and the Tuscan Archipelago were investigated in combination with a molecular phylogenetic analysis aimed at elucidating relationships between subgenera and taxa with different chromosome features. METHODS: Karyotype analysis was performed on population samples of B. pygmaea, B. morisiana, B. trabutii and B. officinalis. Phylogenetic analyses were based on ITS1 nrDNA and matK cpDNA sequences. KEY RESULTS: Four base numbers were found, x = 6, 8, 9 and 15, and three ploidy levels based on x = 8. In subgenus Buglossites the Sardinian endemic B. morisiana is diploid with 2n = 18, while B. pygmaea includes three allopatric cytotypes with 2n = 30 (Sardinia), 2n = 32 (southern Corsica) and 2n = 48 (central northern Corsica and Capraia). In subgenus Borago, the Moroccan endemic B. trabutii and the widespread B. officinalis have 2n = 12 and 2n = 16, respectively. Molecular data support the monophyly of Borago, while relationships in subgenus Borago remain unclear. Borago trabutii appears as the earliest divergent lineage and is sister to a clade with B. officinalis, B. morisiana and B. pygmaea. Subgenus Buglossites is also monophyletic, but no correspondence between ITS1 phylogeny and B. pygmaea cytotypes occurs. CONCLUSIONS: Chromosome variation in Borago is wider than previously known. Two base numbers may represent the ancestral condition in this small genus, x = 6 or x = 8. An increase in chromosome number and karyotype asymmetry, a decrease in chromosome size and heterochromatin content, and the appearance of polyploidy are the most significant karyological changes associated with the divergence of the Buglossites clade. High ITS1 variation in the tetra- and hypotetraploid races of B. pygmaea suggests a multiple origin, while the lower polymorphism of the hexaploid race and its allopatric distribution in the northernmost part of the range is better explained with a single origin via union of unreduced and reduced gametes.

Borago↗