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Results for “karyotype evolution”

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PubMed2001

Silver staining of nucleolar organizer regions (NOR) in some species of Hymenoptera (bees and parasitic wasp) and Coleoptera (lady-beetle).

Adaptations of the nucleolar organizer regions (NOR) banding technique using precipitation of silver salts significantly improved the NOR characterization of some species of hymenopterans and one coleopteran. The bee Melipona marginata (2n = 18) showed one metacentric pair of chromosomes with a NOR in the pericentromeric position. The parasitic wasp Mellitobia australica (2n = 12) also showed one metacentric pair with a strongly Ag-positive NOR. The male lady-beetle Cycloneda sanguinea (2n = 18 + Xy(p)) displayed a NOR on a pair of acrocentric autosomes. In the male Euglossa sp. (a haplodiploid species) (n = 21) the NOR were multiple, and occurred in five chromosomes. In the bee Plebeia sp. 1 (2n = 34) the NOR seemed restricted to one of the homologues of a metacentric pair. The systematic advances brought out by using this technique in the context of current theories of karyotypic evolution of these taxa are described and discussed.

Animals↗
PubMed2001

Comparison between the G-banded karyotype of the aoudad (Ammotragus lervia) and sheep (Ovis aries).

Karyotypes of the aoudad and sheep were compared on the basis of G-banded chromosomes at the 450 band level. The common G-banded karyotype showed the homology of all aoudad chromosomes (2n=58) with sheep chromosomes (2n=54) or sheep chromosome arms. The results of cytogenetic investigations suggest that in this case karyotype evolution has led to reduction in chromosome number as a result of centric fusions. The formation of the first metacentric chromosome occurred in the aoudad. The homology of the G-banding pattern in sheep and aoudad suggests the conservation in linear arrangement of genetic material. Thus comparative cytogenetics can be a useful tool in gene mapping.

Journal Article↗
PubMed1992

Cytogenetic analysis of hemopoietic peripheral blood cells collected by leukapheresis after intensive chemotherapy in advanced phase Philadelphia-positive chronic myelogenous leukemia.

Peripheral hemopoietic blood cells previously collected by leukapheresis were reinfused in advanced phase Philadelphia (Ph)-positive chronic myelogenous leukemic patients to promote the recovery of bone marrow function after intensive radiochemotherapy. Cytogenetic analysis was performed on these cells, induced to proliferate and to be mobilized by a first administration of marrow toxic drugs and collected when the white blood cell count was very low. In five patients only Ph-negative apparently normal cells were found. In five cases different proportions of Ph+/Ph- cells were observed and in the remaining five cases only Ph+ cells were present. Chromosomal abnormalities other than Ph, not detected in the cytogenetic analysis performed on bone marrow cells before chemotherapy treatment, were found in five cases. These findings confirm that Ph- cells can persist in the marrow of Ph+ patients in the advanced phase of disease and indicate that a high percentage of leukemic cells retain karyotype evolution not detectable using standard drawing and culture techniques.

Antineoplastic Agents↗
PubMedDate not supplied

[Interstitial telomere repeats as markers of evolutionary changes in the mammalian karyotype: human chromosome 2].

Telomer repeats represented by hexamer (TTAGGG)n at chromosome termini are required for correct function and chromosome stability. At the same time, interstitial telomer sequence (ITS) located far from the chromosome ends are known for several mammalian genomes, including the human genome. It is assumed that these repeats mark the points of fusion or other chromosome reconstructions of ancestors. Exact localization of all interstitial telomer sequences in the genome could greatly improve our understanding of the mechanism of karyotype evolution and species origin. We have developed a software for a search of interstitial telomer sequences in complete sequences of mammalian genomes. We have demonstrated the evolutionary significance of repeats by an example of human chromosome 2. The results and supplementary materials are available at the site of the Institute of Cytology and Genetics: http://www.bionet.nsc.ru/labs/theorylabmain/orlov/telomere/.

Chromosomes, Human, Pair 2↗
PubMed1990

Analysis of autosomal dosage compensation involving the alcohol dehydrogenase locus in Drosophila melanogaster.

An example of autosomal dosage compensation involving the expression of the alcohol dehydrogenase (Adh) locus is described. Flies trisomic for a quarter of the length of the left arm of chromosome two, including Adh, have diploid levels of enzyme activity and alcohol dehydrogenase messenger RNA. Subdivision of the compensating trisomic into smaller ones revealed a region that exerts an inverse regulatory effect on alcohol dehydrogenase activity and messenger RNA levels and a smaller region surrounding the structural gene that exhibits a direct gene dosage response. The two opposing effects are of sufficient magnitude that they cancel when simultaneously present resulting in the observed compensation in the larger aneuploid. An Adh promoter-white structural gene fusion construct is affected by the inverse regulatory region indicating that the effect is mediated through the Adh promoter sequences. The role of autosomal dosage compensation in understanding aneuploid syndromes and karyotype evolution in Drosophila species is discussed.

Alcohol Dehydrogenase↗
PubMed1990

[Cytogenetics on malignant lymphoma].

Translocations involving band q32 on chromosome 14 are commonly identified as a 14q + marker-chromosome and the involvement is the single most frequent abnormality in various types of lymphoid cancer. Based on these findings, we have proposed that the 14q + marker-positive lymphoid cancer should be divided into subclasses according to the precise translocations, each of which is a primary chromosome change, and the subclass initiates serial processing of the karyotype evolution associated with the development of more aggressive lymphoid cancer. The proposal is strongly supported by recent advances in molecular genetics. Genes or unknown DNA sequences, which had evolutionally been conserved, were isolated from the breakpoint on the partner chromosome of the 14q+ translocation, and the DNA sequences identified to juxtapose to the IgH gene locus on chromosome 14 band q32 accompanied by individual translocation. Thus, we can subclassify the lymphoid cancers marked with chromosome changes involving the loci of other functional genes.

Chromosomes, Human, Pair 14↗
PubMed1989

[Genome mapping in silver fox. Syntenic genes in Carnivora].

Hamster X fox somatic cell hybrids segregating individual fox chromosomes in different combinations were used to assign seven structural loci to fox chromosomes. The gene for ME1 was mapped on the VFU1 chromosome, the genes for ADK and PP being located on the VFU4 chromosome. The gene for GSR was assigned to the VFU7 chromosome and the genes for MPI and COT1 were assigned to the VFU15 chromosome. Localization of these genes enhances the established fox genetic map and extends the known syntenic homologies between the fox and other mammalian. The comparison of data on gene mapping has provided basis for suggestion that there are significant differences in rates of karyotypic evolution in many mammalian taxa.

Animals↗
PubMed1989

P185BCR-ABL in two patients with late appearing Philadelphia chromosome-positive acute nonlymphocytic leukemia.

Two patients with acute nonlymphocytic leukemia (ANLL) who had normal karyotypes at diagnosis and developed the Philadelphia (Ph) translocation during leukemia relapse are described in this report. Patient 1 relapsed with Ph-positive acute leukemia, FAB classification M1. The Ig heavy chain locus and T cell receptor gamma and beta genes of relapse cells from this patient were all found to be germline configuration confirming the diagnosis of M1 acute leukemia. Patient 2 displayed a complex karyotypic evolution leading to Ph-positive M4 relapse. Ph-positive relapse specimens from both patients expressed P185BCR-ABL protein and RNA gene products that were identified serologically and by polymerase chain amplification of the BCR-ABL RNA junction. In vitro derived myeloid cell lines from relapse M1 leukemia cells of patient 1 also expressed the P185BCR-ABL protein. In two described patients, late appearance of the Ph translocation that encodes P185BCR-ABL coincided with relapse of acute leukemia. We conclude that P185BCR-ABL may be a strong indicator of Ph-positive acute leukemias.

Female↗
PubMed1983

Cytogenetic approaches to the clarification of pathogenesis in lymphoid malignancies: clinicopathologic characterization of 14q+ marker-positive non-T-cell malignancies.

The clinicopathologic features of 53 patients with various types of non-T-cell malignancies were compared with the karyotypic findings. Although all chromosomes underwent numerical and structural rearrangements, a 14q+ marker chromosome (14q32 translocation), which was found in 31 patients, was the single most common abnormality. In terms of survival, no significant difference was noted between the 14q+ positive and negative patients. Donor chromosomes of a 14q32 translocation, which were identified in 27 patients, were quite variable. However, certain chromosomes were predisposed to act as donor chromosomes in the 14q32 translocation. An 8;14 translocation [t(8;14) (q24;q32)] was found in six patients with diffuse non-Burkitt's lymphoma and in four patients with Burkitt's lymphoma-leukemia; in all these patients a stem line or the subline with a t(8;14) had partial trisomy for 1q. An 11;14 translocation [t(11;14) (q13;q32)] was observed in one patient each with diffuse or follicular lymphoma and in two with myeloma; three of the four patients had also structural rearrangements of chromosome 1 in the same cells. A 14;18 translocation [t(14;18) (q32;q21)] was found in six patients with follicular lymphoma and in one with diffuse lymphoma; however, no common involvement of other chromosomes was detected among clones of these abnormal cells with a t(14;18). The median survival was 8 months for patients with a t(8;14) and 39 months for patients with a t(11;14). The difference between the two survival curves was of borderline significance [p = 0.06]. In contrast, patients with a t(14;18) survived significantly longer than those with a t(8;14) [p less than 0.001] or those with a t(11;14) [p = 0.03]. These findings revealed that in non-T-cell malignancies, the clinicopathologic features of the patients with a 14q+ marker depend upon the precise 14q32 translocation and the subsequent karyotypic evolution, although the translocation was not always correlated with a particular type of lymphoid malignancy.

Adult↗
PubMed1982

[Chromosomal abnormalities of the blastic phase of chronic myeloid leukemia].

The chromosomal involvement in the development of malignancy in chronic myeloid leukemia is not a random event. A second Ph1, a trisomy 8, an isochromosome 17q, a trisomy 17 are the main abnormalities. These aberrations use to occur as a karyotypic evolution, either simple or complicated. An extra-medullary development of blastic transformation was demonstrated by chromosomal analysis. It is difficult to demonstrate a correlation between chromosomal abnormalities and clinical evolution in the acute phase of chronic myeloid leukemia.

Chromosome Aberrations↗
PubMed1995

Detection of numerical alterations for chromosomes 7 and 12 in benign thyroid lesions by in situ hybridization. Histological implications.

Polysomies of chromosomes 7 and 12 have been frequently observed by conventional cytogenetics in a subgroup of thyroid follicular adenomas and in some cases of thyroid goiters. To further study possible cytogenetic similarities between these two types of thyroid lesions, we have used fluorescence in situ hybridization (FISH) to detect polysomies of chromosomes 7 and/or 12 in isolated nuclei from frozen and paraffin-embedded material of goiters and thyroid follicular adenomas and compared results with previous ones obtained by flow cytometry and conventional cytogenetics. With a set of two alpha-satellite DNA probes specific for the centromeric regions of chromosomes 7 and 12, used either separately (single-target fluorescence in situ hybridization) or simultaneously (double-target fluorescence in situ hybridization), we detected polysomies of chromosome 7 in 35.7% of the thyroid follicular adenomas and in 10.7% of the goiters. Polysomies of chromosome 12 were detected in 29.6% of the thyroid follicular adenomas and 6.7% of the goiters. The significantly higher frequency of adenomas with numerical alterations for chromosomes 7 and/or 12 supports the idea of a biological continuum and karyotypic evolution between both lesions. It is also noteworthy that polysomies of chromosomes 7 and/or 12 were observed only in lesions with an exclusive (or predominant) microfollicular histological component, as detected by enzymatic in situ hybridization on frozen sections.

Adenoma↗
PubMed1993

Clinical impact of breakpoint position within M-bcr in chronic myeloid leukemia.

We have analyzed the M-bcr breakpoint position in 133 Philadelphia-positive chronic myeloid leukemia patients and correlated the findings with clinical, hematologic, and cytogenetic data. We also investigated the splicing pattern of the BCR-ABL mRNA in 30 patients, using reverse transcriptase PCR. No statistically significant differences were found between breakpoint position within M-bcr and clinical parameters at diagnosis, the karyotypic evolution pattern, or the leukemic phenotype during blast crisis. Furthermore, the breakpoint position within M-bcr did not correlate with the duration of chronic phase or survival time. When the splicing pattern of the BCR-ABL mRNA was compared with the results of the genomic breakpoint mapping, it was found that approximately 60% (8/14) of the patients with a 5' break expressed b2a2 fusion mRNA, whereas all patients (10/10) with a 3' break expressed b3a2 BCR-ABL mRNA.

Adolescent↗
PubMedDate not supplied

The influence of sequential, in vitro passage on secretion of matrix metalloproteinases by human brain tumour cells.

Matrix metalloproteinases (MMP) are a family of zinc-dependent enzymes which degrade various components of the extracellular matrix (ECM) and play an important role in facilitating tumour cell invasion of the normal brain. The family includes the gelatinases, stromelysins and collagenases. Preliminary studies have shown that there is a differential expression four metalloproteinases in human brain tumour cell lines derived from neoplasms of various histological types and grades of malignancy. Morphological and antigenic changes in human glioma-derived cell lines over many serial in vitro passages have been reported in earlier studies. When established cell lines are maintained in culture over a long period, it is possible that the secretion of enzymes such as metalloproteinases may differ according to the passage level examined. This report presents a study on the secretion of four matrix metalloproteinases - interstitial collagenase (MMP-), 72-kDa and 92-kDa gelatinases (MMP-2 and MMP-9 respectively), and stromelysin (MMP-3) - in three human brain tumour-derived cell lines at sequentially increasing passage numbers, ranging from passage 2 to passage 50; foetal astrocytes were used as a positive control. Reverse zymography and substrate degradation analysis were employed to demonstrate the presence of these enzymes in cell- conditioned culture medium. Aminophenyl mercuric acetate (APMA) was used to activate latent zymogen. Results demonstrate that there is no definite pattern of change in the levels of enzyme secretion common to all cell lines studied. Instead, the fluctuations in APMA- activated metalloproteinase activity in serial passage seems to vary considerably depending on the cell line and the type of enzyme studied. The variation in metalloproteinase expression observed on serial passage may be due to in vitro selection processes or karyotype evolution where the transcription of either the enzyme and/or its inhibitor may be affected. Thus an imbalance of the two products could be occurring in serial passage. Ideally, experiments requiring the measurement of relative enzyme activities should use cultures as near to the biopsy stage as possible, i.e. very low passages, to avoid artifacts that may arise on prolonged culturing.

Astrocytoma↗
PubMed2003

Hybridization and introgression of the genomes of Drosophila nasuta and Drosophila albomicans: evolution of new karyotypes.

Drosophila nasuta (2n = 8) and Drosophila albomicans (2n = 6) are cross-fertile allopatric sibling chromosomal races of the nasuta subgroup of Drosophila. Hybrids of these races can be maintained for any number of generations. Some of the introgressed hybrid lineages of D. nasuta and D. albomicans, after passing through a transient phase of karyotypic polymorphism, ended up with a stable karyotype whose composition is different from those of the parental races. Such hybrid populations were called cytoraces, in which the chromosomes of D. nasuta and D. albomicans are represented in different combinations. The karyotypic composition of 16 such cytoraces have been presented and discussed with reference to evolutionary strategies such as balancing selection, directional selection, and sex-specific effect on different components of the evolving karyotypes.

Animals↗
PubMed1988

Evidence for eight tandem and five centric fusions in the evolution of the karyotype of Aethomys namaquensis A. Smith (Rodentia: Muridae).

G- and C-banded chromosomes of Aethomys namaquensis (2n = 24), A. chrysophilus (2n = 44), and Praomys coucha (2n = 36) are compared and contrasted with published material on Australian Muridae and North American Sigmodontidae. Direction and types of chromosomal rearrangements are established using cladistic methodology. An acrocentric morphology for chromosomes 5, 14, 15 and 20 (numbering system from Peromyscus) are proposed as primitive for the common ancestor of the Muridae and Sigmodontidae rodent lineages. Reduced diploid number of Aethomys namaquensis is derived by eight tandem and five centric fusions since divergence from the common ancestor with A. chrysophilus. The two species of Aethomys share one derived metacentric chromosome that distinguishes them from Praomys. Praomys has unique chromosomes which can be derived from the proposed primitive condition by five centric fusions and five pericentric inversions. It is concluded that karyotypic orthoselection for tandem and centric fusions is best explained by cellular or biochemical mechanisms rather than variation in population characteristics.

Animals↗
PubMed2005

Karyotypic diversity and evolution of Loricariidae (Pisces, Siluriformes).

We present cytogenetic analyses of four fish species, belonging to four Loricariidae subfamilies: Neoplecostomus microps (Neoplecostominae) with 2n=54 chromosomes, Harttia loricariformis (Loricariinae) with 2n=56 chromosomes, Hypostomus affinis (Hypostominae) with 2n=66 chromosomes and Upsilodus sp. (Upsilodinae), with 2n=96 chromosomes. In addition to karyotypes, data on the location of 18s rDNA sites are presented, derived from indirect (silver nitrate impregnation) and direct (FISH) methods. There is only one pair of nucleolar organizing regions (NORs) per species, except in H. affinis. Diversity and NOR macrokaryotypic evolution in the species analyzed are discussed in relation to the evolution of the Loricariidae as a whole. In addition, a revision of the cytogenetic data available for this family is presented.

Animals↗