ABSTRACT
The karyotypes of CHO(dhfr-) and CHO(dhfr-)/susp Chinese hamster ovary cell lines were investigated with the use of GTG-staining. Modal chromosome set consists of 20 and 18 chromosomes respectively. The karyotypes of both cell lines were stable with constant ratio of normal chromosomes and chromosomes with structural rearrangements. Monosomy for chromosomes 1, 2, 4, 5, 8 was observed in both cell lines and for chromosome 9 in CHO(dhfr-)/susp cell line. The differences between CHO(dhfr-) cell lines studied by us consists of inclusion of part of chromosome 7 in der(6)t(1;6), rearrangement of del(5) and monosomy of chromosome 9. It was shown that in karyotypes of all CHO cell lines studied up today there are 5 common structurally chromosome rearrangements: del(2), inv(3), add(6), del(9) and mar1. In both CHO(dhfr-) cell lines investigated by us three unique chromosome rearrangements: del(1), der(6)t(1,6) and mar3 were revealed. Necessity of simultaneous GTG and FISH analysis of chromosomes rearrangements in the CHO cell lines under study is discussed.
Subject(s)
Abnormal Karyotype , Chromosomes, Mammalian/genetics , Cytogenetics , Animals , CHO Cells , Cricetinae , CricetulusSubject(s)
Cytokinins/biosynthesis , Electroporation/methods , Plasmids/genetics , Protein Engineering/methods , Proteobacteria/physiology , Transformation, Bacterial/genetics , Cytokinins/genetics , Gene Expression Regulation, Bacterial/physiology , Phototrophic Processes/physiology , Plasmids/administration & dosage , Recombinant Proteins/biosynthesis , Transfection/methodsABSTRACT
A study of peripheral blood smears from irradiated Chernobyl liquidators and other subjects has shown nuclei of some lymphocytes to have a protrusion into the cytoplasm. Such abnormal nuclei are called "tailed" nuclei (TN). Sixteen main morphologic types, observed in human peripheral blood lymphocytes, are described. The frequency of appearance of lymphocytes with TN in a group of Chernobyl liquidators was significantly higher than in control groups (p < 0.001, in all cases). A positive correlation was found between the TN frequency in lymphocytes and dicentric chromosomes in lymphocytes cultured to metaphase (p < 0.001). Elevated frequencies of dicentrics, higher than 0.1%, were found in 17 out of 22 subjects in whom the frequency of lymphocytes with TN was 0.8% and more. Abnormalities of the TN type in lymphocytes are likely to result from breakdown of chromosome bridges formed by dicentrics. The TN can be considered as a possible marker of irradiation and, therefore, their detailed study is important.
Subject(s)
Cell Nucleus/radiation effects , Chromosome Aberrations , Adult , Aged , Cell Nucleus/ultrastructure , Chromosomes, Human/radiation effects , Chromosomes, Human/ultrastructure , Humans , Lymphocytes/radiation effects , Lymphocytes/ultrastructure , Male , Middle Aged , Radioactive Hazard Release , UkraineABSTRACT
Chromosomal analysis of immortalized rat embryo fibroblasts (IE5) and transformed by HPV18 E6+E7 genes (A4E5) or HPV16 E7 alone (trB4; trF8; trC2) variants have been done. Transformed cell lines represented heterogeneous cell populations containing neardiploid subpopulations with 41-44 chromosomes and also heterogeneous polyploid cells in contrast to immortal cells IE5 that contained normal number of chromosomes-42. In transformed cells the abnormalities of interphase nuclei (giant-, micro-, apoptotic nuclei) were observed which could reflect genomic instability of polyploid cells. Several chromosomal alterations were revealed in immortal IE5 cells, but only reciprocal translocation t(8; 10) (q22q12.3) was stable and kept in cells transformed by HPV18 E6+E7 genes or HPV16 E7 alone. We can conclude that genomic instability and clonal expansion of the cells with specific chromosomal alterations contribute to HPV-mediated transformation.
