Chromosome segregation from cell hybrids. VII. Reverse segregation from karyoplast hybrids suggests control by cytoplasmic factors

Genome ◽  
1992 ◽  
Vol 35 (3) ◽  
pp. 537-540 ◽  
Author(s):  
Jennifer A. Marshall Graves ◽  
Iole Barbieri
Keyword(s):  
Chromosome Segregation ◽  
Human Cell ◽  
Chinese Hamster ◽  
Segregation Pattern ◽  
Chromosome Loss ◽  
Human Chromosomes ◽  
Cell Hybrids ◽  
Cytoplasmic Factors

Using human and Chinese hamster established lines as cell parents, we constructed hamster–human cell hybrids and human cell – hamster karyoplast hybrids. The cell hybrids retained one or two sets of hamster chromosomes and lost most of the human chromosomes. The karyoplast hybrids, however, retained a full set of human chromosomes and lost most of the Chinese hamster chromosomes. This reverse segregation pattern implies that cytoplasmic factors are major determinants of the direction of chromosome segregation.Key words: cell hybrids, chromosome loss, cytoplasmic factors, reverse segregation.

Chromosome segregation from cell hybrids. IV. Movement and position of segregant set chromosomes in early-phase interspecific cell hybrids

1988 ◽  
Vol 89 (1) ◽  
pp. 49-56
Author(s):  
P.A. Zelesco ◽  
J.A. Graves
Keyword(s):  
Chromosome Segregation ◽  
Early Phase ◽  
Metaphase Plate ◽  
Central Position ◽  
Chromosome Loss ◽  
Human Chromosomes ◽  
Hybrid Cells ◽  
Multipolar Mitosis ◽  
Cell Hybrids ◽  
G 11

We searched for evidence of aberrant movement or position of segregant set chromosomes in C-banded and G-11-banded early-phase hamster-mouse and hamster-human cell hybrids that had been prepared with minimal disruption. No evidence was obtained for an increased frequency of multipolar mitosis, delayed or precocious metaphase congression or anaphase segregation, or for exclusion of chromosomes from the daughter nuclei. However, in hamster-human hybrids, segregant set (human) chromosomes were observed to assume a central position within a ring of hamster chromosomes on the metaphase plate. Such non-random positioning may imply that the centromeres of segregant chromosomes make aberrant, or simply less efficient, attachments to the spindle in hybrid cells. This aberrant position may perhaps result indirectly in chromosome loss by interfering with the normal processes of replication, repair or transcription.

Chromosome segregation from cell hybrids.II. Do differences in parental cell growth rates and phase times determine direction of loss?

1986 ◽  
Vol 28 (5) ◽  
pp. 735-743 ◽  
Author(s):  
Jennifer A. Marshall Graves ◽  
Jaclyn M. Wrigley
Keyword(s):  
Cell Cycle ◽  
Chromosome Segregation ◽  
Chinese Hamster ◽  
Parental Cell ◽  
S Phase ◽  
Chromosome Loss ◽  
Parent Cell ◽  
Cycle Times ◽  
Cell Hybrids ◽  
The One

The hypothesis that the direction of chromosome segregation in cell hybrids is determined by the interaction of parent cell cycles, or S-phase times, predicts that the segregant parent will always be the one with the longer cycle, or the longer S phase, and that late replicating chromosomes will be more frequently lost. We have tested this hypothesis by studying cell cycle parameters of mouse, Chinese hamster, and platypus parent cells and by observing chromosome loss and replication patterns in hybrids between them. Two types of hybrids have been studied: mouse–hamster hybrids showed gradual segregation, in one or other direction, of 10–60% chromosomes, while rodent–platypus hybrids (which could be selected under conditions optimal for either parent cell) showed rapid and extreme segregation of platypus chromosomes. We found no correlation between the direction of segregation and the relative lengths of parental cycle times, or phase times, nor between sequence of replication and frequency with which segregant chromosomes are lost. We therefore conclude that the direction and extent of segregation is not directly determined by the interaction of parental cycle or phase times.Key words: cell hybrids, chromosome loss, cell cycle, S phase.

Chromosome segregation from cell hybrids. I. The effect of parent cell ploidy on segregation from mouse – Chinese hamster hybrids

1984 ◽  
Vol 26 (5) ◽  
pp. 557-563 ◽  
Author(s):  
Jennifer A. Marshall Graves
Keyword(s):  
Chromosome Number ◽  
Chromosome Segregation ◽  
Chinese Hamster ◽  
Chromosome Loss ◽  
Parent Cell ◽  
Cell Hybrids ◽  
Parental Factor ◽  
Species Combination ◽  
Mouse Cells ◽  
Input Ratio

To determine whether the dosage of some parental factor influences the direction and extent of chromosome segregation, I have constructed hybrids between polyploid series of mouse and Chinese hamster lines. The input ratio of mouse: hamster chromosomes varied from 3.3 (in hybrids between diploid hamster and polyploid mouse cells) and 0.9 (in hybrids between polyploid hamster and near-diploid mouse cells). Mouse chromosomes were retained and hamster chromosomes were lost from all hybrids with input ratios ≥ 1.3; the extent of hamster chromosome loss increased from 25 to 60% as the proportion of mouse chromosomes was increased. Reverse segregation was observed in hybrids in which the ratio was 0.9; hybrids between polyploid hamster and diploid mouse cells retained most hamster chromosomes and lost 52% of mouse chromosomes. I conclude that the direction and extent of chromosome segregation from these hybrids depends on the dosage of some factor contained in the parent cells; because the volumes of polyploid cells are proportional to chromosome number, this factor could be chromosomal, nuclear, or cytoplasmic. Dosage differences should therefore be considered when comparing chromosome segregation from hybrids with cells of the same species combination, but which might differ in chromosome number (e.g., diploid lines and established lines), or cell volume (e.g., cells from different tissues).Key words: cell hybrids, mouse – hamster, segregation, chromosome loss, ploidy.

Segregation of recessive phenotypes in somatic cell hybrids: role of mitotic recombination, gene inactivation, and chromosome nondisjunction

1981 ◽  
Vol 1 (4) ◽  
pp. 336-346
Author(s):  
C E Campbell ◽  
R G Worton
Keyword(s):  
Somatic Cell ◽  
Chinese Hamster ◽  
Mitotic Recombination ◽  
Chinese Hamster Cell ◽  
Gene Inactivation ◽  
Chromosome Loss ◽  
Resistance Locus ◽  
Chromosome 2 ◽  
Somatic Cell Hybrids ◽  
Cell Hybrids

Somatic cell hybrids heterozygous at the emetine resistance locus (emtr/emt+) or the chromate resistance locus (chrr/chr+) are known to segregate the recessive drug resistance phenotype at high frequency. We have examined mechanisms of segregation in Chinese hamster cell hybrids heterozygous at these two loci, both of which map to the long arm of Chinese hamster chromosome 2. To follow the fate of chromosomal arms through the segregation process, our hybrids were also heterozygous at the mtx (methotrexate resistance) locus on the short arm of chromosome 2 and carried cytogenetically marked chromosomes with either a short-arm deletion (2p-) or a long-arm addition (2q+). Karyotype and phenotype analysis of emetine- or chromate-resistant segregants from such hybrids allowed us to distinguish four potential segregation mechanisms: (i) loss of the emt+- or chr+-bearing chromosome; (ii) mitotic recombination between the centromere and the emt or chr loci, giving rise to homozygous resistant segregants; (iii) inactivation of the emt+ or chr+ alleles; and (iv) loss of the emt+- or chr+-bearing chromosome with duplication of the homologous chromosome carrying the emtr or chrr allele. Of 48 independent segregants examined, only 9 (20%) arose by simple chromosome loss. Two segregants (4%) were consistent with a gene inactivation mechanism, but because of their rarity, other mechanisms such as mutation or submicroscopic deletion could not be excluded. Twenty-one segregants (44%) arose by either mitotic recombination or chromosome loss and duplication; the two mechanisms were not distinguishable in that experiment. Finally, in hybrids allowing these two mechanisms to be distinguished, 15 segregants (31%) arose by chromosome loss and duplication, and none arose by mitotic recombination.

Localization of genes on human chromosomes by studies of human-Chinese hamster somatic cell hybrids

1973 ◽  
Vol 20 (3) ◽  
pp. 195-202 ◽  
Author(s):  
Ans Jongsma ◽  
Harry Someren ◽  
Andries Westerveld ◽  
Ann Hagemeijer ◽  
Peter Pearson
Keyword(s):  
Somatic Cell ◽  
Chinese Hamster ◽  
Human Chromosomes ◽  
Somatic Cell Hybrids ◽  
Cell Hybrids

scholarly journals Human Chromosomes 9, 12, and 15 Contain the Nucleation Sites of Stress-Induced Nuclear Bodies

2002 ◽  
Vol 13 (6) ◽  
pp. 2069-2079 ◽  
Author(s):  
Marco Denegri ◽  
Daniela Moralli ◽  
Mariano Rocchi ◽  
Marco Biggiogera ◽  
Elena Raimondi ◽  
...  
Keyword(s):  
Heat Shock ◽  
Human Cell ◽  
Hela Cells ◽  
Heat Shock Factor ◽  
Nuclear Bodies ◽  
Chromosome 9 ◽  
Heat Shock Factor 1 ◽  
Human Chromosomes ◽  
Cell Hybrids ◽  
Nucleation Sites

We previously reported the identification of a novel nuclear compartment detectable in heat-shocked HeLa cells that we termed stress-induced Src-activated during mitosis nuclear body (SNB). This structure is the recruitment center for heat shock factor 1 and for a number of RNA processing factors, among a subset of Serine-Arginine splicing factors. In this article, we show that stress-induced SNBs are detectable in human but not in hamster cells. By means of hamster>human cell hybrids, we have identified three human chromosomes (9, 12, and 15) that are individually able to direct the formation of stress bodies in hamster cells. Similarly to stress-induced SNB, these bodies are sites of accumulation of hnRNP A1-interacting protein and heat shock factor 1, are usually associated to nucleoli, and consist of clusters of perichromatin granules. We show that the p13-q13 region of human chromosome 9 is sufficient to direct the formation of stress bodies in hamster>human cell hybrids. Fluorescence in situ hybridization experiments demonstrate that the pericentromeric heterochromatic q12 band of chromosome 9 and the centromeric regions of chromosomes 12 and 15 colocalize with stress-induced SNBs in human cells. Our data indicate that human chromosomes 9, 12, and 15 contain the nucleation sites of stress bodies in heat-shocked HeLa cells.

Specific chromosome loss associated with the expression of tumorigenicity in human cell hybrids

1981 ◽  
Vol 7 (6) ◽  
pp. 699-712 ◽  
Author(s):  
Eric J. Stanbridge ◽  
Robert R. Flandermeyer ◽  
David W. Daniels ◽  
Walter A. Nelson-Rees
Keyword(s):  
Human Cell ◽  
Chromosome Loss ◽  
Specific Chromosome ◽  
Cell Hybrids

Chromosome segregation from cell hybrids. VI. Centromeres of both parental chromosome sets stain with antikinetochore antibody

Genome ◽  
1989 ◽  
Vol 32 (2) ◽  
pp. 271-274 ◽  
Author(s):  
Paula A. Zelesco ◽  
Jennifer A. Marshall Graves
Keyword(s):  
Protein Binding ◽  
Chromosome Segregation ◽  
Chinese Hamster ◽  
Crest Syndrome ◽  
Parental Chromosome ◽  
Cell Hybrids

Antikinetochore antibodies obtained from serum of patients with the CREST syndrome of scleroderma were used to test the hypothesis that there are differences in protein binding to retained- and segregant-set centromeres in Chinese hamster – human hybrids. This hypothesis is not supported since identical staining of the two types of kinetochores was observed with CREST antibody.Key words: chromosome segregation, antikinetochore staining, CREST antibodies, cell hybrids.

Chromosome segregation from cell hybrids. III. Segregation is independent of spindle constitution

Genome ◽  
1987 ◽  
Vol 29 (4) ◽  
pp. 528-531 ◽  
Author(s):  
Paula A. Zelesco ◽  
Jennifer A. Marshall Graves
Keyword(s):  
Somatic Cell ◽  
Key Words ◽  
Chromosome Segregation ◽  
Chinese Hamster ◽  
Somatic Cell Hybrids ◽  
Cell Hybrids ◽  
Mouse Somatic Cell ◽  
Β Tubulin

Hamster β-tubulin (detected as a mutant subunit that confers Colcemid resistance) is either not expressed or is underexpressed in Chinese hamster–mouse somatic cell hybrids. This selectivity of tubulin expression suggests that a uniparental mouse spindle might preferentially engage mouse chromosomes and lead to loss of hamster chromosomes. However, the repression of hamster tubulin was found to have no bearing on the direction of chromosome segregation occurring in eight hybrids studied, some of which segregated predominantly mouse and others hamster chromosomes. Key words: chromosome segregation, cell hybrids, spindle, tubulin.

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