Enhancement of the synthesis of specific cellular polypeptides in a temperature-sensitive chinese hamster cell line (K12) Defective for entry into S Phase

1978 ◽  
Vol 95 (3) ◽  
pp. 295-306 ◽  
Author(s):  
Jose A. Melero ◽  
V. Fincham
Keyword(s):  
Cell Line ◽  
Chinese Hamster ◽  
Chinese Hamster Cell ◽  
S Phase ◽  
Temperature Sensitive ◽  
Chinese Hamster Cell Line

Presence or absence of a G1 period in the cell cycle and growth control in a Chinese hamster cell line

1985 ◽  
Vol 158 (1) ◽  
pp. 276-279 ◽  
Author(s):  
D. Wynford-Thomas ◽  
G. Marin ◽  
A. LaMontagne ◽  
David M. Prescott
Keyword(s):  
Cell Cycle ◽  
Cell Line ◽  
Chinese Hamster ◽  
Growth Control ◽  
Chinese Hamster Cell ◽  
Chinese Hamster Cell Line

THE ESTABLISHMENT AND CHROMOSOME ANALYSIS OF A NEW CELL LINE OF CHINESE HAMSTER FROM SPONTANEOUS TRANSFORMATION IN VITRO

1971 ◽  
Vol 13 (1) ◽  
pp. 9-13 ◽  
Author(s):  
C. C. Lin ◽  
T. D. Chang ◽  
Virginia Niewczas-Late
Keyword(s):  
Cell Line ◽  
Chinese Hamster ◽  
Chromosome Analysis ◽  
Cell Types ◽  
Selective Advantage ◽  
Chinese Hamster Cell ◽  
Major Type ◽  
Spontaneous Transformation ◽  
Chinese Hamster Cell Line

A male Chinese hamster cell line has been established through spontaneous transformation in a skin culture. Chromosome studies at passage 13 revealed one major and one minor type of pseudodiploid cells (77.3 and 20%). At passage 42, only the major subline persisted (78%). The two sublines, especially the major one, had selective advantage over other cell types in this cell line probably because they were more nearly genetically balanced. Autoradiographic studies indicated no overall increase in late replicating chromosomal elements in the two sublines. Both cell types lacked the X chromosome and chromosome 6, but they were largely compensated for by the presence of new marker chromosomes. However, more chromosomal material was missing in the minor type than in the major type, and this may account for the lower adaptability of the former.

Multiple origins of replication in the dihydrofolate reductase amplicons of a methotrexate-resistant chinese hamster cell line

1990 ◽  
Vol 10 (4) ◽  
pp. 1338-1346
Author(s):  
C Ma ◽  
T H Leu ◽  
J L Hamlin
Keyword(s):  
Cell Line ◽  
Dihydrofolate Reductase ◽  
Chinese Hamster ◽  
Chinese Hamster Cell ◽  
Ovary Cell ◽  
Multiple Origins ◽  
Chromosomal Walking ◽  
Chinese Hamster Cell Line ◽  
S Period ◽  
Ovary Cell Line

We recently showed that replication initiates in the early S period at two closely spaced zones in the 240-kilobase (kb) dihydrofolate reductase (DHFR) amplicon of the methotrexate-resistant Chinese hamster ovary cell line CHOC 400. Both of these initiation loci (ori-beta and ori-gamma) have previously been cloned in a recombinant cosmid. In this study, we identified a third early-firing initiation locus (ori-alpha) in the much larger DHFR amplicon of the independently isolated methotrexate-resistant Chinese hamster cell line DC3F-A3/4K (A3/4K). We describe the molecular cloning of this newly identified locus and demonstrate by chromosomal walking that ori-alpha lies approximately 240 kb upstream from ori-beta. Using overlapping cosmid clones for more than 450 kb of DNA sequence from this region of the DHFR domain, we have monitored the replication pattern of the amplicons in synchronized A3/4K cells. These studies suggest that ori-alpha, ori-beta, and ori-gamma are the only early-firing initiation sites in this 450-kb sequence. In addition, we have been able to roughly localize the termini between ori-alpha and ori-beta and between ori-alpha and the next origin in the 5' direction. Thus, we have now isolated the equivalent of three early-firing replicons (including their origins) from a well-characterized chromosomal domain. With these tools, it should be possible to determine those properties that are shared by the origins and termini of different replicons and which are therefore likely to be functionally significant.

Cloning of a human S-phase cell cycle gene: use of transient expression for screening

1987 ◽  
Vol 7 (2) ◽  
pp. 775-779
Author(s):  
A Fainsod ◽  
G Diamond ◽  
M Marcus ◽  
F H Ruddle
Keyword(s):  
Cell Cycle ◽  
Genomic Library ◽  
Chinese Hamster ◽  
Chinese Hamster Cell ◽  
S Phase ◽  
Phase Cell ◽  
Cell Cycle Gene ◽  
Temperature Sensitive ◽  
Specific Cell ◽  
Restrictive Temperature

We report here the cloning of a human cell cycle gene capable of complementing a temperature-sensitive (ts) S-phase cell cycle mutation in a Chinese hamster cell line. Cloning was performed as follows. A human genomic library in phage lambda containing 600,000 phages was screened with labeled cDNA synthesized from an mRNA fraction enriched for the specific cell cycle gene message. Plaques containing DNA inserts which hybridized to the cDNA were picked, and their DNAs were assayed for transient complementation in DNA transformation experiments. The transient complementation assay we developed is suitable for most cell cycle genes and indeed for many genes whose products are required for cell proliferation. Of 845 phages screened, 1 contained an insert active in transient complementation of the ts cell cycle mutation. Introduction of this phage into the ts cell cycle mutant also gave rise to stable transformants which grew normally at the restrictive temperature for the ts mutant cells.

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