Biomaterial Database

Fluctuation analyses of spontaneous mutations to 6-thioguanine resistance in Chinese hamster ovary cells in culture. 1981

J P O'Neill, and P A Brimer, and A W Hsie

Fluctuation analyses of the spontaneous appearance of 6-thioguanine (TG)-resistant mutants in cultured Chinese hamster ovary (CHO) cells were performed to investigate (1) whether the resistance is induced by the selective agent or is the result of a mutation which occurs prior to the TG selection and (2) to estimate the spontaneous mutation rate at the hypoxanthine--guanine phosphoribosyl transferase (hgprt) locus. The potential problem of phenotypic delay was minimized by allowing an adequate expression time through maintenance of the cultures in a division-arrested, viable state. The results demonstrate that the TG-resistant (TGr) cells arise randomly in the cultures, independently of the selective agent, which is consistent with spontaneous mutations. The average values for mutation rate +/- standard deviation, based on 4 independent determinations and 2 methods of calculation, are 3.4 +/- 1.2 X 10(-7) (median method) and 5.1 +/- 1.8 X 10(-7) (mean method) mutants/cell/generation.

UI	MeSH Term	Description	Entries
D008433	Mathematics	The deductive study of shape, quantity, and dependence. (From McGraw-Hill Dictionary of Scientific and Technical Terms, 6th ed)	Mathematic
D009154	Mutation	Any detectable and heritable change in the genetic material that causes a change in the GENOTYPE and which is transmitted to daughter cells and to succeeding generations.	Mutations
D010053	Ovary	The reproductive organ (GONADS) in female animals. In vertebrates, the ovary contains two functional parts: the OVARIAN FOLLICLE for the production of female germ cells (OOGENESIS); and the endocrine cells (GRANULOSA CELLS; THECA CELLS; and LUTEAL CELLS) for the production of ESTROGENS and PROGESTERONE.	Ovaries
D002460	Cell Line	Established cell cultures that have the potential to propagate indefinitely.	Cell Lines,Line, Cell,Lines, Cell
D003412	Cricetulus	A genus of the family Muridae consisting of eleven species. C. migratorius, the grey or Armenian hamster, and C. griseus, the Chinese hamster, are the two species used in biomedical research.	Hamsters, Armenian,Hamsters, Chinese,Hamsters, Grey,Armenian Hamster,Armenian Hamsters,Chinese Hamster,Chinese Hamsters,Grey Hamster,Grey Hamsters,Hamster, Armenian,Hamster, Chinese,Hamster, Grey
D004351	Drug Resistance	Diminished or failed response of an organism, disease or tissue to the intended effectiveness of a chemical or drug. It should be differentiated from DRUG TOLERANCE which is the progressive diminution of the susceptibility of a human or animal to the effects of a drug, as a result of continued administration.	Resistance, Drug
D005260	Female		Females
D005787	Gene Frequency	The proportion of one particular in the total of all ALLELES for one genetic locus in a breeding POPULATION.	Allele Frequency,Genetic Equilibrium,Equilibrium, Genetic,Allele Frequencies,Frequencies, Allele,Frequencies, Gene,Frequency, Allele,Frequency, Gene,Gene Frequencies
D006224	Cricetinae	A subfamily in the family MURIDAE, comprising the hamsters. Four of the more common genera are Cricetus, CRICETULUS; MESOCRICETUS; and PHODOPUS.	Cricetus,Hamsters,Hamster
D000818	Animals	Unicellular or multicellular, heterotrophic organisms, that have sensation and the power of voluntary movement. Under the older five kingdom paradigm, Animalia was one of the kingdoms. Under the modern three domain model, Animalia represents one of the many groups in the domain EUKARYOTA.	Animal,Metazoa,Animalia