Biomaterial Database

Transfer of codominant markers by isolated metaphase chromosomes in Chinese hamster ovary cells. 1977

D A Spandidos, and L Siminovitch

Codominant mutations to methotrexate and ouabain resistance in Chinese hamster ovary cells can be transferred to recipient Chinese hamster ovary cells by isolated metaphase chromosomes. For methotrexate, both the structural change and the increased activity of dihydrofolate reductase (5,6,7,8-tetrahydrofolate:NADP+ oxidoreductase EC 1.5.1.3), characteristic of the donor cells, are observed in the transferents (cells that carry and express functions derived by chromosome transfer). The transferents are unstable in the absence of selection although stable clones can be isolated. From results obtained by fractionation of chromosomes and transfer to recipients, the methotrexate and ouabain markers can be assigned to the middle and large size-classes of chromosomes, respectively. By fractionation and transfer of chromosomes, from transferents to new recipients, evidence has been obtained that chromosome integration is not restricted to a particular chromosomal site in the recipient.

UI	MeSH Term	Description	Entries
D008677	Metaphase	The phase of cell nucleus division following PROMETAPHASE, in which the CHROMOSOMES line up across the equatorial plane of the SPINDLE APPARATUS prior to separation.
D008727	Methotrexate	An antineoplastic antimetabolite with immunosuppressant properties. It is an inhibitor of TETRAHYDROFOLATE DEHYDROGENASE and prevents the formation of tetrahydrofolate, necessary for synthesis of thymidylate, an essential component of DNA.	Amethopterin,Methotrexate Hydrate,Methotrexate Sodium,Methotrexate, (D)-Isomer,Methotrexate, (DL)-Isomer,Methotrexate, Dicesium Salt,Methotrexate, Disodium Salt,Methotrexate, Sodium Salt,Mexate,Dicesium Salt Methotrexate,Hydrate, Methotrexate,Sodium, Methotrexate
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
D010042	Ouabain	A cardioactive glycoside consisting of rhamnose and ouabagenin, obtained from the seeds of Strophanthus gratus and other plants of the Apocynaceae; used like DIGITALIS. It is commonly used in cell biological studies as an inhibitor of the NA(+)-K(+)-EXCHANGING ATPASE.	Acocantherin,G-Strophanthin,Acolongifloroside K,G Strophanthin
D002453	Cell Cycle	The complex series of phenomena, occurring between the end of one CELL DIVISION and the end of the next, by which cellular material is duplicated and then divided between two daughter cells. The cell cycle includes INTERPHASE, which includes G0 PHASE; G1 PHASE; S PHASE; and G2 PHASE, and CELL DIVISION PHASE.	Cell Division Cycle,Cell Cycles,Cell Division Cycles,Cycle, Cell,Cycle, Cell Division,Cycles, Cell,Cycles, Cell Division,Division Cycle, Cell,Division Cycles, Cell
D002460	Cell Line	Established cell cultures that have the potential to propagate indefinitely.	Cell Lines,Line, Cell,Lines, Cell
D002875	Chromosomes	In a prokaryotic cell or in the nucleus of a eukaryotic cell, a structure consisting of or containing DNA which carries the genetic information essential to the cell. (From Singleton & Sainsbury, Dictionary of Microbiology and Molecular Biology, 2d ed)	Chromosome
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
D005799	Genes, Dominant	Genes that influence the PHENOTYPE both in the homozygous and the heterozygous state.	Conditions, Dominant Genetic,Dominant Genetic Conditions,Genetic Conditions, Dominant,Condition, Dominant Genetic,Dominant Gene,Dominant Genes,Dominant Genetic Condition,Gene, Dominant,Genetic Condition, Dominant
D013762	Tetrahydrofolate Dehydrogenase	An enzyme of the oxidoreductase class that catalyzes the reaction 7,8-dihyrofolate and NADPH to yield 5,6,7,8-tetrahydrofolate and NADPH+, producing reduced folate for amino acid metabolism, purine ring synthesis, and the formation of deoxythymidine monophosphate. Methotrexate and other folic acid antagonists used as chemotherapeutic drugs act by inhibiting this enzyme. (Dorland, 27th ed) EC 1.5.1.3.	Dihydrofolate Dehydrogenase,Dihydrofolate Reductase,Folic Acid Reductase,Acid Reductase, Folic,Dehydrogenase, Dihydrofolate,Dehydrogenase, Tetrahydrofolate,Reductase, Dihydrofolate,Reductase, Folic Acid