Isolation of a spontaneous CHO amino acid transport mutant by a combination of tritium suicide and replica plating
A spontaneous transport mutant of Chinese hamster ovary cells, CHY-1, was isolated by a combination of (/sup 3/H)proline suicide and replica plating. The mutant took up less tritium than the parent, resulting in a lower killing rate during storage. Transport by four separate amino acid transport systems (A, ASC, L, Ly+) was examined. The CHY-1 mutant exhibited normal uptake via the ASC, L, and Ly+ systems. By contrast, uptake of the most specific substrate of the A system, 2-(methylamino)-isobutyric acid, was significantly reduced at low, but not high, concentrations, due to a 3.5-fold increase in Km and a 1.5-fold increase in Vmax. Taken together, these data suggest that the CHY-1 mutation may be in the structural gene coding for the A transport protein. The tritium suicide procedure is discussed, and general equations are derived to predict the maximum storage time for the survival of one mutant cell and the optimum size of the cell population for maximum mutant enrichment.
- Research Organization:
- Department of Human Genetics, Yale University School of Medicine, New Haven, CT
- OSTI ID:
- 6856887
- Journal Information:
- Somatic Cell Genet.; (United States), Vol. 8:4
- Country of Publication:
- United States
- Language:
- English
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Related Subjects
AMINO ACIDS
MEMBRANE TRANSPORT
ANIMAL CELLS
GENE MUTATIONS
MUTANTS
SEPARATION PROCESSES
HAMSTERS
OVARIES
PROLINE
PROTEINS
SURVIVAL TIME
TRACER TECHNIQUES
TRITIUM COMPOUNDS
UPTAKE
AMINES
ANIMALS
AZOLES
BODY
CARBOXYLIC ACIDS
FEMALE GENITALS
GONADS
HETEROCYCLIC ACIDS
HETEROCYCLIC COMPOUNDS
ISOTOPE APPLICATIONS
LABELLED COMPOUNDS
MAMMALS
MUTATIONS
ORGANIC ACIDS
ORGANIC COMPOUNDS
ORGANIC NITROGEN COMPOUNDS
ORGANS
PYRROLES
PYRROLIDINES
RODENTS
VERTEBRATES
550401* - Genetics- Tracer Techniques
551001 - Physiological Systems- Tracer Techniques