Coordinate amplification of metallothionein I and II gene sequences in cadmium-resistant CHO variants

Conference · Sat Jan 01 04:00:00 EST 1983

OSTI ID:6047446

Hildebrand, C E; Crawford, B D; Enger, M D

Cadmium-resistanc (Cd/sup r/) variants of the Chinese hamster cell line, CHO, have been derived by stepwise selection for growth in medium containing CdCl/sub 2/. These variants show coordinately increased production of both metallothionein (MT) I and II and were stably resistant to Cd/sup 2 +/ in the absence of continued selection. Genomic DNAs from these Cd/sup r/ sublines were analyzed for both MT gene copy number and MT gene organization, using cDNA sequence probes specific for each of the two Chinese hamster isometallothioneins. These analyses revealed coordinate amplification of MT I and II genes in all Cd/sup r/ variants which had increased copies of MT-encoding sequences. In situ hybridization of an MT-encoding probe to mitotic chromosomes of a Cd/sup r/ variant, which has amplified MT genes at least 14-fold, revealed a single chromosomal site of hybridization. These results suggest that the isoMTs constitute a functionally related gene cluster which amplifies coordinately in response to toxic metal stress.

• Research Organization: Los Alamos National Lab., NM (USA)
• DOE Contract Number: W-7405-ENG-36
• OSTI ID: 6047446
• Report Number(s): LA-UR-83-1151; CONF-830440-3; ON: DE83011139
• Country of Publication: United States
• Language: English

Related Subjects

550400 -- Genetics
560301* -- Chemicals Metabolism & Toxicology-- Cells-- (-1987)
59 BASIC BIOLOGICAL SCIENCES
63 RADIATION, THERMAL, AND OTHER ENVIRON. POLLUTANT EFFECTS ON LIVING ORGS. AND BIOL. MAT.
ANIMAL CELLS
ANIMALS
BODY
CADMIUM
CELL CULTURES
ELEMENTS
FEMALE GENITALS
GENES
GENETIC MAPPING
GONADS
HAMSTERS
HYBRIDIZATION
MAMMALS
MAPPING
METALLOPROTEINS
METALLOTHIONEIN
METALS
ORGANIC COMPOUNDS
ORGANS
OVARIES
PROTEINS
RODENTS
SENSITIVITY
VERTEBRATES