Amplification of the metallothionein-I gene in cadmium-resistant mouse cells
01 Apr 1981-Proceedings of the National Academy of Sciences of the United States of America (National Academy of Sciences)-Vol. 78, Iss: 4, pp 2110-2114
TL;DR: Friend leukemia cells resistant to cadmium toxicity were selected and revealed that the resistant cells are nearly tetraploid and contain, on the average, three very small chromosomes that are absent from non-resistant Friend cells.
Abstract: Friend leukemia cells resistant to cadmium toxicity were selected. More than 70% of total cysteine incorporation in these cells was into the metal-binding protein, metallothionein. We used cDNA and genomic DNA clones containing the metallothionein-I gene to measure the concentration of its mRNA, the rate of gene transcription, and the number of genes. On a per cell basis, optimally induced, cadmium-resistant cells have a 14-fold more metallothionein-I mRNA, a 6-fold higher rate of metallothionein-I gene transcription, and 6-fold more metallothionein-I genes than do nonresistant cells. Metaphase spreads revealed that the resistant cells are nearly tetraploid and contain, on the average, three very small chromosomes that are absent from non-resistant Friend cells.
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TL;DR: This technique is quite simple, requires very small amounts of cells or tissue, and permits the simultaneous analysis of multiple samples, which should be quite useful for studies with various experimental systems of the regulation of specific mRNA levels.
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TL;DR: A plasmid containing the structural gene for thymidine kinase from herpes simplex virus fused to the promoter/regulatory region of the mouse metallothionein-I gene was injected into the pronucleus of fertilized one-cell mouse eggs; the eggs were subsequently reimplanted into the oviducts of pseudopregnant mice.
690 citations
TL;DR: Despite thousands of studies describing the structure, biochemical characteristics, tissue distribution, induction, and consequences of genetic disruption and deliberate overexpression, the evolutionary forces that led to the initial appearance, gene duplications, and nearly ubiquitous expression of MTs remain enigmatic.
Abstract: Biochemistry and genetics are both required to elucidate the function of macromolecules There is no question that metallothioneins (MTs) have unique biochemical properties, but genetic experiments have not substantiated the importance of MTs under physiological conditions Even after thousands of studies describing the structure, biochemical characteristics, tissue distribution, induction, and consequences of genetic disruption and deliberate overexpression, the evolutionary forces that led to the initial appearance, gene duplications, and nearly ubiquitous expression of MTs remain enigmatic
675 citations
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TL;DR: RLC cells in culture appear to be able to accumulate Cd 2+ into metallothionein at a rate comparable to rat liver tissue in vivo when both systems are maximally activated.
32 citations