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V G Chernikov

Publications and source records attributed to V G Chernikov.

4 recordsLinked to original sources
PubMed1976

[Isolation and characteristics of temperature sensitive mutants in a culture of Chinese hamster cells].

The treatment of a temperature-resistant glutamine-independent clone of Chinese hamster cells (237 glu+ tr) with 5-bromodeoxyuridine (BUdR) for 48 or 72 hours at 40 degrees C and subsequent illumination with visible light was used for selection of spontaneous and N-methyl-N'-nitro-N-nitrosoguanidein-induced ts mutants. 30 clones were isolated. Their temperature-sensitivity was studied at two cell densities: 500 and 10000 (or 15 000) cells per dish. 21 clones proved to be temperature-sensitive. The expression of temperature-sensitivity of 11 clones was independent of cell densities used. The remaining 10 clones could be divided in two groups: those expressing temperature-sensitivity only at low plating inoculum (6 clones) and those temperature-sensitive at 10 000 (15 000) plated cells per dish (4 clones). Possible mechanisms of this phenomenon are discussed. Most isolated clones behaved as leaky mutants. Isolation of ts clones without special mutagen treatment from a tr cell population after its permanent incubation at 40 degrees C, restrictive for ts cells, is regarded as strong evidence in favour of the mutagenic effect of BUdR and visible light.

Animals↗
PubMed1976

[Spontaneous and induced mutagenesis in a culture of Chinese hamster cells].

Spontaneous and nitrosoguanidine (NG)-induced rate of reversions to glutamine independence was studied in cultured temperature-sensitive glutamine auxotrophs of Chinese hamster cells. In 3 experiments the spontaneous rate of reversions varied from 0.8-10(-6) to 3.84-10(-6) per cell per generation. A dependence of the yield of NG-induced back mutations upon the time interval between the mutagenic treatment and the transfer to selective conditions (glutamine deficient medium, 40 degrees C) was established. No induced revertants were detected when cells were transferred to selective conditions immediately after the treatment with NG. After 2--3 days cultivation in glutamine containing medium at 36 degrees C and the sunsequent transfer to selective conditions the frequency of induced reversions varied from 0.56-10(-4) to 10.55-10(-4) in different experiments; after 6 days -- from 0.05-10(-4) to 4.0-10(-4). In all cases where induction was detected, the difference, between the frequency of glutamine prototrophs in treated and control plates was significant. Glutamine independence proved to be stable after prolonged cultivation under non-selective conditions, the degree of prototrophy being greatly unequal in different clones. No differnce in this respect was detected between spontaneous and NG-induced revertants. The proposed system of reverse mutations can be used for studying diverse problems of somatic cell genetics.

Aneuploidy↗