Somaclonal variation for morphological traits was studied in both control and mutagen (chemical and physical) treated progenies of two varieties of Solanum viarum. The SC1, SC1M1 (first generation following tissue culture) and SC2, SC2M2 (second generation) of both 2n and 4n varieties on field evaluation showed bidirectional variation for plant height, plant spread, number of flowers and fruits...

To utilize and exploit pollen for in situ mutagen monitoring, screening and toxicology, the range of genetic traits in pollen must be identified and analyzed. Traits that can be considered include ornamentation, shape and form, male sterility viability, intraspecific incompatibility, proteins and starch deposition. To be useful for the development of mutagen detection systems proteins should be...

RNA viruses replicate with a very high error rate and give rise to heterogeneous, highly plastic populations able to adapt very rapidly to changing environments. Viral diseases are thus difficult to control because of the appearance of drug-resistant mutants, and it becomes essential to seek mechanisms able to force the extinction of the quasispecies before adaptation emerges. An alternative to...

The rate of spontaneous generation and the frequency of carcinogen-induced anchorage-independent variants of preneoplastic rat trachéalepithelial (RTE) cells in culture were quantitated. Anchorage-independent variants of different RTE cell lines arose spontaneously by a stochastic process at rates of 0.5 x 10~4 to 5.4 x 1CT4variants/cell/generation, as determined by fluctuation analyses. These...

4-Nitroquinoline-1-oxide is a potent mutagen and carcinogen which induces two main guanine adducts at positions C8 and N2. In ds or ss damaged DNA the ratio C8/N2 adducts is 1:2 and 8-10:1, respectively. In bacteria and yeast 4NQO has been shown to be a base substitution mutagen acting at G residues inducing mainly G to A transitions. We determined the mutational spectrum induced by the 4NQO me...

Exposure to ionizing radiation (IR) is a risk factor for carcinogenesis because it is a mutagen. However, a single 4-Gy whole body X-ray exposure only induced a modest increase of mutations at the Aprt reporter gene locus in mouse T cells. Intriguingly, when the same dose of IR was given in a fractionated protocol (1 Gy x 4 at weekly intervals), there was a strong induction of Aprt mutations in...