[Caffeine modification of the frequency of ethyleneimine- and ethylmethane sulfonate-induced somatic mutations and mitotic crossing over in Drosophila melanogaster].

Frequencies of somatic mosaics in heterozygous females (w+/w; sn+/sn; y sn/++; t+/+sn) and in hemizygous wild type males was estimated after supplementary action of caffeine on early larvae treated with ethylene imine (EI) or ethylmethanesulfonate (EMS). Frequencies of somatic point mutations induced by both EI and EMS, which have been revealed as single spots (w or sn) in hemizygous males, decrease after supplementary effect of caffeine. Frequencies of somatic mosaics decrease also under the caffeine effect on heterozygous females (w+/w) treated by comparatively low doses of EMS which can induce more probably point mutations than chromosome breaks. Caffeine increases the frequency of somatic mosaics at high doses of EMS, which can produce not only point mutations, but also chromosome breaks. Supplementary effect of caffeine on all genotypes of heterozygous females significantly increases the frequencies of EI induced somatic mosaics (mitotic recombinations and chromosome aberrations).