Особенности конъюгации политенных хромосом в потомстве Drosophila melanogaster Meig. после острого γ-облучения
Aim. The purpose of investigation was to study the peculiarities of homologous conjugation of polytene chromosomes in the salivary glands of larvae in Drosophila melanogaster offspring after exposure to acute γ-irradiation. Methods. Experiments were carried out on wild type Oregon-R strain. Three-day-old flies were irradiated by brake gamma rays on the linear electron accelerator LEA-10. The dose rate was 0.4 Gr/sec.The effects of acute γ-radiation at doses of 8 Gr and 16 Gr were studied. Giant chromosomes were investigated in squashed preparations of the salivary glands stained by acetoorcein. Preparations were obtained from the females at the end of third larva stage. Results. The decrease at 41.5 % in asynapsis frequency of homologous chromosomes in salivary gland cells of larvae in Drosophila F1 progeny after γ-irradiation at the dose of 8 Gr was shown. No effect was observed at the dose of 16 Gr. Analysis of variance showed with a high degree of significance (Fφ = 53, p < 0,001) the influence of gradations of factor on the frequency of violations of conjugation of homologous in Drosophila polytene chromosomes. Conclusions. The results suggest a possible effect of gamma-radiation on the trans-interaction of loci of homologous chromosomes due to the changes in the asynapsis frequency.
Keywords: giant chromosomes, spontaneous asynapsis, trans-interactions, ionizing radiation.