ABSTRACT
Verification of hypothesis about mobile element activation radiosensitivity change in the conditions of the prolonged irradiation was the research goal. The estimation of orientation of these changes depending on the accumulated dose and their characteristic times were conducted. Two Drosophila melanogaster strains (Canton-S and P-lines) for 20 generations were in the controlled terms of chronic irradiation with 3-dose rate (1.2 x 10(-8), 0.6 x 10(-8) and 0.12 x 10(-8) Gy/c). The dynamics of hybrid dysgenese frequency was explored for each generation of F1 descendants from Canton-S and P-lines crossing. The gradual change of dose response of hybrid disgenesis depending on duration of irradiation of ancestors and dose rate was shown. The complex dynamics of hybrid dysgenese frequency depending on irradiation duration of ancestors and dose rate was shown. The cumulative effect of the prolonged irradiation shows up as adaptation at the lowest dose rate and as exhaustion at the highest dose rate. Question comes into discussion about the features of transitional process and including of protective and adaptive reactions hierarchy at the conditions of radiation factor chronic action.
Subject(s)
DNA Transposable Elements/radiation effects , Drosophila melanogaster/radiation effects , Gamma Rays , Genome, Insect/radiation effects , Adaptation, Physiological/genetics , Animals , Chimera/genetics , DNA Transposable Elements/genetics , Dose-Response Relationship, Radiation , Drosophila melanogaster/genetics , Female , Gene Frequency , MaleABSTRACT
Historically, the term "intercalary heterochromatin" was based on the finding that induced chromosome rearrangements occur at a higher frequency in the corresponding regions. The available molecular genetic data and, in particular, the results of the Drosophila Genome Project made it possible to decide between two possible explanations of the preferential location of chromosome rearrangement breakpoints in intercalary heterochromatin regions. Namely, a higher frequency of radiation-induced rearrangements in these regions correlates with the DNA content and probably lacks an association with the features of chromatin organization.
Subject(s)
Chromosomes/genetics , Gene Rearrangement/genetics , Genome, Insect/genetics , Heterochromatin/genetics , Animals , Drosophila melanogaster , Gene Rearrangement/radiation effects , Genome, Insect/radiation effectsABSTRACT
This article generalizes the results received by authors in researches of genetic effects of an irradiation for Drosophila. It is supposed, that the main effect of low intensity irradiation is connected with the induced genetic instability on which background the realization of effects of a different direction is possible.
