Бияшева З.М., Тлеубергенова М.Ж., Шайзадинова А.М. Генетические эффекты радона и его дочерних продуктов распада в краткосрочных тест-системах Drоsорhilа melаnоgаster

Казахский национальный университет им. аль-Фараби; Казахстан, г. Алматы

Abstract

The high radiation background of Kazakhstan territory is due to large deposits of uranium ores and
their extraction, the accumulation of mining and uranium processing waste, the consequence of nuclear
weapons tests and other natural and man-made factors. All this leads to contamination of the environment with radionuclides as well as the radon release and accumulation, formed during the decay of
radioactive elements. Radon radionuclides compose more than half of the entire radiation dose which
on average the human body receives from natural and technogenic radionuclides of the environment.
It is proved that radon is the second most frequent cause of lung cancer. This is due to the release of
large positively charged particles – α-particles – during its decay. Therefore, the aim of this work was to
evaluate radon genetic effects in a short-term test-system with attached X chromosomes and attached
X-Y chromosomes of Drosophila melanogaster. Short-term test-systems on Drosophila melanogaster flies
allow determining the mutagenic and carcinogenic effects of environmental components and «trying
on» or transfer the results to human’s organism. The advantage of Drosophila melanogaster flies as a
test object is a well-studied genetics, minimum restrictions on laboratory use, relative cheapness, and
the absence of complex manipulations in content. To determine the genotoxic effects of radon, we used
females EP-2 with attached X-chromosomes and X-Y chromosomes and irradiated wild-type Oregon
males. The isotopes of plutonium and uranium were used as sources of α-radiation. Line EP-2 contains
chromosomal rearrangements with the gene position effect. The emergence of conditional mutations is a
consequence of gene position effect, they arise when the structure of regulatory genes responsible for the
developmental alternate path and the formation of intraspecific features of the organism are disturbed.
Their manifestation at the level of the organism (entirely or in part) depends on the structure of other
regions of the genome. One of the conditional mutation bright properties is morphoses formation – noninherited morphological disorders that are formed when the stressful environmental factors influence the
organism. As a result of flies analysis in first generation the following morphoses were identified: black
spots or melanoma on the abdomen, thorax, wings; twisted, curved, undirected wings or their absence;
disturbance of wings venation, deformation of the head, eye, thorax;; the formation of blisters on the
wings and on the abdomen, etc. All the disturbances had an asymmetric manifestation and looked like
ugliness. The observed morphological changes and the results of statistical analysis indicate the genotoxic activity of α-radiation, the source of which in nature is often radon and its daughter decay products
(DDP).
Key words: morphoses, radon, α-radiation, Drosophila, genotoxicity