Genotoxicity Assessment of Bottom Sediments of the Chumysh River Using the Allium-Test

Abstract

Abstract We performed a bioassay of aqueous extracts from the bottom sediments of the Chumysh River near the settlement of Talmenka (the Altai Territory of Russia) using the Allium test. The presence of toxic components that caused a decrease in the mitotic activity of onion root meristem cells was revealed. The frequency of pathological mitoses, significantly exceeding the background value (on average, 16.3 times), indicates the presence of factors with total mutagenic activity in the samples. We found violations of chromosome divergences (emissions beyond the spindle, lagging, running off and premature chromosome divergence), abnormalities of the mitotic apparatus (multipolar, asymmetric, monocentric mitosis, polyploidy), bridges (single and multiple). The prevalence of spindle pathologies suggests chemical contamination of the bottom sediments. Stress factors present in bottom sediments activate adaptive mechanisms of the test-object cells, aimed at maintaining their viability and reliability of the transmission of genetic information to the next cellular generations. Such adaptation mechanisms include the formation of micronuclei and cell polyploidization.