Radiation biology. Radioecology
ISSN: 0869-8031

Archives → 2021 → V. 61. № 6 → pp. 607-614

Article

Survival and Genetic Instability of Yeast Cells of Various Genotypes after UV Irradiation

E. S. Evstratova¹, V. G. Korolev², V. G. Petin³, M. S. Tolkaeva³

¹National Medical Research Radiological Center of the Ministry of Health of the Russian Federation, Obninsk, Russia ²B. Konstantinov Petersburg Nuclear Physics Institute of National Research Centre “Kurchatov Institute”, Gatchina, Russia ³A. Tsyb Medical Radiological Research Center – branch of the National Medical Research Radiological Center of the Ministry of Health of the Russian Federation, Obninsk, Russia

Abstract

The study of the genetic instability patterns of cells after exposure to UV radiation is an urgent task, since this effect may precede cancer. New experimental results associated with survival and genetic instability of haploid and diploid Saccharomyces cerevisiae yeast cells of wild-type and UV sensitive mutants surviving after exposure to 254 nm UV light are presented and discussed. The dependence of cell survival on UV light fluence for haploid strain of wild-type was sigmoid and exponential for UV sensitive strains. The shape of the survival curves for diploid wild-type strains was also sigmoid, while homozygous diploid UV sensitive mutants exhi-bited both exponential and sigmoid survival curves being always more sensitive than their parental strains. Genetic instability was determined by the delayed appearance of clones by cells surviving UV exposure. This effect was shown to be well expressed and attained 100% for diploid both wild-type and mutant cells. On the contrary, haploid cells showed significantly less genetic instability (30–50%) independently of their sensiti-vity. It is concluded that genetic instability is mainly determined by cell ploidy rather than the cell ability to recover from UV radiation damage and the shape of survival curve as it is conventionally asserted for Saccharomyces cerevisiae yeast cells.

Keywords

Ultraviolet radiation, yeast cells, genetic instability, survival, haploid and diploid cells