Life span alteration after irradiation in Drosophila Melanogaster strains with mutations of HSF and HSPS

Institute of biology of Komi Science Center of RAS, Kommunisticheskaja St. 28, 167982 Syktyvkar, Russian Federation

Abstract

The life span alteration after low doze gamma-irradiation in Drosophila wild type strain Canton-S and strains with mutations of heat shock factor (1-4alleles) and heat shock proteins (Hsp70Ba³⁰⁴, Hsp83^e6A, Hsp22^EY09909) was investigated. Chronic gamma-irradiation (0.017 and 0.17 cGy/h) on pre-imago stages was used as a priming dose (absorbed doses were 6 and 60 cGy). Paraquat, a free radical inducing agent, was a challenging factor (20 mM for one day). It was shown that chronic irradiation led to adaptive response in all samples except homozygous males and females with mutations of Hsf⁴ and Hsp70Ba³⁰⁴. The adaptive response persisted in Hsp22 homozygous males, but not in females. Drosophila Hsp and Hsf mutation homozygotes did not demonstrate the adaptive response in the majority of cases, implying an important role of those genes in radioation hormesis.