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Biogerontology (2009) 10:311 DOI 10.1007/s10522-008-9147-5
RESEARCH ARTICLE
Life span alteration after irradiation in Drosophila melanogaster strains with mutations of Hsf and Hsps
A. Moskalev M. Shaposhnikov E. Turysheva
Received: 2 March 2008 / Accepted: 6 May 2008 / Published online: 13 June 2008 Springer Science+Business Media B.V. 2008
Abstract The life span alteration after c-irradiation and/or paraquat treatment in Drosophila in wild type strain Canton-S and strains with mutations of heat shock factor (14 alleles) and heat shock proteins (Hsp70Ba304,
Hsp83e6A, Hsp22EY09909, Hsp67BbEY099099) was investi
gated. Chronic low-dose rate c-irradiation (0.017 and0.17 cGy/h) on pre-imago stages was used as a priming dose (absorbed doses were 4 and 40 cGy). Paraquat, a free radical inducing agent, was a challenging factor (20 mM for 1 day). It was shown that chronic irradiation led to adaptive response in both sexes except homozygous males and females with mutations of Hsf4 and Hsp70Ba304. The gender-specic differences in stress response were discovered in wild type strain Canton-S, Hsp22EY09909Hsp67BbEY09909 homozygotes and Hsp83e6A
heterozygotes: the adaptive response persisted in males, but not in females. Thus, 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 radiation hormesis and adaptation to stresses.
Keywords Adaptive response Drosophila
Heat shock proteins Life span Low doses
Introduction
Practically all living organisms (from bacteria to mammals) are able to quickly respond and adapt to various external stresses. The phenomenon when a cell or an organism, after it had been exposed to low doses of stressors, exhibits increased tolerance to a damaging action is referred to as hormesis. This effect is induced by various damages including alkylating agents, heat and oxidative stress, ionizing radiation, heavy metals, hypergravity (Crawford and Davies 1994; Le Bourg et al. 2002; Le Bourg 2007; Sorensen et al. 2007). The main biological sense of such adaptive response is to protect the cells and organisms from high doses of dangerous factors (ionizing radiation, mutagens, and extreme temperature).
When studying chromosome aberrations of human lymphocytes after irradiation Wolf et al. discovered the phenomenon of radioadaptive response (Olivieri et al. 1984). Later on, the existence of adaptive response was conrmed in in vitro and in vivo experiments with the use of different endpoints,...