Effect of Low Doses (5-40 cGy) of Gamma-irradiation on Lifespan and Stress-related Genes Expression Profile in Drosophila melanogaster

Abstract

Studying of the effects of low doses of γ-irradiation is a crucial issue in different areas of interest, from environmental safety and industrial monitoring to aerospace and medicine. The goal of this work is to identify changes of lifespan and expression stress-sensitive genes in Drosophila melanogaster, exposed to low doses of γ-irradiation (5 – 40 cGy) on the imaginal stage of development. Although some changes in life extensity in males were identified (the effect of hormesis after the exposure to 5, 10 and 40 cGy) as well as in females (the effect of hormesis after the exposure to 5 and 40 cGy), they were not caused by the organism “physiological” changes. This means that the observed changes in life expectancy are not related to the changes of organism physiological functions after the exposure to low doses of ionizing radiation. The identified changes in gene expression are not dose-dependent, there is not any proportionality between dose and its impact on expression. These results reflect nonlinear effects of low dose radiation and sex-specific radio-resistance of the postmitotic cell state of Drosophila melanogaster imago.

Continuous Low-Dose-Rate Irradiation Promotes Growth of Silkworms

“…These stimuli include ultraviolet radiation, magnetic and electromagnetic fields, microwaves, ultrasound, and low-dose irradiation. 16 – 23 In silkworms, shortening of the embryogenesis period by several hours was reported after chronic radiation, 100, 1000, and 4000 times exceeding the natural background radiation. 20 The group also reported an increase in the mass of larvae after a single dose of 2 Gy.…”

“…2 , 6 , 9 – 11 In various organisms including mammalians, insects, and plants, beneficial effects of low-dose irradiation have been reported. 16 – 23 Elongation of the life span of irradiated flour beetles ( Tribolium ) was reported more than 40 years ago, 16 and thereafter, the data showing biphasic responses of living organisms to irradiation (ie, beneficial effects at low doses and toxic or harmful effects at high doses) have been accumulating. However, more well-controlled laboratory studies are warranted to clarify the very important issue of the effect of low-dose radiation and to examine the adequateness of the LNT concept.…”

A comparison of the transcriptome of Drosophila melanogaster in response to entomopathogenic fungus, ionizing radiation, starvation and cold shock

“…Stress response on the molecular level is dose-specific. Dose may influence the effects of ionizing radiation [ 30 ]. Low radiation (20-75 cGy) produces minimal cluster damages and breaks of double-stranded DNA, with the main effect related to the induction of active oxygen forms [ 31 ].…”

Effect of irradiation on the survival and susceptibility of femaleAnopheles arabiensisto natural isolates ofPlasmodium falciparum

“…The precise mechanisms behind irradiation-mediated reduction of Plasmodium infection are not yet clear but interferences with mosquito immunity, microbiota and/or parasite infectivity mechanisms are likely. Although it is well-known that irradiation causes DNA damages, oxidative stress, and changes in gene expression including immune genes (Zhikrevetskaya et al ., 2015), its impact on insect host-pathogen interactions remain generally unclear (Morley, 2012). While a study found that irradiated Tephritidae flies displayed damaged midgut and peritrophic membrane resulting in decreased bacterial growth (Lauzon and Potter, 2012), irradiated Spodoptera butterflies showed increased susceptibility to a nucleopolyhedrosis virus (Sayed and El-Helaly, 2018).…”