Low-dose Gamma-irradiation Effect on Early Stage Development and Lifespan in Various Strains of Drosophila melanogaster

Lee, Jin Woo; Seong, Ki Moon; Kim, Cha Soon; Nam, Seon Young; Yang, Kwang Hee; Jin, Young Woo

Abstract

OBJECTIVES
Although ionizing radiation is recognized as being harmful to humans, debate continues regarding the effects of low doses of ionizing radiation. Some studies have reported that low doses of ionizing radiation have a bio-positive effect, namely hormesis, and many researchers have attempted to find concrete and scientific evidence to prove this. To determine whether the discrepancy in effects of low doses of ionizing radiation arises from genetic differences, a study with a multicellular organism system such as fruit flies is needed.
METHODS
After irradiation at a low-dose rate of gamma radiation with chronic (0.2 Gy) and acute (0.2, 0.75 and 4 Gy), the pupa rate, eclosion rate and life span were examined with various wild type strains of Drosophila melanogaster such as W1118, Oregon-R, and Canton-S.
RESULTS
The life span of Oregon-R exposed to both acute and chronic, low-dose radiation (0.2 Gy) was increased. Although there was some difference in the longevity between the acute and chronic radiation rate, no other differences were found. In Canton-S, only acute dose (0.75 Gy) increased the life span, but it did not in W1118.
CONCLUSIONS
Although there were some differences between wild type fruit fly strains in longevity, the low doses of ionizing radiation extended the life span of D. melanogaster. Further studies need to be carried out to explain the difference according to dose and dose rate of radiation in the tested strains.