Biological effects of low-dose γ-ray irradiation on chromosomes and DNA of Drosophila melanogaster

Abstract

While the damage to chromosomes and genes induced by high-dose radiation (HDR) has been well researched in many organisms, the effects of low-dose radiation (LDR), defined as a radiation dose of ≤100 mSv, are still being debated. Recent research has suggested that the biological effects of LDR differ from those observed in HDR. To detect the effect of LDR on genes, we selected a gene of Drosophila melanogaster, known as the multiple wing hair (mwh) gene. The hatched heterozygous larvae with genotype mwh/+ were irradiated by γ-rays of a 60Co source. After eclosion, the wing hairs of the heterozygous flies were observed. The area of only one or two mwh cells (small spot) and that of more than three mwh cells (large spot) were counted. The ratio of the two kinds of spots were compared between groups irradiated by different doses including a non-irradiated control group. For the small spot in females, the eruption frequency increased in the groups irradiated with 20–75 mGy, indicating hypersensitivity (HRS) to LDR, while in the groups irradiated with 200 and 300 mGy, the frequency decreased, indicating induced radioresistance (IRR), while in males, 50 and 100 mGy conferred HRS and 75 and 200 mGy conferred IRR. For the large spot in females, 75 mGy conferred HRS and 100–800 mGy conferred IRR. In conclusion, HRS and IRR to LDR was found in Drosophila wing cells by delimiting the dose of γ-rays finely, except in the male large spot.

Ionizing radiation alters functional neurotransmission in Drosophila larvae

“…Several studies showed that many important neurotoxic consequences of radiation exposure in mammals could be reasonably mimicked in Drosophila ( Pandey and Nichols, 2011 ). Ionizing radiation induces DNA damage and neuron death in Drosophila ( Kim et al, 2015 ; Sudmeier et al, 2015 ; Tanaka and Furuta, 2021 ). Ionizing radiation during the larval stage reduced brain size, delayed development, and reduced survival to adulthood ( Paithankar et al, 2017 ; Wagle and Song, 2020 ).…”

Correlation between Irradiation Treatment and Metabolite Changes in Bactrocera dorsalis (Diptera: Tephritidae) Larvae Using Solid-Phase Microextraction (SPME) Coupled with Gas Chromatography-Mass Spectrometry (GC-MS)

“…Various approaches were developed with the aim of determining radiation dosage in insects, but they largely remain at the experimental concept stage [ 12 ]. One approach is to observe the increase in abundance of insect gut bacteria, another assesses the damage to genes and chromosomes, and another records changes to the structure of sperm and mitochondria [ 13 , 14 , 15 , 16 , 17 ]. Problems with such approaches are large individual differences in histomorphology; therefore, the sensitivity and application of these approaches on a high-throughput level is problematic.…”

Low Dose and Non-Targeted Radiation Effects in Environmental Protection and Medicine—A New Model Focusing on Electromagnetic Signaling

“…These ideas are fiercely unpopular among those who wish to promote a threshold model of radiation protection because any possibility that radiation might cause any adverse low dose effects, means that a precautionary approach is likely to be retained when setting dose limits [ 21 , 22 , 23 , 24 ]. The reality is that low dose hypersensitivity exists [ 25 , 26 , 27 , 28 ] and non-targeted effects (discussed in the next section), can result in both “good” and “bad” effects [ 2 , 29 , 30 , 31 , 32 ]. The debate should not really be centered on whether low doses of radiation are good or bad but should be concerned with how systems deal with low doses of stressors and whether improved modelling or approaches such as adverse outcome pathway (AOP) analysis can improve our ability to understand and thus predict individual responses.…”