Copplestone David, Coates Christopher J, Lim Jenson
Biological and Environmental Sciences, Faculty of Natural Sciences, University of Stirling, Stirling FK9 4LA, Scotland, UK.
Department of Biosciences, Faculty of Science and Engineering, Swansea University, Swansea SA2 8PP, Wales, UK; Zoology, Ryan Institute, School of Natural Sciences, University of Galway, Galway H91 TK33, Ireland.
Sci Total Environ. 2023 Jun 10;876:162742. doi: 10.1016/j.scitotenv.2023.162742. Epub 2023 Mar 10.
Larvae of the greater wax moth Galleria mellonella are common pests of beehives and commercial apiaries, and in more applied settings, these insects act as alternative in vivo bioassays to rodents for studying microbial virulence, antibiotic development, and toxicology. In the current study, our aim was to assess the putative adverse effects of background gamma radiation levels on G. mellonella. To achieve this, we exposed larvae to low (0.014 mGy/h), medium (0.056 mGy/h), and high (1.33 mGy/h) doses of caesium-137 and measured larval pupation events, weight, faecal discharge, susceptibility to bacterial and fungal challenges, immune cell counts, activity, and viability (i.e., haemocyte encapsulation) and melanisation levels. The effects of low and medium levels of radiation were distinguishable from the highest dose rates used - the latter insects weighed the least and pupated earlier. In general, radiation exposure modulated cellular and humoral immunity over time, with larvae showing heightened encapsulation/melanisation levels at the higher dose rates but were more susceptible to bacterial (Photorhabdus luminescens) infection. There were few signs of radiation impacts after 7 days exposure, whereas marked changes were recorded between 14 and 28 days. Our data suggest that G. mellonella demonstrates plasticity at the whole organism and cellular levels when irradiated and offers insight into how such animals may cope in radiologically contaminated environments (e.g. Chornobyl Exclusion Zone).
大蜡螟幼虫是蜂箱和商业养蜂场的常见害虫，在更多实际应用场景中，这些昆虫可作为啮齿动物的替代体内生物测定模型，用于研究微生物毒力、抗生素研发和毒理学。在本研究中，我们旨在评估背景伽马辐射水平对大蜡螟的假定不利影响。为此，我们将幼虫暴露于低剂量（0.014 毫戈瑞/小时）、中等剂量（0.056 毫戈瑞/小时）和高剂量（1.33 毫戈瑞/小时）的铯-137 环境中，并测量幼虫的化蛹情况、体重、粪便排出量、对细菌和真菌攻击的易感性、免疫细胞计数、活性和活力（即血细胞包囊化）以及黑化水平。低剂量和中等剂量辐射的影响与所使用的最高剂量率的影响可区分开来——后者的昆虫体重最轻且化蛹更早。总体而言，随着时间推移，辐射暴露调节了细胞免疫和体液免疫，幼虫在较高剂量率下表现出更高的包囊化/黑化水平，但对细菌（发光杆菌）感染更易感。暴露 7 天后几乎没有辐射影响的迹象，而在 14 至 28 天之间记录到了明显变化。我们的数据表明，大蜡螟在受到辐射时在整个生物体和细胞水平上表现出可塑性，并为这类动物在放射性污染环境（如切尔诺贝利禁区）中的应对方式提供了见解。
