Fruit Flies Provide New Insights in Low-Radiation Background Biology at the INFN Underground Gran Sasso National Laboratory (LNGS)

Abstract

Deep underground laboratories (DULs) were originally created to host particle, astroparticle or nuclear physics experiments requiring a low-background environment with vastly reduced levels of cosmic-ray particle interference. More recently, the range of science projects requiring an underground experiment site has greatly expanded, thus leading to the recognition of DULs as truly multidisciplinary science sites that host important studies in several fields, including geology, geophysics, climate and environmental sciences, technology/instrumentation development and biology. So far, underground biology experiments are ongoing or planned in a few of the currently operating DULs. Among these DULs is the Gran Sasso National Laboratory (LNGS), where the majority of radiobiological data have been collected. Here we provide a summary of the current scenario of DULs around the world, as well as the specific features of the LNGS and a summary of the results we obtained so far, together with other findings collected in different underground laboratories. In particular, we focus on the recent results from our studies of Drosophila melanogaster, which provide the first evidence of the influence of the radiation environment on life span, fertility and response to genotoxic stress at the organism level. Given the increasing interest in this field and the establishment of new projects, it is possible that in the near future more DULs will serve as sites of radiobiology experiments, thus providing further relevant biological information at extremely low-dose-rate radiation. Underground experiments can be nicely complemented with above-ground studies at increasing dose rate. A systematic study performed in different exposure scenarios provides a potential opportunity to address important radiation protection questions, such as the dose/dose-rate relationship for cancer and non-cancer risk, the possible existence of dose/dose-rate threshold(s) for different biological systems and/or end points and the possible role of radiation quality in triggering the biological response.

The Phenotypic and Transcriptomic Response of the Caenorhabditis elegans Nematode to Background and Below-Background Radiation Levels

“…This point was initially and reasonably brought up by Washington University's Jonathan Katz ( 62 ), and, in our response to his critique in which we agreed with his calculations, we posited the idea that biological “sensors” rival our most sensitive radiation detection instruments [Castillo and Smith response to Professor Katz, Castillo et al ( 63 )]. And, in agreement with the Morciano et al ( 20 ) work with Drosophila underground at Italy's Gran Sasso lab, we provide further evidence that multicellular organisms are also capable of responding to these vanishingly low differences in radiation fields. These results and those coming from other deep underground laboratories provide impetus to document the mechanisms in single-celled prokaryotes and multi-celled eukaryotes of the response to these minute differences in ionizing radiation and to identify the organismal response apparatus.…”

“…Castillo et al ( 17 – 19 ) have documented a stress response in two bacterial species within 48 h of being brought underground and grown in the absence of normal radiation levels. Morciano et al ( 20 ) were the first group to document these effects in a multi-cellular organism ( Drosophila) , with reduced radiation causing a 30% reduction in fertility in males and females, while also causing an increase in life span.…”

Oxidative Stress From Exposure to the Underground Space Environment

“…Due to the shielding effect of overburden, the underground space environment, especially the deep underground, exists in a state of low background radiation (79). In the past few decades, several deep underground laboratories have focused on the influence of low background radiation on living organisms (76,78,(80)(81)(82)(83)(84)(85)(86)(87)(88). Among these, most have observed oxidative stress in living organisms exposed to low background radiation.…”

Underground Radiobiology: A Perspective at Gran Sasso National Laboratory

“…More recently, the PULEX-COSMIC SILENCE experiments get more insight into the role of environmental radiation in the biological response of different in vitro mammalian cellular systems of rodent (7-9) and human origin (10,11). In 2018, we obtained the first evidence of the influence of environmental radiation on the response of a complex organism, namely Drosophila melanogaster (12,13).…”