Terrestrial gastropods (Helix spp) as sentinels of primary DNA damage for biomonitoring purposes: A validation study

Abstract

We validated the alkaline comet assay in two species of land snail (Helix aspersa and Helix vermiculata) to test their suitability as sentinels for primary DNA damage in polluted environments. The study was conducted under the framework of a biomonitoring program for a power station in Central Italy that had recently been converted from oil to coal-fired plant. After optimizing test conditions, the comet assay was used to measure the % Tail DNA induced by in vitro exposure of hemocytes to different concentrations of a reactive oxygen species (H2 O2 ). The treatment induced significant increases in this parameter with a concentration effect, indicating the effectiveness of the assay in snail hemocytes. After evaluating possible differences between the two species, we sampled them in three field sites at different distances from the power station, and in two reference sites assumed to have low or no levels of pollution. No species differences emerged. Percent Tail DNA values in snails from the sites near the power station were higher than those from control sites. An inverse correlation emerged between % Tail DNA and distance from the power station, suggesting that the primary DNA damage decreased as distance increased away from the pollution source. Detection of a gradient of heavy metal concentration in snail tissues suggests that these pollutants are a potential cause of the observed pattern. The comet assay appears to be a suitable assay and Helix spp. populations suitable sentinels to detect the genotoxic impact of pollutants.

The Comet Assay and its applications in the field of ecotoxicology: a mature tool that continues to expand its perspectives

“…Although collection requires some skill, obtaining haemocytes from bivalve adductor muscles or haemocoel (e.g., pericardial) in bivalves and gastropods is proved to be feasible and able to yield cells apt for the Comet Assay in both number and quality. Still, it has been noted, concerning terrestrial snails, that broken or detached epiphragms may cause significant dehydration of tissues, hampering collection of haemolymph (Angeletti et al, 2013 ). Altogether, it is likely that haemolymph collection needs to be properly set and tested for each target organism.…”

“…Gastropods take the place of bivalves in terrestrial environments and the use of snails (like Helix spp.) as effective sentinels for genotoxicants has been demonstrated in situ (Angeletti et al, 2013 ).…”

The transcriptome of a “sleeping” invader: de novo assembly and annotation of the transcriptome of aestivating Cornu aspersum

“…At the same time, some of its excretions are being investigated for potential medical applications [7, 8], whereas they have already been used for healing burn-wounds [8]. Additionally, it is used as an index of soil and air quality in urban and industrial areas [9–12], whereas products originating from closely related species such as Helix pomatia or Helix lucorum are used in cancer diagnostic protocols [13–17]. …”

Frog as Sentinel of Human Cancer Incidence in Southern Italy’s So-Called ‘Terra dei Fuochi’

“…2). It offers a simple way of evaluating the damage caused by a clastogenic agent by measuring breaks in the DNA chain of animal and plant cells, for example in fish [24][25], mollusks [26][27], earthworms [28][29][30] or arthropods [31][32][33].…”