Ecogenotoxicology in earthworms: A review

Abstract

Pollutant dynamics and bioavailability greatly differ in soil and aquatic systems. Therefore, specific approaches and models are needed to assess the impact of soil contamination to terrestrial ecosystems. Earthworms among other soil invertebrates have received more attention because of their ecological importance. They represent a dominant part of the soil biomass and are soil engineers regulating important soil processes, notably fertilization. The release in soils of pollutants known for their persistence and/or their toxicity is a concern. Exposure of terrestrial species to pollutants that may alter genomic function has become an increasing topic of research in the last decade. Indeed, genome disturbances due to genetic and epigenetic mechanisms may impair growth, as well as reproduction and population dynamics in the long term. Despite their importance in gene expression, epigenetic mechanisms are not yet understood in soil invertebrates. Until now, pollutant-induced changes in genome expression in natural biota are still being studied through structural alteration of DNA. The first biomarker relating to genotoxicant exposure in earthworms from multi-contaminated soils reported is DNA adducts measurements. It has been replaced by DNA breakage measured by the Comet assay, now more commonly used. Functional genomic changes are now being explored owing to molecular “omic” technologies. Approaches, objectives and results are overviewed herein. The focus is on studies dealing with genotoxicity and populational effects established from environmentally-relevant experiments and in situ studies.

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

“…Soils are complex associations with high binding capacity to both inorganic and organic molecules, which may, as well as certain modifications along time (e.g., aging and weathering), modulate the biological effects of contamination. For these reasons, toxicity to terrestrial species cannot be directly extrapolated from aquatic species, meaning that specific approaches and models are needed to assess the impact of soil pollutants on terrestrial biota (Vasseur and Bonnard, 2014 ).…”

“…The application of Comet Assay to earthworms, and consequently the use of such extraordinary prospectors as sentinels for the presence of genotoxicants in soil, started in the nineties of the last century (Singh et al, 1988 ; Verschaeve and Gilles, 1995 ; Salagovic et al, 1996 ), and since then has been extensively revised (Cotelle and Férard, 1999 ; Espinosa-Reyes et al, 2010 ; Liu et al, 2010 ; Atli Şekeroglu et al, 2011 ; Lionetto et al, 2012 ; Andem et al, 2013 ; Vernile et al, 2013 ; Fujita et al, 2014 ; Vasseur and Bonnard, 2014 ; Zhang et al, 2014 ). Several earthworms comparative studies have been performed (Vasseur and Bonnard, 2014 ). Eisenia fetida and Aporrectodea caliginosa showed an equivalent sensitivity, as assessed by Comet Assay (Klobučar et al, 2011 ).…”

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].…”

Polycyclic aromatic hydrocarbons bioavailability in industrial and agricultural soils: Linking SPME and Tenax extraction with bioassays

“…Pollutant dynamics and bioavailability greatly differ between soil and sediments (Vasseur & Bonnard 2014), and there are very few studies to date that have focused on testing SPME and Tenax-TA extraction methods in a comparative manner to assess bioavailability in historically PAH-contaminated soils, especially not in agricultural soils (Cachada et al 2014).…”