Evolutionary Toxicology as a Tool to Assess the Ecotoxicological Risk in Freshwater Ecosystems

Marianna Rusconi,Fabrizio Stefani,Roberta Bettinetti,Stefano Polesello

doi:10.3390/w10040490

Marianna Rusconi, Fabrizio Stefani + Show 2 more

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https://doi.org/10.3390/w10040490

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Abstract

Borrowing the approaches of population genetics, evolutionary toxicology was particularly useful in assessing the transgenerational effects of a substance at sublethal concentrations, as well as evaluating genetic variation in populations exposed to pollutants. Starting from assays in controlled conditions, in recent years this approach has also found successful applications multi-stressed natural systems. It is also able to exploit the huge amount of data provided by Next Generation Sequencing (NGS) techniques. Similarly, the focus has shifted from effects on the overall genetic variability, the so-called “genetic erosion”, to selective effects induced by contaminants at more specific pathways. In the aquatic context, effects are usually assessed on non-model species, preferably native fish or macroinvertebrates. Here we provide a review of current trends in this specific discipline, with a focus on population genetics and genomics approaches. In addition, we demonstrate the potential usefulness of predictive simulation and Bayesian techniques. A focused collection of field and laboratory studies is discussed to demonstrate the effectiveness of this approach, covering a range of molecular markers, different endpoints of genetic variation, and different classes of chemical contaminants. Moreover, guidelines for a future implementation of evolutionary perspective into Ecological Risk Assessment are provided.

Highlights

In recent years, many genetic approaches have been adopted to investigate the effects of contaminants on gene transcription and evolutionary change
The term borrows from the approach of population genetics and aims to identify causal links between toxicant pressures and changes in genetic variability at the population level [9] by applying the approaches and indicators that have proven to be informative in sister disciplines, such as conservation genetics [10,11]
This study demonstrated two of the four cornerstones of evolutionary toxicology [7] in a single case: genetic erosion due to the synergistic effect of habitat fragmentation and contaminant exposure, and an increased mutation rate mirrored in the high frequency of private alleles

Summary

Introduction

Many genetic approaches have been adopted to investigate the effects of contaminants on gene transcription and evolutionary change Among these approaches, gene expression (either surveying a set of traditional candidate genes or undertaking a genome-wide analysis) has been widely applied [1], whereas the potential of quantitative genetics and population genetics have only been partially explored [2,3]. Gene expression (either surveying a set of traditional candidate genes or undertaking a genome-wide analysis) has been widely applied [1], whereas the potential of quantitative genetics and population genetics have only been partially explored [2,3] In this context, evolutionary toxicology, despite being described more than 20 years ago [4], has only recently been proposed for ecotoxicological assessment [5,6,7,8].

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