Genetic and Molecular Ecotoxicology: A Research Framework

Abstract

Participants at the Napa Conference on Genetic and Molecular Ecotoxicology assessed the status of this field in light of heightened concerns about the genetic effects of exposure to hazardous substances and recent advancements in our capabilities to measure those effects. We present here a synthesis of the ideas discussed throughout the conference, including definitions of important concepts in the field and critical research needs and opportunities. While there were many opinions expressed on these topics, there was general agreement that there are substantive new opportunities to improve the impact of genetic and molecular ecotoxicology on prediction of sublethal effects of exposure to hazardous substances. Future studies should emphasize integration of genetic ecotoxicology, ecological genetics, and molecular biology and should be directed toward improving our understanding of the ecological implications of genotoxic responses. Ecological implications may be assessed at either the population or ecosystem level; however, a population-level focus may be most pragmatic. Recent technical advancements in measuring genetic and molecular responses to toxicant exposure will spur rapid progress. These new techniques have considerable promise for increasing our understanding of both mechanisms of toxicity on genes or gene products and the relevance of detrimental effects to individual fitness. -Environ Health Perspect 102 (Suppl 12):3-8 (1994)

Monitoring adaptive genetic responses to environmental change

“…Climate change induced by increased greenhouse gas emissions has emerged as a top concern, both scientifically and politically (Kerr 2007;Moss et al 2010), with increasing evidence that it has already affected populations of many plant and animal species (Parmesan 2006). Organisms also confront other environmental challenges like pollution (Anderson et al 1994), emerging pathogens (Parker & Gilbert 2004), and newly introduced species that alter patterns of predation or competition (Mack et al 2000). Finally, the intensified harvesting of wild populations via fishing and hunting radically alters population demographics and selection regimes (Allendorf et al 2008;Coltman 2008).…”

The midgut epithelium of aquatic arthropods: a critical target organ in environmental toxicology.

“…aegypti AEIMUC1 and C. tentans CTTUB1 are excellent examples of MRGs of aquatic arthropods that can be readily identified using molecular biological techniques. The importance and need of more sensitive and quantifiable biological markers in ecotoxicological testing has been stressed previously (2,12,13). Identification and characterization of more MRGs in the arthropod midgut may lead to additional, sensitive, molecular-based, in vitro approaches for environmental bioreporting (14).…”

“…Unfortunately, the use of such a selectively neutral gene provided no insight into the molecular mechanisms that conditioned arthropod survivorship. Delineating potential metal-responsive genes (MRGs) or other genes that impact gene flow and condition the population genetic structure of aquatic arthropods could provide a mechanistic understanding of fundamental responses to ecotoxicological insults and could be exploited to develop new molecular bioreporter systems (2,5,(12)(13)(14)(15)(16). RNA or protein products of a given MRG could be exploited as specific biomarkers of the presence or absence of heavy metals (2,5,(12)(13)(14)(15)(16).…”

Analysis of Genetic Similarity of Limnocharis Flava Individuals Growing Around a Gold Mining Area With Arsenic Contamination

“…Several plants, such as Allium cepa, Hordeum vulgare, Arabidopsis thaliana, Glycine max, Vicia faba and Zea mays, have been used as strong bioindicators of the genetic toxicity of environmental pollutants in recent years. Research on the effects of contaminant exposure on biological systems has historically focused on mechanisms o f damage, and researchers have primarily studied test organisms exposed in laboratory settings (Anderson et al, 1994;Shugart and Theodorakis, 1994). Belfiore and Anderson (2001) have presented a summary of contemporary genetic assessment methods and a review of published studies of genetic effects in field-exposed aquatic organisms.…”