Evolutionary Toxicology and Transcriptomic Approaches - Ecological Biomarkers: Indicators of Ecotoxicological Effects - page 361

14
Evolutionary Toxicology and
Transcript omic Approaches
Justine Marchand, Françoise Denis, and Jean Laroche
CONTENTS
14.1 Introduction ........................................................................................................................ 361
14.2 Major Evolutionary Forces That Change Genetic Variability ..................................... 362
14.2.1 Mutation .................................................................................................................. 362
14.2.2 Genetic Drift ........................................................................................................... 363
14.2.3 Migration ................................................................................................................. 363
14.2.4 Selection .................................................................................................................. 364
14.3 Common Markers of Genetic Diversity in Ecotoxicology ........................................... 364
14.4 Links between Chemical Stress, Genetic Diversity, and Phenotypic Responses ........ 366
14.4.1 Chemical Contamination and Impact on Genetic Diversity ........................... 366
14.4.1.1 Direct Interactions between Pollutants and DNA
through Mutations .................................................................................. 366
14.4.1.2 Indirect Effects ........................................................................................ 367
14.4.2 Transmission of Resistance to Contaminants .................................................... 371
14.4.3 Cost of Resistance to Toxicants ............................................................................ 372
14.5 Toxicant-Altered Gene Expression .................................................................................. 373
14.5.1 A Priori Approach .................................................................................................. 374
14.5.2 “Global” Approach (Open System) ..................................................................... 374
14.5.3 Combining the Two Approaches ......................................................................... 376
14.5.4 New Insights Exploring Gene Regulation and Genomics ............................... 376
14.6 Conclusions ......................................................................................................................... 376
Acknowledgment ........................................................................................................................ 377
References ..................................................................................................................................... 377
14.1 Introduction
Biomarkers can reflect the actual state of health of organisms or populations, but do not
provide information on the potential of a population to survive in a polluted environment.
Genetic approaches can, however, produce relevant knowledge in an ecotoxicology study.
Indeed, the genetic variation in populations results from their evolutionary histories and
represents the raw material that has, or has not, enabled the evolutionary adaptation of
these populations faced with environmental challenges (global change, hypoxia, emerg-
ing contaminants, multistress, etc.).
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