pyrethroid resistance and suggest using resistance in the model invertebrate H.
azteca to further our understanding of evolutionary toxicology in wild populations.
Keywords Adaptation, Evolutionary toxicology, Hyalella azteca, Mosquito,
Pyrethroid resistance
Definitions
Adaptation: Any heritable, genetically based tolerance mechanism. Adaptation
occurs at the level of the population.
Chemotherapeutant: Chemical agents or drugs that are selectively toxic to the
causative agent of a disease or infection.
Cytochrome P450: Genes that code for enzymes that are involved in the formation
(synthesis) and breakdown (metabolism) of various molecules and chemicals within
cells.
DNA Methylation: The addition of a methyl group to DNA, sometimes resulting in
the alteration of gene expression.
EC 50 : The concentration that produces the designated effect in 50% of the population over a given period. Here, it is used primarily to describe an effect of immobilization on the organism of interest (moribund + dead) as a response to pyrethroid
toxicity unless otherwise noted.
ET 50 : Median effective time, e.g., the time required until impaired swimming and/or
attachment behavior becomes apparent in 50% of the population.
Epigenetics: The study of mechanisms that facilitate phenotypic variation through
genotype-environment interactions.
Epimutation: Epigenetic alterations that are specific and heritable.
Evolutionary Toxicology: The study of the effects of pollution on the genetics of
wild populations.
Fitness: A measurement of the ability of an organism to survive, grow, and
reproduce in its environment.
KDT 50 : The time it takes to a produce a knockdown phenotype in 50% of the
population.
“Knockdown” Phenotype: Paralysis caused from acute pyrethroid exposure in
sensitive animals.
Kdr: A knockdown resistance mutation, attributed to a change in the target site that
reduces pyrethroid binding affinity, thereby conferring resistance to the typical
mechanism of action for pyrethroids.
LC 50 : The concentration that produces mortality in 50% of the population over a
given period.
Log K ow : The logarithm of the octanol-water partition coefficient; the higher the
Log K ow , the greater the potential of a chemical to partition into sediment, soil, and
organic matter.
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K. M. Major and S. M. Brander
azteca to further our understanding of evolutionary toxicology in wild populations.
Keywords Adaptation, Evolutionary toxicology, Hyalella azteca, Mosquito,
Pyrethroid resistance
Definitions
Adaptation: Any heritable, genetically based tolerance mechanism. Adaptation
occurs at the level of the population.
Chemotherapeutant: Chemical agents or drugs that are selectively toxic to the
causative agent of a disease or infection.
Cytochrome P450: Genes that code for enzymes that are involved in the formation
(synthesis) and breakdown (metabolism) of various molecules and chemicals within
cells.
DNA Methylation: The addition of a methyl group to DNA, sometimes resulting in
the alteration of gene expression.
EC 50 : The concentration that produces the designated effect in 50% of the population over a given period. Here, it is used primarily to describe an effect of immobilization on the organism of interest (moribund + dead) as a response to pyrethroid
toxicity unless otherwise noted.
ET 50 : Median effective time, e.g., the time required until impaired swimming and/or
attachment behavior becomes apparent in 50% of the population.
Epigenetics: The study of mechanisms that facilitate phenotypic variation through
genotype-environment interactions.
Epimutation: Epigenetic alterations that are specific and heritable.
Evolutionary Toxicology: The study of the effects of pollution on the genetics of
wild populations.
Fitness: A measurement of the ability of an organism to survive, grow, and
reproduce in its environment.
KDT 50 : The time it takes to a produce a knockdown phenotype in 50% of the
population.
“Knockdown” Phenotype: Paralysis caused from acute pyrethroid exposure in
sensitive animals.
Kdr: A knockdown resistance mutation, attributed to a change in the target site that
reduces pyrethroid binding affinity, thereby conferring resistance to the typical
mechanism of action for pyrethroids.
LC 50 : The concentration that produces mortality in 50% of the population over a
given period.
Log K ow : The logarithm of the octanol-water partition coefficient; the higher the
Log K ow , the greater the potential of a chemical to partition into sediment, soil, and
organic matter.
110
K. M. Major and S. M. Brander