Heritable oxidative phosphorylation differences in a pollutant resistant Fundulus heteroclitus population

Area of Science:

• Environmental toxicology
• Evolutionary biology
• Metabolic biochemistry

Background:

• Anthropogenic pollution can drive adaptive evolution in wild populations.
• Killifish (Fundulus heteroclitus) from the Elizabeth River, VA, exhibit resistance to certain contaminants.
• Previous studies indicated differences in hepatocyte oxidative phosphorylation (OxPhos) metabolism between polluted and reference killifish populations.

Purpose of the Study:

• To determine if enhanced OxPhos metabolism and toxicity resistance in Elizabeth River killifish are heritable.
• To compare OxPhos metabolism in laboratory-reared generations with field-caught fish.
• To investigate the genetic basis of adaptation to pollution.

Main Methods:

• Measuring OxPhos metabolism in laboratory-reared F3 generation Elizabeth River killifish and F1 generation King's Creek killifish.
• Comparing metabolic data with previous findings from field-caught fish.
• Assessing the impact of acute benzo[a]pyrene exposure on OxPhos function in laboratory-reared fish.

Main Results:

• Laboratory-reared F3 Elizabeth River fish exhibited significantly higher State 3 respiration and complex II activity, and lower complex I activity compared to F1 King's Creek fish.
• Higher routine metabolism was consistently observed in Elizabeth River fish (both field-caught and lab-reared).
• Acute benzo[a]pyrene exposure did not alter OxPhos function in lab-reared F3 Elizabeth River fish, mirroring field-caught results.

Conclusions:

• The enhanced OxPhos metabolism and toxicity resistance observed in the Elizabeth River killifish population are heritable traits.
• Genetic changes in physiological homeostasis contribute to enhanced routine metabolism and pollution resistance.
• Environmental factors interact with evolved genetic changes to modulate physiological mechanisms underlying adaptation.