Variable Temperature Stress in the Nematode Caenorhabditis elegans (Maupas) and Its Implications for Sensitivity to an Additional Chemical Stressor

摘要: A wealth of studies has investigated how chemical sensitivity is affected by temperature, however, almost always under different constant rather than more realistic fluctuating regimes. Here we compared the nematode Caenorhabditis elegans responds to copper at temperatures (8–24°C) and fluctuation conditions low (±4°C) high (±8°C) amplitude (averages 12, 16, 20°C 16°C respectively). The DEBkiss model was used interpret effects on energy budgets. Increasing temperature from 12–24°C reduced time first egg, life-span population growth rates consistent with driven metabolic rate change. Responses 8°C did not, accord this pattern (including a deviation Temperature Size Rule), identifying cold stress effect. High variation around mean 12°C impacted reproduction body size nematodes kept matching average temperatures. Copper exposure reproduction, consequently growth. Sensitivity (EC50 values), similar intermediate (12, 20°C) higher 24°C especially innately stressful condition. not increase sensitivity. Indeed variable including condition, reduced. identified increased maintenance costs assimilation as possible mechanisms for concentration effects. Model analysis combined effects, demonstrated no additional joint stressor response. Hence, concerns that fluctuations may sensitise species co-stressor seem unfounded in case.