Temperature, oxygen, and diet modulate gene transcription and metabolic capacities in yellow perch

Abstract

To unambiguously interpret the impacts of environmental contamination on fish condition, it is important to understand the confounding effects of natural environmental factors. In this study, we measured the effects of temperature (11, 20, and 28 °C), oxygen level, and dietary restriction on yellow perch (Perca flavescens) using biometric endpoints and enzymatic and transcriptomic endpoints in liver. Fulton’s condition factor (FCF) and pyloric cæca index were significantly correlated (Spearman’s coefficient = 0.18; p value = 0.0002) and decreased under heat stress. Both hypoxia and dietary restriction also negatively affected FCF. These changes, indicating modifications in growth and energy accumulation, were also detected at the enzymatic level. Glucose-6-phosphate dehydrogenase activity was only affected by temperature, whereas nucleoside diphosphate kinase activity decreased under hypoxic and restricted diet conditions. Temperature stress was also observed at the transcription level for genes associated with energy metabolism, oxidative stress response, and apoptosis. This study will contribute to a better understanding of the influences of natural stressors on these biomarkers of condition and metabolic capacities, which are commonly used in ecotoxicological studies.