Synergistic effects of bisphenol A and elevated temperature on lipid metabolism and fatty acid synthase in the marine rotifer Brachionus plicatilis

This study examines how bisphenol A (BPA) and elevated temperature (30 °C) affect growth, reproduction, oxidative stress, and lipid metabolism in the marine rotifer Brachionus plicatilis. We found that 30 °C alone increased reproductive output but shortened lifespan, whereas 30 °C and exposure to BPA reversed reproductive gains and restored lifespan to 25 °C control levels. Reactive oxygen species levels, as well as superoxide dismutase and catalase activities, were highest at 30 °C plus BPA exposure, indicating synergistic oxidative stress. Analysis of the single-exon FASN gene in B. plicatilis, B. rotundiformis, and B. koreanus showed two NADB_Rossmann domains and conserved fatty acid synthesis sites, although B. plicatilis displayed unique loop and interdomain variations. Expression of FASN was elevated at 30 °C but reverted to near-control levels at 30 °C plus BPA, whereas FABP, MGAT, and DGAT were consistently upregulated. These results reveal how BPA and temperature interact to modulate survival, lipid metabolism, and potential structural adaptations in B. plicatilis.